[The antigenic structure of influenza B viruses isolated in 1991]. / Antigennaia struktura virusov grippa B, vydelennykh v 1991 g.

A comparative immunological analysis of the antigenic structure of reference influenza B viruses of 1940-1984 and isolates of 1986-1991 using monospecific antibodies to individual antigenic determinants and monoclonal antibodies to hemagglutinin of B/Oregon/5/80 virus demonstrated a further antigenic drift of influenza B viruses from the reference variants B/Victoria/2/87 and B/Yamagata/16/88. Alongside with circulation of viruses with new antigenic properties, variants were found in the epidemic outbreak of 1991 whose hemagglutinin had common antigenic markers with those of variants of the previous years.

[An analysis of the antigenic structure of the hemagglutinins from different strains of the influenza B virus by using monoclonal antibodies]. / Analiz antigennoi struktury gemaggliutininov razlichnykh shtammov virusa B s pomoshch'iu monoklonal'nykh antitel.

A comparative immunological analysis of the antigenic composition of hemagglutinin (HA) of influenza B virus drift-variants isolated during 46 years was carried out using monoclonal antibodies (MAb) to HA of B/Oregon 5/80 virus in HI test and solid-phase enzyme immunoassay. The presence of type- and group-specific antigenic determinants was demonstrated which agreed with our previous data obtained in studies with polyvalent sera. However, using Mab three more group-specific determinants were detected which characterize HA of influenza B viruses isolated in 1970-1979, 1970-1984, and 1970-1986.

[Antigenic-genetic connections between human and animal influenza viruses]. / Antigenno-geneticheskie sviazi virusov grippa cheloveka i zhivotnykh.

A comparative immunological analysis of the composition of antigenic determinants (AGD) in hemagglutinins of human influenza A virus (HIAV) of the serosubtypes H1, H2, H3, and in hemagglutinins of animal influenza viruses (AIV) of the serosubtypes H1, H3-H6, H8-H11 with 25 polyclonal highly active sera was demonstrated. Using original monospecific mon AGD in HIAV and AIV hemagglutinins was demonstrated. Using original monospecific antibodies to individual AGD, those AGD contributing to similarity and differences between HIAV and AIV were determined. It was found that influenza A. virus strains isolated from man in the USSR in 1986 were identical in the antigenic structure of hemagglutinin with that isolated from a tern in 1973 (A/tern/Turkmenistan/18/73).

[Immunologic analysis of the antigenic properties of neuraminidase from drift-variants of influenza virus B]. / Immunologicheskii analiz antigennykh svoistv neiraminidazy dreif-variantov virusa grippa B.

The antigenic features of neuraminidases of several drift variants of influenza B virus were studied by enzyme immunoassay using antiserum to influenza B/USSR/100/83 virus neuraminidase isolated by pronase. Studies using immunosorption and competitive solid-phase enzyme immunoassay showed the presence in the antineuraminidase serum of at least two antibody subpopulations capable to inhibiting the activity of the enzyme and interacting with neuraminidase antigenic determinants: one detecting the antigenic determinant common for B/100/83 and B/Lee/40 viruses, and the other characterizing the antigenic determinant inherent in neuraminidase of B/100/83 virus and enzymes of drift variants isolated in 1970-1986 and lacking in the enzyme of B/Lee/40 virus.

[Identification of the antigenic components of the host cell in isolated glycoproteins of the influenza virus]. / Identifikatsiia antigennykh komponentov kletki khoziaina v izolirovannykh glikoproteidakh virusa grippa.

Immunological analysis performed by solid-phase enzyme immunoassay and complement fixation test revealed the presence of host cell antigenic components in purified intact influenza virions and isolated hemagglutinins and glycoproteins. Three antigens inherent to chick embryo cells were identified in virus preparations: the species-specific antigen, heterogenetic Forssman antigen, and one similar to human group A antigen. Antisera to purified whole-virion influenza vaccines, to glycoproteins and to hemagglutinin isolated from them were found to contain antibody populations which were conducive to broad cross reactions between them and heterotypic virus antigens. To avoid erroneous results, these antibody populations must be removed from the sera by pre-adsorption with host cell antigens.

[Detection and identification of host cell antigens in the composition of influenza B virus]. / Vyiavlenie i identifikatsiia antigenov kletki khoziaina v sostave virusa grippa B.

Two heterogeneous antigens, Forssman antigen and an antigen similar to human group A antigen, were detected by enzyme-immunoassay in cells of normal chick embryo CAMN and MDCK culture (dog kidney). Both these antigens were associated with purified influenza B virus preparations reproduced in these cultures since the variants under study actively reacted with antibodies both to Forssman antigen and to human A antigen. Serological differences between the variants grown in different cell systems were due to the presence in their composition of the species-specific cell component typical either of chick embryo tissues or MDCK cultures, since the viruses of chicken origin contained the specific cell antigen CAMN, whereas the same viruses grown in MDCK did not contain it but had the specific activity for dog kidney cells. The virus-specific activity of the variants under study showed no significant differences in relation to host cells.

[Use of monospecific antibodies for determining the antigenic determinant composition in the hemagglutinins of the H3N2 influenza viruses of 1979-1983]. / Ispol'zovanie monospetsificheskikh antitel dlia opredeleniia sostava antigennykh determinant v gemaggliutininakh virusov grippa H3N2 1979-1983 gg.

The study of the antigenic composition of hemagglutinins of influenza H3N2 viruses isolated during epidemic outbreaks in 1979-1983, carried out by means of monospecific antibodies to individual antigenic determinants, showed heterogeneity of the antigenic structure of epidemically active variants. Some variants were antigenically identical to A/Bangkok/1/79 virus. Hemagglutinin structure of A/Shanghai/31/80, A/Philippines/2/82 and the like was found to contain a qualitatively new antigenic determinant heretofore undetectable in H1N1, H3N2 viruses.

[Antigenic determinants of the hemagglutinins of influenza viruses of the "Spanish era"]. / Antigennye determinanty gemaggliutininov virusov grippa "ispanskoi éry".

Fractions of immunoglobulins G isolated from highly active hyperimmune rabbit sera and inhibitor-free antisera for influenza A viruses of the "Spanish" era different periods (1930-1978) were tested with a wide spectrum of human and animal viruses by the HI and CF tests. In hemagglutinins of Hswl, H0, and H1 viruses common antigens were found dissimilarly expressed in different variants as indicated by both various degrees of serological activity of the viruses and by great differences in the availability of cross-reactive antibody in various sera.

[Hemagglutinin antigenic determinants of influenza viruses H1N1 isolated 1953-1957 in the composition of the hemagglutinins of influenza viruses H1N1 isolated 1978-1979]. / Antigennye determinanty gemaggliutininov virusov grippa H1N1 1953-1957 gg. vydeleniia v sostave gemaggluitininov virusov grippa H1N1 1978-1979 gg. vydeleniia.

Immunological analysis of antigenic determinants in the composition of hemagglutinins (HA) of H1N1 viruses isolated in the epidemic season of 1978-1979 showed their difference from A/USSR/090/77 virus HA. The A/Brazil/11/78 HA is characterized by 3 antigenic determinants two of which are identical with those of A/USSR/090/77 HA and one shows relationship with HA determinant of A/Omachi/1/53 virus, A/Fukushima/103/78 and A/Kagoshima/22/79 HAs are characterized by 1 determinant common with that of A/USSR/090/77 HA and 2 determinants identical with A/Omachi/1/53 virus HA. HAs of these viruses contain a determinant responsible for the antigenic relation of A/Omahi/1/53 HA with that of H1N1 viruses isolated in 1956-1957. The results suggest that the antigenic drift of HA of H1N1 viruses isolated in 1977-1979 occurs by the cycle characteristic of HA of H1N1 viruses isolated in 1950-1957. By the sensitivity to alpha-, beta-, and gamma-inhibitory of rabbit serum H1N1 viruses isolated in 1947-1957 and in 1977-1979 are quite similar with the exception of A/USSR/184/79 virus showing high sensitivity to gamma-inhibitors like H2N2 and H2N2 viruses.

[Importance of cross-reacting antibodies in creating resistance to influenza]. / Znachenie perekrestno reagiruiushchikh antitel v sozdanii rzistentnosti k grippoznoi infektsii.

Hyperimmune rabbit serum to A/PR8/34 virus was analysed by selective adsorption of antibody by viruses belonging to hemagglutinin subtypes H0, H1 and Hsw1. The presence of three antigenic determinants was demonstrated in viral HA: one was common for HA of H0, H1, and Hsw1 viruses, the other was common for HA of H0, H1 and Hsw1 viruses, and the third was strain-specific for this virus. The protective effect of formalin-inactivated influenza vaccines prepared from virus variants with H0 and H1 hemagglutinins against challenge with A/PR8/34 virus was studied. The presence in the vaccine influenza virus of at least one antigenic determinant common with that of the challenge virus was shown to create a certain degree of protection in mice against influenza. The presence of two antigenic determinants in HA of vaccine and challenge virus increased considerably the protective effect of the vaccine.

[Isolation of strain-specific and cross-reacting antibodies to influenza virus hemagglutinins from heterogenous populations of hyperimmune influenza sera]. / Vydelenie shtammospetsificheskikh i perekrestno reagiruiushchikh antitel k gemaggliutininam virusov grippa iz geterogennykh populiatsii protivogrippoznykh giperimmunnykh syvorotok.

A population of monoreceptor cross-reacting antibodies to a common antigenic determinant H1.1 present on the surface of hemagglutinin molecules of H0, H1 and Hsw1 subtypes has been isolated from a heterogenous population of antihemagglutinating antibodies of influenza hyperimmune sera. Selective adsorption yields highly active strain-specific sera to HA of A/FM/1/47 and A/Netherlands/36/56 viruses. Populations of strain-specific antibodies to HA of A/Moscow/Pan/52 and A/USSR/090/77 viruses were found to be identical, attesting to the complete similarity of the antigenic composition of HA of these viruses. The hyperimmune serum of A/Brazil/11/78 virus was found to contain a population of strain-specific antibodies different from HA of other H1N1 viruses studied. This shows that drift variants of A/USSR/090/77 virus appeared in 1978.

[General antigenic determinants in the hemagglutinin composition of influenza viruses H0, H1 and Hsw1]. / Obshchie antigennye determinanty v sostave gemaggliutininov virusov grippa H0, H1 i Hsw1.

The antigenic properties of influenza type A viruses with hemagglutinin subtypes H0, H1, and Hsw1 were studied by hemagglutination-inhibition test, indirect solid-phase radioimmunoassay and biological neutralization test using highly potent hyperimmune rabbit sera. The results obtained indicate the presence of common antigenic determinants in hemagglutinins of H0, H1 and Hsw1 viruses.

[Influenza virus neuraminidase and its role in anti-influenzal immunity]. / Neiraminidaza virusa grippa i ee rol' v protivogrippoznom immunitete.

The direct relationship between immunogenicity of H3N2 formolvaccine and neuraminidase activity was established. A single intranasal immunization of mice with the vaccine having a titer of hemagglutinin 1:20,000-1:40,000 in 0.5 ml with active neuraminidase increased the resistance of the animals to the challenge with mouse-adapted influenza A/USSR/053/74 (H3N2) virus almost 5-fold. A vaccine with the same hemagglutinin titer but with neuraminidase inactivated by physico-chemical factors or blocked by specific antibody exerted a protective effect 2.5-3 fold weaker than the vaccine with the active enzyme.

[Antigenic determinants in the composition of the hemagglutinins of the influenza virus H1N1 isolated in 1977 and of the H1N1 viruses isolated in 1947--1956]. / Antigennye determinanty v sostave gemaggliutininov virusa grippa H1N1, vydelennogo v 1977 g., i virusov H1N1, izolirovannykh v 1947--1956 gg.

A comparative analysis of hemagglutinins (HA) of the A/USSR/090/77 (H1N1) virus isolated in 1977 and A/FM/47, A/Leningrad/49, A/Pan/52, and A/Netherlands/56 viruses with the antigenic formula (H1N1) was done. By the method of cross adsorption of rabbit influenza antisera, HA of the viruses under study were found to contain three antigenic determinants: one is common for all the variants studied, another characterizes the relationships of individual variants isolated in different years, and the third is strain-specific, determining the antigenic differences between the variants. According to our results, the influenza A/USSR/090/77 (H1N1) virus has in its HA three antigenic determinants closely related or identical to those of HA of a/leningrad/49 and A/Pan/52 viruses.

[Changes in antigenic determinant H3 in type A influenza virus]. / Ob izmenenii antigennoi determinanty H3 u virusa grippa tipa A.

The analysis of immune and hyperimmune rabbit sera to influenza A/USSR/0249/75. A/Victoria/3/75, and A/Tokyo/1/75 viruses showed the H3 antigenic determinant common for hemagglutinins of influenza viruses of the Hong Kong variety to be poorly manifest in viruses isolated in 1975 in contrast to type A viruses isolated in previous years. Antibody to the H3 antigen is usually absent in immune sera and appears only in hyperimmune sera after reimmunization of the animals. The quantitative decrease of the H3 antigen in viruses isolated in 1975 was also clearly detected in tests of adsorption of anti-H3 monoreceptor sera.

[Evolution of H3 antigen of influenza viruses isolated during 1968-1976]. / Evoliutsiia antigena H3 iz virusov grippa, vydelennykh v 1968-1976 gg.

Influenza viruses type A isolated in 1968--1976 were found to have changes in the content of the antigenic determinant H3. The experiments showed that while in the viruses isolated in 1968--1972 the H3 antigen was dominating, in the A/Port Chalmers/1/73 virus and some viruses isolated in 1975--1976 this antigen became more and more minor. A correlation was observed between the content of H3 antigen in viruses and the capacity of anti-H3 antiserum to inhibit the infectious activity of viruses. The prepared monospecific serum to H3 antigen contained no antibody to the other two antigenic determinants of virus or to neuraminidase and host cell antigen and was completely free from inhibitors. The serum could be used in HI, CFT, and immunodiffusion tests for the analysis of the antigenic composition of newly isolated influenza viruses.

[Comparative analysis of the antigenic composition of the hemagglutinins of influenza viruses A/England/42/72, A/Port Chalmers/73 and A/USSR/053/74]. / Sravnitel'nyi analiz antigennogo sostava gemaggliutininov virusov grippa A/Angliia/42/72. A/Port Chalmers/73 and A/USSR/053/74

The presence of three antigenic determinants was demonstrated by the method of selective adsorption of inhibitor-free sera (HI test) and complement-fixation test (CFT) in hemagglutinins (HA) of influenza A/Port Chalmers/73 and A/USSR/053/74 viruses. These variants with closely similar antigenic composition have two antigenic determinants related with NA of A/England/42/72 virus, whereas the third antigenic determinant is specific only for them and is lacking in A/England/42/72 virus NA. According to the results obtained the antigenic composition of HA of these viruses may be designated in the following way: A/England/42/72--H3 H6 H7, A/Port Chalmers/73 and A/USSR/053/74--H3 H7 H8. A method is suggested for preparation of monospecific serum to the antigenic determinant H3 common to all variants of the Hong Kong variety of influenza virus. This serum is free from nonspecific inhibitors, contains no antibody to the host cell antigens and may be used both in CFT and HI test for rapid identification of new influenza virus isolates.