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Ten hybridomas secreting monoclonal antibodies (Mab) against recombinant HIV-1 and HIV-2 antigens were produced (3 Mab anti-gag protein, 2 anti-env1, and 5 anti-env2). In the immunoblotting assay all the anti-gag Mabs reacted with HIV capsid protein p24, whereas one of them reacted also with p55 protein and with 7 other polypeptides. Another anti-gag Mab cross-reacted with the antigen of subpopulation of human peripheral blood lymphocytes. The third one interacted with the antigen of both HIV-1 and HIV-2. All the 10 Mabs interacted with natural HIV antigens and can be used for identification and differentiation of HIV-1 and HIV-2.

The paper describes the enzyme immunoassay system for detection of human immunodeficiency virus antigens, which is based on the use of rabbit anti-HIV antibodies and monoclonal antibodies to HIV-1 gene proteins gag. The system may be useful in the examination of laboratory and clinical samples to reveal both free and conjugated antigens in the composition of immune complexes. The sensitivity of the assay system under development is 0.5 ng/ml at 100% specificity.

A comparative study of testing methods for polyclonal and monoclonal antibodies to human interferon using direct and reverse neutralization of the antiviral activity of interferon as well as ELISA was carried out. The activity of antibodies in ELISA was dozens of times higher than in neutralization tests. Polyclonal antibodies from the sera of mice immunized with alpha 2 interferon had a higher neutralizing capacity. M-5 monoclonal antibodies in specimens of ascitic fluid induced by inoculation of mice with hybrid cells exhibited an increase in both binding and neutralizing activity as compared with specimens of the culture fluid. Immunoglobulins from the ascitic and culture fluid of nonproductive myeloma cells as well as hybridomas producing monoclonal antibodies of other specificities showed practically no reaction with interferon in any of the tests under study. The screening of monoclonal antibodies intended for research and biotechnological purposes requires a composite analysis in both neutralization and binding tests in order to recover purposefully the hybrid clones producing antibodies with both or one of these properties.

Monoclonal MAK-14-7 antibodies to the surface antigen of Venezuelan equine encephalomyelitis virus and OKA series to vaccinia virus antigens were studied by enzyme-immunoassay (EIA) on the solid phase of the infected Vero, BHK-21, and HeLa cells. The immunoglobulins under study from the culture and ascitic fluids of hybridomas were shown to bind specifically with the appropriate antigens of the infected cells. The activity of monoclonal antibodies to viral antigens in EIA on the solid phase of the infected cells was 10-fold higher than in indirect immunofluorescence test. The method has a number of useful advantages such as the simplicity of preparation of the antigen solid phase, rapidly obtainable results, long-term preservation of ready panels with the specific antigen at room temperature. The high sensitivity of the method makes it effectively useful for screening of hybrid clones producing monoclonal antibodies.

The conditions of immunoenzyme assay have been studied on the solid state phase of infected cells using the model of monoclonal antibodies MAK-14-7 to the virus of Venezuelan equine encephalomyelitis (VVEE) and monoclonal antibodies OKA-1 to vaccine virus in the systems of VNK-21 cells or 4647 cells infected by VVEE, or HeLa cells infected by vaccine virus. The titer of monoclonal antibodies detected grows with the dose of infected cells fixed in the holes of micropanel used for reaction and with the multiplicity of infection. The most intensive and contrasting dyeing of conjugate has been registered when the cells have been fixed with 0.25% glutaraldehyde 24 h after infection. The titers of ascytic preparations of monoclonal antibodies MAK-14-7 and OKA-1 under the optimal conditions of immunoenzyme assay reaction on the solid phase of infected cells present 1 : 10 000 and 1 : 100 000.

The specific activity of diagnostic preparations based on monoclonal IgM MAK-14-7 interacting with the antigens of the Venezuela equine encephalomyelitis virus, monoclonal IgG KAMA-51 interacting with the antigens of the forest spring encephalitis virus and monoclonal IgA OKA and IgM OKA binding to the antigens of the vaccine virus was studied by the enzymatic immunological and immunofluorescent tests. Both the ascitic preparations of the antibodies and the fluorescein isothiocyanate-conjugated reagents such as MAK-FITC, KAMA-FITC and OKA-FITC were characterized by high specificity and activity. The specific sensitivity and activity of the monoclonal immunoglobulins was completely maintained in the mixed and combined preparations.