Acquisition of CD80 (B7-1) by T cells

Citation
H. Sabzevari et al., Acquisition of CD80 (B7-1) by T cells, J IMMUNOL, 166(4), 2001, pp. 2505-2513
Citations number
38
Categorie Soggetti
Immunology
Journal title
JOURNAL OF IMMUNOLOGY
ISSN journal
00221767 → ACNP
Volume
166
Issue
4
Year of publication
2001
Pages
2505 - 2513
Database
ISI
SICI code
0022-1767(20010215)166:4<2505:AOC(BT>2.0.ZU;2-6
Abstract
Activation of T cells usually requires two signals. Signal 1 is mediated vi a a peptide-MHC on the APC; signal 2 is mediated via a costimulatory molecu le on the APC surface. We demonstrate here that naive CD4(+) T cells actual ly acquire the costimulatory molecule CD80 (B7-1) from syngeneic APCs after activation. This phenomenon was demonstrated showing acquisition of CD80 b y T cells from CD80/CD86 (B7-2) knockout mice, and by treating T cells with cyclohexamide to further rule out endogenous expression of CD80 by T cells . Moreover, no CD80 mRNA could be detected in T cells that had acquired CD8 0, The amount of acquisition of CD80 by T cells was shown to be directly re lated to both the strength of signal 1 and the amount of CD80 on the APC, S pecificity of this acquisition was also shown by the lack of acquisition by T cells from CD28 knockout mice (implicating CD28 in this process), the la ck of acquisition of CD40 (another molecule on the APC surface) by T cells, and confocal microscopy studies. We demonstrate for the first time that 1) naive T cells, following acquisition of CD80 from APCs, were themselves sh own to be capable of acting as APCs; and 2) memory T cells that have acquir ed CD80 from APCs undergo apoptosis in the presence of increased levels of signal 1. Thus we demonstrate both immunostimulatory and immunoregulatory f unctions as a result of CD80 acquisition by different T cell populations. T he Journal of Immunology, 2001, 166: 2505-2513.