Desenvolvimento e caracterização de anticorpo monoclonal antiquitooligômeros como potencial ferramenta no tratamento de infecções fúngicas

The search for a fast and accurate diagnosis of fungal infections is fundamental, since over one million individuals die each year due to systemic mycoses. Candida albicans, Aspergillus fumigatus, Pneumocystis jirovecii and Cryptococcus neoformans are the most prevalent fungal pathogens and they are responsible for high rates of morbi-mortality. One of the main components of the cell wall is chitin, a polymer formed by N-acetylglucosamine units linked through \03B2-1,4 bonds. Chitin is essential for the cell wall rigidity and integrity, a promising target for therapy and diagnosis, since it is not synthesized by humans or animals. In this study, monoclonal antibodies (mAb) were developed against chitin oligomers using the hybridoma technique. Functional assays characterized mAbs against chitin oligomers as potential tools for diagnosis and treatment of fungal infections ELISA assays have shown that the mAbs have affinity and specificity with chitin oligomers and its derivatives, since they did not bind to any other cell type such as protozoa, bacteria and animal cells. Immunofluorescence analyzes have shown that the mAbs bind to C. albicans. In vitro tests have shown that the mAbs increased the fungicidal capacity of amphotericin B (AmB) and fluconazole, drugs regularly used for the treatment of fungal infections. HC6/DD11 and AF1/CC5 mAbs were able to interfere with two of the major antifungal resistance factors, the biofilm formation and melanin production. In a murine model of C. neoformans infection, the combined administration of antichitin mAb HC6/DD11 and subinhibitory doses of AmB promoted animal survival around 100%. The data obtained in this work corroborate the hypothesis that chitin antibodies developed against chitooligomers are an auxiliary tool for the diagnosis and treatment of fungal infections caused by C. neoformans.