Directing the Mucosal Immune Response

Science's STKE  21 Nov 2006:
Vol. 2006, Issue 362, pp. tw398
DOI: 10.1126/stke.3622006tw398

The mucosal lining of the intestine is stuffed with antibody-secreting B cells, which produce vast quantities of immunoglobulin A (IgA), a specialized form of antibody equipped specifically for secretion across the gut wall, where it protects against enteric pathogens. The cues that make a mucosal B cell produce IgA, rather than any of the other forms of antibody, are unclear. Mora et al. now show that another immune cell, the dendritic cell, imparts this information within lymphoid tissue associated with the gut. Once activated by the gut dendritic cells, B cells become "imprinted" to enter the circulation and then home back to the mucosal lining to begin IgA production. Induction depended on the vitamin A metabolite retinoic acid, which may explain why vitamin A deficiency exacerbates childhood diarrheal disease in the developing world.

J. R. Mora, M. Iwata, B. Eksteen, S.-Y. Song, T. Junt, B. Senman, K. L. Otipoby, A. Yokota, H. Takeuchi, P. Ricciardi-Castagnoli, K. Rajewsky, D. H. Adams, U. H. von Andrian, Generation of gut-homing IgA-secreting B cells by intestinal dendritic cells. Science 314, 1157-1160 (2006). [Abstract] [Full Text]