Unveiling Vasculature-Associated Lymphoid Tissue (VALT) in Goats: A Novel Player in Kidney Inflammation

Recently, we reported a uniquely developed tertiary lymphoid tissue around the blood vessels and named it vasculature-associated lymphoid tissue (VALT) in nephritis model mouse kidneys. We established the role of VALT in the pathogenesis of kidney disease by providing immune effector cells. However, there are no reports concerning its occurrence in the goat kidney. Therefore, this study was designed to characterize the formation and activity of VALT in goats.

Kidney samples from different goats were grouped into healthy kidney (HK), which showed normal structure, and inflamed kidney (IK), which showed glomerular hypertrophy, hypercellularity, mesangial matrix expansion, adherence of podocytes to parietal cells and tubular dilatation.

Immunohistochemistry revealed infiltrating T cells, B cells and macrophages in both the glomerulus and tubulointerstitium of IK. Furthermore, cell clusters were observed in the perivascular area of the arcuate and interlobular arteries and veins of IK rather than HK, and these clusters were considered VALT. Cell characterization revealed that VALT was composed of T cells, B cells and macrophages and vascularized with numerous high endothelial venules. Juxtaposition of infiltrating lymphocytes and macrophages in VALT suggested possible antigen presentation to lymphocytes in situ. Moreover, the presence of Ki67+ proliferating cells and CD138+ plasma cells in VALT indicated its active immune status.

Therefore, we conclude that VALT develops in goat IK and participates in renal lesion development by providing effector cells.