Antigenic specificity

One component of the age-ielated decline in immune function is decreased production of the lymphokine that promotes the growth of T-ceUs, interleukin 2 (IL-2). Administration of recombinant-derived IL-2, both in vitro and in vivo, appears to restore certain immune functions in aged mice. Recovery of T-regulatory effects on B-ceU differentiation has been reported in human cells from elderly patients treated with IL-1 and/or IL-2 (42). Similar effects have been observed in the presence of the pentapeptide thymopentin [69558-55-0] (Arg Lys Asp Val Tyr), a weU-known IL-2 inducer. Recombinant IL-2 adrninistered to aged mice for three weeks has been shown to correct the T-ceU functional deficiency associated with antigen-specific immunoglobulin production by certain lymphoid tissue (43). 

It is clear that generated by such a random process the initial repertoire of antigen specifity in all individuals of human beings should be quite similar. This implies that initially in each individal there develop lymphocytes which recognize antigens of this very individual, i.e. autoantigens. 

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. 

Quintana FJ, Gerber D, Kent SC, Cohen IR, Shai Y (2005) HIV-1 fusion peptide targets the TCR and inhibits antigen-specific T cell activation. J Chn Invest 115 2149-2158 Reeves JD, Gallo SA, Ahmad N, Miamidian JL, Harvey PE, Sharron M, Pohlmann S, Sfakianos JN, Derdeyn CA, Blumenthal R, Hunter E, Dorns RW (2002) Sensitivity of HIV-1 to entry inhibitors correlates with envelope/coreceptor affinity, receptor density, and fusion kinetics. Proc Natl Acad Sci USA 99 16249-16254... 

Inadequate performance may result from lack of antigen specificity, e.g., tumor-specific antigens are often differentiation antigens which also occur, although in a lower density on nontarget cells (Poste, 1984). 

Treter S, Luqman M Antigen-specific T cell tolerance down-regulates mast cell responses in vivo. Cell Immunol 2000 206 116-124. 

The clinical relevance of this finding was suggested by the observation that mice were more susceptible to sepsis following infection with Streptococcus pneumoniae when basophils were depleted before the second vaccination with pneumoccocal antigen [22]. Antigen-specific IgG antibodies produced after the second vaccination were significantly lower in the basophil-depleted mice than in control mice. Thus, basophils are important contributors to humoral memory immune responses. 

Lore K, Smed-Sorensen A, Vasudevan J, Mascola JR, Koup RA (2005) Myeloid and plasmacytoid dendritic cells transfer HIV-1 preferentially to antigen-specific CD4-t T cells. J Exp Med... 

There are two pneumococcal vaccines, a 7-valent conjugated vaccine for children younger than 6 years of age and a 23-purified-capsular polysaccharide antigen vaccine for adults. The 23 capsular types in the vaccine represent at least 85% to 90% of the serotypes that cause invasive pneumococcal infections among children and adults in the United States.41 After vaccination, an antigen-specific antibody response, indicated by a twofold or greater rise in serotype-specific antibody, develops within 2 to 3 weeks in 80% or more of healthy young adults.42... 

Debes GF, Bonhagen K, Wolff T, et al. CC chemokine receptor 7 expression by effector/memory CD4+ T cells depends on antigen specificity and tissue localization during influenza A virus infection. J Virol 2004 78 7528-7535. 

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