Mucosal memory--maintenance and recruitment

The maintenance of IgA antibody responses at mucosal surfaces is the outcome of influences on IgA precursor cell dissemination from the mucosal inductive sites, such as the intestinal Peyer's patches, their selective extravasation at mucosal effector sites and the retention and local proliferation of these cell populations under local influences. Examination of these local post-extravasational effects has implicated cytokines as major regulatory elements in this process. This paper will address the role of cytokines in induction and expression of IgA responses and the differential requirements for cytokine signals among IgA-committed B cell subsets in both rodent and domestic livestock species. The way in which cytokines influence local immunity in the gut with respect to microbial and parasitic challenge and comparative cytokine effects in extra-intestinal sites, particularly the eye, will be presented, and opportunities for therapeutic interventions to modify cytokine expression will be discussed.