26 June 2012
Vol 5, Issue 230

About The Cover

Cover image expansion

Online Cover This week features a Research Article that examined how the inhibitory receptor PD-1 blocks the proliferation of activated human CD4+ T cells, thereby preventing the expansion of autoreactive T cells. By inhibiting Ras and Akt signaling pathways, PD-1 affected components of the cell cycle machinery to lock T cells in the G1 phase of the cell cycle and prevent their proliferation. The image shows a T cell. [Image: Dennis Kunkel Microscopy, Inc.]