Altered hepatic clearance and killing of Candida albicans in the isolated perfused mouse liver model

Abstract

The adherence of Candida albicans was studied in situ by using the perfused mouse liver model. After exhaustive washing, 106 C. albicans were infused into mouse livers. At the time of recovery, 62 ± 5% (mean ± standard error of the mean) of the infused C. albicans were recovered from the liver and 14 ± 3% were recovered from the effluent for a total recovery of 76 ± 4%. This indicates that 86 ± 3% of the original inoculum was trapped by the liver and that 24 ± 4% was killed within the liver. Chemical pretreatment of C. albicans with 8 M urea, 12 mM dithiothreitol, 2% β-mercaptoethanol, 1% sodium dodecyl sulfate, 10% Triton X-100, or 3 M potassium chloride or enzyme pretreatment with α-mannosidase, α-chymotrypsin, subtilisin, β-N-acetyl-glucosaminidase, pronase, trypsin, papain, or lipase did not alter adherence of C. albicans to hepatic tissue. By contrast, pepsin pretreatment significantly decreased hepatic trapping. Simultaneous perfusion with either 100 mg of C. albicans glycoprotein per liter or 100 mg of C. albicans mannan per liter also decreased trapping. Furthermore, both substances eluted previously trapped C. albicans from hepatic tissue. Chemical pretreatment with 8 M urea, 12 mM dithiothreitol, or 3 M KCl or enzymatic pretreatment with α-mannosidase, subtilisin, α-chymotrypsin, or papain increased killing of C. albicans three- to fivefold within hepatic tissue. The data suggest that mannose-containing structures on the surface of C. albicans, for example, mannans or glucomannoproteins, mediate adherence of C. albicans within the liver. Indirectly, chemical and enzymatic pretreatment renders C. albicans more susceptible to hepatic killing.