Objective-HSP60-specific T cells contribute to the development of the immune responses in atherosclerosis. This can be dampened by regulatory T cells activated via oral tolerance induction, and we explored the effect of oral tolerance induction to HSP60 and the peptide HSP60 (253 to 268) on atherosclerosis. Methods and Results-HSP60 and HSP60 (253 to 268) were administered orally to LDLr Ϫ/Ϫ mice before induction of atherosclerosis and resulted in a significant 80% reduction in plaque size in the carotid arteries and in a 27% reduction in plaque size at the aortic root. Reduction in plaque size correlated with an increase in CD4 ϩ CD25 ϩ Foxp3 ϩ regulatory T cells in several organs and in an increased expression of Foxp3, CD25, and CTLA-4 in atherosclerotic lesions of HSP60-treated mice. The production of interleukin (IL)-10 and transforming growth factor (TGF)-␤ by lymph node cells in response to HSP60 was observed after tolerance induction. Conclusion-Oral tolerance induction to HSP60 and a small HSP60-peptide leads to an increase in the number of CD4 ϩ CD25 ϩ Foxp3 ϩ regulatory T cells, resulting in a decrease in plaque size as a consequence of increased production of IL-10 and TGF-␤. We conclude that these beneficial results of oral tolerance induction to HSP60 and HSP60 (253 to 268) may provide new therapeutic approaches for the treatment of atherosclerosis. (Arterioscler Thromb Vasc Biol.

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Objective-The chemokine receptor CXCR3 is implicated in migration of leukocytes to sites of inflammation.Antagonizing CXCR3 may be a strategy to inhibit inflammation-induced leukocyte migration and subsequently reduce atherosclerosis. We used the CXCR3 specific antagonist NBI-74330 to block CXCR3-mediated signaling in peritonitis and diet-induced atherosclerosis. Methods and Results-Antagonizing CXCR3 with NBI-74330 resulted in a significant reduction in CD4 ϩ T cell and macrophage migration to the peritoneal cavity, which was as shown in ex vivo migration studies totally CXCR3 dependent. Atherosclerotic lesion formation in the aortic valve leaflet area and the entire aorta was significantly inhibited in NBI-74330 treated mice. Lymph nodes draining from the aortic arch were significantly smaller in treated mice and were enriched in regulatory T cells and contained fewer activated T cells, whereas the markers for regulatory T cells within the lesion were enhanced after NBI-74330 treatment. Conclusion-This

TLR agonists are attractive candidate adjuvants for therapeutic cancer vaccines as they can induce a balanced humoral and T cell–mediated immune response. With a dense network of dendritic cells (DCs) and draining lymphatics, the skin provides an ideal portal for vaccine delivery. Beside direct DC activation, TLR agonists may also induce DC activation through triggering the release of inflammatory mediators by accessory cells in the skin microenvironment. Therefore, a human skin explant model was used to explore the in vivo potential of intradermally delivered TLR agonists to stimulate Langerhans cells and dermal DCs in their natural complex tissue environment. The skin-emigrated DCs were phenotyped and analyzed for T cell stimulatory capacity. We report that, of six tested TLR-agonists, the TLR2 and -3 agonists peptidoglycan (PGN) and polyribosinic-polyribocytidylic acid (Poly I:C) were uniquely able to enhance the T cell–priming ability of skin-emigrated DCs, which, in the case of PGN, was accompanied by Th1 polarization. The enhanced priming capacity of Poly I:C–stimulated DCs was associated with a strong upregulation of appropriate costimulatory molecules, including CD70, whereas that of PGN-stimulated DCs was associated with the release of a broad array of proinflammatory cytokines. Transcriptional profiling further supported the notion that the PGN- and Poly I:C–induced effects were mediated through binding to TLR2/nucleotide-binding oligomerization domain 2 and TLR3/MDA5, respectively. These data warrant further exploration of PGN and Poly I:C, alone or in combination, as DC-targeted adjuvants for intradermal cancer vaccines.