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Titolo:
APOPTOSIS OF ILEAL PEYERS PATCH B-CELLS IS INCREASED BY GLUCOCORTICOIDS OR ANTIIMMUNOGLOBULIN ANTIBODIES
Autore:
MOTYKA B; BHOGAL HS; REYNOLDS JD;
Indirizzi:
UNIV CALGARY,HLTH SCI CTR,DEPT MED PHYSIOL,IMMUNOL RES GRP,3330 HOSP DR NW CALGARY AB T2N 4N1 CANADA UNIV CALGARY,HLTH SCI CTR,DEPT MED PHYSIOL,IMMUNOL RES GRP CALGARY ABT2N 4N1 CANADA
Titolo Testata:
European Journal of Immunology
fascicolo: 7, volume: 25, anno: 1995,
pagine: 1865 - 1871
SICI:
0014-2980(1995)25:7<1865:AOIPPB>2.0.ZU;2-3
Fonte:
ISI
Lingua:
ENG
Soggetto:
MURINE BONE-MARROW; ENDOGENOUS ENDONUCLEASE ACTIVATION; MONOCLONAL-ANTIBODIES; LYMPHOCYTES-B; SHEEP; DEATH; THYMOCYTES; SELECTION; RESCUE; DNA;
Keywords:
PEYERS PATCH; B CELL; APOPTOSIS; SURFACE IG; GLUCOCORTICOID;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
43
Recensione:
Indirizzi per estratti:
Citazione:
B. Motyka et al., "APOPTOSIS OF ILEAL PEYERS PATCH B-CELLS IS INCREASED BY GLUCOCORTICOIDS OR ANTIIMMUNOGLOBULIN ANTIBODIES", European Journal of Immunology, 25(7), 1995, pp. 1865-1871

Abstract

The ileal Peyer's patch (PP) in sheep plays a central role in the development and production of B cells. Associated with a tremendous amount of B cell proliferation in this site is the extensive diversification of the Ig repertoire by somatic hypermutation. Very few (<5 %) of the B cells produced in the ileal PP differentiate and emigrate; instead, the vast majority of these cells soon die, and we have previously shown that death is associated with apoptosis. When placed in culture, ileal PP B cells die rapidly by apoptosis, such that after 24 h, 60 +/-1 % of DNA is fragmented. Here, we show that the extent of this spontaneous B cell apoptosis in culture, as quantitated by DNA fragmentation, was significantly increased in a dose-dependent manner by the glucocorticoids hydrocortisone or dexamethasone. Furthermore, treatment of lambs with 2-2.5 mg/kg of dexamethasone resulted in a marked increase in the number of apoptotic cells in the ileal PP and an increase in ileal PP B cell DNA fragmentation to 20 +/- 6 %, compared with 2.4 +/- 0.1 % in untreated lambs. Anti-immunoglobulin (Ig) antibodies also increased the extent of DNA fragmentation in cultured ileal PP B cells. After 24 or 48h of culture with anti-Ig (PIg47A), DNA fragmentation was 74 +/- 2 % and 75 +/- 3 %, respectively. Ileal PP B cells are rescued from apoptosis by agents that activate protein kinase C and increase cytosolic Ca2+, and here we show that this treatment also results in apoptotic rescue in the presence of dexamethasone or anti-Ig. We speculate that the apoptosis of ileal PP B cells in situ may be modulated by glucocorticoids and by the cross-linking of surface Ig. Apoptosis, induced by a signal through surface Ig; may be an important mechanism in the deletion of self-reactive B cells during the expansion of the Ig repertoire in the ileal PP.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/09/20 alle ore 05:24:38