Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunological cross-reactivity among nematodes has hampered the development of specific serodiagnostic assays for onchocerciasis. In the present study, an Onchocerca volvulus adult worm complementary DNA expression library was differentially screened with human sera from patients infected with O. volvulus and with an omnibus anti-nematode serum pool comprised of sera from patients infected with Brugia malayi, Loa loa, Wuchereria bancrofti, Mansonella perstans, Strongyloides stercoralis, Ancylostoma duodenale, Ascaris lumbricoides, and Dracunculus medinensis. Seven Onchocerca-specific clones were identified and screened with individual onchocerciasis patient sera. Additional studies were performed to characterize the most immunoreactive clones, OC 3.6 and OC 9.3. OC 3.6 produced a 152-kD beta-galactosidase fusion protein that was recognized in dot-immunoblots by 54 of 55 sera from onchocerciasis patients (98%). The OC 3.6 DNA insert is 996 bp long with an open reading frame of 627 bp and a 369-bp untranslated 3' end. OC 3.6 is closely related to a previously reported clone (OV 33-3), but it differs from that clone at both the 5' and 3' ends. OC 9.3 contained a novel 565-bp insert and produced a 138-kD fusion protein that was recognized by 46 of 55 sera from onchocerciasis patients (83%). Additional studies are in progress to develop and evaluate immunodiagnostic tests for onchocerciasis based on measurement of antibodies to these promising recombinant antigens.
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PMID:Molecular cloning and characterization of recombinant parasite antigens for immunodiagnosis of onchocerciasis. 184 Jun 5

Specific, serological diagnosis is one of the main goals in onchocerciasis research. To date this objective has been hampered by (a) scarcity of parasite material, and (b) antigenic cross-reaction between Onchocerca volvulus and other nematode species. In order to obtain specific antigens, and in amounts suitable for study, molecular biological techniques have been adopted. A lambda gt11 cDNA expression library prepared from O. volvulus adult female worms was screened using infected human sera from onchocerciasis patients and rabbit hyperimmune sera raised against Onchocerca and genus-specific Onchocerca antigen extracts. Five clones were selected and their inserts expressed as beta-galactosidase fusion proteins. The fusion proteins were examined using individual sera from patients with O. volvulus or Wuchereria bancrofti infections. Three of the fusion proteins were recognised by more than 80% of O. volvulus sera and exhibited weak reactivity with a few W. bancrofti sera. One of these three clones was recognised to a significantly greater degree by sera from sowda than from generalised onchocerciasis patients.
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PMID:Cloning of specific diagnostic antigens of Onchocerca volvulus. 225 40

A cDNA expression library constructed from RNA derived from adult stage Brugia pahangi (mixed sexes) was screened with pooled sera from chronic, amicrofilaremic cases of human lymphatic filariasis from the Indonesian island of Tanjungpinang, where Brugia malayi is endemic. Polyclonal antisera raised to purified beta-galactosidase fusion proteins from two of the most highly reactive clones identified a protein of Mr 70,000 in all stages examined (microfilariae, L3 and adults) of both B. malayi and Brugia pahangi. Derivation of the amino acid sequence from these two overlapping cDNAs identified the encoded protein as a member of the heat shock protein 70 family, and showed the closest similarity to the constitutively expressed "heat shock cognate 70" (hsc70) protein. Hybridization of hsc70 cDNAs to RNA and DNA from B. pahangi under stringent conditions identified a major transcript of 2.4 kb and revealed the existence of a family of related genes. In vitro culture of larval stages of B. pahangi at elevated temperatures (43 degrees C) resulted in increased expression of hsc70, and a classic heat shock response in which five proteins (mr 18,500, 22,000, 62,000, 70,000, and 85,000) were exclusively synthesized in microfilariae. Analysis of cross-reactivities by Western blotting implied that antibody generated by infection with B. malayi was directed at filarial-specific determinants of Brugia hsc70. However, ELISA with recombinant fusion proteins for both Plasmodium falciparum and Schistosoma mansoni hsc70 indicated that some individuals with Brugian or Bancroftian filariasis did produce antibodies which cross-reacted with plasmodial and schistosomal homologs. Thus filarial-specific antibody responses were not generated in all individuals, indicating that this molecule would not be suitable for diagnostic purposes. ELISA with a purified beta-galactosidase fusion protein from B. pahangi showed antibody responses to hsc70 across the clinical spectrum of filariasis. Alignment of the derived amino acid sequences from B. pahangi, P. falciparum, S. mansoni and rat hsc70 homologs, and comparison of the immunologic reactivity of the products of the two cDNA clones by Western blotting and ELISA suggested that these determinants were located primarily at the C terminus of the protein.
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PMID:Heat shock cognate 70 is a prominent immunogen in Brugian filariasis. 265 68