Keeping STATs on Memory CD8+ T Cells Janelle A. Olson, Stephen C. Jameson  Immunity  Volume 35, Issue 5, Pages 663-665 (November 2011) DOI: 10.1016/j.immuni.2011.11.006 Copyright © 2011 Elsevier Inc. Terms and Conditions

Figure 1 Keeping Memory CD8+ T Cells on Track Following CD8+ T cell activation and initial proliferation, responding cells face divergent fates. With persistent T cell receptor stimulation and/or inflammatory cues, the short-lived effector pool is favored. The new studies suggest the production of a stable memory CD8+ T pool involves activation of STAT3 (which, in this case, may be predominantly induced by IL-10 and IL-21). Active STAT3 induces SOCS3, an inhibitor of various cytokine receptors (including the proinflammatory cytokine, IL-12) but STAT3 also promotes expression of Bcl-6, a transcription factor that can enhance memory CD8+ T cell differentiation. In these ways, STAT3 may reinforce memory CD8+ T cell differentiation as well as insulate the burgeoning memory pool from being diverted into the effector pool. Data from Siegel et al. indicate that STAT3 could also play a role in the initial expansion of human activated CD8+ T cells. Immunity 2011 35, 663-665DOI: (10.1016/j.immuni.2011.11.006) Copyright © 2011 Elsevier Inc. Terms and Conditions