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

A genetically engineered Eimeria tenella antigen (GX3262), produced as a fusion protein with beta-galactosidase and identified with a monoclonal antibody, induced partial but significant protection in young broiler chickens against experimental E. tenella and Eimeria acervulina infections. The antigen appears to share a T-helper cell epitope with the parasite as evidenced by (a) booster inoculation with either the recombinant antigen or with a small number of live oocysts enhanced the protective immunity in GX3262 primed chickens, and (b) ability of the antigen to induce in vitro stimulation of T-cells from chickens immunized with antigen or parasite. These observations suggest the feasibility of a single vaccination of 1 or 2-day-old broilers with GX3262 to induce an acceptable degree of protective immunity. The implications of the observations reported here are far reaching in terms of a practical coccidiosis vaccine for poultry, and show for the first time that 1-day-old broiler chickens can be efficiently vaccinated with a recombinant antigen against one or more species of Eimeria.
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PMID:Potential of a recombinant antigen as a prophylactic vaccine for day-old broiler chickens against Eimeria acervulina and Eimeria tenella infections. 158 58

In the small intestine mucosa of 24 gnotobiotic farrows experimentally infected with the oocysts of coccidiosis of Isospora suis (infection administration--100,000 oocysts) on the first day after the delivery, we carried out the microdensitometric evaluation of the activity of beta-D-glucosidase (phlorizin-hydrolase; hetero-beta-galactosidase; lactase-beta-glucosidase complex; EC. 3.2.1.21). Great attention was paid to the topochemistry of enzyme, deposited in a microvillous zone of enterocytes. We studied likewise the activity of beta-D-glucosidase in the striped fringe of enterocytes of the four control gnotobiotic farrows, in the age from 2 to 5 days. We found out that in healthy farrows the reaction product of studied disaccharidase is located in high concentrations in the microvillous zone of absorptive cells of the whole small intestine. We proved a topographic gradient at which the beta-D-glucosidase activity decreases in control farrows the duodenum mucosa in the aboral direction. When using the choice substrate for beta-D-glucosidase (5-Br-4-Cl-beta-indolyl-3-D-glucoside) we did not prove the enzyme deposition in the small intestine wall. The negative enteral effect of coccidiosis I. suis was provable in the farrows experimentally infected already on the first day after the infection (DPI) when the beta-D-glucosidase activity decreased within the whole small intestine by 15% (ileum) and even by 23% (middle jejunum). The activity reduction had been deepening since the first after the infection and it reached its maximum on the 9th day after the infection when the enzyme concentration in the microvillous zone of absorptive cells reached only 11% of the activity level found in control farrows. On the 10th and 11th day after the infection we registered the increase of the density of beta-D-glucosidase reaction product, however the microvillous zone was even in that final stage of experimental infection significantly deficient (31% of intestine mucosa activity of control farrows).
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PMID:[beta-D-glucosidase in the microvillous zone of small intestine enterocytes in experimental coccidiosis in suckling piglets]. 177 25

A fusion protein of beta-galactosidase and Eimeria tenella produced in a recombinant Escherichia coli strain was injected into chickens and elicited partial protection against an oral challenge with Eim. tenella parasites. The fusion protein contained a 31 kilodalton (kD) coccidial antigen designated as 5401. The DNA sequencing of the 5401 antigen-coding sequence revealed that this protein segment was highly negatively charged and strongly hydrophilic, and contained an amino-acid sequence repeated five times. A dose-titration study showed that immunizing chickens with a single subcutaneous injection of the 5401 antigen at 1,200 to 4,800 nanograms (ng)/bird in Freund's complete adjuvant decreased lesion scores, mortality, and feed conversions compared to unimmunized, challenged controls. Using the 1,200 and 2,400 ng/bird of the 5401 antigen, group weight gains were higher than for the unimmunized, challenged birds. In three other trials using the 5401 antigen at 2,400 ng/bird with light, medium, and heavy coccidial infections, significant protection was evidenced by reduced lesion scores, increased individual weight gains, or both. In addition, feed conversions were reduced when compared with unimmunized controls or birds immunized with a noncoccidial protein E. coli extract. Western blot analysis of sporozoite preparations with serum from 5401-immunized birds labeled two antigenic bands of 66 and less than 200 kD. These results indicate that the coccidial proteins produced in E. coli are potentially effective immunogens for protecting chickens against avian coccidiosis.
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PMID:Genetically engineered antigen confers partial protection against avian coccidial parasites. 262 19

Eimeria are the causative agents of coccidosis, a disease which is of world wide economic importance in the poultry industry. Immunity resulting from infection is species-specific and both antibody and cell-mediated responses have been implicated. As an initial step in the development of a genetically-engineered vaccine against coccidiosis, libraries of EcoRI-digested genomic DNA from E. tenella have been constructed in Escherichia coli using the expression vector lambda amp3. Screening of the libraries with serum from chickens immunized by infection has identified at least 24 different recombinant phage which produce eimeria antigens fused to beta-galactosidase. A significant proportion of the Eimeria DNA inserts cross-hybridise with each other and contain sequences which are highly represented in the genome. The identification of these clones will enable the isolation of intact genes from E. tenella DNA and facilitate detailed analysis of the antigens and immune responses.
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PMID:Isolation of lambda amp3 genomic recombinants coding for antigens of Eimeria tenella. 294 50