Modulation of interferon-gamma receptor during human T lymphocyte alloactivation.
Previous work has shown that neutralization of physiologically secreted interferon(IFN)-gamma or blockade of its receptor during T lymphocyte activation inhibits both proliferation and cytotoxic T lymphocyte generation, suggesting that IFN-gamma plays a crucial role in T lymphocyte induction and differentiation. In this study, the kinetics of the surface expression of the 90-kDa IFN-gamma receptor (IFN-gamma R) was followed during human mixed lymphocyte reaction (MLR) to alloantigens. IFN-gamma R mRNA is constitutively expressed on resting peripheral blood lymphocytes emerging from nylon wood column (NW-PBL) and its expression increases two- to threefold on alloactivated NW-PBL. IFN-gamma R protein is poorly expressed on the membrane of resting CD3+ cells, but up-modulates after 3-day MLR and sharply down-modulates at day 6. Both the p55 and the p75 chains of interleukin-2 receptor (IL-2R) were shown to up-modulate in parallel with IFN-gamma R, whereas they were still highly expressed at day 6. After alloactivation, IFN-gamma and IL-2 secretion starts at 24 h, peaks at day 3 and decreases just when IFN-gamma R and IL-2R begin to up-modulate. Proliferation peaks at day 6. Lastly, stimulation with distinct cell populations showed that the intensity of lymphocyte proliferation, IFN-gamma R membrane up-modulation, and IFN-gamma and IL-2 secretion are regulated in a parallel manner, thus suggesting that they are interrelated. Taken as whole these results demonstrate that increased expression of IFN-gamma R on T lymphocytes can be a critical event during their activation, and strongly support the hypothesis that IFN-gamma/IFN-gamma R interaction provides a signal for its progression.
Novelli
F
F
Immunogenetics and Histocompatibility CNR Center, Torino.
Giovarelli
M
M
Gentz
R
R
Zucca
M
M
di Pierro
F
F
Garotta
G
G
Forni
G
G
D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000378:metabolism*; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D012333:RNA, Messenger / Q000235:genetics; D017471:Receptors, Interferon / Q000378:metabolism*; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors; D015854:Up-Regulation; D000096743:Interferon gamma Receptor
D007371:Interferon-gamma; D007376:Interleukin-2; D012333:RNA, Messenger; D017471:Receptors, Interferon; D015375:Receptors, Interleukin-2; D000096743:Interferon gamma Receptor