title: Effect of the secretory leucocyte proteinase inhibitor (SLPI) on Candida albicans biological processes: a therapeutic alternative?
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of SLPI on the growth and biological processes of Candida albicans.
  
  
  METHODS
  Two C. albicans strains were used in this study, a clinical isolate resistant to fluconazole (PRI) and a reference strain ATCC 24433. The minimal inhibitory concentration (MIC) was determined according to the CLSI methodology. The influence of SLPI on secreted serine proteinase activities (SSP) was measured by the cleavage of specific substrate, and surface hydrophobicity was determined by the aqueous-hydrocarbon biphasic separation method. Flow cytometry was performed to investigate receptors for SLPI and variations in the cell wall mannoprotein expression. Interaction between yeast and epithelium was assessed using the MA-104 cells lineage. Ultrastructure was analyzed by transmission electron microscopy (TEM).
  
  
  RESULTS
  MIC values were calculated as 18 and 18.9μM for the PRI and ATCC 24433, respectively. SSP activity was reduced by 48.8% by 18μM of SLPI and cell surface hydrophobicity increased by 11.1%. Flow cytometry suggest the existence of SLPI binding sites on the surface of the yeast. Results showed a reduction in the expression of mannoproteins in 20.8% by the cells treated with 80μM of SLPI, and 18μM reduced the adhesion of yeasts to mammalian cells in 60.1%. TEM revealed ultrastructural changes in cells treated with 80μM of SLPI, such as the presence of membrane-like structures within the cytoplasm.
  
  
  CONCLUSIONS
  SLPI exerts a significant influence on C. albicans viability and biological processes. Considering its constitutive and physiologic features, SLPI may become a promising tool for the development of new methodologies for the treatment and control of candidiasis.
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: José Alexandre da Rocha
authors.initials: JA
authors.lastname: Curvelo
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Anna Léa Silva
authors.initials: AL
authors.lastname: Barreto
authors.affiliation: Faculdade de Odontologia, Universidade Federal Fluminense, Niterói, Brazil.
authors.forename: Maristela Barbosa
authors.initials: MB
authors.lastname: Portela
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Daniela Sales
authors.initials: DS
authors.lastname: Alviano
authors.affiliation: Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Carla
authors.initials: C
authors.lastname: Holandino
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Thaís
authors.initials: T
authors.lastname: Souto-Padrón
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: rasoares@micro.ufrj.br.
authors.forename: Rosangela Maria de Araújo
authors.initials: RM
authors.lastname: Soares
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001686:Biological Phenomena / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects* / Q000648:ultrastructure; D002448:Cell Adhesion / Q000187:drug effects; D025141:Drug Resistance, Fungal; D005434:Flow Cytometry; D015725:Fluconazole / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008854:Microscopy, Electron; D009761:Nystatin / Q000494:pharmacology; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D008562:Membrane Glycoproteins; D053481:Secretory Leukocyte Peptidase Inhibitor; C025363:mannoproteins; D009761:Nystatin; D015725:Fluconazole
keywords: Candida albicans; Protease inhibitor; SLPI; Virulence factors