Characterization of tissue-specific type III interferon (IFN-λ3) receptor (IL-10R2/IFNLR1) transcript and protein expression in bovine immune and epithelial cells 2217

Description Type I and III interferons are the first and most important mediators of the innate immune response against viral pathogens. The type III interferon receptor complex is composed of the widely expressed IL-10R2 subunit and the unique IFNLR1 subunit that is critical for downstream signaling. In humans and mice, the expression of IFNLR1 is largely restricted to epithelial cells and some leukocytes. However, the bovine tissue-specific expression pattern of IFNLR1 has not been previously characterized. Here we examined the transcription and expression of bovine IFNLR1, as well as transcript levels of IL10R2 in immune and epithelial cells. CD3 + (pan) T-cells, CD4+ T-cells, CD8+ T-cells, γδ T-cells, Natural Killer (NK) cells, (sIgM+ pan) B-cells, and monocytes were isolated by FACS cell sorting, as well as RNA from 22 tissues collected at necropsy. RT-qPCR analyses revealed elevated IFNLR1 transcript levels in the thymus, tonsils, kidney, liver, ileum, jejunum, duodenum, lungs and in B-cells, while the lowest IFNLR1 transcript levels were observed in brain stem, cerebellum, and bronchus, and within monocyte, NK, neutrophil, and T-cell populations. Immune and epithelial cells had abundant IL10R2 transcripts. To examine surface expression, antibodies were prepared against the extracellular domain of bovine IFNLR1. Flow cytometry revealed surface IFNLR1 expression on B-cells. This study details the first characterization of the type III interferon receptor distribution in bovines. Funding Sources Supported by USDA ARS Project 5030-32000-229-000-D. Topic Categories Veterinary and Comparative Immunology (VET)