Hung CY, Yu JJ, Cole GT; American Society for Microbiology. General Meeting.
Abstr Gen Meet Am Soc Microbiol. 1999 May 30-Jun 3; 99: 312 (abstract no. F-83).
Med. Coll. of Ohio, Toledo.
Study of cell wall antigens of Coccidioides immitis which elicit cellular and humoral immune responses is relevant to our understanding of pathogenesis, mechanisms of host resistance to infection, and identification of antigens which are possible vaccine candidates. We previously puri- fied an immunodominant spherule outer wall glycoprotein (SOWgp) which stimulates both human cellular and humoral immune respones. The genes that encode SOWgps of three different isolates of C. immitis have been cloned. Analysis of their DNA sequences has revealed that sow genes of C735, C634, and Silveira contain 6, 5, and 4 copies of a 47-amino acid tandem repeat flanked by conserved N-terminal and C- terminal nonrepeat regions. Each repeat has a SPPPPP motif which has also been identified in cell wall proteins of plants. The sow of each isolate is a single copy gene, based on Southern hybridization. An examination of the levels of expression of sow in the saprobic phase and during first and second generation of the parasitic cycle was conducted by Northern blot analysis. The sow gene is up-regulated during the spherule isotropic growth phase, and down-regulated during the segmentation and endosporulation stages. Parallel studies of the amount of SOWgp produced by these same cell preparations were conducted by quantitative Western blot analyses. The amount of SOWgp constitutes 2% of the total protein of young spherules and 8% of that of mature spherules. The results of these studies indicated that SOWgp is a parasitic phase-specific antigen. Two of the sow genes (C735 and Silveira) were expressed by Escherichia coli and the recombinant proteins (rSOWs) have been purified. All sera (n=20) from patients with coccidioidomycosis which were tested in immunoblots and ELISAs recognized the recombinant antigens. No reactivity with the recombinant proteins was detected with sera from patients with histoplasmosis or blastomycosis. The rSOW is considered a potential diagnostic reagent, and a candidate antigen for a vaccine against coccidioidomycosis. The recombinant antigen is currently under evaluation for its ability to immunoprotect BALB/c mice against coccidioidal infection.
Publication Types:
Keywords:
- Animals
- Antigens
- Antigens, Fungal
- Antigens, Surface
- Base Sequence
- Blotting, Northern
- Cell Wall
- Coccidioides
- Coccidioidomycosis
- Enzyme-Linked Immunosorbent Assay
- Gene Expression
- Glycoproteins
- Humans
- Mice
- Mice, Inbred BALB C
- Recombinant Proteins
- genetics
- immunology
Other ID:
UI: 102195696
From Meeting Abstracts