Effector functions

The residues not in the framework region form the loops between the p strands. These loops may vary in length and sequence among immunoglobulin chains of different classes but are constant within each class the sequence of the loops is invariant. The functions of these loops are not known, but they are probably involved in the effector functions of antibodies. When an antibody-antigen complex has been formed, signals are... 

T-c fl effector functions Antibody response T-cell effector functions... 

Ueno T, Fujiwara M, Tomiyama H, Onodera M, Takiguchi M (2004) Reconstitution of anti-HIV effector functions of primary human CD8 T lymphocytes by transfer of HIV-specific alphabeta TCR genes. Eur J Immunol 34 3379-3388... 

Vig M, DeHaven WI, Bird GS, Billingsley JM, Wang H, Rao PE, Hutchings AB, Jouvin MH, Putney JW, Kinet JP Defective mast cell effector functions in mice lacking the CRACMl pore subunit of store-operated calcium release-activated calcium channels. Nat Immunol 2008 9 89-96. 

Five classes of H chain have been found in humans (Table 50-7), distinguished by differences in their Cjl regions. They are designated y, a, i 5, and e. The i and e chains each have four domains rather than the usual three. The type of H chain determines the class of immunoglobulin and thus its effector function. There are thus five immunoglobulin classes IgG, IgA, IgM, IgD, and IgE. The biologic functions of these five classes are summarized in Table 50-8. 

The Constant Regions Determine Class-Specific Effector Functions... 

The constant regions of the immunoglobulin molecules, particularly the C 2 and 0 3 (and C 4 of IgM and IgE), which constitute the Fc fragment, are responsible for the class-specific effector functions of the different immunoglobulin molecules (Table 50-7, bottom part), eg, complement fixation or transplacental passage. 

Complement is not a single protein but comprises a group of functionally linked proteins that interact with each other to provide mar of the effector functions of humoral immunity and inflammation. Most of the components of the system are present in the serum as proenzymes, i.e. enzyme precursors. Activation of a complement molecule occurs as a result of proteolytic cleavage of the molecule, which in itself confers proteolytic activity on the molecule. Thus, many components of the system serve as the substrate of a prior component and, in turn, activate a subsequent component. This pattern of sequential activation results in the system being called the complement cascade. ... 

Lymphocyte response and effector function has recently been reviewed with respect to lymphocyte receptors, lymphocyte activation, T cell effector functions and lymphocyte physiology. The role of cell surface... 

Janeway, C.A. and Golstein, P. (1993). Lymphocyte activation and effector functions. The role of cell surface molecules. Curr. Opin. Immunol. 5, 313-323. 

McColl SR, Hachicha M, Levasseur S, Neote K, Schall TJ. Uncoupling of early signal transduction events from effector function in human peripheral blood neutrophils in response to recombinant macrophage inflammatory proteins-1 alpha and -1 beta. J Immunol 1993 150 4550 1560. 

Kim CH, Broxmeyer HE. Chemokines signal lamps for trafficking of T and B cells for development and effector function. J Leukoc Biol 1999 65 6-15. 

Sallusto F, Lenig D, Forster R, Lipp M, Lanzavecchia A. Two subsets of memory T lymphocytes with distinct homing potentials and effector functions. Nature 1999 401 708-712. 

Matsuda JL, Zhang Q, Ndonye R, Richardson SK, Howell AR, Gapin L. T-bet concomitantly controls migration, survival and effector functions during the development of Va 14i NKT cells. Blood 2006 107 2795-2805. 

Broxmeyer HE, Cooper S, Hangoc G, Gao JL, Murphy PM. Dominant myelopoi-etic effector functions mediated by chemokine receptor CCR1. J Exp Med 1999 189(12) 1987-1992. 

Eisner J, Petering H, Hochstetter R, et al. The CC chemokine antagonist Met-RANTES inhibits eosinophil effector functions through the chemokine receptors CCR1 and CCR3. Eur J Immunol 1997 27(ll) 2892-2898. 

Administration of Tyv-specific monoclonal antibodies to rat pups already infected with intestinal larvae causes larvae in the epithelium to be expelled (Carlisle et al, 1990). Only the LI stage is susceptible to expulsion once the larva has moulted to L2 it resists the effects of the antibodies (Carlisle et al, 1990). Expulsive immunity is transferred by three IgG isotypes, F(ab )2 fragments, as well as IgM (Carlisle et al., 1991a). These findings argue against a role for Fc-mediated effector functions and imply that antibodies against Tyv can disturb the larva s niche in a direct fashion. 

T Helper Cell Cytokine Responses During Intestinal Nematode Infection Induction, Regulation and Effector Function... 

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