[Persistence of the genes of epidemic influenza viruses (H1N1) in natural populations]. / Persistentsiia genov épidemicheskikh virusov grippa (H1N1) v prirodnykh populiatsiiakh.

A comparative study of antigenic determinants and genome of the analogues of epidemic H1N1 variants isolated from various animal species and from man in the USSR and Mongolia in 1978--1980 was carried out. The analysis of the antigenic determinants of hemagglutinins of the viruses isolated in this period from man, domestic and wild birds and animals performed with a set of monoclonal antibodies to the epidemic reference A/Brazil/11/78 virus revealed their close similarity in the structure of the antigenic sites. Study of neuraminidase of these viruses with a set of monoclonal antibodies to the A/Denver/1/57 strain showed their relationship with neuraminidase of the viruses isolated in 1957 and revealed its trend for changes in individual antigenic determinants. The analysis of genomes of the viruses isolated in Mongolia from man and animals by the methods of RNA polyacrylamide gel electrophoresis and RNA--RNA hybridization showed them to be close to each other and to differ from the epidemic A/USSR/90/77 strain. At the same time, the Mongolian isolates showed differences in the electrophoretic mobility of the genome fragments coding for hemagglutinin and neuraminidase synthesis.

[Comparative study of the RNA and proteins of antigenically similar human and animal influenza A viruses]. / Sravnitel'noe izuchenie RNK i belkov antigenno skhodnykh virusov grippa A zhivotnykh i cheloveka.

In 1976-1979 in various regions of the USSR influenza viruses were isolated from mammals and birds and found to be antigenically similar with human influenza viruses having hemagglutinin H0, H1, and neuraminidase N1. Comparative studies of electrophoretic mobility in polyacrylamide gel of RNAs and proteins of these viruses and human influenza viruses sharing common antigens with them were carried out. By the mobility in gel of genome fragments, the virus isolated from a squirrel, A/squirrel/Vladivostok/1004/79 (H0N1), was found to be similar to human A/PR/8/34 (H0N1) virus; both viruses had a similar polypeptide composition. In contrast, the virus isolated in 1978 from a turkey, A/turkey/Kiev/292/78 (H1N1), by the mobility in gel of genome fragments including those coding for hemagglutinin and neuraminidase differed significantly from antigenically similar epidemic viruses: A/FM/1/47/ (H1N1) and a virus isolated during an epidemic in the same year, A/USSR/90/77/ (H1N1) despite the similarity with the latter in the polypeptide spectrum. Hemagglutinin of a virus isolated in 1976 from blue whales, A/whale/TO/19/76, was serologically identified as HO, neuraminidase of this virus as Nav2. An analysis of genome fragments of the whale virus showed the gene 4 coding for hemagglutinin to be similar by mobility in gel with the corresponding fragment of human influenza virus A/PR/8/34 (H0N1), and the gene 6 coling for neuraminidase in most influenza A viruses to be similar by mobility in gel with the gene 6 of A/pintail/Primorie/695/76 (H2Nav2) virus. An analysis of proteins of this virus by mobility in gel showed all its proteins, with the exception of one with a molecular weight of about 70,000 daltons, to be similar with those of human A/PR/8/34 (H0N1) virus. The protein with the molecular weight of about 70,000 daltons is assumed to be neuraminidase of the second avian type (Nav2). A similar protein was found in avian viruses A/pintail/Primorie/18/76 (H2Nav2), and A/tern/Turkmenia/18/73 (Hav7 Nav2). The antigenic analysis of these strains using a panel of 6 monoclonal antibody to the A/Brazil/11/76 (H1N1) strain revealed a close similarity in the antigenic structure of hemagglutinin of human influenza virus A/USSR/90/77 (H1N1) which had caused an epidemic outbreak in the USSR in 1977-1978 and A/turkey/Kiev/292/78 (H1N1) virus. Human and animal influenza viruses with hemagglutinin of the HO type did not react with any of the 6 clones under study.

Comparison of influenza viruses isolated from man and from whales.

Four isolates of influenza virus strains from Moscow and Habarovsk that caused outbreaks of influenza in November and December 1977 in several cities of the USSR were studied and their haemagglutinins and neuraminidases were compared with those of other human and animal influenza viruses including A/whale/Pacific Ocean/76. In H1 tests these isolates, designated A/USSR/77, reacted with immune serum against A/FM/1/47 (H1N1) to the homologous titre, and with antiserum against A/whale/PO/19/76 virus to 1/8 of the homologous titre. In neuraminidase inhibition tests all A/USSR/77 isolates showed the presence of human N1 type neuraminidase, more closely related to A/sw/New Jersey/76 (Hsw1N1) than to A/FM/1/47 (H1N1) virus. The haemagglutinin of A/whale/Pacific Ocean/19/76 virus occupies an intermediate position between H0 and H1, but its neuraminidase is close to Nav2. The virus from whales multiplies better at low (28 degrees C) and at high (40 degrees C) temperatures than do the viruses of human origin that were tested.

[RNA-synthesizing complex of the Sendai virus in the nucleoli of infected Erlich ascitic carcinoma cells]. / RNK-sinteziruiushchii kompleks virusa Sendai v iadryshkakh zarazhennykh kletok astsitnoi kartsinomy Erlikha.

A virus-specific complex with sedimentation constant of 250S and buoyant density 1.35 g/cm3 in cesium chloride density gradient is formed within 20--24 hours after infection in nucleoli of Ehrlich ascitic carcinoma cells infected with Sendai virus. The complex contains a rapidly sedimenting RNA (70--90S) which is about 50% stable to RN-ase. The complex has RNA-polymerase activity in a cell-free system; the product of the RNA-polymerase reaction is a RNA with sedimentation constant 50S. It is suggested that the virus-specific structure with sedimentation constant 250 S found in nucleoli is the Sendai virus replicative complex.