Complement mediated tumor immune escape and its application in immune checkpoint inhibitors therapy

Abstract

The complement system is an important part of the innate immune system. More evidence showed that the function of complement was not only limited to the elimination of pathogens and other risk factors from the body but also affected the immune escape mechanism of the tumor through different activating pathways. Because of the complex and important role of complement in the tumor, this review expounds the mechanism of complement system participating in immune escape of the tumor from three aspects: complement inherent components, complement activation products and complement regulatory proteins. Additionally, these mechanisms are expected to provide a new application of complement in tumor immunotherapy with immune checkpoint inhibitors. Key words: Tumor escape; Complement activation; Complement system proteins; Immunosuppressive agents; Immunotherapy