We used a panel of monoclonal antibodies to H9 hemagglutinin to select 18 escape mutants of mouse-adapted influenza A/Swine/Hong Kong/9/98 (H9N2) virus. Cross-reactions of the mutants with the antibodies and the sequencing of hemagglutinin genes revealed two minimally overlapping epitopes. We mapped the amino acid changes to two areas of the recently reported three-dimensional structure of A/Sw...

Biochemical changes in the influenza virus hemagglutinin during intracellular transport to the apical plasma membrane of epithelial cells were investigated in Madin-Darby canine kidney (MDCK) cells and in LLC-PK1 cells stably transfected with a hemagglutinin gene. After pulse-labeling a substantial fraction of hemagglutinin was observed to become insoluble in isotonic solutions of Triton X-100....

Current models for membrane fusion in diverse biological processes are focused on the local action of fusion proteins present in the contact zone where the proteins anchored in one membrane might interact directly with the other membrane. Are the fusion proteins outside of the contact zone just bystanders? Here we assess the role of these "outsider" proteins in influenza virus hemagglutinin-med...

background : avian influenza virus (aiv) infection is a major cause of bird and human morbidity and mortality. we aimed to evaluate a specific and sensitive multiplex rt-pcr that can simultaneously detect influenza type a viruses and differenti­ate the two most important subtypes of avian influenza viruses h7 and h9 subtypes. methods : a multiplex reverse transcriptase-polymerase chain reaction...

canine distemper virus (cdv) creates a very contagious viral multi-systemic canine distemper (cd) disease that affects most species of carnivora order. the virus is genetically heterogeneous, particularly in section of the hemagglutinin (h) gene. sequence analysis of the h gene can be useful to investigate distinction of various lineages related to geographical distribution and cdv molecular ep...

abstract : avian influenza virus (aiv) infection is a major cause of influenza mortality in birds and can cause human mortality and morbidity. although the risk of infection with avian influenza virus (aiv) is generally low for most people, the pathogenic virus can cross the species barrier and acquires the ability to infect and be transmitted among the human population; therefore the rapid ide...

Abstract : Avian influenza virus (AIV) infection is a major cause of influenza mortality in birds and can cause human mortality and morbidity. Although the risk of infection with avian influenza virus (AIV) is generally low for most people, the pathogenic virus can cross the species barrier and acquires the ability to infect and be transmitted among the human population; therefore the ra...

The composition of the plasma membrane domains of epithelial cells is maintained by biosynthetic pathways that can sort both proteins and lipids into transport vesicles destined for either the apical or basolateral surface. In MDCK cells, the influenza virus hemagglutinin is sorted in the trans-Golgi network into detergent-insoluble, glycosphingolipid-enriched membrane domains that are proposed...

In Madin-Darby canine kidney (MDCK) cells (a polarized epithelial cell line) infected with influenza virus, the hemagglutinin behaves as an apical plasma membrane glycoprotein. To determine biochemically the domain on the plasma membrane, apical or basolateral, where newly synthesized hemagglutinin first appears, cells were cultured on Millipore filters to make both cell surface domains indepen...

Rapid antigenic evolution in the influenza A virus hemagglutinin precludes effective vaccination with existing vaccines. To understand this phenomenon, we passaged virus in mice immunized with influenza vaccine. Neutralizing antibodies selected mutants with single-amino acid hemagglutinin substitutions that increased virus binding to cell surface glycan receptors. Passaging these high-avidity b...