Last updated: 2022-04-27

Checks: 7 0

Knit directory: amnio-cell-free-RNA/

This reproducible R Markdown analysis was created with workflowr (version 1.6.2). The Checks tab describes the reproducibility checks that were applied when the results were created. The Past versions tab lists the development history.


Great! Since the R Markdown file has been committed to the Git repository, you know the exact version of the code that produced these results.

Great job! The global environment was empty. Objects defined in the global environment can affect the analysis in your R Markdown file in unknown ways. For reproduciblity it’s best to always run the code in an empty environment.

The command set.seed(20200224) was run prior to running the code in the R Markdown file. Setting a seed ensures that any results that rely on randomness, e.g. subsampling or permutations, are reproducible.

Great job! Recording the operating system, R version, and package versions is critical for reproducibility.

Nice! There were no cached chunks for this analysis, so you can be confident that you successfully produced the results during this run.

Great job! Using relative paths to the files within your workflowr project makes it easier to run your code on other machines.

Great! You are using Git for version control. Tracking code development and connecting the code version to the results is critical for reproducibility.

The results in this page were generated with repository version 43f8f24. See the Past versions tab to see a history of the changes made to the R Markdown and HTML files.

Note that you need to be careful to ensure that all relevant files for the analysis have been committed to Git prior to generating the results (you can use wflow_publish or wflow_git_commit). workflowr only checks the R Markdown file, but you know if there are other scripts or data files that it depends on. Below is the status of the Git repository when the results were generated:


Ignored files:
    Ignored:    .Rhistory
    Ignored:    .Rproj.user/
    Ignored:    .bpipe/
    Ignored:    analysis/obsolete_analysis/
    Ignored:    code/.bpipe/
    Ignored:    code/.rnaseq-test.groovy.swp
    Ignored:    code/obsolete_analysis/
    Ignored:    data/.bpipe/
    Ignored:    data/190717_A00692_0021_AHLLHFDSXX/
    Ignored:    data/190729_A00692_0022_AHLLHFDSXX/
    Ignored:    data/190802_A00692_0023_AHLLHFDSXX/
    Ignored:    data/200612_A00692_0107_AHN3YCDMXX.tar
    Ignored:    data/200612_A00692_0107_AHN3YCDMXX/
    Ignored:    data/200626_A00692_0111_AHNJH7DMXX.tar
    Ignored:    data/200626_A00692_0111_AHNJH7DMXX/
    Ignored:    data/CMV-AF-database-final-included-samples.csv
    Ignored:    data/GONE4.10.13.txt
    Ignored:    data/HK_exons.csv
    Ignored:    data/HK_exons.txt
    Ignored:    data/IPA molecule summary.xls
    Ignored:    data/IPA-molecule-summary.csv
    Ignored:    data/deduped_rRNA_coverage.txt
    Ignored:    data/gene-transcriptome-analysis/
    Ignored:    data/hg38_rRNA.bed
    Ignored:    data/hg38_rRNA.saf
    Ignored:    data/ignore-overlap-mapping/
    Ignored:    data/ignore/
    Ignored:    data/rds/
    Ignored:    data/salmon-pilot-analysis/
    Ignored:    data/star-genome-analysis/
    Ignored:    output/c2Ens.RData
    Ignored:    output/c5Ens.RData
    Ignored:    output/hEns.RData
    Ignored:    output/keggEns.RData
    Ignored:    output/obsolete_output/

Unstaged changes:
    Modified:   .gitignore

Note that any generated files, e.g. HTML, png, CSS, etc., are not included in this status report because it is ok for generated content to have uncommitted changes.


These are the previous versions of the repository in which changes were made to the R Markdown (analysis/STAR-FC-RUV-exclude-US-ab.Rmd) and HTML (docs/STAR-FC-RUV-exclude-US-ab.html) files. If you’ve configured a remote Git repository (see ?wflow_git_remote), click on the hyperlinks in the table below to view the files as they were in that past version.

File Version Author Date Message
Rmd 43f8f24 Jovana Maksimovic 2022-04-27 wflow_publish(c("analysis/STAR-FC-all.Rmd", "analysis/STAR-FC-exclude-US-ab.Rmd",
html 3b51ada Jovana Maksimovic 2021-12-03 Build site.
Rmd 85a6971 Jovana Maksimovic 2021-12-03 wflow_publish(c("analysis/STAR-FC-all.Rmd", "analysis/STAR-FC-exclude-US-ab.Rmd",
html 41ad3da Jovana Maksimovic 2021-11-24 Build site.
Rmd d2811a1 Jovana Maksimovic 2021-11-24 wflow_publish(files = paste0("analysis/", list.files("analysis/",
html ccd6c80 Jovana Maksimovic 2021-10-29 Build site.
Rmd 02eba43 Jovana Maksimovic 2021-10-29 wflow_publish(c("analysis/index.Rmd", "analysis/STAR-FC-all.Rmd",
html 77ba079 Jovana Maksimovic 2021-09-25 Build site.
Rmd e20c62d Jovana Maksimovic 2021-09-25 wflow_publish(c("analysis/index.Rmd", "analysis/salmon-limma-voom.Rmd",
Rmd 2b6479a Jovana Maksimovic 2021-07-26 Move/remove olds files.
html 4af30fb Jovana Maksimovic 2020-12-21 Build site.
Rmd 3ba9d96 Jovana Maksimovic 2020-12-21 wflow_publish(c("analysis/index.Rmd", "analysis/STAR-FC-RUV-exclude-US-ab.Rmd"))

library(here)
library(tidyverse)
library(EnsDb.Hsapiens.v86)
library(readr)
library(limma)
library(edgeR)
library(NMF)
library(patchwork)
library(EGSEA)
library(RUVSeq)
#source(here("code/output.R"))

The data showed some adapter contamination and sequence duplication issues. Adapters were removed using Trimmomatic and both paired and unpaired reads were retained. Only paired reads were initially mapped with Star in conjunction with GRCh38 and gencode_v34 to detect all junctions, across all samples. Paired and unpaired reads were then mapped to GRCh38 separately using Star. Duplicates were removed from paired and unpaired mapped data using Picard MarkDuplicates. Reads were then counted across features from gencode_v34 using featureCounts.

Data import

Set up DGElist object for downstream analysis. Sum paired and unpaired counts prior to downstream analysis.

rawPE <- read_delim(here("data/star-genome-analysis/counts-pe/counts.txt"), delim = "\t", skip = 1)
rawSE <- read_delim(here("data/star-genome-analysis/counts-se/counts.txt"), delim = "\t", skip = 1)
samps <- strsplit2(colnames(rawPE)[c(7:ncol(rawPE))], "_")[,5]
batch <- factor(strsplit2(colnames(rawPE)[c(7:ncol(rawPE))], 
                                     "_")[,1], labels = 1:2)
batch <- tibble(batch = batch, id = samps)
colnames(rawPE)[7:ncol(rawPE)] <- samps
colnames(rawSE)[7:ncol(rawSE)] <- samps

counts <- rawPE[, 7:ncol(rawPE)] + rawSE[, 7:ncol(rawSE)] 
dge <- DGEList(counts = counts,
                 genes = rawPE[,c(1,6)])
dge
An object of class "DGEList"
$counts
  CMV30 CMV31 CMV8 CMV9 CMV26 CMV27 CMV14 CMV15 CMV20 CMV21 CMV1 CMV2 CMV3 CMV4
1     0     0    0    0     2     2     0     1     0     1    1    0    1    0
2    58    95   58   59   113   101    60    48    79    71   54   63   39   46
3     1     0    0    0     0     0     0     0     0     0    0    0    0    0
4     0     0    0    0     0     0     0     0     0     0    1    0    1    0
5     0     0    0    0     0     0     0     0     0     0    0    0    0    0
  CMV10 CMV11 CMV18 CMV19 CMV35 Corriel NTC-2 CMV51 CMV52 CMV53 CMV54 CMV56
1     0     0     0     0     1       1     0     0     0     0     0     0
2    62    35    51    45    59      84     0    63    28    49    46    37
3     0     0     0     0     0       1     0     0     0     0     0     0
4     0     0     0     0     0       0     0     0     0     0     0     0
5     0     0     0     0     0       0     0     0     0     0     0     0
  CMV57 CMV58 CMV60 CMV61
1     0     2     1     2
2    59    82    44    36
3     0     0     0     0
4     0     0     1     0
5     0     0     0     0
60664 more rows ...

$samples
      group lib.size norm.factors
CMV30     1  4673630            1
CMV31     1  5232010            1
CMV8      1  3594801            1
CMV9      1  3425478            1
CMV26     1  4892776            1
25 more rows ...

$genes
             Geneid Length
1 ENSG00000223972.5   1735
2 ENSG00000227232.5   1351
3 ENSG00000278267.1     68
4 ENSG00000243485.5   1021
5 ENSG00000284332.1    138
60664 more rows ...

Load sample information and file names.

samps1 <- read_csv(here("data/CMV-AF-database-corrected-oct-2020.csv"))
samps2 <- read_csv(here("data/samples.csv"))

samps1 %>% full_join(samps2, by = c("sequencing_ID" = "SampleId")) %>%
  mutate(pair = ifelse(!is.na(matched_pair), matched_pair,
                        ifelse(!is.na(MatchedPair), MatchedPair, NA)),
         CMV_status = ifelse(!is.na(CMV_status), CMV_status,
                         ifelse(!is.na(TestResult), TestResult, NA)),
         Sex = toupper(Sex),
         Indication = tolower(Indication)) %>%
  dplyr::rename(sex = Sex, 
         id = sequencing_ID, 
         indication = Indication,
         GA_at_amnio = `GA_at_amnio-completed_weeks`) -> samps
       
read_csv(file = here("data/metadata.csv")) %>%
  inner_join(read_csv(file = here("data/joindata.csv")), 
                      by = c("Record.ID" = "UR")) %>%
  right_join(samps, by = c("ID post-extraction" = "id")) %>%
  na_if("NA") %>%
  mutate(sex = ifelse(!is.na(sex), sex,
                        ifelse(!is.na(Sex), toupper(Sex), NA)),
         GA_at_amnio = ifelse(!is.na(GA_at_amnio), GA_at_amnio,
                         ifelse(!is.na(GA.at.amnio), GA.at.amnio, NA))) %>%
  dplyr::rename(id = `ID post-extraction`) %>%
  dplyr::select(id, 
                CMV_status, 
                pair, 
                sex, 
                GA_at_amnio, 
                indication) %>%
  left_join(batch) %>%
  dplyr::filter(id %in% colnames(dge)) %>%
  drop_na() -> targets

m <- match(colnames(dge), targets$id)
targets <- targets[m[!is.na(m)], ]
  
targets
# A tibble: 26 x 7
   id    CMV_status pair  sex   GA_at_amnio indication batch
   <chr> <chr>      <chr> <chr> <chr>       <chr>      <fct>
 1 CMV30 pos        L1    F     21          no_us_ab   1    
 2 CMV31 neg        L1    F     21          no_us_ab   1    
 3 CMV8  neg        L2    F     23          no_us_ab   1    
 4 CMV9  pos        L2    F     23          no_us_ab   1    
 5 CMV26 pos        L3    F     22          no_us_ab   1    
 6 CMV14 neg        L4    F     21          no_us_ab   1    
 7 CMV15 pos        L4    F     22          no_us_ab   1    
 8 CMV20 pos        L5    M     21          no_us_ab   1    
 9 CMV21 neg        NC1   F     21          no_us_ab   1    
10 CMV1  pos        M1    F     21          no_us_ab   1    
# … with 16 more rows

Quality control

Genes that do not have an adequate number of reads in any sample should be filtered out prior to downstream analyses. From a biological perspective, genes that are not expressed at a biologically meaningful level in any condition are not of interest. Statistically, we get a better estimate of the mean-variance relationship in the data and reduce the number of statistical tests that are performed during differential expression analyses.

Filter out lowly expressed genes and genes without Entrez IDs and calculate TMM normalization factors.

z <- dge[, colnames(dge) %in% targets$id] # retain only relevant samples
z$genes$Ensembl <- strsplit2(z$genes$Geneid, ".", fixed = TRUE)[,1]
z$group <- targets$CMV_status

edb <- EnsDb.Hsapiens.v86 # add Gene Symbols and Entrez IDs
z$genes <- left_join(z$genes, ensembldb::genes(edb, 
                                        filter = GeneIdFilter(z$genes$Ensembl), 
                                        columns = c("gene_id", 
                                                    "symbol", 
                                                    "entrezid"), 
                                        return.type = "data.frame"), 
                       by = c("Ensembl" = "gene_id"))
z$genes$entrezid <- unlist(sapply(z$genes$entrezid, function(x) {
  if(is.null(x)) NA else x[length(x)]
}), use.names = FALSE)

keep <- !is.na(z$genes$entrezid) & !is.null(z$genes$entrezid)
x <- z[keep, ] # remove genes without Entrez IDs

keep <- filterByExpr(x, group = z$group)
x <- x[keep, ] # remove lowly expressed genes

y <- calcNormFactors(x)
y
An object of class "DGEList"
$counts
   CMV30 CMV31 CMV8 CMV9 CMV26 CMV14 CMV15 CMV20 CMV21 CMV1 CMV2 CMV3 CMV4
32    20    36   28   42    28    25    19    26    18   32   25   55   31
52    88    73   55   43    55    75    53    64    55   61   68   36   62
55     6    15   17   15    15     9    14    13    12    7   10   16   12
63   148   172  148  126   175   179   176   141   179  155  194  121  123
64    14    15   14   11    20    14     9    13    14   13   13   19   10
   CMV10 CMV11 CMV19 CMV35 CMV51 CMV52 CMV53 CMV54 CMV56 CMV57 CMV58 CMV60
32    15    11    22    24    25    19    23    20    18    23    24     8
52    69    11    35    47    59    49    42    37    38    49    65    49
55     7     2    11     9    19     9     6    12     7     7     7     5
63   156    44   107   164   144    71    71   137   136   122   131    88
64     9     3     6     9    14     3     9    12     5     7    12     5
   CMV61
32    20
52    49
55     6
63   108
64     3
12727 more rows ...

$samples
      group lib.size norm.factors
CMV30     1  4673630     1.017563
CMV31     1  5232010     1.052277
CMV8      1  3594801     1.052059
CMV9      1  3425478     1.026378
CMV26     1  4892776     1.068518
21 more rows ...

$genes
               Geneid Length         Ensembl       symbol  entrezid
32 ENSG00000230021.10   5495 ENSG00000230021 RP5-857K21.4 101928626
52 ENSG00000228794.10  15682 ENSG00000228794    LINC01128    643837
55  ENSG00000230368.2   1971 ENSG00000230368       FAM41C    284593
63 ENSG00000188976.11   5540 ENSG00000188976        NOC2L     26155
64 ENSG00000187961.14   3402 ENSG00000187961       KLHL17    339451
12727 more rows ...

$group
[1] "pos" "neg" "neg" "pos" "pos"
21 more elements ...

Plotting the distribution log-CPM values shows that a majority of genes within each sample are either not expressed or lowly-expressed with log-CPM values that are small or negative.

L <- mean(z$samples$lib.size) * 1e-6
M <- median(z$samples$lib.size) * 1e-6

par(mfrow = c(1,2))
lcpmz <- cpm(z, log = TRUE)
lcpm.cutoff <- log2(10/M + 2/L)
nsamples <- ncol(z)
col <- scales::hue_pal()(nsamples)
plot(density(lcpmz[,1]), col = col[1], lwd = 1, ylim = c(0, 2), las = 2, 
     main = "", xlab = "")
title(main = "Unfiltered data", xlab = "Log-cpm")
abline(v = lcpm.cutoff, lty = 3)
for (i in 2:nsamples){
  den <- density(lcpmz[,i])
  lines(den$x, den$y, col = col[i], lwd = 1)
}

lcpmy <- cpm(y, log=TRUE)
plot(density(lcpmy[,1]), col = col[1], lwd = 1, ylim = c(0, 0.25), las = 2, 
     main = "", xlab = "")
title(main = "Filtered data", xlab = "Log-cpm")
abline(v = lcpm.cutoff, lty = 3)
for (i in 2:nsamples){
  den <- density(lcpmy[,i])
  lines(den$x, den$y, col = col[i], lwd = 1)
}

Version Author Date
4af30fb Jovana Maksimovic 2020-12-21

Although in excess of 30 million reads were obtained per sample, we can see that after mapping, duplicate removal and quantification of gene expression the median library size is just under than 4 million reads. This suggests that we are likely to only be capturing the most abundant cfRNAs.

It is assumed that all samples should have a similar range and distribution of expression values. The raw data looks fairly uniform between samples, although TMM normalization further improves this.

dat <- data.frame(lib = y$samples$lib.size,
                  status = y$group,
                  sample = colnames(y))
p1 <- ggplot(dat, aes(x = sample, y = lib, fill = status)) +
  geom_bar(stat = "identity") +
  theme(axis.text.x = element_text(angle = 45, hjust = 1)) +
  labs(x = "Sample", y = "Library size",
       fill = "CMV Status") +
  geom_hline(yintercept = median(dat$lib), linetype = "dashed") +
  scale_x_discrete(limits = dat$sample)

dat <- reshape2::melt(cpm(y, normalized.lib.sizes = FALSE, log = TRUE),
                      value.name = "cpm")
dat$status <- rep(y$group, each = nrow(y))
colnames(dat)[2] <- "sample"
p2 <- ggplot(dat, aes(x = sample, y = cpm, fill = status)) +
  geom_boxplot(show.legend = FALSE, outlier.size = 0.75) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1, size = 7)) +
  labs(x = "Sample", y = "Library size",
       fill = "CMV Status") +
  geom_hline(yintercept = median(dat$lib), linetype = "dashed")

dat <- reshape2::melt(cpm(y, normalized.lib.sizes = TRUE, log = TRUE),
                      value.name = "cpm")
dat$status <- rep(y$group, each = nrow(y))
colnames(dat)[2] <- "sample"
p3 <- ggplot(dat, aes(x = sample, y = cpm, fill = status)) +
  geom_boxplot(show.legend = FALSE, outlier.size = 0.75) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1, size = 7)) +
  labs(x = "Sample", y = "Library size",
       fill = "CMV Status") +
  geom_hline(yintercept = median(dat$lib), linetype = "dashed")

p1 / (p2 + p3) + plot_layout(guides = "collect")

Version Author Date
4af30fb Jovana Maksimovic 2020-12-21

Multi-dimensional scaling (MDS) plots show the largest sources of variation in the data. They are a good way of exploring the relationships between the samples and identifying structure in the data. The following series of MDS plots examines the first four principal components. The samples are coloured by various known features of the samples such as CMV Status and foetal sex. The MDS plots do not show the samples strongly clustering by any of the known features of the data, although there does seem to be some separation between the CMV positive and negative samples in the 1st and 2nd principal components. This indicates that there are possibly some differentially expressed genes between CMV positive and negative samples.

A weak batch effect is also evident in the 3rd principal component, when we examine the plots coloured by batch.

dims <- list(c(1,2), c(1,3), c(2,3), c(3,4))
vars <- c("CMV_status", "pair", "sex", "GA_at_amnio", "indication", "batch")
patches <- vector("list", length(vars))

for(i in 1:length(vars)){
  p <- vector("list", length(dims))
  
  for(j in 1:length(dims)){
    mds <- plotMDS(cpm(y, log = TRUE), top = 1000, gene.selection="common", 
                   plot = FALSE, dim.plot = dims[[j]])
    dat <- tibble::tibble(x = mds$x, y = mds$y,
                          sample = targets$id,
                          variable = pull(targets, vars[i]))
    
    p[[j]] <- ggplot(dat, aes(x = x, y = y, colour = variable)) +
      geom_text(aes(label = sample), size = 2.5) +
      labs(x = glue::glue("Principal component {dims[[j]][1]}"), 
           y = glue::glue("Principal component {dims[[j]][2]}"),
           colour = vars[i])
  }
  
  patches[[i]] <- wrap_elements(wrap_plots(p, ncol = 2, guides = "collect") +
    plot_annotation(title = glue::glue("Coloured by: {vars[i]}")) &
    theme(legend.position = "bottom"))
  
}

wrap_plots(patches, ncol = 1)

Version Author Date
4af30fb Jovana Maksimovic 2020-12-21

RUVSeq analysis

Given that there is a lot ov variability between the samples and it is not clearly associated with any of the known features of the data, we will use and RUVSeq analysis to remove some of the unwanted variation from the data. We will estimate the unwanted variation using the expression of known house-keeping genes (HKG), as defined using the Human BodyMap 2.0 data, in our dataset.

The heatmap below shows the expression of the HKG in our samples. Although the expression is fairly uniform, some variability is apparent between the samples.

hkGenes <- read.delim(here("data/HK_genes.txt"), stringsAsFactors = FALSE, 
                      header = FALSE, col.names = c("SYMBOL","REFSEQ"), 
                      strip.white = TRUE)

aheatmap(cpm(y[y$genes$symbol %in% hkGenes$SYMBOL,], log = TRUE),
         main = "log2 CPM Expression of HKG", labRow = NA,  
         annCol = list(GA_at_amnio = targets$GA_at_amnio, 
                       CMV_result = targets$CMV_status, 
                       Pair = targets$pair,
                       Sex = targets$sex),
         annColors = list(scales::brewer_pal(palette = "Dark2")(length(unique(targets$GA_at_amnio))),
                          scales::hue_pal()(length(unique(targets$CMV_status))),
                          scales::hue_pal()(length(unique(targets$pair))),
                          scales::brewer_pal(palette = "Set1")(length(unique(targets$sex)))),
         scale = "none")

Version Author Date
4af30fb Jovana Maksimovic 2020-12-21

The scree plot shows that most of the variation in the negative control genes is captured by the first principal component.

PCs <- prcomp(t(y$counts[which(y$genes$symbol %in% hkGenes$SYMBOL),]), 
              center = TRUE, scale = TRUE, retx=TRUE)
loadings = PCs$x # pc loadings
plot(PCs, type="lines") # scree plot

Version Author Date
4af30fb Jovana Maksimovic 2020-12-21

Using the RUVg function, we will estimate the unwanted variation in our data using the HKG for k = 1, 2 and 3.

yRg1 <- RUVg(y$counts, which(y$genes$symbol %in% hkGenes$SYMBOL), k=1)
yRg2 <- RUVg(y$counts, which(y$genes$symbol %in% hkGenes$SYMBOL), k=2)
yRg3 <- RUVg(y$counts, which(y$genes$symbol %in% hkGenes$SYMBOL), k=3)

The RLE plots below show that RUVg adjustment is a significant improvement over the raw data with k=1. The improvements with k=2 and k=3 are relatively minor in comparison.

par(mfrow=c(2,2))
plotRLE(y$counts, ylim=c(-0.5,0.5), las=2, main="Raw", 
        cex.axis = 0.6)
plotRLE(yRg1$normalizedCounts, ylim=c(-0.5,0.5), las=2, main="RUVg k=1", 
        cex.axis = 0.6)
plotRLE(yRg2$normalizedCounts, ylim=c(-0.5,0.5), las=2, main="RUVg k=2", 
        cex.axis = 0.6)
plotRLE(yRg3$normalizedCounts, ylim=c(-0.5,0.5), las=2, main="RUVg k=3", 
        cex.axis = 0.6)

Version Author Date
77ba079 Jovana Maksimovic 2021-09-25
4af30fb Jovana Maksimovic 2020-12-21

The MDS plots of the RUVg normalised counts show clearer separation between the CMV positive and CMV negative samples.

mds <- plotMDS(cpm(y$counts, log = TRUE), top = 1000, gene.selection="common", 
               plot = FALSE)
dat <- tibble::tibble(x = mds$x, y = mds$y,
                      sample = targets$id,
                      status = targets$CMV_status)

p <- ggplot(dat, aes(x = x, y = y, colour = status)) +
  geom_text(aes(label = sample), size = 2.5) +
  labs(x = "Principal component 1", 
       y = "Principal component 2",
       colour = "CMV status") +
  ggtitle("Raw")

mds <- plotMDS(cpm(yRg1$normalizedCounts, log = TRUE), top = 1000, 
               gene.selection="common", plot = FALSE)
dat1 <- tibble::tibble(x = mds$x, y = mds$y,
                      sample = targets$id,
                      status = targets$CMV_status)

p1 <- ggplot(dat1, aes(x = x, y = y, colour = status)) +
  geom_text(aes(label = sample), size = 2.5) +
  labs(x = "Principal component 1", 
       y = "Principal component 2",
       colour = "CMV status") +
  ggtitle("RUVg k=1")

mds <- plotMDS(cpm(yRg2$normalizedCounts, log = TRUE), top = 1000, 
               gene.selection="common", plot = FALSE)
dat2 <- tibble::tibble(x = mds$x, y = mds$y,
                      sample = targets$id,
                      status = targets$CMV_status)

p2 <- ggplot(dat2, aes(x = x, y = y, colour = status)) +
  geom_text(aes(label = sample), size = 2.5) +
  labs(x = "Principal component 1", 
       y = "Principal component 2",
       colour = "CMV status") +
  ggtitle("RUVg k=2")

mds <- plotMDS(cpm(yRg3$normalizedCounts, log = TRUE), top = 1000, 
               gene.selection="common", plot = FALSE)
dat3 <- tibble::tibble(x = mds$x, y = mds$y,
                      sample = targets$id,
                      status = targets$CMV_status)

p3 <- ggplot(dat3, aes(x = x, y = y, colour = status)) +
  geom_text(aes(label = sample), size = 2.5) +
  labs(x = "Principal component 1", 
       y = "Principal component 2",
       colour = "CMV status") +
  ggtitle("RUVg k=3")

((p | p1) / (p2 | p3)) + 
  plot_layout(guides = "collect") & 
  theme(legend.position = "bottom")

Version Author Date
4af30fb Jovana Maksimovic 2020-12-21

Differential expression analysis

We will look for differentially expressed genes, using the negative binomial GLM approach implemented in edgeR. This is done by considering a design matrix that includes both the covariates of interest (CMV result) and the factors of unwanted variation calculated by RUVg. The CMV positive samples were compared to the CMV negative (normal) samples. A summary of the numbers of differentially expressed genes is shown below, as well as the top 20 differentially expressed genes. The full results tables were exported as csv files.

norm <- yRg1
SA <- paste(targets$CMV_status, targets$indication, sep=".")
SA <- factor(SA) 
design <- model.matrix(~0 + SA + targets$pair + norm$W)
colnames(design) <- gsub("SA", "", colnames(design), fixed=TRUE)
colnames(design) <- gsub("targets$", "", colnames(design), fixed=TRUE)
colnames(design) <- gsub("norm$", "", colnames(design), fixed=TRUE)

y <- estimateGLMCommonDisp(y, design)
y <- estimateGLMTagwiseDisp(y, design)
fit <- glmFit(y, design)
cont <- makeContrasts(PvsNinNoUsAb=pos.no_us_ab-neg.no_us_ab, 
                      levels=design) 
lrt <- glmLRT(fit, contrast = cont[,1])
fitSum <- summary(decideTests(lrt, p.value = 0.05))
fitSum
       -1*neg.no_us_ab 1*pos.no_us_ab
Down                                6
NotSig                          12669
Up                                 57

There were 6 down-regulated and 57 up-regulated genes between CMV positive and CMV negative samples at FDR < 0.05.

These are the top 10 differentially expressed genes.

top <- topTags(lrt, n = 500)$table
readr::write_csv(top, path = here("output/star-fc-ruv-no_us_ab.csv"))
Warning: The `path` argument of `write_csv()` is deprecated as of readr 1.4.0.
Please use the `file` argument instead.
head(top, n=10)
                  Geneid Length         Ensembl symbol entrezid    logFC
51897 ENSG00000130303.13   1101 ENSG00000130303   BST2      684 2.999180
19329 ENSG00000206337.12  11058 ENSG00000206337   HCP5    10866 4.249069
45751 ENSG00000140853.15  12386 ENSG00000140853  NLRC5    84166 2.383186
14201  ENSG00000138646.9   4764 ENSG00000138646  HERC5    51191 2.574700
15204 ENSG00000137628.17   6746 ENSG00000137628  DDX60    55601 1.361080
2240   ENSG00000225492.6   2352 ENSG00000225492 GBP1P1   400759 1.623236
8687  ENSG00000115415.20   9770 ENSG00000115415  STAT1     6772 1.068691
2095  ENSG00000137965.11   2038 ENSG00000137965  IFI44    10561 1.559327
56048 ENSG00000157601.14   8616 ENSG00000157601    MX1     4599 1.396454
46903 ENSG00000132530.17   6615 ENSG00000132530   XAF1    54739 2.173485
        logCPM       LR       PValue          FDR
51897 3.743995 77.13126 1.599655e-18 2.036681e-14
19329 3.762132 64.01509 1.234697e-15 7.860081e-12
45751 3.080983 53.36323 2.772378e-13 1.176597e-09
14201 3.082940 52.64308 4.000173e-13 1.273255e-09
15204 6.360766 43.79753 3.641642e-11 9.273076e-08
2240  2.475198 42.69792 6.388002e-11 1.355534e-07
8687  8.158457 42.32467 7.731135e-11 1.406183e-07
2095  5.027355 40.01255 2.523369e-10 4.015941e-07
56048 7.263061 39.49613 3.287104e-10 4.650157e-07
46903 5.946511 38.03100 6.962962e-10 8.865244e-07

The following plots show the expression of the top 12 ranked differentially expressed genes for CMV positive and CMV negative samples. Although there is significant variability within the groups and the log2 fold changes are not large, there are obvious differences in expression for the top ranked genes.

dat <- reshape2::melt(cpm(norm$normalizedCounts, log = TRUE),
                      value.name = "cpm")
dat$status <- rep(y$group, each = nrow(y))
dat$gene <- rep(y$genes$Geneid, ncol(y))

p <- vector("list", 12)

for(i in 1:length(p)){
p[[i]] <- ggplot(data = subset(dat, dat$gene == top$Geneid[i]), 
       aes(x = status, y = cpm, colour = status)) +
  geom_jitter(width = 0.25) +
  stat_summary(fun = "mean", geom = "crossbar") +
  labs(x = "Status", y = "log2 Norm. CPM", colour = "Status") +
  ggtitle(top$symbol[i]) +
  theme(plot.title = element_text(size = 8),
        plot.subtitle = element_text(size = 7),
        axis.title = element_text(size = 8),
        axis.text.x = element_text(size = 7))
}

wrap_plots(p, guides = "collect", ncol = 3) & 
  theme(legend.position = "bottom")

Version Author Date
ccd6c80 Jovana Maksimovic 2021-10-29
77ba079 Jovana Maksimovic 2021-09-25
4af30fb Jovana Maksimovic 2020-12-21
topTags(lrt, n = Inf)$table %>% 
  mutate(sig = ifelse(FDR <= 0.05, "<= 0.05", "> 0.05")) -> dat

ggplot(dat, aes(x = logFC, y = -log10(PValue), color = sig)) +
  geom_point(alpha = 0.75) +
  ggrepel::geom_text_repel(data = subset(dat, FDR < 0.05), 
            aes(x = logFC, y = -log10(PValue), 
                label = symbol), 
            size = 2, colour = "black", max.overlaps = 15) +
  labs(x = expression(~log[2]~"(Fold Change)"), 
       y = expression(~-log[10]~"(P-value)"),
       colour = "FDR") +
  scale_colour_brewer(palette = "Set1")
Warning: ggrepel: 22 unlabeled data points (too many overlaps). Consider
increasing max.overlaps

Version Author Date
41ad3da Jovana Maksimovic 2021-11-24
4af30fb Jovana Maksimovic 2020-12-21
cut <- 0.05
aheatmap(cpm(norm$normalizedCounts[y$genes$Geneid %in% 
                                     top$Geneid[top$FDR < cut], ], 
             log = TRUE), 
         annCol = list(CMV_result = targets$CMV_status),
         Colv = NA,
         labRow = NA,
         main = glue::glue("DEGs at FDR < {cut}"))

Gene set enrichment analysis (GSEA)

Testing for enrichment of Gene Ontology (GO) categories among statistically significant differentially expressed genes.

go <- goana(top$entrezid[top$FDR < 0.05], universe = y$genes$entrezid, 
            trend = y$genes$Length)
topGO(go, number = Inf) %>%
  mutate(FDR = p.adjust(P.DE)) %>%
  dplyr::filter(FDR < 0.05) %>%
  knitr::kable(format.args = list(scientific = -1), digits = 50)
Term Ont N DE P.DE FDR
GO:0071357 cellular response to type I interferon BP 70 19 4.386084e-29 9.056386e-25
GO:0060337 type I interferon signaling pathway BP 70 19 4.386084e-29 9.056386e-25
GO:0034340 response to type I interferon BP 74 19 1.460247e-28 3.014825e-24
GO:0045087 innate immune response BP 516 32 3.450131e-28 7.122796e-24
GO:0043207 response to external biotic stimulus BP 849 37 1.103255e-27 2.277561e-23
GO:0051707 response to other organism BP 849 37 1.103255e-27 2.277561e-23
GO:0009615 response to virus BP 231 25 1.139246e-27 2.351631e-23
GO:0051607 defense response to virus BP 178 23 3.247837e-27 6.703860e-23
GO:0009607 response to biotic stimulus BP 876 37 3.400202e-27 7.018018e-23
GO:0098542 defense response to other organism BP 628 33 7.781113e-27 1.605944e-22
GO:0006952 defense response BP 913 34 7.725421e-23 1.594372e-18
GO:0006955 immune response BP 1177 37 1.205522e-22 2.487836e-18
GO:0044419 interspecies interaction between organisms BP 1439 38 1.079944e-20 2.228572e-16
GO:0002376 immune system process BP 1887 40 1.503002e-18 3.101446e-14
GO:0009605 response to external stimulus BP 1674 37 2.151662e-17 4.439740e-13
GO:0002252 immune effector process BP 776 27 6.572497e-17 1.356103e-12
GO:0034097 response to cytokine BP 802 27 1.506197e-16 3.107586e-12
GO:0034341 response to interferon-gamma BP 121 14 6.003540e-16 1.238590e-11
GO:0019221 cytokine-mediated signaling pathway BP 505 22 1.156473e-15 2.385803e-11
GO:0071346 cellular response to interferon-gamma BP 109 13 4.867799e-15 1.004178e-10
GO:0071345 cellular response to cytokine stimulus BP 740 24 2.981998e-14 6.151266e-10
GO:0060333 interferon-gamma-mediated signaling pathway BP 61 10 3.190993e-13 6.582062e-09
GO:0048525 negative regulation of viral process BP 77 10 3.651886e-12 7.532380e-08
GO:0016032 viral process BP 793 22 1.104693e-11 2.278429e-07
GO:1903900 regulation of viral life cycle BP 126 11 2.363926e-11 4.875360e-07
GO:0044403 symbiotic process BP 828 22 2.579348e-11 5.319390e-07
GO:0050792 regulation of viral process BP 178 12 5.729023e-11 1.181439e-06
GO:0045071 negative regulation of viral genome replication BP 48 8 7.523824e-11 1.551488e-06
GO:0043903 regulation of symbiotic process BP 190 12 1.227846e-10 2.531819e-06
GO:0019079 viral genome replication BP 109 10 1.256000e-10 2.589746e-06
GO:0045069 regulation of viral genome replication BP 85 9 3.102545e-10 6.396827e-06
GO:1903901 negative regulation of viral life cycle BP 63 8 7.286919e-10 1.502344e-05
GO:0002831 regulation of response to biotic stimulus BP 277 13 7.619469e-10 1.570830e-05
GO:0001817 regulation of cytokine production BP 440 15 2.634164e-09 5.430328e-05
GO:0006950 response to stress BP 2756 35 4.664049e-09 9.614471e-05
GO:0009617 response to bacterium BP 335 13 7.641215e-09 1.575084e-04
GO:0001816 cytokine production BP 483 15 9.317185e-09 1.920458e-04
GO:0019058 viral life cycle BP 279 12 9.903336e-09 2.041177e-04
GO:0002697 regulation of immune effector process BP 231 11 1.535657e-08 3.164990e-04
GO:0031347 regulation of defense response BP 432 14 1.852250e-08 3.817302e-04
GO:0046977 TAP binding MF 7 4 1.908904e-08 3.933869e-04
GO:0050776 regulation of immune response BP 513 15 2.088272e-08 4.303302e-04
GO:0071310 cellular response to organic substance BP 1817 27 3.483927e-08 7.178981e-04
GO:0010033 response to organic substance BP 2227 30 3.673166e-08 7.568558e-04
GO:0002682 regulation of immune system process BP 909 19 4.385823e-08 9.036550e-04
GO:0001730 2’-5’-oligoadenylate synthetase activity MF 3 3 1.166218e-07 2.402760e-03
GO:0007166 cell surface receptor signaling pathway BP 1939 27 1.386210e-07 2.855870e-03
GO:0002483 antigen processing and presentation of endogenous peptide antigen BP 13 4 3.813412e-07 7.856010e-03
GO:0019885 antigen processing and presentation of endogenous peptide antigen via MHC class I BP 13 4 3.813412e-07 7.856010e-03
GO:0042605 peptide antigen binding MF 13 4 3.813412e-07 7.856010e-03
GO:0050688 regulation of defense response to virus BP 59 6 4.307267e-07 8.872108e-03
GO:0002484 antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway BP 4 3 4.648328e-07 9.574160e-03
GO:0002486 antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-independent BP 4 3 4.648328e-07 9.574160e-03
GO:0070887 cellular response to chemical stimulus BP 2197 28 4.710929e-07 9.702159e-03
GO:0042221 response to chemical BP 2816 32 5.781947e-07 1.190734e-02
GO:0002684 positive regulation of immune system process BP 579 14 6.837330e-07 1.408011e-02
GO:0019883 antigen processing and presentation of endogenous antigen BP 15 4 7.226124e-07 1.488003e-02
GO:0045088 regulation of innate immune response BP 208 9 7.901610e-07 1.627021e-02
GO:0003725 double-stranded RNA binding MF 66 6 8.454313e-07 1.740743e-02
GO:0001818 negative regulation of cytokine production BP 160 8 1.152596e-06 2.373080e-02
GO:0032480 negative regulation of type I interferon production BP 39 5 1.297205e-06 2.670686e-02
GO:0060760 positive regulation of response to cytokine stimulus BP 42 5 1.894800e-06 3.900825e-02
GO:0032101 regulation of response to external stimulus BP 631 14 1.901747e-06 3.914936e-02
GO:0035455 response to interferon-alpha BP 19 4 2.021568e-06 4.161398e-02
GO:0050778 positive regulation of immune response BP 379 11 2.227128e-06 4.584320e-02
GO:0002480 antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-independent BP 6 3 2.307710e-06 4.749959e-02
GO:0042612 MHC class I protein complex CC 6 3 2.307710e-06 4.749959e-02

GSEA helps us to interpret the results of a differential expression analysis. The camera function performs a competitive test to assess whether the genes in a given set are highly ranked in terms of differential expression relative to genes that are not in the set. We have tested several collections of gene sets from the Broad Institute’s Molecular Signatures Database MSigDB.

Build gene set indexes.

gsAnnots <- buildIdx(entrezIDs = y$genes$entrezid, species = "human",
                     msigdb.gsets = c("h", "c2", "c5"))
[1] "Loading MSigDB Gene Sets ... "
[1] "Loaded gene sets for the collection h ..."
[1] "Indexed the collection h ..."
[1] "Created annotation for the collection h ..."
[1] "Loaded gene sets for the collection c2 ..."
[1] "Indexed the collection c2 ..."
[1] "Created annotation for the collection c2 ..."
[1] "Loaded gene sets for the collection c5 ..."
[1] "Indexed the collection c5 ..."
[1] "Created annotation for the collection c5 ..."
[1] "Building KEGG pathways annotation object ... "

The GO gene sets consist of genes annotated by the same GO terms.

c5Cam <- camera(cpm(norm$normalizedCounts, log = TRUE), 
                gsAnnots$c5@idx, design, contrast = cont[,1], trend.var = TRUE)
write.csv(c5Cam[c5Cam$FDR < 0.05,], 
          file = here("output/star-fc-ruv-no_us_ab-gsea-c5.csv"))
head(c5Cam, n = 20)
                                                                     NGenes
GO_RESPONSE_TO_TYPE_I_INTERFERON                                         48
GO_DEFENSE_RESPONSE_TO_VIRUS                                            111
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_PEPTIDE_ANTIGEN     11
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_ANTIGEN             13
GO_INTERFERON_GAMMA_MEDIATED_SIGNALING_PATHWAY                           43
GO_RESPONSE_TO_INTERFERON_GAMMA                                          71
GO_CELLULAR_RESPONSE_TO_INTERFERON_GAMMA                                 59
GO_CYTOSOLIC_RIBOSOME                                                    98
GO_ESTABLISHMENT_OF_PROTEIN_LOCALIZATION_TO_ENDOPLASMIC_RETICULUM        96
GO_NEGATIVE_REGULATION_OF_VIRAL_GENOME_REPLICATION                       40
GO_RESPONSE_TO_INTERFERON_ALPHA                                          18
GO_REGULATION_OF_EPIDERMAL_GROWTH_FACTOR_ACTIVATED_RECEPTOR_ACTIVITY     18
GO_RIBOSOMAL_SUBUNIT                                                    147
GO_CYTOSOLIC_LARGE_RIBOSOMAL_SUBUNIT                                     54
GO_RESPONSE_TO_VIRUS                                                    166
GO_MHC_CLASS_I_PROTEIN_COMPLEX                                            7
GO_TRANSLATIONAL_INITIATION                                             136
GO_NEGATIVE_REGULATION_OF_VIRAL_PROCESS                                  68
GO_POSITIVE_REGULATION_OF_T_CELL_MEDIATED_IMMUNITY                       19
GO_NEGATIVE_REGULATION_OF_CELL_KILLING                                   12
                                                                     Direction
GO_RESPONSE_TO_TYPE_I_INTERFERON                                            Up
GO_DEFENSE_RESPONSE_TO_VIRUS                                                Up
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_PEPTIDE_ANTIGEN        Up
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_ANTIGEN                Up
GO_INTERFERON_GAMMA_MEDIATED_SIGNALING_PATHWAY                              Up
GO_RESPONSE_TO_INTERFERON_GAMMA                                             Up
GO_CELLULAR_RESPONSE_TO_INTERFERON_GAMMA                                    Up
GO_CYTOSOLIC_RIBOSOME                                                     Down
GO_ESTABLISHMENT_OF_PROTEIN_LOCALIZATION_TO_ENDOPLASMIC_RETICULUM         Down
GO_NEGATIVE_REGULATION_OF_VIRAL_GENOME_REPLICATION                          Up
GO_RESPONSE_TO_INTERFERON_ALPHA                                             Up
GO_REGULATION_OF_EPIDERMAL_GROWTH_FACTOR_ACTIVATED_RECEPTOR_ACTIVITY        Up
GO_RIBOSOMAL_SUBUNIT                                                      Down
GO_CYTOSOLIC_LARGE_RIBOSOMAL_SUBUNIT                                      Down
GO_RESPONSE_TO_VIRUS                                                        Up
GO_MHC_CLASS_I_PROTEIN_COMPLEX                                              Up
GO_TRANSLATIONAL_INITIATION                                               Down
GO_NEGATIVE_REGULATION_OF_VIRAL_PROCESS                                     Up
GO_POSITIVE_REGULATION_OF_T_CELL_MEDIATED_IMMUNITY                          Up
GO_NEGATIVE_REGULATION_OF_CELL_KILLING                                      Up
                                                                           PValue
GO_RESPONSE_TO_TYPE_I_INTERFERON                                     1.442340e-25
GO_DEFENSE_RESPONSE_TO_VIRUS                                         3.115429e-14
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_PEPTIDE_ANTIGEN 8.569185e-12
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_ANTIGEN         1.469222e-11
GO_INTERFERON_GAMMA_MEDIATED_SIGNALING_PATHWAY                       3.285295e-11
GO_RESPONSE_TO_INTERFERON_GAMMA                                      1.569388e-09
GO_CELLULAR_RESPONSE_TO_INTERFERON_GAMMA                             2.434963e-09
GO_CYTOSOLIC_RIBOSOME                                                2.586488e-09
GO_ESTABLISHMENT_OF_PROTEIN_LOCALIZATION_TO_ENDOPLASMIC_RETICULUM    4.154581e-09
GO_NEGATIVE_REGULATION_OF_VIRAL_GENOME_REPLICATION                   3.253787e-08
GO_RESPONSE_TO_INTERFERON_ALPHA                                      5.451047e-08
GO_REGULATION_OF_EPIDERMAL_GROWTH_FACTOR_ACTIVATED_RECEPTOR_ACTIVITY 5.653844e-08
GO_RIBOSOMAL_SUBUNIT                                                 5.673604e-08
GO_CYTOSOLIC_LARGE_RIBOSOMAL_SUBUNIT                                 9.336398e-08
GO_RESPONSE_TO_VIRUS                                                 1.237235e-07
GO_MHC_CLASS_I_PROTEIN_COMPLEX                                       1.535221e-07
GO_TRANSLATIONAL_INITIATION                                          1.581173e-07
GO_NEGATIVE_REGULATION_OF_VIRAL_PROCESS                              1.682684e-07
GO_POSITIVE_REGULATION_OF_T_CELL_MEDIATED_IMMUNITY                   2.224482e-07
GO_NEGATIVE_REGULATION_OF_CELL_KILLING                               2.380612e-07
                                                                              FDR
GO_RESPONSE_TO_TYPE_I_INTERFERON                                     8.886259e-22
GO_DEFENSE_RESPONSE_TO_VIRUS                                         9.597079e-11
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_PEPTIDE_ANTIGEN 1.759825e-08
GO_ANTIGEN_PROCESSING_AND_PRESENTATION_OF_ENDOGENOUS_ANTIGEN         2.262969e-08
GO_INTERFERON_GAMMA_MEDIATED_SIGNALING_PATHWAY                       4.048141e-08
GO_RESPONSE_TO_INTERFERON_GAMMA                                      1.611500e-06
GO_CELLULAR_RESPONSE_TO_INTERFERON_GAMMA                             1.991919e-06
GO_CYTOSOLIC_RIBOSOME                                                1.991919e-06
GO_ESTABLISHMENT_OF_PROTEIN_LOCALIZATION_TO_ENDOPLASMIC_RETICULUM    2.844041e-06
GO_NEGATIVE_REGULATION_OF_VIRAL_GENOME_REPLICATION                   2.004658e-05
GO_RESPONSE_TO_INTERFERON_ALPHA                                      2.688852e-05
GO_REGULATION_OF_EPIDERMAL_GROWTH_FACTOR_ACTIVATED_RECEPTOR_ACTIVITY 2.688852e-05
GO_RIBOSOMAL_SUBUNIT                                                 2.688852e-05
GO_CYTOSOLIC_LARGE_RIBOSOMAL_SUBUNIT                                 4.108682e-05
GO_RESPONSE_TO_VIRUS                                                 5.081736e-05
GO_MHC_CLASS_I_PROTEIN_COMPLEX                                       5.730358e-05
GO_TRANSLATIONAL_INITIATION                                          5.730358e-05
GO_NEGATIVE_REGULATION_OF_VIRAL_PROCESS                              5.759455e-05
GO_POSITIVE_REGULATION_OF_T_CELL_MEDIATED_IMMUNITY                   7.213177e-05
GO_NEGATIVE_REGULATION_OF_CELL_KILLING                               7.333477e-05

The Hallmark gene sets are coherently expressed signatures derived by aggregating many MSigDB gene sets to represent well-defined biological states or processes.

hCam <- camera(cpm(norm$normalizedCounts, log = TRUE), 
               gsAnnots$h@idx, design, contrast = cont[,1], trend.var = TRUE)
head(hCam, n = 20)
                                         NGenes Direction       PValue
HALLMARK_INTERFERON_ALPHA_RESPONSE           81        Up 3.210087e-42
HALLMARK_INTERFERON_GAMMA_RESPONSE          147        Up 3.835202e-28
HALLMARK_MYC_TARGETS_V1                     198      Down 2.289784e-07
HALLMARK_E2F_TARGETS                        196      Down 2.321102e-07
HALLMARK_INFLAMMATORY_RESPONSE              116        Up 1.072819e-06
HALLMARK_TNFA_SIGNALING_VIA_NFKB            162        Up 8.852168e-06
HALLMARK_OXIDATIVE_PHOSPHORYLATION          197      Down 2.967850e-05
HALLMARK_KRAS_SIGNALING_UP                  133        Up 1.049788e-04
HALLMARK_ALLOGRAFT_REJECTION                102        Up 3.771055e-04
HALLMARK_IL6_JAK_STAT3_SIGNALING             47        Up 7.380124e-04
HALLMARK_G2M_CHECKPOINT                     194      Down 9.731403e-04
HALLMARK_COMPLEMENT                         140        Up 1.423210e-03
HALLMARK_DNA_REPAIR                         145      Down 8.261581e-03
HALLMARK_APICAL_SURFACE                      31        Up 9.219329e-03
HALLMARK_TGF_BETA_SIGNALING                  52        Up 1.459303e-02
HALLMARK_FATTY_ACID_METABOLISM              138      Down 2.395387e-02
HALLMARK_MITOTIC_SPINDLE                    192      Down 2.739468e-02
HALLMARK_MYOGENESIS                         122      Down 4.548808e-02
HALLMARK_UV_RESPONSE_DN                     134        Up 6.837902e-02
HALLMARK_REACTIVE_OXIGEN_SPECIES_PATHWAY     43      Down 6.877153e-02
                                                  FDR
HALLMARK_INTERFERON_ALPHA_RESPONSE       1.605043e-40
HALLMARK_INTERFERON_GAMMA_RESPONSE       9.588005e-27
HALLMARK_MYC_TARGETS_V1                  2.901378e-06
HALLMARK_E2F_TARGETS                     2.901378e-06
HALLMARK_INFLAMMATORY_RESPONSE           1.072819e-05
HALLMARK_TNFA_SIGNALING_VIA_NFKB         7.376806e-05
HALLMARK_OXIDATIVE_PHOSPHORYLATION       2.119893e-04
HALLMARK_KRAS_SIGNALING_UP               6.561172e-04
HALLMARK_ALLOGRAFT_REJECTION             2.095031e-03
HALLMARK_IL6_JAK_STAT3_SIGNALING         3.690062e-03
HALLMARK_G2M_CHECKPOINT                  4.423365e-03
HALLMARK_COMPLEMENT                      5.930043e-03
HALLMARK_DNA_REPAIR                      3.177531e-02
HALLMARK_APICAL_SURFACE                  3.292618e-02
HALLMARK_TGF_BETA_SIGNALING              4.864342e-02
HALLMARK_FATTY_ACID_METABOLISM           7.485584e-02
HALLMARK_MITOTIC_SPINDLE                 8.057260e-02
HALLMARK_MYOGENESIS                      1.263558e-01
HALLMARK_UV_RESPONSE_DN                  1.719288e-01
HALLMARK_REACTIVE_OXIGEN_SPECIES_PATHWAY 1.719288e-01

Barcode plots show the enrichment of gene sets among up or down-regulated genes. The following barcode plots show the enrichment of the top 4 hallmark gene sets among the genes differentially expressed between CMV positive and CMV negative samples.

par(mfrow=c(2,2))
sapply(1:4, function(i){
  barcodeplot(lrt$table$logFC, gsAnnots$h@idx[[rownames(hCam)[i]]], 
              main = rownames(hCam)[i], cex.main = 0.75)
})

[[1]]
NULL

[[2]]
NULL

[[3]]
NULL

[[4]]
NULL

The curated gene sets are compiled from online pathway databases, publications in PubMed, and knowledge of domain experts.

c2Cam <- camera(cpm(norm$normalizedCounts, log = TRUE), 
                gsAnnots$c2@idx, design, contrast = cont[,1], trend.var = TRUE)
write.csv(c2Cam[c2Cam$FDR < 0.05,], 
          file = here("output/star-fc-ruv-no_us_ab-gsea-c2.csv"))
head(c2Cam, n = 20)
                                                  NGenes Direction       PValue
MOSERLE_IFNA_RESPONSE                                 27        Up 1.654534e-41
BROWNE_INTERFERON_RESPONSIVE_GENES                    55        Up 4.090221e-36
SANA_RESPONSE_TO_IFNG_UP                              48        Up 1.081287e-32
HECKER_IFNB1_TARGETS                                  59        Up 2.857179e-31
FARMER_BREAST_CANCER_CLUSTER_1                        15        Up 1.266765e-28
DAUER_STAT3_TARGETS_DN                                49        Up 7.717137e-26
BOSCO_INTERFERON_INDUCED_ANTIVIRAL_MODULE             59        Up 5.615093e-25
EINAV_INTERFERON_SIGNATURE_IN_CANCER                  24        Up 4.597601e-24
REACTOME_INTERFERON_ALPHA_BETA_SIGNALING              44        Up 2.120702e-22
BENNETT_SYSTEMIC_LUPUS_ERYTHEMATOSUS                  24        Up 1.758712e-21
BOWIE_RESPONSE_TO_TAMOXIFEN                           16        Up 4.992374e-21
SANA_TNF_SIGNALING_UP                                 63        Up 1.693553e-20
BOWIE_RESPONSE_TO_EXTRACELLULAR_MATRIX                16        Up 7.713092e-20
RADAEVA_RESPONSE_TO_IFNA1_UP                          45        Up 7.789974e-20
SEITZ_NEOPLASTIC_TRANSFORMATION_BY_8P_DELETION_UP     56        Up 5.422838e-19
ZHANG_INTERFERON_RESPONSE                             18        Up 9.644047e-19
ROETH_TERT_TARGETS_UP                                 13        Up 3.256419e-18
TAKEDA_TARGETS_OF_NUP98_HOXA9_FUSION_3D_UP           129        Up 6.104824e-17
DER_IFN_ALPHA_RESPONSE_UP                             67        Up 3.089815e-16
KRASNOSELSKAYA_ILF3_TARGETS_UP                        30        Up 2.227155e-14
                                                           FDR
MOSERLE_IFNA_RESPONSE                             6.189610e-38
BROWNE_INTERFERON_RESPONSIVE_GENES                7.650758e-33
SANA_RESPONSE_TO_IFNG_UP                          1.348365e-29
HECKER_IFNB1_TARGETS                              2.672177e-28
FARMER_BREAST_CANCER_CLUSTER_1                    9.477937e-26
DAUER_STAT3_TARGETS_DN                            4.811635e-23
BOSCO_INTERFERON_INDUCED_ANTIVIRAL_MODULE         3.000866e-22
EINAV_INTERFERON_SIGNATURE_IN_CANCER              2.149953e-21
REACTOME_INTERFERON_ALPHA_BETA_SIGNALING          8.815052e-20
BENNETT_SYSTEMIC_LUPUS_ERYTHEMATOSUS              6.579340e-19
BOWIE_RESPONSE_TO_TAMOXIFEN                       1.697861e-18
SANA_TNF_SIGNALING_UP                             5.279653e-18
BOWIE_RESPONSE_TO_EXTRACELLULAR_MATRIX            2.081592e-17
RADAEVA_RESPONSE_TO_IFNA1_UP                      2.081592e-17
SEITZ_NEOPLASTIC_TRANSFORMATION_BY_8P_DELETION_UP 1.352456e-16
ZHANG_INTERFERON_RESPONSE                         2.254899e-16
ROETH_TERT_TARGETS_UP                             7.166036e-16
TAKEDA_TARGETS_OF_NUP98_HOXA9_FUSION_3D_UP        1.268786e-14
DER_IFN_ALPHA_RESPONSE_UP                         6.083683e-14
KRASNOSELSKAYA_ILF3_TARGETS_UP                    4.165893e-12

The following barcode plots show the enrichment of the top 4 curated gene sets among the genes differentially expressed between CMV positive and CMV negative samples.

par(mfrow=c(2,2))
sapply(1:4, function(i){
  barcodeplot(lrt$table$logFC, gsAnnots$c2@idx[[rownames(c2Cam)[i]]], 
              main = rownames(c2Cam)[i], cex.main = 0.75)
})

[[1]]
NULL

[[2]]
NULL

[[3]]
NULL

[[4]]
NULL

The KEGG gene sets encompass all of the pathways defined in the Kegg pathway database.

keggCam <- camera(cpm(norm$normalizedCounts, log = TRUE), 
                  gsAnnots$kegg@idx, design, contrast = cont[,1],
                  trend.var = TRUE)
head(keggCam, n = 20)
                                       NGenes Direction       PValue
Ribosome                                  125      Down 2.592451e-09
Oxidative phosphorylation                 117      Down 1.227633e-08
Huntington's disease                      172      Down 8.984765e-08
Parkinson's disease                       122      Down 1.390630e-07
Type I diabetes mellitus                   12        Up 4.426308e-06
Antigen processing and presentation        39        Up 4.486566e-06
Autoimmune thyroid disease                 10        Up 5.168647e-06
Allograft rejection                         9        Up 8.201676e-06
Graft-versus-host disease                   8        Up 1.019338e-05
Cytokine-cytokine receptor interaction     83        Up 2.366610e-05
Measles                                    89        Up 2.547842e-05
Mineral absorption                         36        Up 3.617398e-05
Spliceosome                               128      Down 7.110886e-05
Cysteine and methionine metabolism         32      Down 1.318477e-04
NOD-like receptor signaling pathway       117        Up 1.617333e-04
Hepatitis C                                98        Up 1.982165e-04
Systemic lupus erythematosus               79      Down 2.738858e-04
DNA replication                            33      Down 3.964001e-04
Leishmaniasis                              39        Up 4.621177e-04
Influenza A                               119        Up 7.141495e-04
                                                FDR
Ribosome                               7.544031e-07
Oxidative phosphorylation              1.786206e-06
Huntington's disease                   8.715222e-06
Parkinson's disease                    1.011683e-05
Type I diabetes mellitus               2.148680e-04
Antigen processing and presentation    2.148680e-04
Autoimmune thyroid disease             2.148680e-04
Allograft rejection                    2.983360e-04
Graft-versus-host disease              3.295860e-04
Cytokine-cytokine receptor interaction 6.740201e-04
Measles                                6.740201e-04
Mineral absorption                     8.772190e-04
Spliceosome                            1.591745e-03
Cysteine and methionine metabolism     2.740549e-03
NOD-like receptor signaling pathway    3.137627e-03
Hepatitis C                            3.605063e-03
Systemic lupus erythematosus           4.688281e-03
DNA replication                        6.408469e-03
Leishmaniasis                          7.077697e-03
Influenza A                            1.039087e-02
par(mfrow=c(2,2))
sapply(1:4, function(i){
  barcodeplot(lrt$table$logFC, gsAnnots$kegg@idx[[rownames(keggCam)[i]]], 
              main = rownames(keggCam)[i], cex.main = 0.75)
})

[[1]]
NULL

[[2]]
NULL

[[3]]
NULL

[[4]]
NULL

Brain development genes

Test only the specialised brain development gene set.

brainSet <- readr::read_delim(file = here("data/brain-development-geneset.txt"),
                              delim = "\t", skip = 2, col_names = "BRAIN_DEV")
brainSet
# A tibble: 51 x 1
   BRAIN_DEV 
   <chr>     
 1 AC139768.1
 2 ADGRG1    
 3 AFF2      
 4 ALK       
 5 ALX1      
 6 BPTF      
 7 CDK5R1    
 8 CEP290    
 9 CLN5      
10 CNTN4     
# … with 41 more rows
bd <- estimateGLMCommonDisp(y[y$genes$symbol %in% brainSet$BRAIN_DEV, ], design)
bd <- estimateGLMTagwiseDisp(bd, design)
fit <- glmFit(bd, design)
lrt <- glmLRT(fit, contrast = cont[,1])
fitSum <- summary(decideTests(lrt, p.value = 0.05))
fitSum
       -1*neg.no_us_ab 1*pos.no_us_ab
Down                                0
NotSig                             27
Up                                  0
topBD <- topTags(lrt, n = Inf)$table
topBD
                  Geneid Length         Ensembl  symbol entrezid        logFC
54718 ENSG00000053438.11   1329 ENSG00000053438    NNAT     4826 -0.537591945
47853  ENSG00000176749.9   3948 ENSG00000176749  CDK5R1     8851  0.350228715
13911  ENSG00000132467.4   2020 ENSG00000132467    UTP3    57050  0.150980929
58386 ENSG00000158352.15  10333 ENSG00000158352 SHROOM4    57477  0.135574765
28963 ENSG00000167081.18   4904 ENSG00000167081    PBX3     5090  0.174840665
59824 ENSG00000155966.14  14241 ENSG00000155966    AFF2     2334 -0.238503656
42132 ENSG00000114062.21  12808 ENSG00000114062   UBE3A     7337  0.075543365
51917 ENSG00000130479.11   4933 ENSG00000130479   MAP1S    55201  0.091152453
57747 ENSG00000146950.13   8218 ENSG00000146950 SHROOM2      357  0.064492085
10970 ENSG00000185008.17  16663 ENSG00000185008   ROBO2     6092 -0.109558277
2823  ENSG00000092621.12   9217 ENSG00000092621   PHGDH    26227 -0.088099558
46775 ENSG00000040531.16   4949 ENSG00000040531    CTNS     1497  0.090532438
7681  ENSG00000074047.21   7341 ENSG00000074047    GLI2     2736 -0.103710921
59499 ENSG00000102038.15   4363 ENSG00000102038 SMARCA1     6594 -0.072068909
47791 ENSG00000196712.18  27130 ENSG00000196712     NF1     4763 -0.051665030
16275 ENSG00000164258.12   1174 ENSG00000164258  NDUFS4     4724 -0.052647809
9697  ENSG00000144619.15   9123 ENSG00000144619   CNTN4   152330 -0.059754938
3760  ENSG00000185630.19  21370 ENSG00000185630    PBX1     5087 -0.031177920
54624 ENSG00000198646.14  11133 ENSG00000198646   NCOA6    23054 -0.022938219
45778 ENSG00000205336.13   8659 ENSG00000205336  ADGRG1     9289  0.027875067
39080 ENSG00000102805.16  22814 ENSG00000102805    CLN5     1203 -0.021421501
33637 ENSG00000110697.13   6442 ENSG00000110697 PITPNM1     9600 -0.015269358
37089 ENSG00000198707.16  10442 ENSG00000198707  CEP290    80184 -0.012809850
23659 ENSG00000128573.26  16334 ENSG00000128573   FOXP2    93986 -0.015712817
49155 ENSG00000171634.18  15119 ENSG00000171634    BPTF     2186  0.008271003
1293  ENSG00000131238.17   5088 ENSG00000131238    PPT1     5538 -0.008859866
24536  ENSG00000164690.8   5234 ENSG00000164690     SHH     6469  0.005095123
        logCPM           LR      PValue        FDR
54718 6.823064 9.6780357735 0.001864839 0.05035065
47853 3.961733 3.8756422412 0.048991563 0.66138609
13911 4.964934 1.5887711535 0.207501790 0.97718143
58386 5.420945 1.5198600995 0.217640666 0.97718143
28963 4.825089 1.3545185993 0.244489720 0.97718143
59824 1.889023 0.9966171709 0.318130440 0.97718143
42132 7.720328 0.7486381115 0.386907756 0.97718143
51917 4.816488 0.4646697381 0.495449613 0.97718143
57747 5.891710 0.4407987731 0.506737173 0.97718143
10970 3.995909 0.3886502594 0.533009737 0.97718143
2823  4.107322 0.3197734323 0.571743836 0.97718143
46775 2.885607 0.3019623260 0.582654826 0.97718143
7681  2.350289 0.2668836550 0.605429945 0.97718143
59499 7.435325 0.2395818778 0.624508268 0.97718143
47791 7.823021 0.2093952474 0.647241816 0.97718143
16275 4.867483 0.1957308749 0.658189055 0.97718143
9697  2.553660 0.0995111148 0.752417106 0.97718143
3760  8.695648 0.0848243125 0.770863079 0.97718143
54624 7.391398 0.0783063039 0.779605912 0.97718143
45778 4.486981 0.0240799519 0.876681652 0.97718143
39080 3.553017 0.0216022853 0.883150049 0.97718143
33637 5.387911 0.0113309948 0.915227589 0.97718143
37089 6.738401 0.0069432105 0.933592383 0.97718143
23659 6.032058 0.0064680259 0.935900009 0.97718143
49155 9.113684 0.0061993323 0.937242739 0.97718143
1293  4.260589 0.0037098593 0.951431989 0.97718143
24536 3.482033 0.0008181163 0.977181434 0.97718143

The following plots show the expression of the top 9 genes from the brain development set as ranked by their differential expression with regard to CMV positive and CMV negative status.

b <- norm$normalizedCounts[y$genes$entrezid %in% topBD$entrezid[1:9], ]
dat <- reshape2::melt(cpm(b, log = TRUE),
                      value.name = "cpm")
dat$status <- rep(targets$CMV_status, each = nrow(b))
dat$gene <- rep(y$genes$Geneid[y$genes$entrezid %in% topBD$entrezid[1:9]], 
                ncol(b))

p <- vector("list", 9)

for(i in 1:length(p)){
p[[i]] <- ggplot(data = subset(dat, dat$gene == topBD$Geneid[i]), 
       aes(x = status, y = cpm, colour = status)) +
  geom_jitter(width = 0.25) +
  stat_summary(fun = "mean", geom = "crossbar") +
  labs(x = "Status", y = "log2 CPM", colour = "Status") +
  ggtitle(topBD$symbol[i]) +
  theme(plot.title = element_text(size = 8),
        plot.subtitle = element_text(size = 7),
        axis.title = element_text(size = 8),
        axis.text.x = element_text(size = 7))
}

wrap_plots(p, guides = "collect", ncol = 3) & 
  theme(legend.position = "bottom")

Summary

Although the effective library sizes were low, the data is generally of good quality. We found at total of 63 differentially expressed genes at FDR < 0.05. The significant genes were enriched for GO terms associated with interferon response and similar. Further gene set testing results indicate an upregulation of interferon response genes in the CMV positive samples, relative to the CMV negative samples, which is consistent with the top genes from the DE analysis.


sessionInfo()
R version 4.0.2 (2020-06-22)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: CentOS Linux 7 (Core)

Matrix products: default
BLAS:   /config/binaries/R/4.0.2/lib64/R/lib/libRblas.so
LAPACK: /config/binaries/R/4.0.2/lib64/R/lib/libRlapack.so

locale:
 [1] LC_CTYPE=en_AU.UTF-8       LC_NUMERIC=C              
 [3] LC_TIME=en_AU.UTF-8        LC_COLLATE=en_AU.UTF-8    
 [5] LC_MONETARY=en_AU.UTF-8    LC_MESSAGES=en_AU.UTF-8   
 [7] LC_PAPER=en_AU.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_AU.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats4    parallel  stats     graphics  grDevices utils     datasets 
[8] methods   base     

other attached packages:
 [1] RColorBrewer_1.1-2          RUVSeq_1.24.0              
 [3] EDASeq_2.24.0               ShortRead_1.48.0           
 [5] GenomicAlignments_1.26.0    SummarizedExperiment_1.20.0
 [7] MatrixGenerics_1.2.1        matrixStats_0.59.0         
 [9] Rsamtools_2.6.0             Biostrings_2.58.0          
[11] XVector_0.30.0              BiocParallel_1.24.1        
[13] EGSEA_1.18.1                pathview_1.30.1            
[15] topGO_2.42.0                SparseM_1.78               
[17] GO.db_3.12.1                graph_1.68.0               
[19] gage_2.40.1                 patchwork_1.1.1            
[21] NMF_0.23.0                  cluster_2.1.0              
[23] rngtools_1.5                pkgmaker_0.32.2            
[25] registry_0.5-1              edgeR_3.32.1               
[27] limma_3.46.0                EnsDb.Hsapiens.v86_2.99.0  
[29] ensembldb_2.14.0            AnnotationFilter_1.14.0    
[31] GenomicFeatures_1.42.1      AnnotationDbi_1.52.0       
[33] Biobase_2.50.0              GenomicRanges_1.42.0       
[35] GenomeInfoDb_1.26.7         IRanges_2.24.1             
[37] S4Vectors_0.28.1            BiocGenerics_0.36.1        
[39] forcats_0.5.1               stringr_1.4.0              
[41] dplyr_1.0.4                 purrr_0.3.4                
[43] readr_1.4.0                 tidyr_1.1.2                
[45] tibble_3.1.2                ggplot2_3.3.5              
[47] tidyverse_1.3.0             here_1.0.1                 
[49] workflowr_1.6.2            

loaded via a namespace (and not attached):
  [1] rappdirs_0.3.3           rtracklayer_1.50.0       Glimma_2.0.0            
  [4] R.methodsS3_1.8.1        bit64_4.0.5              knitr_1.31              
  [7] R.utils_2.10.1           aroma.light_3.20.0       multcomp_1.4-16         
 [10] DelayedArray_0.16.3      data.table_1.13.6        hwriter_1.3.2           
 [13] KEGGREST_1.30.1          RCurl_1.98-1.3           doParallel_1.0.16       
 [16] generics_0.1.0           metap_1.4                org.Mm.eg.db_3.12.0     
 [19] TH.data_1.0-10           RSQLite_2.2.5            bit_4.0.4               
 [22] mutoss_0.1-12            xml2_1.3.2               lubridate_1.7.9.2       
 [25] httpuv_1.5.5             assertthat_0.2.1         xfun_0.23               
 [28] hms_1.0.0                evaluate_0.14            promises_1.2.0.1        
 [31] fansi_0.5.0              progress_1.2.2           caTools_1.18.1          
 [34] dbplyr_2.1.0             readxl_1.3.1             Rgraphviz_2.34.0        
 [37] DBI_1.1.1                geneplotter_1.68.0       tmvnsim_1.0-2           
 [40] htmlwidgets_1.5.3        ellipsis_0.3.2           backports_1.2.1         
 [43] annotate_1.68.0          PADOG_1.32.0             gbRd_0.4-11             
 [46] gridBase_0.4-7           biomaRt_2.46.3           HTMLUtils_0.1.7         
 [49] vctrs_0.3.8              cachem_1.0.4             withr_2.4.2             
 [52] globaltest_5.44.0        prettyunits_1.1.1        mnormt_2.0.2            
 [55] lazyeval_0.2.2           crayon_1.4.1             genefilter_1.72.1       
 [58] labeling_0.4.2           pkgconfig_2.0.3          nlme_3.1-152            
 [61] ProtGenerics_1.22.0      GSA_1.03.1               rlang_0.4.11            
 [64] lifecycle_1.0.0          sandwich_3.0-0           BiocFileCache_1.14.0    
 [67] mathjaxr_1.2-0           modelr_0.1.8             cellranger_1.1.0        
 [70] rprojroot_2.0.2          GSVA_1.38.2              Matrix_1.3-2            
 [73] zoo_1.8-9                reprex_1.0.0             whisker_0.4             
 [76] png_0.1-7                viridisLite_0.4.0        bitops_1.0-7            
 [79] R.oo_1.24.0              KernSmooth_2.23-18       blob_1.2.1              
 [82] R2HTML_2.3.2             doRNG_1.8.2              jpeg_0.1-8.1            
 [85] scales_1.1.1             memoise_2.0.0.9000       GSEABase_1.52.1         
 [88] magrittr_2.0.1           plyr_1.8.6               safe_3.30.0             
 [91] gplots_3.1.1             zlibbioc_1.36.0          compiler_4.0.2          
 [94] plotrix_3.8-1            KEGGgraph_1.50.0         DESeq2_1.30.1           
 [97] cli_3.0.0                EGSEAdata_1.18.0         MASS_7.3-53.1           
[100] tidyselect_1.1.0         stringi_1.5.3            highr_0.8               
[103] yaml_2.2.1               askpass_1.1              locfit_1.5-9.4          
[106] ggrepel_0.9.1            latticeExtra_0.6-29      grid_4.0.2              
[109] tools_4.0.2              rstudioapi_0.13          foreach_1.5.1           
[112] git2r_0.28.0             farver_2.1.0             digest_0.6.27           
[115] Rcpp_1.0.6               broom_0.7.4              later_1.1.0.1           
[118] org.Hs.eg.db_3.12.0      httr_1.4.2               Rdpack_2.1              
[121] colorspace_2.0-2         rvest_0.3.6              XML_3.99-0.5            
[124] fs_1.5.0                 splines_4.0.2            sn_1.6-2                
[127] multtest_2.46.0          plotly_4.9.3             xtable_1.8-4            
[130] jsonlite_1.7.2           R6_2.5.0                 TFisher_0.2.0           
[133] KEGGdzPathwaysGEO_1.28.0 pillar_1.6.1             htmltools_0.5.1.1       
[136] hgu133plus2.db_3.2.3     glue_1.4.2               fastmap_1.1.0           
[139] DT_0.17                  codetools_0.2-18         mvtnorm_1.1-1           
[142] utf8_1.2.1               lattice_0.20-41          numDeriv_2016.8-1.1     
[145] hgu133a.db_3.2.3         curl_4.3                 gtools_3.8.2            
[148] openssl_1.4.3            survival_3.2-7           rmarkdown_2.6           
[151] org.Rn.eg.db_3.12.0      munsell_0.5.0            GenomeInfoDbData_1.2.4  
[154] iterators_1.0.13         haven_2.3.1              reshape2_1.4.4          
[157] gtable_0.3.0             rbibutils_2.0