CCR10 Deficiency Reduces Blood Pressure Elevations, End-Organ Damage, and Cutaneous Infiltration of Regulatory T Cells in a Murine Model of Hypertension

Emerging evidence suggests a key role for inflammation and immune cell activation in the pathogenesis of hypertension and its associated end-organ damage. Regulatory T cells (Tregs) function primarily to limit inflammation and are generally considered protective in hypertension. However, Treg subsets can also have tissue-specific functions and play pathogenic roles in some inflammatory diseases through mechanisms, such as limiting angiogenesis. As such, the role of Tregs and its subsets in hypertension remain unclear. Recently, we demonstrated that CCR10+ Tregs are selectively decreased in the circulation of hypertensive patients. CCR10 is a key chemokine receptor for recruitment of immune cells to the skin. Although the skin has not been well studied in hypertension, prior reports in humans demonstrate that loss of skin microvessels (microvascular rarefaction) is a putative mechanism for blood pressure (BP) elevations in hypertension. Recent evidence also suggests that Tregs can promote apoptosis of vascular smooth muscle cells and endothelial cells (ECs). Thus, we hypothesized that CCR10+ Tregs promote hypertension through skin infiltration leading to enhanced microvascular rarefaction. Herein, we demonstrate that, compared to normotensive littermates, male mice with angiotensin II (Ang II)-induced hypertension have selectively increased abundance of CCR10+ Tregs in the skin (p=0.0004) with a corresponding decrease in the circulation (p=0.003). These mice also displayed increased cutaneous levels of the CCR10 ligand CCL27 (p=0.0007), suggesting a mechanism for increased CCR10+ Treg infiltration. To test a causal role of CCR10 in hypertension, we infused Ang II in control CCR10+/+ or CCR10-deficient (CCR10−/−) mice for 4 weeks. Our results demonstrate that CCR10−/− mice exhibit significant reductions in systolic blood pressure (p=0.004), albuminuria (p=0.01), and cardiac fibrosis (p=0.04) compared to wild type mice after Ang II infusion. In addition, CCR10−/− mice had a selective decrease in Tregs in the skin (p=0.02) without change in abundance of conventional CD4+ or CD8+ T cells after Ang II. CCR10−/− mice also exhibited greater cutaneous arteriolar density (p=0.02) after Ang II, consistent with reduced skin microvascular rarefaction. Finally, using PrediXcan, we demonstrate that higher genetically predicted levels of CCR10 are associated with increased risk of hypertension in humans. Taken together, our data suggest that CCR10 promotes Ang II-induced BP elevations and associated end-organ injury, at least in part by promoting Treg recruitment to the skin leading to microvascular rarefaction. K08HL153786, 5T32HL144446-05. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.