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Titolo:
Regulation of humoral immune responses by CD21/CD35
Autore:
Chen, ZB; Koralov, SB; Kelsoe, G;
Indirizzi:
Duke Univ, Med Ctr, Dept Immunol, Durham, NC 27710 USA Duke Univ Durham NC USA 27710 Med Ctr, Dept Immunol, Durham, NC 27710 USA
Titolo Testata:
IMMUNOLOGICAL REVIEWS
, volume: 176, anno: 2000,
pagine: 194 - 204
SICI:
0105-2896(200008)176:<194:ROHIRB>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
FOLLICULAR DENDRITIC CELLS; CENTER B-CELLS; HUMAN LYMPHOCYTES-B; MOUSE COMPLEMENT RECEPTOR-1; GERMINAL CENTER REACTION; T-DEPENDENT ANTIGEN; ANTIBODY-RESPONSE; IN-SITU; AFFINITY MATURATION; GUINEA-PIGS;
Tipo documento:
Review
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
84
Recensione:
Indirizzi per estratti:
Indirizzo: Kelsoe, G Duke Univ, Med Ctr, Dept Immunol, Box 3010, Durham, NC 27710 USADuke Univ Box 3010 Durham NC USA 27710 010, Durham, NC 27710 USA
Citazione:
Z.B. Chen et al., "Regulation of humoral immune responses by CD21/CD35", IMMUNOL REV, 176, 2000, pp. 194-204

Abstract

Before antigen-specific immunity arises, the complement system responds byactivation through the classical and/or alternative pathways leading to the covalent deposition of complement fragments. Three models, not mutually exclusive, hat-e been proposed to explain how these complement fragments interact with their receptors, CD21/CD35, to enhance humoral immune responses:i) CD21/CD35 retain and focus antigens for optimal presentation; ii) CD21/CD35 on B cells serve as enhancing co-receptors for B-cell antigen receptor(BCR) signaling; iii) CD21/CD35 regulate B-cell responses, by CD19 aggregation. The coreceptor model led us to predict that CD21/CD35 may lower the threshold of BCR affinity to diversify the repertoire of humoral immune responses, bur surprisingly, CD21/CD35-deficient mice expressing a transgenic BCR with very low affinity (K(d)approximate to 1.2x10(5) M-1) for the (4-hydroxy-3-nitrophenyl)acetyl hapten generated significant antibody and germinal center responses to even low doses of antigens in alum. The magnitudes ofthese responses were much below those of normal controls but higher doses of antigens substantially rectified these deficits. Thus, while CD21/CD35 play important roles in humoral immunity, our observations provide little support to the hypothesis that CD21/CD35 promote clonal diversity in immune responses by helping recruit low-affinity B cells.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/11/20 alle ore 15:54:57