Analysis of CVC1302-Mediated Enhancement of Monocyte Recruitment in Inducing Immune Responses.

Monocytes (Mos) are believed to play important roles during the generation of immune response. In our previous study, CVC1302, a complex of PRRs agonists, was demonstrated to recruit Mo into lymph nodes (LNs) in order to present antigen and secret chemokines (CXCL9 and CXCL10), which attracted antigen-specific CD4 T cells. As it is known that Mos in mice are divided into two main Mo subsets (Ly6C Mo and Ly6C Mo), we aimed to clarify the CVC1302-recruiting Mo subset and functions in the establishment of immunity. In this study, we found that CVC1302 attracted both Ly6C Mo and Ly6C Mo into draining LNs, which infiltrated from different origins, injection muscles and high endothelial venule (HEV), respectively. We also found that the numbers of OVA Ly6C Mo in the draining LNs were significantly higher compared with OVA Ly6C Mo. However, the levels of CXCL9 and CXCL10 produced by Ly6C Mo were significantly higher than Ly6C Mo, which plays important roles in attracting antigen-specific CD4 T cells. Under the analysis of their functions in initiating immune responses, we found that the ability of the Ly6C monocyte was mainly capturing and presenting antigens, otherwise; the ability of the Ly6C monocyte was mainly secreting CXCL9 and CXCL10, which attracted antigen-specific CD4 T cells through CXCR3. These results will provide new insights into the development of new immunopotentiators and vaccines.