Batf3-dependent CD8α+ Dendritic Cells Aggravates Atherosclerosis via Th1 Cell Induction and Enhanced CCL5 Expression in Plaque Macrophages

Dendritic cells (DCs) play an important role in controlling T cell-mediated adaptive immunity in atherogenesis. However, the role of the basic leucine zipper transcription factor, ATF-like 3 (Batf3)-dependent CD8α+ DC subset in atherogenesis remains unclear. Here we show that Batf3−/−Apoe−/− mice, lacking CD8α+ DCs, exhibited a significant reduction in atherogenesis and T help 1 (Th1) cells compared with Apoe−/− controls. Then, we found that CD8α+ DCs preferentially induce Th1 cells via secreting interleukin-12 (IL-12), and that the expression of interferon-gamma (IFN-γ)or chemokine (C-C motif) ligand 5 (CCL5) in aorta were significantly decreased in Batf3−/−Apoe−/− mice. We further demonstrated that macrophages were the major CCL5-expressing cells in the plaque, which was significantly reduced in Batf3−/−Apoe−/− mice. Furthermore, we found CCL5 expression in macrophages was promoted by IFN-γ. Finally, we showed that Batf3−/−Apoe−/− mice displayed decreased infiltration of leukocytes in the plaque. Thus, CD8α+ DCs aggravated atherosclerosis, likely by inducing Th1 cell response, which promoted CCL5 expression in macrophages and increased infiltration of leukocytes and lesion inflammation. •Ablation of CD8α+DCs in Batf3−/−Apoe−/− mice alleviated atherosclerosis, reduced Th1 cells and CCL5 expression.•Th1 cell cytokine IFN-γ promoted CCL5 expression in macrophages.•Reduction of Th1 cells and CCL5 expression helps to explain decreased aortic accumulation of inflammatory leukocytes. Dendritic cells (DCs) play an important role in controlling T cell-mediated adaptive immunity in atherogenesis. However, the role of Batf3-dependent CD8α+DC subset in atherogenesis remains unclear. Here we found that ablation of CD8α+DCs in Batf3−/−Apoe−/− mice alleviated atherosclerosis. Our data suggested that Batf3-dependent CD8α+DCs from western diet-treated mice preferentially induce Th1 cell polarization via secreting IL-12. Th1 cells promoted CCL5 expression on macrophages via IFN-γ secretion. Lack of CD8α+DCs-dependent enhancement of Th1 cells and CCL5 expression might explain decreased aortic accumulation of inflammatory leukocytes.