CHARACTERIZATION OFCYTOKINE SECRETING B CELL SUBPOPULATIONS IN HUMAN TONSILS

JAVIER DE ROSA; LINDYBETH SARMIENTO VARON; PABLO MARIANO FERNÁNDEZ; KARINA PASQUEVICH; ANDRES BLANCO; ARIEL BILLORDO; PLACIDA BAZ; ELOÍSA I. ARANA

Congreso; Biociencias 2017; 2017

Tonsils are secondary lymphoid organs which must grant immunologic protection against pathogens and tolerance against inoffensiveAgs in air and food. They are mostly B-cell (Bc) maturation anddifferentiation sites. Bc are able to secrete multiple cytokines underdifferent stimuli, independently of their role as Ag presentingand 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 was to characterize suchunconventional immune functions of tonsillar Bc, i.e different Bc subsets with regulatory and pro-inflammatoryprofiles, within the human oropharyngeal cavity. Allmeasurements were done by FACS. We determined tonsillar Bc expression of IL6,IL8, IFNg, IL5, TNFa, IL21, IL10 and TGFb at different time-points post stimulation. Also, we established thekinetics of appearance of IL10 (regulatory cytokine) expressing Bc (B10) and comparedit with that of pro-inflammatory cytokine-expressing Bc (IL6 and IL8) for 5patients upon 0; 16; 32 and 72hs stimulation, via TLR9 and CD40L. The proportion of B10increased between 16 and 72 hs inall cases. Notably, the percentage of B10 detected at the different timepoints depended on the cause of surgery, an issue that is addressed in adifferent poster in the same Congress. The results varied across individuals; hence,we showed the contour plots of a single patient and graph lines plotting theresults of 5 different patients for the cytokine kinetics. Importantly, we also found arelevant proportion of IL17-expressing B cells in tonsils which is, to ourknowledge, the first time that is reported in literature. Collectively, theseresults demonstrate that despite disease-associated changes, Bc from thosedamaged tonsils preserve their immune competence to secrete a number ofcytokines. This study advances our understanding of the immune functions of thetonsils.