title: Characterization and in vitro activities of cell-free antigens from Histoplasma capsulatum-loaded biodegradable microspheres.
abstract: In the last decades, the incidence of histoplasmosis, a pulmonary fungal disease caused by Histoplasma capsulatum, has increased worldwide. In this context, vaccines for the prevention of this infection or therapies are necessary. Cell-free antigens (CFAgs) from H. capsulatum when administered for murine immunization purposes are able to confer protection and control of the infection, since they activate cellular immunity. However, the most of vaccination procedures need several antigens administrations and immunoadjuvants, which are not approved for use in humans. The aim of this study was to develop and characterize a vaccination approach using biodegradable PLGA microspheres (MS) that could allow the controlled and/or sustained release of the encapsulated antigens from H. capsulatum. CFAgs-loaded MS presented a size less than 10 microm, were marked engulfed by bone marrow-derived macrophages (BMDM phi) and induced the nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) production by these cells. Our data show that CFAgs-loaded MS induce cell activation, suggesting an immunostimulant effect to be further investigated during immunization procedures. CFAgs-loaded MS present potential to be used as vaccine in order to confer protection against H. capsulatum infection.
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n, 14040-903 Ribeirão Preto, São Paulo, Brazil.
authors.forename: Daiane F
authors.initials: DF
authors.lastname: dos Santos
authors.forename: Roberto
authors.initials: R
authors.lastname: Nicolete
authors.forename: Patrícia R M
authors.initials: PR
authors.lastname: de Souza
authors.forename: Cláudia da S
authors.initials: Cda S
authors.lastname: Bitencourt
authors.forename: Rubens R
authors.initials: RR
authors.lastname: dos Santos
authors.forename: Vânia L D
authors.initials: VL
authors.lastname: Bonato
authors.forename: Célio L
authors.initials: CL
authors.lastname: Silva
authors.forename: Lúcia H
authors.initials: LH
authors.lastname: Faccioli
mesh_terms: D000818:Animals; D000946:Antigens, Fungal / Q000737:chemistry* / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry* / Q000493:pharmacokinetics*; D002478:Cells, Cultured; D006658:Histoplasma / Q000737:chemistry* / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008863:Microspheres; D013347:Subcellular Fractions / Q000737:chemistry / Q000378:metabolism
chemical_list: D000946:Antigens, Fungal; D001672:Biocompatible Materials