CHARACTERIZATION OFCYTOKINE SECRETING B CELL SUBPOPULATIONSIN HUMAN TONSILS

LINDYBETH SARMIENTO VARON; ARIEL BILLORDO; ELOISA ARANA; PABLO FERNÁNDEZ; JAVIER DE ROSA; PLÁCIDA BAZ

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

Tonsils are secondary lymphoid organs which must grant immunologic protectionagainst pathogens and tolerance against inoffensive Ags in air and food. They aremostly B-cell (Bc) maturation and differentiation sites. Bc are able to secretemultiple cytokines under different stimuli, independently of their role as Agpresenting and Ab producing cells. It is likely that alteration of the immuneequilibrium activation/regulation may trigger recurrent tonsillitis (RT) and/orhypertrophy (HT) leading in turn to tonsillectomy. Hence, the aim of our work wasto characterize such unconventional immune functions of tonsillar Bc, i.e differentBc subsets with regulatory and pro-inflammatory profiles, within the humanoropharyngeal cavity. All measurements were done by FACS. We determinedtonsillar Bc expression of IL6, IL8, IFN, IL5, TNF, IL21, IL10 and TGFatdifferent time-points post stimulation. Also, we established the kinetics ofappearance of IL10 (regulatory cytokine) expressing Bc (B10) and compared it withthat of pro-inflammatory cytokine-expressing Bc (IL6 and IL8) for 5 patients upon 0;16; 32 and 72 hs stimulation, via TLR9 and CD40L. The proportion of B10increased between 16 and 72 hs in all cases. Notably, the percentage of B10detected at the different time points depended on the cause of surgery, an issuethat is addressed in a different poster in the same Congress. The results variedacross individuals; hence, we showed the contour plots of a single patient andgraph lines plotting the results of 5 different patients for the cytokine kinetics.Importantly, we also found a relevant proportion of IL17-expressing B cells intonsils which is, to our knowledge, the first time that is reported in literature.Collectively, these results demonstrate that despite disease-associated changes,Bc from those damaged tonsils preserve their immune competence to secrete anumber of cytokines. This study advances our understanding of the immunefunctions of the tonsils