[Isolation and comparative study of highly reproductive recombinant influenza A viruses with a high antibody sensitivity]. / Poluchenie i sravnitel'noe izuchenie vysokoreproduktivnykh rekombinantov virusa grippa A s vysokoi chuvstvitel'nost'iu k antitelam.

The possibility of generating avid and highly reproductive recombinants of influenza A virus (H3N2, H3N1) using strain A/PR/8/34 (H1N1) as a donor of high reproductive activity was demonstrated. In the process of recombination, the transmission of the gene responsible for synthesis of avid hemagglutinin H3 from one virus variant to another provides for high avidity of recombinants. However, a possible influence of other influenza A virus genes on the manifestation of avidity cannot be ruled out.

[The heterogeneity of an influenza virus A population in its capacity to induce the synthesis of avid antibodies]. / Geterogennost' populiatsii virusa grippa A po sposobnosti indutsirovat' sintez avidnykh antitel.

Influenza A virus variants were found to be capable of inducing synthesis of avid antibodies when different species and lines of animals were immunized. CBA mice were the most convenient model permitting differentiation of "avidogenic" from "nonavidogenic" virus variants with a high degree of certainty. Recombinants may differ from parental viruses in their capacity to induce synthesis of avid antibody; with this, the transmission of only one gene (HA) from the "avidogenic" parent into the system of genes of A/PR/8/34 st in ensured a high "avidogenicity" of the recombinant. The "avidogenic" virus variants had a more marked protective effect than "nonavidogenic" ones.

[Study of influenza virus hemagglutinin H3 avidity using monoclonal antibodies]. / Izuchenie avidnosti gemaggliutinina H3 virusa grippa s pomoshch'iu monoklonal'nykh antitel.

The results of a comparative study of the features of antigenic determinants of avid and non-avid variants of influenza virus hemagglutinin H3 and of the influence of the mode of antigen presentation on the degree of its avidity are presented. The avidity of influenza virus hemagglutinin was shown to be determined by the capacity of individual antigenic determinants to interaction with antibodies. The antigenic determinants of avid hemagglutinin possessing a high functional activity in interaction with antibodies may have the spatial configuration which does not change in different modes of the antigen presentation. Isolation of hemagglutinin from virions of non-avid virus variants may lead to increased functional activity of individual antigenic determinants (and the antigen molecule as a whole) probably due to an increased degree of exposure and/or complementarity of the determinants for active centres of antibody.

[Structural characteristics of a population of antigenic variants of the influenza A(H3N2) virus]. / Osobennosti struktury populiatsii antigennykh variantov virusa grippa A(H3N2).

The data have been obtained indicating that clone distribution by the antigen avidity in the population of influenza A (H3N2) virus corresponds to normal distribution. The degree of avidity of individual strains is determined by the predominant content of clones with high or low avidity. Virus purification by ultracentrifugation in sucrose density gradient results in increasing the avidity of the preparation as compared with the original allantoic cultures. Defective virions may differ in avidity from intact viral particles of the same strain and in this way affect the "total" avidity of a virus preparation.