Secreted dipeptidyl peptidases as potential virulence factors for Microsporum canis.
Dermatophytoses caused by Microsporum canis are frequently encountered in cats and dogs; they are highly contagious and readily transmissible to humans. In this study, two single genes, respectively coding for dipeptidyl peptidases IV and V (DppIV and DppV), were isolated and characterized. Both proteins share homology with serine proteases of the S9 family, some of which display properties compatible with implication in pathogenic processes. Both genes are expressed in vivo in experimentally infected guinea-pigs and in naturally infected cats, and when the fungus is grown on extracellular matrix proteins as the sole nitrogen and carbon source. DppIV and V were produced as active recombinant proteases in the yeast Pichia pastoris; the apparent molecular weight of rDppV is 83 kDa, whereas rDppIV appears as a doublet of 95 and 98 kDa. Like other members of its enzymatic subfamily, rDppIV has an unusual ability to cleave Pro-X bonds. This activity does not enhance the solubilization of keratin by fungal secreted endoproteases, and the protease probably acts solely on small soluble peptides. RDppV showed no ability to induce delayed-type hypersensitivity (DTH) skin reactions in guinea-pigs, despite the known immunogenic properties of homologous proteins.
Vermout
Sandy
S
Department of Infectious and Parasitic Diseases, Parasitology, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.
Baldo
Aline
A
Tabart
Jérémy
J
Losson
Bertrand
B
Mignon
Bernard
B
D000595:Amino Acid Sequence; D000818:Animals; D003881:Dermatomycoses / Q000382:microbiology / Q000473:pathology*; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D005260:Female; D006168:Guinea Pigs; D006968:Hypersensitivity, Delayed; D008864:Microsporum / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D013047:Specific Pathogen-Free Organisms; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
D037521:Virulence Factors; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases