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Complement evasion by Candida is dependent on glucose concentration

Abstract number: R2462

Lesiak I., Vogl G., Lass-Flörl C., Speth C., Dierich M.P., Würzner R.

Objectives: Pathogenic fungi represent a major threat to immunocompromised hosts, leading to severe, and often lethal, systemic opportunistic infections. Factor H (FH), a soluble plasma protein consisting of 20 short consensus repeats (SCRs), is the main fluid phase inhibitor of the alternative pathway of complement. C4b-binding protein (C4bp), having a polymeric structure composed of 6–8 identical alpha-chains and a single beta-chain, is the main fluid-phase inhibitor of the classical and lectin pathways of complement. Both proteins can be acquired onto the surface of various human pathogens conveying resistance to complement destruction and thus contributing to their pathogenic potential. We have recently shown that Candida albicans evades complement by binding both FH and C4bp. Preliminary data suggest that a glucose transporter molecule is involved in this binding. The aim of this study was to assess whether complement evasion via this mechanism is dependent on the glucose concentration present.

Methods: Immunofluorescence, fluorescence activated cell sorting and specific constructs of the proteins investigated, as well as antibodies directed against particular parts thereof have been used to identify and characterise these virulence factors.

Results and Discussion: We now show that binding of factor H and C4bp is strongly dependent on the glucose concentration present and discuss important implications, e.g. for diabetics.

Conclusion: By acquiring complement regulators from the host, yeasts are able to evade the destructive action of complement. This acquisition, however is dependent on the glucose concentration present.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Barcelona, Spain
Presentation type:
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