Superantigen-like effects of a Candida albicans polypeptide.
The amino terminal sequence of the Candida albicans cell wall protein Int1 exhibited partial identity with the major histocompatibility complex (MHC) class II binding site of the Mycoplasma arthritidis superantigen MAM. Int1-positive C. albicans blastospores activated human T lymphocytes and expanded Vbeta subsets 2, 3, and/or 14; Int1-negative strains were inactive. Release of interferon-gamma (IFN-gamma) but not of tumor necrosis factor-alpha or interleukin-6 was Int1 dependent; interleukin-4 and interleukin-10 were not detected. T lymphocyte activation, Vbeta expansion, and IFN-gamma release were associated with a soluble polypeptide that encompassed the first 263 amino acids of Int1 (Pep(263)). Monoclonal antibody 163.5, which recognizes an Int1 epitope that overlaps the region of identity with MAM, significantly inhibited these activities when triggered by Int1-positive blastospores or Pep(263) but not by staphylococcal enterotoxin B. Histidine(263) was required. Pep(263) bound to T lymphocytes and MHC class II and was detected in the urine of a patient with C. albicans fungemia. These studies identify a candidal protein that displays superantigen-like activities.
Devore-Carter
Denise
D
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8064, USA.
Kar
Sujata
S
Vellucci
Vincent
V
Bhattacherjee
Vasker
V
Domanski
Paul
P
Hostetter
Margaret K
MK
D002176:Candida albicans / Q000235:genetics / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D017353:Gene Deletion; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation; D045645:Mycoplasma arthritidis / Q000235:genetics; D011485:Protein Binding; D018089:Superantigens / Q000235:genetics / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014556:Urine / Q000737:chemistry
D015815:Cell Adhesion Molecules; D016207:Cytokines; D005656:Fungal Proteins; D000949:Histocompatibility Antigens Class II; D018089:Superantigens; C097687:alphaINT1 protein, Candida albicans