Prevailing Role of Mucosal Igs and B Cells in Teleost Skin Immune Responses to Bacterial Infection

Abstract The skin of vertebrates is the outermost organ body and serves as first line defense against external aggressions. In contrast to mammalian skin, that teleost fish lacks keratinization has evolved operate a mucosal surface containing skin-associated lymphoid tissue (SALT). Thus far, IgT representing prevalent Ig in SALT have only been reported upon infection with parasite. However, very little known about types B cells Igs responding bacterial mucosa, well inductive or effector role such responses. To address these questions, this study, we analyzed immune response trout one most widespread pathogens, Flavobacterium columnare. This pathogen induced strong innate inflammatory responses at initial phases infection. More critically, found mucus having survived contained significant IgT- but not IgM- IgD-specific titers bacteria. Moreover, demonstrate local proliferation production IgT+ specific titers, respectively, within Thus, our findings represent demonstration main isotype by mucosa that, because large its probably represents prominent IgT-inductive site fish.