Tumor-released autophagosomes induces CD4+ T cell-mediated immunosuppression via a TLR2–IL-6 cascade

<h3>Background</h3> CD4⁺ T cells are critical effectors of anti-tumor immunity, but how tumor cells influence CD4⁺ T cell effector function is not fully understood. Tumor cell-released autophagosomes (TRAPs) are being recognized as critical modulators of host anti-tumor immunity during tumor progression. Here, we explored the mechanistic aspects of TRAPs in the modulation of CD4⁺ T cells in the tumor microenvironment. <h3>Methods</h3> TRAPs isolated from tumor cell lines and pleural effusions or ascites of cancer patients were incubated with CD4⁺ T cells to examine the function and mechanism of TRAPs in CD4⁺ T cell differentiation and function. TRAPs-elicited CD4⁺ T cells were tested for their suppression of effector T cell function, induction of regulatory B cells, and promotion of tumorigenesis and…