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Inhibition of cell cycle progression by rapamycin induces T cell clonal anergy even in the presence of costimulation
Author(s): Powell JD, Lerner CG, Schwartz RH
Source: JOURNAL OF IMMUNOLOGY    Volume: 162    Issue: 5    Pages: 2775-2784    Published: MAR 1 1999  
Times Cited: 102     References: 49     
Abstract: Costimulation (signal 2) has been proposed to inhibit the induction of T cell clonal anergy by either directly antagonizing negative signals arising from TCR engagement (signal 1) or by synergizing with signal 1 to produce IL-2, which in turn leads to proliferation and dilution of negative regulatory factors. To better define the cellular events that lead to the induction of anergy, we used the immunosuppressive agent rapamycin, which blocks T cell proliferation in late G1 phase but does not affect costimulation-dependent IL-2 production. Our data demonstrate that full T cell activation (signal 1 plus 2) in the presence of rapamycin results in profound T cell anergy, despite the fact that these cells produce copious amounts of IL-2, Similar to conventional anergy (induction by signal 1 alone), the rapamycin-induced anergic cells show a decrease in mitogen-activated protein kinase activation, and these cells can be rescued by culture in IL-2, Interestingly, the rapamycin-induced anergic cells display a more profound block in IL-3 and IFN-gamma production upon rechallenge. Finally, in contrast to rapamycin, full T cell activation in the presence of hydroxyurea (which inhibits the cell cycle in early S phase) did not result in anergy, These data suggest that it is neither the direct effect of costimulation nor the subsequent T cell proliferation that prevents anergy induction, but rather the biochemical events that occur upon progression through the cell cycle from G1 into S phase.
Document Type: Article
Language: English
Reprint Address: Schwartz, RH (reprint author), NIAID, Cellular & Mol Immunol Lab, NIH, Bldg 4,Room 111,9000 Rockville Pike, Bethesda, MD 20892 USA
Addresses:
1. NIAID, Cellular & Mol Immunol Lab, NIH, Bethesda, MD 20892 USA
Publisher: AMER ASSOC IMMUNOLOGISTS, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA
Subject Category: Immunology
IDS Number: 168NK
ISSN: 0022-1767
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