Issues

Cover picture: A dendritic cell from rat pseudoafferent intestinal lymph, labeled for major histocompatibility complex class II (red) and apoptotic DNA (green). The DNA derives from endocytosed enterocytes, as these dendritic cells also contain nonspecific esterase variants with the electrophoretic characteristics of enterocyte esterases, and some contain enterocyte-restricted cytokeratin. These features are only found in a CD4^-OX41^- subpopulation of dendritic cells. This subpopulation of rapidly turning over dendritic cells migrates constitutively and continually into T cell areas of mesenteric lymph nodes. We suggest that this subpopulation may be involved, directly or indirectly, in crosstolerance to self-antigens and in the induction of oral tolerance. See related article in this issue by Huang et al., .