Tcell

Replacing (ficell)s - (Tcell)x with AE and rearranging yields... 

Autoimmune Disease. Figure 2 Generation of autoreactivity. APC, antigen presenting cell IFN, interferon LPS, lipopolysaccharide MHC, major histocompatibility complex T, T-lymphocyte TCR, Tcell (antigen) receptor TLR, toll like receptors. For details see text. 

KCa2.3 SKCa3 KCNN3 1q21.3 B.Adrg.Tcells... 

Marrack P et al. Genomic-scale analysis of gene expression in resting and activated Tcells. Curr Opin Immunol 2000 12 206-209. 

IL-3 Tcell Bone marrow cells Growth/differentiation of all cell types... 

IL-4 Tcell B cell Stimulation of immunoglobulin (Ig) heavy chain switching to IgE... 

IL-5 Tcell B cell, eosinophil Growth /differentiation of eosinophils... 

Zambricki EA, Kambham N, Beilhack A, Loh J, Hou JZ, Negrin RS Differential impact of mTOR inhibition on CD4+CD25+Foxp3+ regulatory T cells as compared to conventional CD4+ Tcells. Blood 2008 111 453-462. 

An important trigger for apoptosis is known as the Fas system. This is used by cytotoxic Tcells, for example, which eliminate infected cells in this way (top left). Most of the body s cells have Fas receptors (CD 95) on their plasma membrane. If a T cell is activated by contact with an MHC presenting a viral peptide (see p. 296), binding of its Fas ligands occurs on the target cell s Fas receptors. Via the mediator protein FADD ( Fas-associated death domain ), this activates cas-pase-8 inside the cell, setting in motion the apoptotic process. 

Padovan, E. et al. (1997) Penicilloyl peptides are recognized as Tcell antigenic determinants in penicillin allergy. European Journal of Immunology, 111 (6), 1303-1307. 

The various organs of the immune system such as spleen, lymph nodes, thymus and bone marrow containing the cells involved in the various immune responses offer the possibility to harvest these cells and perform in vitro assays for evaluation of effects on the immune system. When part of an in vivo animal study this may indicate a direct toxic effect of pharmaceuticals, that is, immunosuppression (Table 18.2). So, it is feasible to obtain cell suspensions for further evaluation such as determination of cellular subsets of T and B leukocytes by fluorescent activated cell sorter analysis (FACS analysis), and determination of natural killer (NK) cell activity of the spleen cell population. An advantage of this approach is that it may lead to identification of a biomarker to be used in clinical studies. In addition, in vitro stimulation of spleen cells with mitogens activating specific subsets may indicate potential effects on the functionality of splenic cell populations. Concanavalin A (Con A) and phytohemagglutinin (PHA) activate Tcells, while lipopolysaccharide (LPS) activates primarily B cell populations. Blood is collected for total white blood cell (WBC) determination and blood cell differential count. In addition, serum can be obtained for determination of serum immunoglobulins. 

In the additional functional (TIER-2) studies the immune system is more thoroughly investigated, while the animals are exposed to one or more doses of xenobiotics. Immune responses to several different types of antigens may be determined, including Tcell-dependent antigens like tetanus toxoid and ovalbumin, sheep red blood cells (SRBC) [38—41] and T cell-independent antigens like EPS [38,... 

TCell Mediated Cytoxidty against Virus-Infected Cells... 

TCell Dependent Delayed Type J Hypersensitivity ogainst Virus... 

Protection of rats from devl. of Pseudomonas aeruginosa infections Activation of multiple effector pathwaye (Tcells, Bcells, macrophages) Protection of mice from devl. of C. albicans infection (macrophages) Polysaccharides as antineoplastic immunostimulators (NK cells) Proliferative responses of blood lymphocytes Protection of ginseng saponins of immunosuppression in mice Inhibition on bacterial endotoxin-induced embryolethality in rats Induction of neutrophil accumulation in mice... 

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