IMMUNOMODULATORY EFFECT OF U-OMP19 IN A PAPAIN-INDUCED ALLERGY MODEL

PUEBLAS CASTRO C.V.; CORIA M.L.; BRUNO L.; PASQUEVICH, K.; CASSATARO J.

Congreso; LXVIII ANNUAL MEETING OF SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI); 2020

Allergies are T helper 2 immune responses mediated by IgE, in-duced by an antigen called allergen. Many allergens are proteases;thus, allergy models were developed using cysteine proteases likepapain.At our laboratory we had demonstrated the potential of U-Omp19as an adjuvant in vaccine formulations against infectious diseasesinducing a Th1 response. Therefore, the main objective of this workwas to evaluate its potential to modulate allergic responses.To this end an allergy model induced by papain was performed atour laboratory. Mice (n=5/group) were subcutaneously immunizedwith OVA, OVA+papain or OVA+papain+U-Omp19. The antibody re-sponse was assessed by analyzing anti-OVA IgE, IgG1 and IgG2ain serum by indirect ELISA. The specific cellular immune responsewas also measured, analyzing the levels of cytokines associatedwith a Th2 response (IL-5 and IL-13) in OVA-stimulated splenocytesupernatants by ELISA.Our results indicate that the allergic response was induced whenmice were immunized with OVA plus papain. In this group, we havefound a significant increase in anti-OVA IgE levels (p <0.05, ANO-VA + Bonferroni Test), and a specific OVA Th2 response, given thesignificant increases in IL-5 and IL-13 levels (p <0.01 for IL-5 andp<0.001 for IL-13, ANOVA + Bonferroni Test), compared to the ad-ministration of OVA alone. In contrast, when U-Omp19 was added tothe formulation, anti-OVA IgE levels were modulated or not elicitedand were similar to levels induced by OVA delivered alone group.Besides, the T helper 2 cytokines production were not induced.Together our results using a model of allergic disease constitute aproof of concept that indicates that U-Omp19 is capable of prevent-ing/modulating the papain induced allergic response. This workpaves the way of future research on the immunomodulatory poten-tial of U-Omp19 in allergic responses