IL-2 regulates perforin and granzyme gene expression in CD8+ T cells independently of its effects on survival and proliferation.
Perforin and the serine protease granzymes are key effectors of CD8+ T cell granule-mediated cytotoxicity, but the requirements for their expression remain largely undefined. We show in this study that IL-2 increased the expression of perforin and granzyme A, B, and C mRNA; intracellular granzyme B protein levels; and cytolytic function in a dose-dependent manner during primary activation of murine CD8+ T cells in vitro. Two approaches showed that these responses were not a consequence of the effects of IL-2 on cell survival and proliferation. First, IL-2 enhancement of perforin and granzyme expression was equivalent in CD8+ T cells from wild-type and bcl-2 transgenic mice, although only the latter cells survived in low concentrations or the absence of added IL-2. This property of bcl-2 transgenic T cells also allowed the demonstration that induction of granzyme A, B, and C mRNA and granzyme B protein required exogenous IL-2, whereas induction of perforin and IFN-gamma expression did not. Second, analysis of perforin and granzyme mRNA levels in cells separated according to division number using the dye CFSE showed that the effects of IL-2 were unrelated to division number. Together, these findings indicate that IL-2 can directly regulate perforin and granzyme gene expression in CD8+ T cells independently of its effects on cell survival and proliferation.
Janas
Michelle L
ML
Cooperative Research Center for Vaccine Technology and Queensland Institute of Medical Research, Brisbane, Australia.
Groves
Penny
P
Kienzle
Norbert
N
Kelso
Anne
A
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D053804:Granzymes; D007376:Interleukin-2 / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger / Q000032:analysis; D012697:Serine Endopeptidases / Q000235:genetics*
D007376:Interleukin-2; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D054353:Perforin; D053804:Granzymes; C509214:Gzmb protein, mouse; C509216:Gzmc protein, mouse; D012697:Serine Endopeptidases