RESUMO

Aim:Cryptococcus neoformans is the major agent of cryptococcosis. The main virulence factor is the polysaccharide (PS) capsule. Changes in cryptococcal PS properties have been poorly elucidated. Materials & methods: We analyzed the mechanical properties of secreted PS and intact capsules, using dynamic light scattering and optical tweezers. Results: Storage and loss moduli showed that secreted PS behaves as a viscoelastic liquid, while capsular PS behaves as a viscoelastic solid. The secreted PS remains as a viscoelastic fluid at different temperatures with thermal hysteresis after 85°C. Antibody binding altered the viscoelastic behavior of both secreted and capsular PS. Conclusion: Deciphering the mechanical aspects of these structures could reveal features that may have consequences in novel therapies against cryptococcosis.

Assuntos

Anticorpos Antifúngicos/metabolismo , Cryptococcus neoformans/química , Polissacarídeos/fisiologia , Temperatura , Fatores de Virulência/fisiologia , Anticorpos Antifúngicos/imunologia , Cápsulas Fúngicas/química , Cápsulas Fúngicas/imunologia , Cápsulas Fúngicas/fisiologia , Pinças Ópticas , Tamanho da Partícula , Polissacarídeos/química , Polissacarídeos/imunologia , Polissacarídeos/metabolismo , Reologia , Fatores de Virulência/química , Fatores de Virulência/imunologia , Fatores de Virulência/metabolismo , Substâncias Viscoelásticas