ABSTRACT
Cultivation conditions for recombinant Escherichia coli strain KPR-42 producing human gamma-interferon in liquid nutrient medium were optimized. Glucose content in the medium was optimized by the reason that glucose catabolism products cause the medium acidification. That permitted to prolong fermentation time and increase recombinant protein content in the cells by 23-25%, avoiding expendable enrichment of the medium by nutrient components.
Subject(s)
Biotechnology/methods , Escherichia coli/growth & development , Interferon-gamma/biosynthesis , Culture Media , Escherichia coli/genetics , Escherichia coli/metabolism , Humans , Recombinant ProteinsABSTRACT
Enzyme immunoassay (EIA) using recombinant antigens for the detection of Treponema pallidum-specific antibodies in sera of syphilis patients was developed. Four low-molar-mass Treponema antigens (Tp15, Tp17, TmpA, Tp47) were investigated; 17- and 47-kDa proteins were demonstrated as immunodominant as they permitted to obtain the most sensitive EIA. Using a mixture of these proteins a 3rd-generation-EIA kit Dia-Syph was constructed, its sensitivity being 99.4% during tests of 165 sera of syphilitic patients. No false result was obtained on the commercial panel PSS01 (BBI, USA). The specificity of the elaborated test system (99.7%) was determined on 295 sera.
Subject(s)
Antibodies, Bacterial/blood , Antigens, Bacterial/immunology , Enzyme-Linked Immunosorbent Assay , Syphilis Serodiagnosis , Treponema pallidum/immunology , Antigens, Bacterial/genetics , Antigens, Bacterial/isolation & purification , Humans , Recombinant Proteins/immunology , Recombinant Proteins/isolation & purification , Sensitivity and Specificity , Treponema pallidum/genetics , Treponema pallidum/metabolismABSTRACT
The human colostrum stimulated by suboptimal doses (50 ng/ml) of lipopolysaccharide (LPS) has induced proliferation of mouse splenocytes. Addition of the human colostrum has elicited a rise in splenocyte culture supernatants. Effect of human colostrum on Ig synthesis was dose-dependent and was expressed at 0.5% concentrations in the medium. In contrast to the human colostrum, the bovine colostrum exerted a suppressive effect on proliferation of mouse splenocytes and Ig synthesis induced by suboptimal doses of LPS. Bovine casein did not significantly affect the Ig synthesis by mouse splenocytes. Suppression of the Ig synthesis was associated with bovine colostral globulins. Using the ELISPOT method we have found that a rise in the Ig level in the culture after treatment with the human colostrum was due to an increase of the number of IgG2a-secreting cells. B-cell promoting fraction was found after HPLC gel-filtration. The molecular weight of this fraction was 70-75 kD.
