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The elimination phase, also known as immunosurveillance, includes innate and adaptive immune responses to tumour cells. For the innate immune response, several effector cells such as natural killer cells and T cells are activated by the inflammatory cytokines, which are released by the growing tumour cells, macrophages and stromal cells ...
An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellular bacteria, protozoa, helminths, and fungi which could cause serious problems to the health of the host organism if not cleared from the body.
The adaptive immune system evolved in early vertebrates and allows for a stronger immune response as well as immunological memory, where each pathogen is "remembered" by a signature antigen. [55] The adaptive immune response is antigen-specific and requires the recognition of specific "non-self" antigens during a process called antigen ...
[1] [2] The process of clonal deletion helps prevent recognition and destruction of the self host cells, making it a type of negative selection. Ultimately, clonal deletion plays a role in central tolerance. [3] Clonal deletion can help protect individuals against autoimmunity, which is when an organism produces and immune response on its own ...
Stimulating cells to secrete a variety of cytokines that influence the function of other cells involved in adaptive immune responses and innate immune responses. [ 3 ] [ 4 ] Cell-mediated immunity is directed primarily at microbes that survive in phagocytes and microbes that infect non-phagocytic cells.
The result of central tolerance is a population of lymphocytes that do not mount immune response towards self-antigens. These cells use their TCR or BCR specificity to recognize foreign antigens, in order to play their specific roles in immune reaction against those antigens.
T cells contribute to immune defenses in two major ways: some direct and regulate immune responses; others directly attack infected or cancerous cells. [7] CD4+ lymphocytes, also called "helper" T cells, are immune response mediators, and play an important role in establishing and maximizing the capabilities of the acquired immune response. [3]
In immunology, clonal selection theory explains the functions of cells of the immune system (lymphocytes) in response to specific antigens invading the body. The concept was introduced by Australian doctor Frank Macfarlane Burnet in 1957, in an attempt to explain the great diversity of antibodies formed during initiation of the immune response.