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)

Recombinant Onchocerca volvulus Ag have been derived from expression libraries and examined for their ability to stimulate PBMC from patients infected with O. volvulus. Ten clones producing recombinant Ag were selected and plaque purified; lysogens were produced and found to express beta-galactosidase fusion proteins ranging in molecular mass from 115 to 138 kDa. When ammonium sulfate-precipitated lysates of these recombinant phage clones were examined for their ability to stimulate PBMC from a patient with onchocerciasis, all 10 recombinants produced stimulation above that to nonrecombinant phage. When individual fusion proteins, affinity purified on anti-beta-galactosidase linked to agarose, were used to stimulate PBMC from patients with onchocerciasis, only one of the recombinant Ag induced PBMC proliferation (stimulation index greater than 4) above that to Ag from nonrecombinant phage. Characterization of the DNA coding for this Ag showed it to be 1.2 kb in length with a small (90 bp) open reading frame; furthermore, it appears to be Onchocerca specific (on genomic dot blots) and single copy. Using overlapping peptides encompassing the entire open reading frame, one T cell epitope has been localized.
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PMID:The identification of an Onchocerca-specific recombinant antigen containing a T cell epitope. 169 1

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 Taenia crassiceps metacestode cDNA expression library in lambda gt 11 was screened with rabbit antisera to metacestodal T. solium and T. saginata crude extract. Primary clones (121) were identified, and after rescreening and lysogenization in Escherichia coli Y 1089, were tested in Western blot for reactivity with the same antisera. In addition, analyses were performed with rabbit antisera directed towards T. crassiceps and Echinococcus granulosus metacestode crude extract, sera from humans with neurocysticercosis (Mexico) and other important helminth diseases, mice and calves with experimental T. crassiceps and T. saginata infections and normal sera. Of those tested, 22 clones expressing beta-galactosidase fusion proteins (approximately 118-132 kDa) were reactive with IgG antibodies of cysticercotic patients and T. crassiceps infected mice. Of these clones, 11 were also sero-positive with calf-IgG antibodies against T. saginata larvae. None of the 22 clones reacted with IgG antibodies due to human cystic and alveolar echinococcosis, intestinal/hepatic or urinary schistosomiasis, African onchocerciasis or with sera from uninfected controls (man, rabbit, calf and mouse). Of these 22 clones, 15 have been subcloned into the plasmid vectors pGEX-2T (modified) and pT7T3 alpha 19. Expressed glutathione-S-transferase fusion proteins were again tested for sensitivity and specificity by Western blot, and concentrated by affinity chromatography. The nucleotide sequence of the cDNA inserts of 9 clones has been determined in pT7T3 alpha 19 and revealed identity in 4 and 5 clones, respectively.
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PMID:Preparation and sequence analysis of Taenia crassiceps metacestode recombinant antigens with potential for specific immunodiagnosis of human cerebral cysticercosis. 771 96