CD4(+) T 细胞在肿瘤和慢性病毒免疫反应中的作用

Immunotherapies are mainly aimed to promote a CD8 + T cell response rather than a CD4 + T cell response as cytotoxic T lymphocytes (CTLs) can directly kill target cells. Recently, CD4 + T cells have received more attention due to their diverse roles in tumors and chronic viral infections.

In antitumor and antichronic viral responses, CD4 + T cells relay help signals through dendritic cells to indirectly regulate CD8 + T cell response, interact with B cells or macrophages to indirectly modulate humoral immunity or macrophage polarization, and inhibit tumor blood vessel formation.

Additionally, CD4 + T cells can also exhibit direct cytotoxicity toward target cells.

However, regulatory T cells exhibit immunosuppression and CD4 + T cells become exhausted, which promote tumor progression and chronic viral persistence.

Finally, we also outline immunotherapies based on CD4 + T cells, including adoptive cell transfer, vaccines, and immune checkpoint blockade.

Overall, this review summarizes diverse roles of CD4 + T cells in the antitumor or protumor and chronic viral responses, and also highlights the immunotherapies based on CD4 + T cells, giving a better understanding of their roles in tumors and chronic viral infections.