背景 | Interleukin-17A (IL-17A), also known as CTLA-8, belongs to the IL-17 cytokine family. IL-17A is expressed in memory Th17 cells and is a product of memory CD4+T cells. In addition to Th17 cells, IL-17A can also be produced by various immune cells, including CD8+T cells γδ T cells, natural killer T (NKT) cells, monocytes, and neutrophils. IL-17A plays a crucial role in the host's defense mechanisms against many bacterial and fungal pathogens, as well as in allergic and autoimmune responses. IL-17A plays a role in viral infection by promoting neutrophil inflammation. IL-17A is a homodimeric cytokine with similar biological activity to IL-17F. IL-17A and IL-17RA have high affinity binding, and IL-17RA is essential for the biological activity of IL-17A. IL-17A cannot bind to T cells, B cells, and myeloid cells lacking IL-17RA. IL-17A is associated with various autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, asthma, and psoriasis. IL-17A also plays a pathogenic role in cancer. During tumor development, IL-17A recruits bone marrow-derived suppressor cells (MDSCs) to suppress anti-tumor immunity. IL-17A also promotes tumor growth in vivo by inducing IL-6. |