Differential up-regulation of the B7-1 and B7-2 costimulatory molecules after Ig receptor engagement by antigen.

摘要: Ag-pulsed B cells are potent APCs, in part, because of the ability Ig receptor to mediate rapid and specific Ag uptake. However, it is also known that full T cell activation requires signals delivered by costimulatory molecules, which naive seem lack. This study examines effect engagement has on expression function a new CD28 counter-receptor, B7-2. Unlike B7-1 (B7), B7-2 was rapidly induced surface after either anti-Ig mAbs or hen egg lysozyme (HEL) normal HEL-specific transgenic cells, respectively. Furthermore, up-regulated tolerant isolated from HEL/anti-HEL double mice stimulation, although at lower levels than nontolerant cells. No significant B7-1(B7) were observed under these conditions. Finally, molecules cross-linking costimulated proliferation CD28-dependent manner, independent expression. Thus, effectiveness Ag-specific as APCs depends both their enhanced uptake, mediated receptor, immediate up-regulation molecule,