title: Delayed-type hypersensitivity responses to a cell wall fraction of the mycelial phase of Coccidioides immitis.
abstract: A skin test-active fraction was isolated from the mycelial-phase cell walls of Coccidioides immitis. This alkali-soluble, water-soluble antigen (C-ASWS) elicited positive reactions in 22 of 24 (92%) of the Coccidioides-sensitized guinea pigs whereas only 14 (54%) of the same guinea pigs reacted to commercial coccidioidin (BioCox). None of the 21 Histoplasma-sensitized guinea pigs cross-reacted with the C-ASWS antigen. Footpad tests in mice actively infected with Coccidioides further established the efficacy of the C-ASWS antigen in eliciting a delayed-type hypersensitivity response. One-microgram doses of C-ASWS produced reactions comparable to 100-mug doses of nondialyzable coccidioidin (Smith's lot 64 D4). The C-ASWS fractions isolated from three different C. immitis strains showed similar reactivity in terms of the number of positive reactions produced in Coccidioides-sensitized guinea pigs. However, the induration responses (diameter in millimeters) elicited by the C-ASWS fraction of one strain were significantly less than those elicited by the C-ASWS fractions of the other two C. immitis strains.
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000946:Antigens, Fungal / Q000302:isolation & purification; D002462:Cell Membrane / Q000276:immunology; D005591:Chemical Fractionation; D003045:Coccidioides / Q000276:immunology*; D003046:Coccidioidin / Q000008:administration & dosage; D006168:Guinea Pigs; D006658:Histoplasma / Q000276:immunology; D006659:Histoplasmin / Q000008:administration & dosage; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007271:Injections, Intradermal; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D012882:Skin Tests
chemical_list: D000946:Antigens, Fungal; D003046:Coccidioidin; D006659:Histoplasmin