Innate immunity, a vital component of the immune system, consists of tissue macrophages, which ingest invading microorganisms and destroy them. The complement system, which includes antibodies and T cells, works synergistically with these proteins to clear microbial infections both directly and indirectly. Inflammatory responses are also a part of innate immunity. In contrast, acquired immunity (immunosuppression) focuses on the elimination of invading pathogens.
In innate immunity, B cells originate in the bone marrow and circulate to peripheral tissues. These tissues include the thymus, spleen, and lymph nodes. The thymus produces T-lymphocytes and T cells, which then produce antibodies and eliminate damaged or old red blood cells. Adaptive immunity develops after the body recognizes an antigen. Adaptive immunity, on the other hand, takes time to develop complex responses against foreign invaders.
In cancer, immune cells play a critical role in fighting tumors. But while B cells regulate immune system function, immune cells can have pro and anti-tumor effects. These effects depend on the type of immune cells present in the tumor. The local cytokine milieu, accessory stromal cells, and tumor-specific interactions may play a role in regulating tumor immunity. Bone is a particularly unique immune-privileged environment, containing low levels of cytotoxic T and NK cells but high numbers of regulatory T and myeloid-derived suppressor cells.
Stress, like any other type of stress, affects the immune system. When our immune system is under stress, it knows. In chronic and psychological stress, it starts to produce less natural killer cells, or “killer cells,” and the lymphocytes that fight viruses and other invaders. Stress also impairs the immune system’s ability to work properly. And since stress reduces immune function, it is important to manage your stress levels.