DNA methylation-based immune cell profiling in mouse blood using MouseRS-CMD.

We present MouseRS-CMD, a murine DNA methylation-based immune cell deconvolution tool. Neutrophils, monocytes, natural killer cells, B cells, CD4 + and CD8 + T cells were purified. DNA methylation was measured with the Illumina Mouse Methylation BeadChip at > 285,000 CpG loci for reference library development and in eye and terminal bleed whole blood with flow cytometry measurements for validation. The IDOL algorithm identified an optimal reference library of 300 CpGs with RMSE < 2.7 for four cell types and < 3.5 for all cell types. MouseRS-CMD enables immune profiling in archival samples and reduces confounding from cell type heterogeneity in molecular studies.