title: Serum-mediated enhancement of TNF-alpha release by human monocytes stimulated with the yeast form of Candida albicans.
abstract: The role of serum in the production of tumor necrosis factor-alpha (TNF-alpha) by human monocytes stimulated with yeast-form Candida albicans was studied. Pre-exposure of C. albicans to human pooled serum enhanced both TNF-alpha mRNA and cytokine secretion compared with C. albicans preincubated with medium only. Serum factors involved were >30 kDa, were efficiently inhibited by D-mannose, and recognized both Ca++-dependent and -independent pathways. Preincubation of yeasts with rabbit mannose-binding protein (MBP) resulted in dose-related enhancement of TNF-alpha secretion, through a Ca++-dependent pathway inhibited by D-mannose. TNF-alpha levels were similarly induced in C. albicans preincubated with vitronectin and with serum. Ca++ depletion did not affect cytokine release, while D-mannose supplementation displayed inhibition. The latter effect was abolished after Ca++ depletion. These data call for an involvement of both MBP and vitronectin in the serum-mediated enhancement of TNF-alpha release upon stimulation of monocytes with yeast forms of C. albicans.
authors.affiliation: I Chair of Clinical Microbiology, Faculty of Medicine, "La Sapieza" University of Rome, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Ghezzi
authors.forename: G
authors.initials: G
authors.lastname: Raponi
authors.forename: S
authors.initials: S
authors.lastname: Angeletti
authors.forename: C
authors.initials: C
authors.lastname: Mancini
mesh_terms: D000818:Animals; D001769:Blood; D002118:Calcium / Q000097:blood; D002176:Candida albicans / Q000187:drug effects / Q000502:physiology*; D002352:Carrier Proteins / Q000494:pharmacology / Q000502:physiology; D002478:Cells, Cultured; D003470:Culture Media; D004492:Edetic Acid / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D008358:Mannose / Q000494:pharmacology; D037241:Mannose-Binding Lectins; D009000:Monocytes / Q000187:drug effects / Q000382:microbiology* / Q000502:physiology*; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics; D011817:Rabbits; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism; D019096:Vitronectin / Q000494:pharmacology / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D003470:Culture Media; D037241:Mannose-Binding Lectins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D019096:Vitronectin; D004492:Edetic Acid; D008358:Mannose; D002118:Calcium