Immunoevasion

Immune evasion is a mechanism to evade the defenses of the immune system. Various parasitic microorganisms use these mechanisms to avoid being destroyed by the host's humoral or cellular response to any foreign organism.

This mechanism is also one of the main ones used by tumors. To counteract tumor immunoevasion, therapeutic approaches have been developed that can enhance the activity of the immune system (for example, immunotherapy based on cytokines or other immunomodulatory molecules) or provoke a specific immune response, either by culturing in vivo or by using the patient's own immune cells stimulated and cultured ex vivo that are subsequently reintroduced into the patient.

Another case is the inability of natural killer cells to kill some types of cancer cells. Some research suggests that cancer cells may escape the immune system partially mediated by TNF-producing innate lymphoid cells, through a decrease in the production of IFN-γ (Interferon gamma) to that of TNF. Likewise, an increase in the gene expression of immunological control receptors could be produced as the tumors grow. Thus, "cytokine TGF-β signaling drives evasion of the immune system by converting NK cells to innate lymphoid cells within the tumor microenvironment".