Enhance innate immune response against bacteria by Peptidoglycans recognition proteins (PGRPs)

TODONE MARCOS; ROMASANTA PABLO; FERNÁNDEZ LYNCH M JULIETA; NOLI TRUANT SOFÍA; ANTONOGLOU M BELEN; SARRATEA M BELEN; PEREZ LUCÍA; FERNÁNDEZ MARISA; DE MARZI MAURICIO; MALCHIODI EMILIO

Los Cocos, Córdoba

Congreso; LXII Reunión Científica Anual de la SAI; 2013

Sociedad Argentina de Inmunología

PGRPs are proteins that recognize pathogen associated molecular patterns (PAMPs), which bind to, and in some cases hydrolyze, Peptidoglycan (PGN). With the aim to study the role of these proteins in the innate immune response, we have produced different recombinant human PGRPs. Previously, we have determined that PGRP-S, PGRP-Iα and PGRP-Iβ bind to monocytes membrane increasing their capacity to phagocyte S. aureus and blocking the effect of PGN on cell proliferation. Recently, we have studied if the presence of PGRPs modulates the release and expression of monocyte activation related cytokines and membrane markers. We have observed, by ELISA, that S.aureus PGN incubated with PGRP increases the levels of IL8, IL12, TNF-α and IL-1β in the supernatant of monocytes culture 45-125% with respect controls (PGN without PGRP) but decreases the secretion of IL-10. By Flow Cytometry (FC), we have found that cells treated with PGN-PGRPs had a 15-35% increase expression of CD14, CD80 and CD86 depending on the essayed PGRP. Finally, in order to determine the role of the PGRPs in apoptotic processes, we have incubated monocytes with PGN of S. aureus treated or not with PGRPs, observing a 38-65 % decrease of early apoptosis with respect to controls. These results suggest that the PGRPs would increase the cellular activation as well as the inflammatory response to eliminate bacteria more efficiently and would provide a protective effect on monocytes, by blocking the action of the PGNs in the processes of apoptosis.