Abstract
Purpose :
To characterize the single-cell transcriptome of the adult murine lacrimal gland in wild-type mice and mouse models of Sjogren’s syndrome
Methods :
Extraorbital lacrimal glands from adult BALB/cJ male (n=4) and female (n=4) mice, as well as adult NOD.B10.H2b male mice (n=2) and adult MRL-lpr female mice (n=2) were dissected and dissociated for droplet-based single-cell RNA sequencing (sc-RNAseq, 10X Genomics). All mice were 4 months of age at the time of experiment. Cell type annotation and differential gene expression analysis were performed using the Monocle R package. Gene set enrichment analysis (GSEA) was carried out using the Molecular Signatures Database (MSigDB) Hallmark gene sets. Cell type markers and other genes of interest were validated using immunofluorescence.
Results :
A total of 102,431 cells were profiled by sc-RNAseq and included all known major cell types in the lacrimal gland. There was notable sexual dimorphism in the expression of the secretoglobins, with most secretoglobins being preferentially expressed in male lacrimal glands. Analysis of the immune cell clusters identified cells of monocyte lineage, plasma cells, B cells, T cells, NK cells, mast cells and a cluster of GM-CSF-producing innate lymphoid cells (ILCs). Cells of monocyte lineage exhibited dynamic transcriptional profiles that included a sub-population of Cd163-positive, Pf4-positive macrophages. GSEA revealed significant upregulation of interferon signaling in NOD.B10.H2b and MRL-lpr lacrimal glands.
Conclusions :
sc-RNAseq revealed sexual dimorphism in gene expression and diverse immune cell types in lacrimal glands of wild-type mice and mouse models of Sjogren’s syndrome. Interferon signaling appeared to be significantly upregulated in two mouse models of Sjogren’s syndrome. The role of novel immune sub-populations, including innate lymphoid cells and Cd163-positive macrophages, in lacrimal gland disease remains to be elucidated and warrants further investigation.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.