Host-parasite interactions : cloning and characterization of antigens shared between Schistosoma mansoni and its intermediate host, Biomphalaria glabrata /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1993.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | Rabbit antisera, raised against whole, homogenized hepatopancreas from uninfected Biomphalaria glabrata, were used to screen a cDNA library prepared from adult Schistosoma mansoni. Immunoreactive clones fell into three categories: clones identical to SMTM, tropomyosin homologous clones, and myosin homologous clones. The myosin-like clone, pSM20, was used to rescreen the schistosome cDNA library generating several overlapping clones which yielded a 6,986 bp myosin cDNA. The tropomyosin-like clone, pSM4, was used to rescreen the schistosome cDNA library yielding a 1,381 bp cDNA (SmTMII), which encoded a 284 amino acid peptide 65.8% identical to SMTM. Procaryotic expression of SmTMII resulted in a 45 kDa fusion protein immunoreactive with an antiserum specific for SMTM and antisera from mice with chronic schistosomiasis mansoni. Northern analysis showed the adult stage SmTMII mRNA to be 1.6 Kb in size. Southern analysis of the SmTMII gene revealed complex hybridization patterns suggesting the presence of introns or multiple gene copies. The SmTMII cDNA was used to screen a S. glabrata cDNA library resulting in the isolation of four clones (BgTMIIa, BgTMIIb, BgTM4, and BgTM13). BgTM4 was identical with the previously described snail tropomyosin cDNA, Bg39. Clones BgTMIIa and BgTMIIb differed from each other only in the polyadenylation signal used and each encoded an identical 284 amino acid peptide having 94.7% identity with Bg39. The partial BgTM13 cDNA appeared to be homologous to cytoplasmic tropomyosins from other species. The BgTMII peptide had higher amino acid identity with SMTM (68.3%) than with Bg39 (65.1%), and higher identity with SMTM than the two schistosome tropomyosins had with each other (65.8%). Three of four monoclonal antibodies (mAb) directed against SMTM (1F10, 1C1, and 1G6) demonstrated crossreactivity with SmTMII. Two mAb (1F10 and 1C1) crossreacted with B. glabrata antigens from the foot/body but not the hepatopancreas. Epitope mapping located the 1F10 epitope between amino acids 135 and 188, common to all the snail tropomyosin isoforms, and the 1C1 epitope between amino acids 189-213 of BgTMII only. The 1F10 epitope was shared among a variety of invertebrate organisms. On the other hand, mAb 1C1 crossreactivity was limited to the trematodes and pulmonate snails. |
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| Item Description: | Vita. "Major subject: Microbiology." |
| Physical Description: | xii, 119 leaves : illustrations, maps ; 28 cm |
| Bibliography: | Includes bibliographical references. |