T-lymphocytes activation

Lundy SK, Lira SA, Smit JJ, Cook DN, Berlin AA, Lukacs NW. Attenuation of allergen-induced responses in CCR6 / mice is dependent upon altered pulmonary T lymphocyte activation. J Immunol 2005 174(4) 2054—2060. 

Hogaboam, C.M., Snider, D.P. and Collins, S.M. (1997) Cytokine modulation of T-lymphocyte activation by intestinal smooth muscle cells. Gastroenterology 112, 1986-1995. 

Rat 50 or 150 mg/kg ration After 6 weeks altered immune function as evidenced by inhibition of T-lymphocyte activity 11... 

T-lymphocyte activation leads to release of cytokines from type 2 T-helper (TH2) cells that mediate allergic inflammation (interleukin [IL] -4, IL-5, and IL-13). Conversely, type 1 T-helper (THj) cells produce IL-2 and interferon-y that are essential for cellular defense mechanisms. Allergic asthmatic inflammation may result from an imbalance between THj and TH2 cells. 

Disparate effects on T-cell proliferative responses have been reported following exposure to JP-8. Significant suppression of T-cell proliferation is reported following either inhalation or dermal exposure to JP-8 [ 18,20,36], while the response is unaffected following either the oral or dermal exposure routes in other studies [66,71,72], These differences may be explained by variations in exposure routes and in assay methodology, as agents used to evaluate T-lymphocyte activation and proliferation were diverse and included Con A plus IL-2 [18,20], anti-CD3 [36], or Con A only [66,71,72],... 

Ehrlich, J.P., Gunnison, A.F., and Burleson, G.R. 1989. Influenza virus-specific cytotoxic T-lymphocyte activity in Fischer 344 rat lungs as a method to assess pulmonary immunocompetence Effect of phosgene inhalation. Inhalation Toxicol. 1 129—138. 

Pharmacology Tacrolimus is a macrolide immunosuppressant that prolongs the survival of the host and transplanted graft and inhibits T-lymphocyte activation, although the exact mechanism of action is not known. 

Pharmacology Sirolimus, a macrolide immunosuppressive agent, inhibits both T-lymphocyte activation and proliferation that occurs in response to antigenic and cytokine (interleukin-2, -4, and -15) stimulation and also inhibits antibody production. In cells, sirolimus binds to the immunophilin, FK binding protein-12 (FKBP-12), to generate an immunosuppressive complex. 

Pharmacology Tacrolimus is a macrolide immunosuppressant produced by Streptomyces tsukubaensis. The mechanism of action of tacrolimus in atopic dermatitis is not known. It has been demonstrated that tacrolimus inhibits T-lymphocyte activation by first binding to an intracellular protein, FKBP-12. Pharmacokinetics ... 

Minnear, and B. M. Freed. The cigarette tar component p-benzoquinone blocks T lymphocyte activation by inhibiting interleukin-2 production, but not CD25, lCAM-1, or LFA-1 expression. Toxicol Appl Pharmacol 1997 143(1) 30-36. 

Mechanism of Action An immunologic agent that inhibits T-lymphocyte activation by binding to intracellular proteins, forming a complex, and inhibiting phosphatase activity. Therapeutic Effect Suppresses the immunologically mediated inflammatory response prevents organ transplant rejection. 

LPS can be directly mitogenic for T cells [130], but the antitumoral activity of lymphocytes depends on antigen recognition by their TCR in the context of the major histocompatibility complex (MHC) class I or n. Though LPS enhance it, T lymphocyte activity requires APC [131]. The effect of LPS on T lymphocytes has been shown to depend on monocytes independent of MHC, but to be due to the secretion of costimulatory signals and IL-12 in humans [132]. In vivo, LPS induces principally the proliferation of CD8+ T lymphocytes, but also that of CD4+ T and B lymphocytes through the activation of APC and secretion of IFN 0(7(3 in C57BL/6 mice [133],... 

Mechanism of Action Antibodies of multiple specificities interact with lymphocyte surface antigens, depleting numbers of circulating T-lymphocytes and modulating T-lymphocyte activation, homing and cytotoxic processes... 

Binds to an immunophilin protein to form a complex which inhibits the activation ot the mammalian Target of Rapamycin (mTOR)ulatory kinase. This inhibits T lymphocyte activation and proliferation by IL-2. IL-4, and IL-5. 

Bishop DK, Shelby J, Eichwald EJ. 1992. Mobilization of T lymphocytes following cardiac transplantation. Evidence that CD4- positive cells are required for cytotoxic T lymphocyte activation, inflammatory endothelial development, graft infiltration and acute allograft rejection. Transplantation. 53 849-857. 

HVA Cav 1.4 L-type CtlF retinal neurons, immune cells tonic neurotransmitter release, T lymphocyte activation DHPs blind... 

Mouse (C57BL/6N) once (GO) 2.5 M 5 M (decreased cytotoxic T lymphocyte activity) De Krey and Kerkvliet 1995... 

De Krey GK, KerkvlietNI. 1995. Suppression of cytotoxic T lymphocyte activity by 2,3,7,8-tetra-chlorodibenzo-p-dioxin occurs in vivo, but not in vitro, and is independent of corticosterone elevation. Toxicology 97 105-112. 

Kerkvliet NI, Baecher-Steppan L, Smith BB, et al. 1990b. Role of the Ah locus in suppression of cytotoxic T lymphocyte activity by halogenated aromatic hydrocarbons (PCBs and TCDD) ... 

Crabtree, G. R. (1989). Contingent genetic regulatory events in T lymphocyte activation. 

Germain, R. N. (1994). MHC-dependent antigen processinbg and peptide presentation Providing ligands for T lymphocyte activation. Cell 76, 287-299. 

Many studies showed that peptidoglycan in the cell wall stimulates macrophages, antibody formation, and T lymphocyte activity entering the intestine (Dziarski 1991). Certain strains of LAB induce pro-Thl responses, promoted through the receptor-mediated cytokine pathway, and the ability of individual cell wall compounds to induce pro-IFN cytokines (especially IL-12) at a sub-inflammatory level. However, it should be realized that other indirect LAB-induced modulatory mechanisms may also be operative in combating atopy, such as their ability to liberate de novo immunoregulatory peptides from major food proteins via enzymatic hydrolysis. This mechanism has been demonstrated experimentally for some LAB (Matar et al. 1996, Rokka et al. 1997). 

Figure 32.9. Schematic representation of Type I hypersensitivity. Induction Resident respiratory tract dendritic cells (DC) take and process antigen, mature, migrate to the draining lymph nodes, and present antigen to T lymphocytes. Activated T-lymphocytes, in turn, activate B-cell differentiation into antibody-producing plasma cells. IL-4 promotes Ig isotype class switching from IgM to IgE and promotes mast cell development. IgE is associated with mast cells. Elicitation Allergen crosslinks the mast-cell-bound IgE, thereby causing the release of preformed mediators and cytokines. (See Table 32.7.) Inflammation and bronchoconstriction occur.

E. Serfling, A. Avots, and M. Neumaim. The architecture of the inteileukin-2 promoter a reflection of T lymphocyte activation. Bwchim Btophys Acta, 1263 (3), 181-200, 1995. 

Comer, J.E., Chopra, A.K., Peterson, J.W., Konig, R. (2005). Dhect inhibition of T-lymphocyte activation by anthrax toxins in vivo. Infect. Immun. 73 8275-81. 

Li, Q., Hirata, Y., Piao, S., Minami, M. (2000). The byproducts generated during sarin-synthesis in the Tokyo sarin disaster induced inhibition of natural killer and cytotoxic T lymphocyte activity. Toxicology 146 209-20. 

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