کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2167951 | 1092363 | 2008 | 9 صفحه PDF | دانلود رایگان |
It is widely accepted that naïve T cells require two signals, antigen recognition and co-simulation, to become cytotoxic over the course of 3–5 days. However, we observed that freshly isolated murine splenocytes without exposure to antigen become cytotoxic within 24 h after culture with IL-15. IL-15 is a cytokine that promotes homeostatic proliferation, maintenance and activation of memory T cells. The induced cytotoxicity, measured by anti-CD3 redirected 51Cr release, represented the combined activity of T cells regardless of their antigen specificity, and proceeded even when CD44hi (memory-associated phenotype) CD8+ T cells were depleted. Cytotoxic capacity was perforin-dependent and occurred without detectable up-regulation of granzyme B or cell division. After induction, the phenotypic markers for the memory subset and for activation remained unchanged from the expression of resting T cells. Our work suggests that T cells may gain cytotoxic potential earlier than currently thought and even without TCR stimulation.
Journal: Cellular Immunology - Volume 251, Issue 2, 2008, Pages 93–101