Is the role of IgA in local immunity completely known?

IgA antibodies belong to the most important humoral immune factors present on mucosal surfaces. Different defence mechanisms are involved in the permanent and effective surveillance of mucosal surfaces. The robustness of local immunity homeostasis may also explain how the intestinal immune system is able to accommodate a wide range of microbes that have evolved a wide variety of intestinal lifestyles. Bacterial behaviours depend not only on the bacterial species, but also on the host. Commensal bacteria have been directly associated with the proper development of gut-associated lymphoid tissues.