Immunomodulatory effect on the implementation of an ovalbumin-induced allergic response mediated by a non-viable Cutibacterium acnes suspension in mice

ALMOZNI B; DÍAZ AM; MANGONE F; SOTELO A; CANELLADA AM; CASTRO MS

San Miguel deTucumán

Congreso; LXVII Reunión Anual de la Sociedad Argentina de Inmunología; 2019

Sociedad Argentina de Inmunología

Allergic diseases are featured by an exacerbated Th2 immune response characterized by the production of cytokines IL-4, IL-5 and IL-13 and an increased production of IgE. One way to prevent or treat this type of disease is to modulate the Th1 / Th2 balance to a dominant Th1 profile.Cutibacterium acnes (C. acnes) is a Gram-positive anaerobic bacillus present in normal human skin microbiota, which exerts important immunomodulatory effects when is used as heat-killed suspensions. Recent reports demonstrated that C. acnes treatment promotes a type-1 (Th1) immune response which induce IFN-γ release, enhancement IgG2a switch and inhibiting Th2 cell expansion.The aim of this work was to evaluate, in a murine model, the ability of heat-killed C. acnes to regulate this Th2-exaggerated response of ovalbumin (OVA)-induced allergy. BALB/c mice were subcutaneously (sc) injected with lyophilized heat-killed C. acnes (500 μg/animal) on days -7, 7, 14 and 21. The OVA immunization (10 ug OVA + 1 mg alum, 0.25 ml) was performed on days 0, 7 and 21 by sc injection. Blood samples were obtained on day 31 when animals were sacrificed. Control group received only the OVA. Immunological parameters of the allergen-specific immune response (IgE, IgG, IgG1 and IgG2a in sera and cytokines in spleen supernatant) were determined by ELISA.Upon treatment with C.acnes the following effects were observed: (1) a decrease in specific IgE levels (p