Memory for Intestinal Rotavirus

The integrin a 4 b 7 mediates lymphocyte binding to mucosal addressin cell adhesion molecule-1, and its expression defines lymphocytes capable of trafficking through the intestines and the intestinal lymphoid tissues. We examined the ability of discrete a 4 b 7 hi and a 4 b 7 2 subsets of circulating memory phenotype (CD45RA 2 ) CD4 1 T cells to proliferate in response to rotavirus, a ubiquitous intestinal pathogen. a 4 b 7 hi memory (CD45RA 2 ) CD4 1 T cells displayed much greater reactivity to rotavirus than a 4 b 7 2 memory or naive (CD45RA 1 ) CD4 1 T cells. In contrast, a 4 b 7 2 memory cells were the predominant population responsive to mumps antigen after intramuscular vaccination. Our results are consistent with the conclusion that natural rotavirus infection, an enteric pathogen, results in a specific circulating memory CD4 1 response that is largely limited to the gut-homing a 4 b 7 1 subpopulation. This phenotype is not shared with memory cells elicited by intramuscular immunization (shown here) or by skin contact allergens. The results support the hypothesis that gut trafficking memory CD4 1 T cells comprise cellular memory for intestinal antigens and suggest that regulated expression of a 4 b 7 helps target and segregate intestinal versus systemic immune response. ( J. Clin. Invest. 1997. 100:1204–1208.)