Immunity to Parasites and Apoptosis

Vaccination against parasites and apoptosis. Humoral immunity and cellular immunity are ideally two aspects of immunity for infection during parasitic infections. However, in some cases vaccination against parasites can exacerbate the disease and induce tissue damage. A cellular immunity animal model is most useful for better understanding of the immune mechanism of parasites. Athymic mice lacking T cells can not control several parasitic infections. This clearly shows that T cells play an important role in the development of these infections (39, 40).

Apoptosis typically occurs during development and aging and acts as a homeostatic mechanism to maintain cell populations in the tissue. Apoptosis also occurs as a protective mechanism such as an immune response, or when a cell is damaged by a disease or a harmful substance (Norbury and Hickson, 2001). Despite the existence of various physiological and pathological stimuli and conditions that can induce apoptosis, not all cells die from the same stimulus. Radiation or drugs used for cancer chemotherapy can cause DNA damage to some cells, which can lead to apoptotic death via the p53-dependent pathway. Some hormones, such as corticosteroids, can cause apoptosis in some cells such as thymocytes, but other cells are unaffected or even stimulated.

The mechanism of action in the immune response is different between cellular immune response and humoral immune response. Killer T cells, NK cells and macrophages in cellular immune responses and NK cells, macrophages and neutrophils that bind soluble immunoglobulin to the cell surface in humoral immune responses are parasites and cells that eradicate infection These processes So it is important that effector cells accumulate in the place of parasite activity. This movement of effector cells is regulated by chemokines, cytokines and cell adhesion molecules. In most cases cellular and humoral immune responses occur simultaneously

The ultimate goal of the immune response is to eliminate viruses, microorganisms, micro-viruses such as parasites. In most cases, cellular and humoral immune responses work together to fight infectious parasites. Cellular immune responses are important for protecting the body from intracellular viruses and microorganisms and humoral immune responses are important for treating extracellular and large parasites. Transfer of the sera of individuals successful in eradicating the infection to unexposed individuals gives the recipient protection from infection (called "passive immunity"), which can result in the discovery of immunoglobulins or antibodies Was found. This final stage mechanism involved in eradication of parasites or tissue damage caused by an immune response is called effector mechanism.