Humoral immune response in experimental ddY mice Paracoccidioidomycosis

Abstract

Paracoccidioidomycosis (PCM) is a systemic mycosis, restrict to Latin America, with higher incidence in Brazil. ddY mice have been used as experimental PCM model, although there is no data regarding immune response. The aim of the present study was evaluated specific humoral response against the main specific antigen of the fungal Paracoccidioides brasiliensis, the gp43, in ddY mice infected with virulent Pb 18. Antigenemia analysis and histophatological exam in several organs were performed in different time postinfection The results showed increased levels of anti-gp43 IgG on days 14, 17, 21, 24, 28 and 56 post-infection and increased levels of soluble gp-43 on day 28 post-infection. The fungal cells were detected in all organs analyzed (brain, heart, lung, liver, spleen and kidney) in all investigated periods. The granulomatous lesions became predominant 14 days after infection. The results evidence that ddY mice produce humoral immune response to main P. brasiliensis antigen, with high levels until 56 days after infection. Further studies are needed to show that reduction of soluble gp43 in chronic phase correlates with infection control.