Modification of immune response to Diphtheria Toxoid by cytokine neutralization

JOSÉ L. APARICIO; MACARENA A. OTTOBRE SABORIDO

Congreso; Reunión Conjunta de la Sociedad Argentina de Investigación Clínica (SAIC), la Sociedad Argentina de Inmunología (SAI) y la Sociedad Argentina de Fisiología (SAFIS); 2018

Introduction: In previous works, we demonstrated that infection of micewith Lactate dehydrogenase elevating virus (LDV) -a RNA arterivirusthat induces NK, macrophages and B-cell activation- modified Abspecificity to different antigens models such as hGH and OVA. Thiseffect was correlated with secretion of specific cytokines. Recently,we found that an interleukin -IL-17A- is involved in this mechanism.Objective: Expand the studies to an antigen of clinicalrelevance, such as Diphtheria Toxoid (DTx).Methods: C57BL/6J mice (n=18) were inoculated subcutaneouslywith 25μg of DTx in Alum Adjuvant. At day 15, the mice wereboosted with the Ag. At days 4, 7 and 11, half of the animals (n=9)were inoculated intraperitoneally with 150μg of anti-IL-17A MAbin PBS. Another mice group (n=18) were treated as before but infectedwith 2×107 50% infectious doses of LDV in saline at day0. Bleeding was performed at days 8, 21, and 32. Serum lactatedehydrogenase (LDH) levels were determinated enzymaticallyand the titer of Ab anti-DTx was evaluated by indirect ELISA,whereas IL-17A concentration was measured by ELISA sandwich.Results: MAb to IL-17A increased LDH levels in infected-animals treated with DTx (2802±57 and 5020±208U/L, 21 and 32 dpi, respectively, P