CD4+ and CD8+ T cell survival is regulated differentially by protein kinase Cθ c-Rel, and protein kinase B

Samuel D. Saibil, Russell G. Jones, Elissa K. Deenick, Nicole Liadis, Alisha R. Elford, Mitchell G. Vainberg, Heather Baerg, James A. Woodgett, Steve Gerondakis, Pamela S. Ohashi

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39 Citations (Scopus)

Abstract

An effective immune response requires the expansion and survival of a large number of activated T cells. This study compared the role of protein kinase C (PKC) θ and associated signaling molecules in the survival of activated primary CD4+ vs CD8+ marine T cells. We demonstrate that the absence of PKCθ resulted in a moderate survival defect in CD4 + T cells and a striking survival defect of CD8+ T lymphocytes. CD8+ T cells lacking the c-Rel, but not the NF-κB1/p50, member of the NF-κB family of transcription factors displayed a similar impairment in cell survival as PKCθ-/- CD8+ T lymphocytes. This implicates c-Rel as a key target of PKCθ-mediated survival signals in CD8+ T cells. In addition, both c-Rel-/- and PKCθ-/- T cells also displayed impaired expression of the antiapoptotic Bcl-xL protein upon activation. Changes in Bcl-xL expression, however, did not correlate with the survival of CD4+ or CD8+ lymphocytes. The addition of protein kinase B-mediated survival signals could restore partially CD4+ T cell viability, but did not dramatically influence CD8 + survival. Active protein kinase B was also unable to restore proliferative responses in CD8+ PKCθ-/- T cells. The survival of CD4+ and CD8+ T cells deficient in either PKCθ or c-Rel, however, was promoted by the addition of IL-2. Collectively, these data demonstrate that CD4+ and CD8+ T cell survival signals are differentially programmed.

Original languageEnglish
Pages (from-to)2932-2939
Number of pages8
JournalJournal of Immunology
Volume178
Issue number5
Publication statusPublished - 1 Mar 2007
Externally publishedYes

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