MCP-1 production regulated by ATG5 in inflammatory monocytes selectively modulates anti-malarial CD4+ Th1 response

A promising strategy to design effective malaria blood-stage vaccines is to induce parasite-specific CD4+ Th1 cell responses, but the regulatory mechanism of which is still largely unknown. Here, we showed that the ATG5-deficiency in myeloid cells significantly inhibit the growth of rodent blood-stage malaria parasites through specifically enhancing parasite-specific CD4+ Th1 cell responses. This effect was independent of ATG5-mediated canonical autophagy and non-canonical autophagy. Mechanistically, the deficiency of ATG5 promoted the survival of inflammatory monocytes (CD11b+F4/80- cells), and sequentially increased the generation of chemokine MCP-1 in parasite-infected mice. The interaction of CD11b+F4/80- cells-derived MCP-1 with CCR2 on CD4+ Th1 cells for its optimized differentiation dependent on Jak2/stat4 pathway. Therefore, we highlight the previously unrecognized role of ATG5 in the modulation of the survival of inflammatory monocytes to produce MCP-1, and the selective promoting effect of MCP-1 on CD4+ Th1 cell differentiation, which shed new lights on effective malaria vaccine designation. RNASeq analysis of CD11b+ cells isolated from splenocytes of P. yoelii 17XNL-infected mice at Day 0, Day 3 and Day 6 post-infection.