Quantitative Expression of C-Type Lectin Receptors in Humans and Mice

TLDR

C‑type lectin receptors and their adaptor molecules recognize glycosylated self‑antigens and pathogens, yet species‑ and organ‑specific expression profiles remain poorly characterized. The study aimed to quantify mRNA levels of key C‑type lectin receptors and signaling proteins across 11 solid organs in humans and mice. mRNA expression was measured by quantitative analysis in each organ of both species. Mouse organs generally had lower mRNA levels than spleen, except for Dec‑205 and Galectin‑1 in thymus, Src in brain, and several genes in intestine, kidney, and muscle, whereas human lung, liver, and heart showed higher expression; moreover, ischemia‑reperfusion, renal fibrosis, and lupus nephritis in mice markedly up‑regulated Dectin‑1, MR1, Syk, Trem‑1, Tim‑3, DAP‑12, Card‑9, DC‑SIGN, and MR2, highlighting species‑ and organ‑specific expression differences that must be considered.

Abstract

C-type lectin receptors and their adaptor molecules are involved in the recognition of glycosylated self-antigens and pathogens. However, little is known about the species- and organ-specific expression profiles of these molecules. We therefore determined the mRNA expression levels of Dectin-1, MR1, MR2, DC-SIGN, Syk, Card-9, Bcl-10, Malt-1, Src, Dec-205, Galectin-1, Tim-3, Trem-1, and DAP-12 in 11 solid organs of human and mice. Mouse organs revealed lower mRNA levels of most molecules compared to spleen. However, Dec-205 and Galectin-1 in thymus, Src in brain, MR2, Card-9, Bcl-10, Src, and Dec-205 in small intestine, MR2, Bcl-10, Src, Galectin-1 in kidney, and Src and Galectin-1 in muscle were at least 2-fold higher expressed compared to spleen. Human lung, liver and heart expressed higher mRNA levels of most genes compared to spleen. Dectin-1, MR1, Syk and Trem-1 mRNA were strongly up-regulated upon ischemia-reperfusion injury in murine kidney. Tim3, DAP-12, Card-9, DC-SIGN and MR2 were further up-regulated during renal fibrosis. Murine kidney showed higher DAP-12, Syk, Card-9 and Dectin-1 mRNA expression during the progression of lupus nephritis. Thus, the organ-, and species-specific expression of C-type lectin receptors is different between mice and humans which must be considered in the interpretation of related studies.