Differential regulation of T-cell growth by IL-2 and IL-15

GH Cornish, LV Sinclair, DA Cantrell - Blood, 2006 - ashpublications.org
Blood, 2006ashpublications.org
Although interleukin 2 (IL-2) and IL-15 signal through the common gamma chain (γc) and
through IL-2 receptor β–chain (CD122) subunits, they direct distinct physiologic and
immunotherapeutic responses in T cells. The present study provides some insight into why
IL-2 and IL-15 differentially regulate T-cell function by revealing that these cytokines are
strikingly distinct in their ability to control protein synthesis and T-cell mass. IL-2 and IL-15
are shown to be equivalent mitogens for antigen-stimulated CD8+ T cells but not for …
Although interleukin 2 (IL-2) and IL-15 signal through the common gamma chain (γc) and through IL-2 receptor β–chain (CD122) subunits, they direct distinct physiologic and immunotherapeutic responses in T cells. The present study provides some insight into why IL-2 and IL-15 differentially regulate T-cell function by revealing that these cytokines are strikingly distinct in their ability to control protein synthesis and T-cell mass. IL-2 and IL-15 are shown to be equivalent mitogens for antigen-stimulated CD8+ T cells but not for equivalent growth factors. Antigen-primed T cells cannot autonomously maintain amino acid incorporation or de novo protein synthesis without exogenous cytokine stimulation. Both IL-2 and IL-15 induce amino acid uptake and protein synthesis in antigen-activated T cells; however, the IL-2 response is strikingly more potent than the IL-15 response. The differential action of IL-2 and IL-15 on amino acid uptake and protein synthesis is explained by temporal differences in signaling induced by these 2 cytokines. Hence, the present results show that cytokines that are equivalent mitogens can have different potency in terms of regulating protein synthesis and cell growth.
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