INDUCTION OF TH2-MEDIATED ALLERGIC ASTHMA IN A MOUSE STRAIN HIGHLY SUSCEPTIBLE TO DEVELOP TH1 RESPONSES

GLORIA JANET GODOY; LEONARDO RODOLFO SANCHEZ ; LUCIANA GARCIA; CRISTINA MALDONADO; RUBEN DARIO MOTRICH; VIRGINIA ELENA RIVERO

Buenos Aires

Congreso; LXIII ReuniónAnual de SAI, I Meeting LASID-SAI-FAIC, IV Meeting LASID, y II Meeting FAIC. Buenos Aires; 2015

LASIG

NOD mice are highly susceptible to chronic inflammation disorders mostly mediated by Th1 responses. This increased susceptibility has been thought to be related to defects in regulatory T cells (Tregs). Recent findings evidenced that Tregs subsets are heterogeneous and that different Tregs subsets able to specifically regulate Th1, Th2 and Th17 immune responses would exist. In this work, we developed a model of allergic asthma following established immunization protocols with OVA plus aluminum salts in NOD, C57BL/6 and Balb/c mice. We aimed to analyze if regulatory defects observed in NOD mice were general or just restricted to Th1 responses. After immunization, mice from every strain showed clinical signs and symptoms of allergy when challenged intranasally with OVA. Although increased leukocyte counts in broncoalveolar lavage (BAL) were detected in both immunized NOD and Balb/c mice, the highest levels were detected in Balb/c mice (p<0,05). BAL eosinophil counts showed to be high, mild and almost null in immunized Balb/c, NOD and C57BL/6 mice, respectively. Moreover, markedly increased, mildly increased, and null levels of IL4 and IL5 were respectively detected in BAL from immunized Balb/c, NOD and C57BL/6 mice. Lymph node and spleen mononuclear cell cultures revealed that: a pure Th1 specific immune response is induced in C57BL/6 mice, a mixed Th1/Th2 specific immune response is induced in NOD mice, and a pure Th2 specific immune response is induced in Balb/c mice. Serum OVA-specific IgE levels were positive in all strains, but the highest levels were shown in Balb/c mice (p<0,05). Altogether our results show that, although Balb/c mice develop the most pronounced Th2 OVA-specific immune response, NOD mice are also able to induce allergic asthma Th2-mediated immune responses, suggesting that they have regulatory defects not only in controlling Th1 immune responses.