Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Individual human Ig class responses to Onchocerca volvulus antigens have been evaluated by Western blotting using sera from cases of generalized onchocerciasis and chronic hyper-reactive onchocerciasis (Sowda). in all cases except IgG3 the patterns of recognition by human antibody classes were similar in Sowda and generalized onchocerciasis. Weak or undetectable responses were seen with IgG1, IgG2 and IgM. The total profiles of antigens recognized by the other Ig classes were different, although in some cases certain bands were commonly identified. The result with IgG3, however, was striking. Here, two major antigens (9 kD and 72kD) were recognized by IgG3 antibodies in Sowda sera but not generalized onchocerciasis sera. Furthermore, these two antigens were not recognised by any other Ig class, either in generalized or Sowda onchocerciasis, nor were they detected by antibodies of any class present in a collection of sera representative of other nematode infections. This difference in the IgG3 response was so pronounced that Sowda sera could be distinguished from generalized onchocerciasis sera by an IgG3-specific ELISA assay with a PBS parasite extract as the antigen. Thus, a correlation has been established between one particular clinical condition of onchocerciasis (Sowda) and a serological response, defined in terms of both the parasite antigens and an immunoglobulin class restricted antibody response.
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PMID:Unique recognition of a low molecular weight Onchocerca volvulus antigen by IgG3 antibodies in chronic hyper-reactive oncho-dermatitis (Sowda). 322 41

A cDNA from adult female Onchocerca volvulus encoding the C-terminal portion of a tropomyosin isoform (termed MOv-14) has been shown previously to confer protective immunity in rodent models of onchocerciasis. The full-length sequence (designated Ov-tmy-1) obtained by PCR amplification, codes for a protein of 33 kDa and shares 91% identity with tropomyosins from other nematodes, falling to 57% identity with human alpha-tropomyosin. Ov-TMY-1 migrates with an apparent molecular mass of 42 kDa on SDS/PAGE and is present in all life-cycle stages, as determined by immunoblotting. Immunogold electron microscopy identified antigenic sites within muscle blocks and the cuticle of microfilariae and infective larvae. Anti-MOv14 antibodies were abundant in mice exhibiting serum-transferable protection against microfilariae conferred by vaccination with a PBS-soluble parasite extract. In contrast, little or no MOv14-specific antibody was present in mice inoculated with live microfilariae, in which resistance is mediated by antibody-independent mechanisms. In human infections, there was an inverse correlation between anti-tropomyosin IgG levels and densities of microfilariae in the skin. Seropositivity varied with the relative endemicity of infection. An immunodominant B cell epitope within Ov-TMY-1 (AQLLAEEADRKYD) was mapped to the N terminus of the MOv14 protein by using sera from protectively vaccinated mice. Intriguingly, the sequence coincides with an IgE-binding epitope within shrimp tropomyosin, believed to be responsible for hypersensitivity in individuals exhibiting allergy to shellfish. IgG and IgE antibodies reacting with the O. volvulus epitope were detected in human infections. It is concluded that antibody responses to tropomyosin may be important in limiting microfilarial densities in a proportion of individuals with onchocerciasis and have the potential to mediate hypersensitivity reactions to dead microfilariae, raising the possibility of a link with the immunopathology of infection.
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PMID:Tropomyosin implicated in host protective responses to microfilariae in onchocerciasis. 963 87