ABSTRACT
The results of the study into the function of glycoproteins of influenza viruses isolated in the 1987 interepidemic period. Natural isolates were found to have virus particles with deficient neuraminidase activity but retained hemolytic and infectious activity. Biological sequences of the lack of neuraminidase activity in the isolates consisted in disorders of sialic acid metabolism in the infected cells, blocking of the receptor site of hemagglutinin and increased sensitivity to inhibitors. It is assumed that the interepidemic virus isolates represent a biologically heterogeneous population in which particles with deficient neuraminidase activity are prevalent.
Subject(s)
Glycoproteins/physiology , Influenza A virus/physiology , Viral Proteins/immunology , Animals , Chick Embryo , Disease Outbreaks , Glycoproteins/analysis , Guinea Pigs , Hemagglutinins, Viral/analysis , Hemolytic Plaque Technique , Humans , Influenza A virus/isolation & purification , Influenza, Human/microbiology , Neuraminidase/analysis , Viral Proteins/analysisABSTRACT
Cloning in chick embryos and MDCK cell culture of influenza A/USSR/13/81 (H1N1-N3) virus isolated during virological examinations of autopsy materials from a child who had died from acute respiratory virus infection yielded three subpopulations of clones differing in antigenic, biological, physico-chemical properties and glycoprotein structures. One subpopulation contained hemagglutinin (HA) similar to that of the A/PR/8/34 strain and neuraminidase (NA) N3, the other HA similar to that of A/WS/33 and NA N1, and the third HA of the isolate proper and NA of the both serosubtypes mentioned.
Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza A virus/isolation & purification , Hemagglutination Inhibition Tests , Hemagglutinins, Viral/analysis , Humans , Influenza A virus/classification , Influenza A virus/immunology , Neuraminidase/immunology , Viral Plaque Assay , Virus CultivationABSTRACT
Isolated glycoproteins of influenza A/PR/8/34 (H1N1) administered intranasally to white mice were found to increase permeability of lung capillaries.
Subject(s)
Capillary Permeability/drug effects , Glycoproteins/toxicity , Influenza A virus/pathogenicity , Lung/drug effects , Viral Proteins/toxicity , Animals , Capillaries/drug effects , Dose-Response Relationship, Drug , Endothelium/drug effects , Lung/blood supply , Mice , Time FactorsABSTRACT
An influenza A virus whose hemagglutinin belongs to subtype H1 (serovariant WS/33) and neuraminidase to subtypes N1 (serovariant A/PR8/34) N3 was isolated by a method of aborted infection in chick embryos in virological examinations of the lungs and trachea of a 3-month-old infant who died of acute respiratory virus disease during a seasonal rise of ARD incidence in Alma-Ata, the Kazakh SSR, in 1981. The oligopeptide composition of nucleoprotein protein and glycoproteins of the isolate differed from that of the corresponding proteins of the reference serovariants. The electrophoretic analysis of the isolate polypeptides revealed neuraminidase with molecular weight about 70 kD which is unlike the findings with previously known strains. The original structure of the influenza A/USSR, Alma-Ata/13/81 virus proteins rules out the likelihood of laboratory contamination.