Killer T cells

The two types of cell-mediated immunity involve basically different types of T cells. In the delayed-type hypersensitivity response, the T cell, TD, that reacts specifically with antigens secretes interleukins (see Box S3A) that attract and activate macrophages or other leukocytes, thereby causing a slowly developing inflammatory response. A second type of T cell, known as the T killer cell, TK, reacts specifically with antigen that is bound to target cells, causing their lysis. 

The two classes of MHC proteins are displayed on different cell types. Class I MHC proteins are found on almost all nucleated cells, including killer T cells. Class II MHC proteins are found mainly on cells involved in the immune response, including antigen-presenting cells, B cells, and T helper cells, but not T killer cells. 

T-killer cells) are also activated by APC presentation, and directly destroy targeted antigens. 

The principal compounds that act as inhibitors of viral protein synthesis are the interferons. These compounds are members of a naturally occurring family of glycoprotein hormones (RMM 20 000-160 000), which are produced by nearly all types of eukaryotic cell. Three general classes of interferons are known to occur naturally in mammals, namely the a-interferons produced by leucocytes, P-interferons produced by fibroblasts and y-interferons produced by T lymphocytes. They form part of the human immune system. It is believed that the presence of virons and pathogens in the body switches on the mRNA that stimulates the production and release of interferons. These interferons are thought to stimulate the production of proteins that inhibit the synthesis of viral mRNA and viral proteins. a-Interferons also enhance the activity of T killer cells. 

Wiesmuller K-H, Bessler WG, Jurrg G (1992) Solid phase pep-dde syrrtlresis of lipopeptide vaccirres elicidrrg epitope-specific B-, T-helper arrd T-killer cell resporrse. hrt J Pept Proteirr Res 40 255-260. 

The cellular immune system is composed of a number of different forms of T-lymphocytes, two of the principle types being termed T-helper cells and T-kUler cells. As the names imply, following viral infection, for example, T-helper cells prime T-killer cells to initiate the process of destruction of infected cells. In this process numerous... 

Wiesmiiller, K-H., W. G. Bessler, et al. (1992). "Solid phase peptide synthesis of lipopeptide vaccines ehciting epitope-specific B-, T-helper and T-killer cell response." International Journal of Peptide Protein Research 40 255-60. 

DiaZepin Nucleosides. Four naturally occurring dia2epin nucleosides, coformycin (58), 2 -deoxycoformycin (59), adechlorin or 2 -chloro-2 -deoxycoformycin (60), and adecypenol (61), have been isolated (1—4,174,175). The biosynthesis of (59) and (60) have been reported to proceed from adenosine and C-1 of D-ribose (30,176,177). They are strong inhibitors of adenosine deaminase and AMP deaminase (178). Compound (58) protects adenosine and formycin (12) from deamination by adenosine deaminase. Advanced hairy cell leukemia has shown rapid response to (59) with or without a-or P-interferon treatment (179—187). In addition, (59) affects interleukin-2 production, receptor expression on human T-ceUs, DNA repair synthesis, immunosuppression, natural killer cell activity, and cytokine production (188—194). 

COPD is a chronic inflammatory disease that results from prolonged and repeated inhalation of particles and gases, chronic (or latent) infection or an interaction of these factors. In many cases, the inflammation persists even when the exposure (in most cases smoking) is stopped. Prominent among the infiltrating leukocytes are neutrophils, CD8+ lymphocytes (Co-receptor for the T-cell receptor. CD8+ is specific for the class IMHC protein. It is expressed on the surface of cytotoxic T-cells and natural killer cells.) and CD68+ monocytic cells (A lysosomal antigen. All cells that rich in... 

Immune Defense. Figure 2 Cytokines involved in the development of adaptive immune responses in secondary lympoid tissues such as the lymph nodes or spleen. Abbreviations B B-lymphocyte, IFN interferon, Ig immunoglobulin, IL interleukin, NK natural killer cell, TE T-effector (cytotoxic) lymphocyte, TH T-helper lymphocyte... 

Syk and ZAP-70 are early intermediates in the transduction of signals from immune receptors, including the B- and T-cell recqrtors for antigen, activatory natural killer-cell receptors, the mast cell and basophil receptor for IgE, and the widely distributed receptors for the Fc portion of IgG. Immune receptors control checkpoints in lymphocyte development and serve to integrate the responses of innate and acquired immunity. 

Ab, B.K., Kiessling, R., Van, E.J.D., Thole, J.E.. Kumararatne, D.S., Pisa, P., Wondimu. A., Ottenhoff, T.H. (1990). Induction of antigen-specific CD4+ HLA-DR restricted cytotoxic lymphocytes as well as nonspecific nonrestricted killer cells by the recombinant mycobacterial 65 kDa heat shock protein. Eur. J. Immunol. 20, 369-377. 

ZHANG Y, SONG T T, CUNNICK J E, MURPHY p A and HENDRICH s (1999a) Daidzein and genistein glucuronides in vitro are weakly estrogenic and activate human natural killer cells in nutritionally relevant concentrations. /iVMr 129 (2) 399-405. 

The sterols and sterolins in rice bran are potent immunomodulators. The best response was obtained with a 100 1 sterol/sterolin mixture that demonstrated T-cell proliferation from 20% to 920% and active cell antigens after four weeks in human subjects (Bouic et al, 1996). Another in vitro experimental study with sterol/sterolins, demonstrated a significant increase in cytokinines, interleukin-2 and y-interferon between 17% and 41 % in addition to an increase in natural killer cell activity. These experiments (Bouic et al, 1996) prove that sterol/sterolins are potent immunomodulators with important implications for the treatment of immune dysfunction. Rice bran products are excellent dietary supplements for the improvement of immune function. It is probable that the effects of rice bran on diabetes, CVD and cancer all result from improved immune function. 

Morohashi H, Miyawaki T, Nomura H, et al. Expression of both types of human interleukin-8 receptors on mature neutrophils, monocytes, and natural killer cells. J Leukoc Biol 1995 57(1) 180-187. 

Kim JH, Kim HY, Kim S, Chung JH, Park WS, Chung DH. Natural killer T (NKT) cells attenuate bleomycin-induced pulmonary fibrosis by producing interferon-gamma. Am J Pathol 2005 167(5) 1231-1241. 

IL-1 (17.5) Monocyte/macrophage, lymphocyte, neutrophil, endothelium, fibroblast keratinocyte Activation of T cells, B cells, natural killer cells, osteoblasts, and endothelium. Induces fever, sleep, anorexia, ACTH release, hepatic acute phase protein synthesis and HSPs. Leads to myocardial depression, hypercoagulability, hypotension/sbock, and death. Simulates production of TNF, IL-6, and IL-8 and stress hormone release. Suppression of cytochrome P-450, thyro-globulin, and lipoprotein synthesis. Procoagulant activity. Antiviral activity. 

The interleukin-2 receptor (IL-2R) is important in that the cytokine IL-2, secreted by a subset of T-helper cells, enhances the proliferation of activated T and B cells and increases the cytolytic activity of natural killer (NK) cells and the secretion of IgG. 

Byrnes, D. M., M. H. Antoni, K. Goodkin, j. Efantis-Potter, D. Asthana, T. Simon et al., Stressful Events, Pessimism, Natural Killer Cell Cytotoxicity, and Cytotoxic/Suppressor T Cells in Hiv+ Black Women at Riskfor Cervical Cancer , Psychosomatic Medicine 60 (1998) 714-22... 

Other investigators have been unable to demonstrate lead-induced effects on various components of the immune system in laboratory animals. The effects of lead exposure of varying duration on natural killer cell and T-lymphocytc function were investigated in rats. Male Alderly Park rats received lead as lead acetate in the drinking water at lead concentrations equivalent to 14.3 and 143 mg lead/kg/day for... 

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