Cytotoxicity cell-mediated

The mammalian and avian immune systems function similarly both incorporate humoral and cell-mediated cytotoxic mechanisms, " and are thought to share a 160m year old relationship with the reptilian immune system. The immune system of mammals shows sexual dimorphism " a greater immune response is normally observed in females, which has been attributed to differences in steroid hormone concentration. In the toad Bufo regularis, sexual dimorphism of the immune system is also apparent. ... 

Although a humoral immune response is the primaiy protection against most viral and some bacterial diseases, protective defense against other pathogens such as HIV, Plasmodium and Mycobacterium tuberculosis requires a cytotoxic response mediated by CD8+ T-cells (CTL response). Since the introduction of the vaccination concept by Jenner almost 200 yeats ago, only few vaccines have been developed that are able to induce a CTL response. These vaccines are usually attenuated live vaccines that are accompanied by certain risks and are not readily available for most pathogens. The immense appeal of DNA vaccines can be attributed to a considerable part to the fact that they are able to induce... 

Large granular lymphocytes, not belonging to either the T- or B-cell lineage. Natural killer (NK) cells are considered part of the innate defense system since, in contrast to cytotoxic T-cells, they are able to kill certain tumor cells in vitro without prior sensitization. The basal activity of NIC cells increases dramatically following stimulation with type I IFNs. In addition, NK cells display Fc-receptors for IgG and are important mediators of Antibody-Dependent-Cell-mediated-Cytotoxicity (ADCC). 

NK cells possess a receptor for Fc/and this enables them to adhere to target cells coated in antibody with the resultant destruction ofthat cell. This phenomenon is known as antibody-dependent cell-mediated cytotoxicity (ADCC). This was attributed to a separate cell population known as killer (K) cells but these have now been shown to be in effect NK cells. 

Volume 132. Immunochemical Techniques (Part J Phagocytosis and Cell-Mediated Cytotoxicity)... 

These are called delayed hypersensitivity reactions since they normally occur 6-24 hours after exposure. A cell-mediated allergy involves the interaction of food allergens with sensitised lymphocytes, which usually occurs in the gastrointestinal tract. The sensitised lymphocytes produce lymphokines and the generation of cytotoxic T lymphocytes. These latter cells destroy other intestinal cells, including the epithelial cells that are critical for absorption. 

Fischer, K. and Mackensen, A., The flow cytometric PKH-26 assay for the determination of T-cell mediated cytotoxic activity, Methods, 31, 135, 2003. 

CpG ODNs are also effective as vaccine adjuvants to enhance adaptive TH1 cellular immune responses.104 In mice, CpG ODNs can trigger strong TH1 responses,105 enhancing the number and function of tumor-specific Cytotoxic T lymphocytes (CTLs) and IFN-y secreting T cells.106 This has resulted in therapeutic vaccines in mouse tumor models where no other approach has shown comparable efficacy, even with large (1 cm) established tumors.107 108 Even without a vaccine, CpG ODNs can induce CD8+ T cell-mediated regression of established tumors with durable memory responses.109... 

Montavani, A., et. al., Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin on macrophage and natural killer cell-mediated cytotoxicity in mice, Biomedicine, 32, 200, 1980. 

Cell-mediated immunity Mitogen-induced T-cell proliferation, NK cell activity Spontaneous cytotoxicity assays... 

Cell-mediated immunity T-cell cytotoxicity, delayed type hypersensitivity ... 

Cell-mediated immunity Cytotoxic T lymphocyte killing delayed type hypersensitivity response mouse ear swelling test (MEST Gad et al., 1986) guinea pig maximization test (Magnusson and Kligman, 1969). 

Lymphotoxin promotes T-cell-mediates cytotoxicity B cell activation... 

Null cells Antihody-dependent cell-mediated cytotoxicity (ADCC) involving non-T/non-B cells (null cells) with Fc receptors specific for antihody-coated target cells. 

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