Antigenic Characteristics and Genome Composition of a Naturally Occurring Recombinant Influenza Virus Isolated from a Pig in Japan

Abstract

SUMMARYWe performed antigenic analysis of the haemagglutinin and neuraminidase subunits of a recombinant virus (A/swine/Kanagawa/2/78) isolated from a pig in Japan in 1978, using a series of monoclonal antibodies to H1 (Hswl) haemagglutinin and N2 neuraminidases of H2N2 and H3N2 viruses. Results obtained in haemagglutination inhibition tests with five monoclonal antibodies to the haemagglutinin of A/N J/8/76 (H1N1) revealed that the haemagglutinin of three H1N1 and the recombinant viruses were indistinguishable from that of A/N J/8/76. The neuraminidase of A/swine/Kanagawa/2/78 was found to be antigenically similar to A/Kumamoto/22/76 (H3N2, A/Victoria/3/75-1ike strain). The oligonucleotide maps of the entire RNAs of H 1N 1, H1N2 and H3N2 viruses showed that A/swine/Kanagawa/2/78 (HIN2) virus was more similar to swine (H1N1) virus than to A/Kumamoto/22/76 (H3N2) virus. Radioactive cDNA was prepared by reverse transcription of the recombinant virus RNA using a dodecadeoxyribonucleotide primer and used in DNA-RNA hybridization experiments. The results obtained in molecular hybridization based on blotting procedures showed that all cDNA segments except gene 6 hybridized efficiently with RNAs of swine (H 1N 1) influenza virus. The sixth cDNA segment was homologous to the corresponding RNA segment of H3N2 virus. The genetic relatedness of A/swine/Kanagawa/2/78 (H1N2) with either A/swine/Kanagawa/4/78 (HIN 1) or A/Kumamoto/22/76 (H3N2) was clearly established by hybridization between the cDNA segment probes and viral RNA. It was concluded that the neuraminidase gene of A/swine/Kanagawa/2/78 (H1N2) was derived from a human H3N2 virus, while the seven other genes were from a swine H1N1 virus.

Origin and evolutionary characteristics of antigenic reassortant influenza A (H1N2) viruses isolated from man in China

“…In conjunction with our previous reports that two antigenic reassortant (H1N2) viruses, isolated from pigs in 1978 and 1980, contained seven RNA segments from a swine H1NI virus and only one gene, encoding NA, from a human H3N2 virus (Nerome et al, 1983(Nerome et al, , 1985, it is noteworthy that only one gene encoding the HA of a human reassortant H1N2 virus was derived from a Russia-like (H1N1) virus; the remaining seven genes were from Hong Kong-like (H3N2) viruses. Theoreti- The following viruses were used: RI-57 (A/RI/5-/57) (Elleman et al, 1982), RI÷57 (A/RI/5÷/57) (Air et al, 1985), TKY67 (Lentz et al, 1984), NT68, UD072, VIC75, BK79 and HE2489.…”

“…Although reassortant influenza A (H1N2) viruses had been isolated from pigs in Japan in (Nerome et al, 1983, there was no evidence that humans had been infected with antigenic reassortant viruses since the reappearance of H1N1 virus in man in 1977 (Cox et al, 1989). Here we report the antigenic and genetic characteristics of the reassortant (H1N2) influenza viruses isolated from man during influenza outbreaks in China in the winter of 1988/1989.…”

“…Procedures for extraction of viral RNAs have been described previously (Palese & Schulman, 1976;Nerome et al, 1983). The nucleotide sequences examined in the present study were determined by the dideoxynucleotide chain termination method using a series of synthetic oligonucleotide primers (Sanger et al, 1977;Air, 1979;Cox et al, 1986).…”

Molecular Characterization of an H1N2 Swine Influenza Virus Isolated in Miyazaki, Japan, in 2006

“…In Japan, several outbreaks of SIVs have been recorded that have been caused by either classical SIVs, H1N1 and H3N2 of human origin or reassortants among them [3,6,13,20]. Because an extensive epidemiological survey of SIV had not been carried out in Japan, the economic burden and potential public health impact of SIV has not been evaluated in Japan.…”

Sensitive Detection of Viral Antigens with a New Method, “Laser Magnet Immunoassay”

“…An egg-grown influenza virus culture was centrifuged at 6,000 rpm for 30 min for clarification. Then the virus was concentrated by centrifugation at 44,000 x g for 90 min in a Beckman 21 rotor and was further purified in a sucrose density gradient centrifugation using the method described by Nerome et al (6). The virus was inactivated by 0.05% formaldehyde and 0.0100 merthiolate in 0.025 °J o gelatin-phosphate buffered saline (PBS).…”