IMMUNOBIOLOGY Suppressor of cytokine signaling 3 regulates CD8 T-cell proliferation by inhibition

proteins regulate the intensity and dura-tion of cytokine responses. SOCS3 is expressed in peripheral T cells, and re-cent reports have suggested that overex-pression of SOCS3 modulates antigen-and/or costimulation-induced T-cell acti-vation. To study the role of SOCS3 in the regulation of T-cell activation, we used a conditional gene-targeting strategy to generate mice that lack SOCS3 in T/natu-ral killer T cells (Socs3Lck/Lck mice). SOCS3-deficient CD8 T cells showed greater proliferation than wild-type cells in response to T-cell receptor (TCR) liga-tion despite normal activation of signal