Assessment of immunogenicity and protective efficacy of dermatophytes secreted components in the treatment and vaccination against dermatophytosis

Abstract

ABSTRACT In the present study a subunit vaccine against dermatophytosis was prepared. This vaccine contained M. canis exoantigens and Alhydrogel adjuvant. As Microsporum canis represents the most common dermatophyte in pets and is responsible for reported zoonosis but till now there is no effective vaccine used for controlling dermatophytosis in pets. The secreted components by M.canis are considered as the main virulence factor of M.canis and as they are a potential source of antigen to induce protective immunity thus they are also named "exoantigens". The detailed study of M.canis secreted components was so important in developing a protective vaccine. In this study the protein pattern of M. canis exoantigens obtained from 2 local isolates were compared with those obtained from a reference strain using SDS-PAGE revealing 18 clearly detectable protein bands. Protein bands of: 6.5, 10, 15, 20, 31.5, 35, 40, 45, 50, 64, 122, 147kDa were common among the local isolates and reference strain and they were considered species-specific. On the basis of exoantigens pattern reveled by SDS- PAGE the reference strain CBS 136538 Microsporum canis was used in the vaccine preparation. The immunogenicity and protective efficacy of M.canis exoantigens with Alhydrogel adjuvant was evaluated in a vaccine study using guinea pigs model. A challenge test with M.canis virulent strain was carried out as it was found that the prepared vaccine induced a significantly high protection rate. The level of gene expression of two cytokines IFN-γ and IL-4 expressed in peripheral blood mononuclear cells were determined using dynamic quantitative real-time PCR (qRT-PCR) 14 days after vaccination and 10 days after challenge infection showed that the level of IFN-γ and IL-4 mRNA expression was significantly high in the vaccinated guinea pigs (P ≤ 0.002) when compared with control animals. The results also showed that vaccination induced a strong antibody response towards the exoantigens and also induced a positive DTH skin test reaction.

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