Description
Purpose: The goal of this study is to compare the transcriptional phenotype of lymphoid and kidney-infiltrating T cell populations in the setting of systemic inflammatory disease to determine how tissue location alters their phenotype. Methods: mRNA profiles of T cells isolated from 23-week-old nephritic (protein score of 3+ on dipstick) mice were used in this study. T cells were isolated by flow cytometry gated on CD45+Thy1.1+CD44+ and either CD4 or CD8+ T cells. RNA was isolated using the RNeasy Plus Micro Kit (Qiagen). Samples were sequenced using Illumina NextSeq 500 with 75bp paired-end reads and aligned to the mm10 genome using the STAR aligner. The number of uniquely aligned reads ranged from 10 to 12 million. Using an optimized data analysis workflow, Gene-level counts were determined using featureCounts and raw counts were analyzed for differential expression using the “voom” method in the “limma” R package. Results: After determining genes that were differentially expressed between splenic T cells and KIT, we performed gene set enrichment analysis (GSEA. Differentially expressed genes were compared to several previously defined gene signatures that are characteristic of CD8+ and CD4+ T cell exhaustion in the chronic LCMV infection model and tumor infiltrating lymphocytes. Genes from the CD8+ exhaustion cluster were significantly enriched among genes that were differentially expressed in CD8+ KITs vs CD8+ splenocytes. Overall design: mRNA profiles of CD4 and CD8 T cells from spleen and kidney of 23 week old wild MRL/lpr mice were generated in triplicate by sequencing using Illumina NextSeq 500