22 March 1996
Vol 271, Issue 5256

About The Cover

Dendritic cells and T cells interact to initiate an immune response. The scanning electron microscope image shows a male dendritic cell embracing a helper T cell (lower cell, ~7 m in diameter) that recognizes the male antigen H-Y. These same dendritic cells were used to show that a newborn mouse has a competent immune system. See 1723 and related Reports (1726 and 1728) and News story (1665). [Cells cultured by J. P. Ridge. Image: D. Scharf, using the S.E.M. Wideband Multi-Detector Color Synthesizer]