IL-4Rα-Associated Antigen Processing by B Cells Promotes Immunity in Nippostrongylus brasiliensis Infection

In this study,b cell function in protective th2 immunity against n. brasiliensis infection was investigated. protection against secondary infection depended on il-4rα and il-13; but not il-4. protection did not associate with parasite specific antibody responses. re-infection of b cell-specific il-4rα-/- mice resulted in increased worm burdens compared to control mice,despite their equivalent capacity to control primary infection. impaired protection correlated with reduced lymphocyte il-13 production and b cell mhc class ii and cd86 surface expression. adoptive transfer of in vivo n. brasiliensis primed il-4rα expressing b cells into naïve balb/c mice,but not il-4rα or il-13 deficient b cells,conferred protection against primary n. brasiliensis infection. this protection required mhc class ii compatibility on b cells suggesting cognate interactions by b cells with cd4+ t cells were important to co-ordinate immunity. furthermore,the rapid nature of these protective effects by b cells suggested non-bcr mediated mechanisms,such as via toll like receptors,was involved,and this was supported by transfer experiments using antigen pulsed myd88-/- b cells. these data suggest tlr dependent antigen processing by il-4rα-responsive b cells producing il-13 contribute significantly to cd4+ t cell-mediated protective immunity against n. brasiliensis infection. © 2013 horsnell et al.