Toxoplasma gondii chronic infection prevents the development of atopic dermatitis

MATÍAS DAMIÁN PERRONE SIBILIA, MARÍA DE LOS ÁNGELES ALDIRICO, ARIADNA SOTO, MARIANO SERGIO PICCHIO, VANESA ROXANA SÁNCHEZ, NADIA ARCÓN, FLORENCIA MAGALÍ GIORGIO, VALENTINA MARTÍN, VANZULLI SILVIA, IGNACIO MARTÍN FENOY, ALEJANDRA GOLDMAN

Mar del Plata

Congreso; Recunión Anual de la Sociedad Argentina de Inmunología; 2016

We previouslyshowed that T. gondii infection diminishes the susceptibility to developexperimental asthma. The parasite immunomodulatory ability extends to systemiclevel. Hence, these results suggested that this protozoan infection couldmodulate other allergic disorders. The aim of the present work was to studywhether T. gondii infection alsomodulates the development of atopic dermatitis. One month before allergic sensitization, adult BALB/c mice were orallyinfected with T. gondii cysts. Mice wereepicutaneous sensitized with OVA (TDA) or PBS (T). Treatment was repeated twice with a 2-week resting periodbetween each sensitization. Controls include non-infected mice sensitized with OVA(DA) and non-infected mice treated with PBS (N). The analysis was performed oneday after the last week of sensitization. Skin and blood samples were collectedto evaluate histopathology, and OVA-specific IgE, IgG1 and IgG2a antibodiesrespectively. Ex vivo stimulation ofsplenocytes with OVA was performed and supernatant IL-4, IL-5 and IFN-g cytokine levels were evaluated. Allergic miceshowed pathological changes characteristic of atopic dermatitis, compared with normalmice. These changes include epidermal hyperplasia, hyperkeratosis andinfiltration of inflammatory cells in the dermis and epidermis. Mice infectedwith T. gondii before allergicsensitization showed a histopathology similar to normal mice, with no epidermalhyperplasia, orthokeratosis and poor inflammatory infiltrate in the dermis andepidermis. A trend to decreased OVA-specific IgE and significant diminished IgG1 levels in TDAcompared to the DA group were detected (p<0.05). No differences wereobserved in IgG2a levels. T. gondiiinfection also induced a reduction in both OVA specific Th2 IL-4 (p<0.001) andIL-5 (p<0.01) and Th1 IFN-g levels (p<0.01). Theseresults show that, in addition to lung airway inflammation, chronic T.gondii infection can suppress atopic dermatitis.