Laminin-511 and fibronectin degradation with Candida yeast.
BACKGROUND
The invasion mechanism of Candida yeast is still partly unknown. In this study, we tested the ability of different commensal Candida yeast to degrade two basement membrane and extracellular matrix proteins: laminin-511 (Lm-511) and plasma fibronectin.


METHODS
Human Lm-511 was produced by an immortal keratinocyte cell line, labelled with (35)S-methionine and immunoprecipitated from the growth medium with monoclonal antibodies. Human plasma fibronectin was purified from plasma samples of blood donors. Sonicated yeast cells and concentrated yeast cell growth media were incubated with Lm-511 in different pH values and the degradation was detected by fluorography. Fibronectin degradation by yeast was visualized by sodium dodecyl-sulphate polyacrylamide gel electrophoresis.


RESULTS
The reduced 220 kDa fibronectin monomers were found to be degraded at pH 7.8 by 10x concentrated growth media of most strains tested and at pH 3.0 the degradation was more pronounced. Sonicated cell fractions of C. tropicalis and C. parapsilosis caused degradation of plasma fibronectin at pH 7.8. Instead, none of the tested Candida cell fractions degraded Lm-511 under these conditions.


CONCLUSIONS
It seems that cleavage of different laminin isoforms by Candida yeast is a laminin-specific process. The ability to cleave human plasma fibronectin is species- and pH-dependent but not hyphal-dependent and also this degradation may affect epithelial integrity.
Pärnänen
Pirjo
P
Institute of Dentistry, PB 63, FIN-00014, University of Helsinki, Helsinki, Finland. pirjo.parnanen@helsinki.fi
Meurman
Jukka H
JH
Virtanen
Ismo
I
D002175:Candida / Q000145:classification / Q000378:metabolism*; D002176:Candida albicans / Q000378:metabolism; D041221:Candida glabrata / Q000378:metabolism; D041022:Candida tropicalis / Q000378:metabolism; D002458:Cell Fractionation; D045744:Cell Line, Tumor; D017077:Culture Media, Conditioned; D004591:Electrophoresis, Polyacrylamide Gel; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D025301:Hyphae / Q000378:metabolism; D007797:Laminin / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism
D017077:Culture Media, Conditioned; D005353:Fibronectins; C478221:LAMB1 protein, human; D007797:Laminin; D020033:Protein Isoforms; C097043:laminin alpha5; C089141:laminin gamma 1