1 Installation

if (!requireNamespace("BiocManager", quietly = TRUE))
    install.packages("BiocManager")

BiocManager::install("SingleCellMultiModal")

2 Load libraries

library(MultiAssayExperiment)
library(SingleCellMultiModal)

3 CITE-seq dataset

CITE-seq data are a combination of two data types extracted at the same time from the same cell. First data type is scRNA-seq data, while the second one consists of about a hundread of antibody-derived tags (ADT). In particular this dataset is provided by Stoeckius et al. (2017).

3.1 Downloading datasets

The user can see the available dataset by using the default options

CITEseq(DataType="cord_blood", modes="*", dry.run=TRUE, version="1.0.0")
## Dataset: cord_blood
##    ah_id            mode file_size rdataclass rdatadateadded rdatadateremoved
## 1 EH3795    scADT_Counts    0.2 Mb     matrix     2020-09-23             <NA>
## 2 EH3796 scRNAseq_Counts   22.2 Mb     matrix     2020-09-23             <NA>

Or simply by setting dry.run = FALSE it downloads the data and creates the MultiAssayExperiment object.

In this example, we will use one of the two available datasets scADT_Counts:

mae <- CITEseq(
    DataType="cord_blood", modes="*", dry.run=FALSE, version="1.0.0"
)

mae
## A MultiAssayExperiment object of 2 listed
##  experiments with user-defined names and respective classes.
##  Containing an ExperimentList class object of length 2:
##  [1] scADT: matrix with 13 rows and 8617 columns
##  [2] scRNAseq: matrix with 36280 rows and 8617 columns
## Functionality:
##  experiments() - obtain the ExperimentList instance
##  colData() - the primary/phenotype DataFrame
##  sampleMap() - the sample coordination DataFrame
##  `$`, `[`, `[[` - extract colData columns, subset, or experiment
##  *Format() - convert into a long or wide DataFrame
##  assays() - convert ExperimentList to a SimpleList of matrices
##  exportClass() - save data to flat files

Example with actual data:

experiments(mae)
## ExperimentList class object of length 2:
##  [1] scADT: matrix with 13 rows and 8617 columns
##  [2] scRNAseq: matrix with 36280 rows and 8617 columns

3.2 Exploring the data structure

Check row annotations:

rownames(mae)
## CharacterList of length 2
## [["scADT"]] CD3 CD4 CD8 CD45RA CD56 CD16 CD10 CD11c CD14 CD19 CD34 CCR5 CCR7
## [["scRNAseq"]] ERCC_ERCC-00104 HUMAN_A1BG ... MOUSE_n-R5s25 MOUSE_n-R5s31

Take a peek at the sampleMap:

sampleMap(mae)
## DataFrame with 17234 rows and 3 columns
##          assay          primary          colname
##       <factor>      <character>      <character>
## 1        scADT CTGTTTACACCGCTAG CTGTTTACACCGCTAG
## 2        scADT CTCTACGGTGTGGCTC CTCTACGGTGTGGCTC
## 3        scADT AGCAGCCAGGCTCATT AGCAGCCAGGCTCATT
## 4        scADT GAATAAGAGATCCCAT GAATAAGAGATCCCAT
## 5        scADT GTGCATAGTCATGCAT GTGCATAGTCATGCAT
## ...        ...              ...              ...
## 17230 scRNAseq TTGCCGTGTAGATTAG TTGCCGTGTAGATTAG
## 17231 scRNAseq GGCGTGTAGTGTACTC GGCGTGTAGTGTACTC
## 17232 scRNAseq CGTATGCCGTCTTCTG CGTATGCCGTCTTCTG
## 17233 scRNAseq TACACGACGCTCTTCC TACACGACGCTCTTCC
## 17234 scRNAseq ACACGACGCTCTTCCG ACACGACGCTCTTCCG

3.3 scRNA-seq data

The scRNA-seq data are accessible with the name scRNAseq, which returns a matrix object.

head(experiments(mae)$scRNAseq)[, 1:4]
##                 CTGTTTACACCGCTAG CTCTACGGTGTGGCTC AGCAGCCAGGCTCATT
## ERCC_ERCC-00104                0                0                0
## HUMAN_A1BG                     0                0                0
## HUMAN_A1BG-AS1                 0                0                0
## HUMAN_A1CF                     0                0                0
## HUMAN_A2M                      0                0                0
## HUMAN_A2M-AS1                  0                0                0
##                 GAATAAGAGATCCCAT
## ERCC_ERCC-00104                0
## HUMAN_A1BG                     0
## HUMAN_A1BG-AS1                 0
## HUMAN_A1CF                     0
## HUMAN_A2M                      0
## HUMAN_A2M-AS1                  0

3.4 scADT data

The scADT data are accessible with the name scADT, which returns a matrix object.

head(experiments(mae)$scADT)[, 1:4]
##        CTGTTTACACCGCTAG CTCTACGGTGTGGCTC AGCAGCCAGGCTCATT GAATAAGAGATCCCAT
## CD3                  60               52               89               55
## CD4                  72               49              112               66
## CD8                  76               59               61               56
## CD45RA              575             3943              682              378
## CD56                 64               68               87               58
## CD16                161              107              117               82

4 SingleCellExperiment object conversion

Because of already large use of some methodologies (such as in the SingleCellExperiment vignette or CiteFuse Vignette where the SingleCellExperiment object is used for CITE-seq data, we provide a function for the conversion of our CITE-seq MultiAssayExperiment object into a SingleCellExperiment object with scRNA-seq data as counts and scADT data as altExps.

sce <- CITEseq(DataType="cord_blood", modes="*", dry.run=FALSE, version="1.0.0",
              DataClass="SingleCellExperiment")
sce
## class: SingleCellExperiment 
## dim: 36280 8617 
## metadata(0):
## assays(1): counts
## rownames(36280): ERCC_ERCC-00104 HUMAN_A1BG ... MOUSE_n-R5s25
##   MOUSE_n-R5s31
## rowData names(0):
## colnames(8617): CTGTTTACACCGCTAG CTCTACGGTGTGGCTC ... TACACGACGCTCTTCC
##   ACACGACGCTCTTCCG
## colData names(0):
## reducedDimNames(0):
## mainExpName: NULL
## altExpNames(1): scADT

5 Session Info

sessionInfo()
## R version 4.3.1 (2023-06-16)
## Platform: x86_64-pc-linux-gnu (64-bit)
## Running under: Ubuntu 22.04.3 LTS
## 
## Matrix products: default
## BLAS:   /home/biocbuild/bbs-3.17-bioc/R/lib/libRblas.so 
## LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.10.0
## 
## locale:
##  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
##  [3] LC_TIME=en_GB              LC_COLLATE=C              
##  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
##  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
##  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
## [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
## 
## time zone: America/New_York
## tzcode source: system (glibc)
## 
## attached base packages:
## [1] stats4    stats     graphics  grDevices utils     datasets  methods  
## [8] base     
## 
## other attached packages:
##  [1] SingleCellMultiModal_1.12.3 MultiAssayExperiment_1.26.0
##  [3] SummarizedExperiment_1.30.2 Biobase_2.60.0             
##  [5] GenomicRanges_1.52.0        GenomeInfoDb_1.36.2        
##  [7] IRanges_2.34.1              S4Vectors_0.38.1           
##  [9] BiocGenerics_0.46.0         MatrixGenerics_1.12.3      
## [11] matrixStats_1.0.0           BiocStyle_2.28.0           
## 
## loaded via a namespace (and not attached):
##  [1] DBI_1.1.3                     bitops_1.0-7                 
##  [3] formatR_1.14                  rlang_1.1.1                  
##  [5] magrittr_2.0.3                compiler_4.3.1               
##  [7] RSQLite_2.3.1                 DelayedMatrixStats_1.22.6    
##  [9] png_0.1-8                     vctrs_0.6.3                  
## [11] pkgconfig_2.0.3               SpatialExperiment_1.10.0     
## [13] crayon_1.5.2                  fastmap_1.1.1                
## [15] magick_2.7.5                  dbplyr_2.3.3                 
## [17] XVector_0.40.0                ellipsis_0.3.2               
## [19] scuttle_1.10.2                utf8_1.2.3                   
## [21] promises_1.2.1                rmarkdown_2.24               
## [23] purrr_1.0.2                   bit_4.0.5                    
## [25] xfun_0.40                     zlibbioc_1.46.0              
## [27] cachem_1.0.8                  beachmat_2.16.0              
## [29] jsonlite_1.8.7                blob_1.2.4                   
## [31] later_1.3.1                   rhdf5filters_1.12.1          
## [33] DelayedArray_0.26.7           Rhdf5lib_1.22.0              
## [35] BiocParallel_1.34.2           interactiveDisplayBase_1.38.0
## [37] parallel_4.3.1                R6_2.5.1                     
## [39] bslib_0.5.1                   limma_3.56.2                 
## [41] jquerylib_0.1.4               Rcpp_1.0.11                  
## [43] bookdown_0.35                 knitr_1.43                   
## [45] R.utils_2.12.2                httpuv_1.6.11                
## [47] Matrix_1.6-1                  tidyselect_1.2.0             
## [49] abind_1.4-5                   yaml_2.3.7                   
## [51] codetools_0.2-19              curl_5.0.2                   
## [53] lattice_0.21-8                tibble_3.2.1                 
## [55] withr_2.5.0                   shiny_1.7.5                  
## [57] KEGGREST_1.40.0               evaluate_0.21                
## [59] BiocFileCache_2.8.0           ExperimentHub_2.8.1          
## [61] Biostrings_2.68.1             pillar_1.9.0                 
## [63] BiocManager_1.30.22           filelock_1.0.2               
## [65] generics_0.1.3                RCurl_1.98-1.12              
## [67] BiocVersion_3.17.1            sparseMatrixStats_1.12.2     
## [69] xtable_1.8-4                  glue_1.6.2                   
## [71] tools_4.3.1                   AnnotationHub_3.8.0          
## [73] locfit_1.5-9.8                rhdf5_2.44.0                 
## [75] grid_4.3.1                    DropletUtils_1.20.0          
## [77] AnnotationDbi_1.62.2          edgeR_3.42.4                 
## [79] SingleCellExperiment_1.22.0   GenomeInfoDbData_1.2.10      
## [81] HDF5Array_1.28.1              cli_3.6.1                    
## [83] rappdirs_0.3.3                fansi_1.0.4                  
## [85] S4Arrays_1.0.6                dplyr_1.1.3                  
## [87] R.methodsS3_1.8.2             sass_0.4.7                   
## [89] digest_0.6.33                 dqrng_0.3.1                  
## [91] rjson_0.2.21                  memoise_2.0.1                
## [93] htmltools_0.5.6               R.oo_1.25.0                  
## [95] lifecycle_1.0.3               httr_1.4.7                   
## [97] mime_0.12                     bit64_4.0.5

References

Stoeckius, Marlon, Christoph Hafemeister, William Stephenson, Brian Houck-Loomis, Pratip K Chattopadhyay, Harold Swerdlow, Rahul Satija, and Peter Smibert. 2017. “Simultaneous Epitope and Transcriptome Measurement in Single Cells.” Nature Methods 14 (9): 865.