https://en.wikipedia.org/wiki/Avian_influenza - https://en.wikipedia.org/wiki/Avian_influenza or https://en.wikipedia.org/wiki/Avian_influenza ;
H= https://en.wikipedia.org/wiki/Hemagglutinin_%28influenza%29 - https://en.wikipedia.org/wiki/Hemagglutinin_(influenza) or https://en.wikipedia.org/wiki/Hemagglutinin_(influenza) ;
Hemagglutinin is a https://en.wikipedia.org/wiki/Viral_protein#Viral_membrane_fusion_proteins - Class I Fusion Protein , having multifunctional activity as both an attachment factor and https://en.wikipedia.org/wiki/Membrane_fusion_protein - membrane fusion protein . Therefore, HA is responsible for binding Influenza https://en.wikipedia.org/wiki/Virus - virus to https://en.wikipedia.org/wiki/Sialic_acid - sialic acid on the https://en.wikipedia.org/wiki/Cell_membrane - surface of target cells, such as cells in the upper https://en.wikipedia.org/wiki/Respiratory_tract - respiratory tract or https://en.wikipedia.org/wiki/Erythrocytes - erythrocytes , https://en.wikipedia.org/wiki/Hemagglutinin_%28influenza%29#cite_note-pmid19004788-1 - [1] causing as a result the https://en.wikipedia.org/wiki/Receptor-mediated_endocytosis - internalization of the virus. https://en.wikipedia.org/wiki/Hemagglutinin_%28influenza%29#cite_note-2 - [2] Secondarily, HA is responsible for the fusion of the https://en.wikipedia.org/wiki/Viral_envelope - viral envelope with the late https://en.wikipedia.org/wiki/Endosome - endosomal membrane once exposed to low https://en.wikipedia.org/wiki/PH - pH (5.0-5.5). https://en.wikipedia.org/wiki/Hemagglutinin_%28influenza%29#cite_note-3 - [3] The name "hemagglutinin" comes from the https://en.wikipedia.org/wiki/Protein - protein 's ability to cause red blood cells (erythrocytes) to clump together (" https://en.wikipedia.org/wiki/Agglutination_%28biology%29 - agglutinate ") https://en.wikipedia.org/wiki/In_vitro - in vitro . https://en.wikipedia.org/wiki/Hemagglutinin_%28influenza%29#cite_note-4 - [4]
N= https://en.wikipedia.org/wiki/Viral_neuraminidase - https://en.wikipedia.org/wiki/Viral_neuraminidase or https://en.wikipedia.org/wiki/Viral_neuraminidase ;
Viral neuraminidase is a type of https://en.wikipedia.org/wiki/Neuraminidase - neuraminidase found on the surface of https://en.wikipedia.org/wiki/Influenza_virus - influenza viruses that enables the virus to be released from the host cell. Neuraminidases are https://en.wikipedia.org/wiki/Enzyme - enzymes that cleave https://en.wikipedia.org/wiki/Sialic_acid - sialic acid (also called https://en.wikipedia.org/wiki/Neuraminic_acid - neuraminic acid ) groups from https://en.wikipedia.org/wiki/Glycoprotein - glycoproteins . Viral neuraminidase was discovered by https://en.wikipedia.org/wiki/Alfred_Gottschalk_%28biochemist%29 - Alfred Gottschalk at the https://en.wikipedia.org/wiki/WEHI - Walter and Eliza Hall Institute in 1957. https://en.wikipedia.org/wiki/Viral_neuraminidase#cite_note-3 - [3] https://en.wikipedia.org/wiki/Neuraminidase_inhibitors - Neuraminidase inhibitors are antiviral agents that inhibit influenza viral neuraminidase activity and are of major importance in the control of influenza. https://en.wikipedia.org/wiki/Viral_neuraminidase#cite_note-PUB00006572-4 - [4] Viral neuraminidases are the members of the glycoside hydrolase family 34 http://www.cazypedia.org/index.php/Glycoside_Hydrolase_Family_34 - CAZY GH_34 which comprises enzymes with only one known activity; https://en.wikipedia.org/wiki/Sialidase - sialidase or https://en.wikipedia.org/wiki/Neuraminidase - neuraminidase https://en.wikipedia.org/wiki/Enzyme_Commission_number - EC https://enzyme.expasy.org/EC/3.2.1.18 - 3.2.1.18 . Neuraminidases cleave the terminal https://en.wikipedia.org/wiki/Sialic_acid - sialic acid residues from carbohydrate chains in glycoproteins. Sialic acid is a negatively charged sugar associated with the protein and lipid portions of https://en.wikipedia.org/wiki/Lipoproteins - lipoproteins .[ https://en.wikipedia.org/wiki/Wikipedia:Citation_needed - To infect a host cell, the influenza virus attaches to the exterior cell surface using https://en.wikipedia.org/wiki/Hemagglutinin_%28influenza%29 - hemagglutinin , a molecule found on the surface of the virus that binds to sialic acid groups.
DJ So H is "the glue" sticking it to a host-cell, N does the breaking in into the cell so the viral load can get into the host cell...
Viruses do need host cells to reproduce themselves...Both of "H" and "N" there are lots of different subtypes...
https://www.cdc.gov/bird-flu/about/index.html - https://www.cdc.gov/bird-flu/about/index.html or https://www.cdc.gov/bird-flu/about/index.html;
Avian Influenza A(H7) VirusesThere are nine known subtypes of A(H7) viruses A(H7N1), A(H7N2), A(H7N3), A(H7N4), A(H7N5), A(H7N6), A(H7N7), A(H7N8), and A(H7N9)]. Most A(H7) viruses identified worldwide in wild birds and poultry are LPAI viruses.
Avian influenza A(H7) virus infection of humans have occurred sporadically.
The most frequently identified A(H7) viruses associated with human infections are avian influenza A(H7N9) viruses, which were first detected in https://archive.cdc.gov/#/details?url=https://www.cdc.gov/flu/avianflu/h7n9-virus.htm - China in 2013 . While human infections with A(H7N9) viruses are uncommon, they have resulted in severe respiratory illness and death in approximately 40% of reported cases. In addition to A(H7N9) viruses, human infections with A(H7N2), A(H7N3), A(H7N4), and A(H7N7) viruses have been reported and have primarily caused mild to moderate illness with symptoms that included conjunctivitis and/or upper respiratory tract symptoms. - https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H7N7 - https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H7N7 or https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H7N7 ; In 2003, 89 people in the Netherlands were confirmed to have been infected by H7N7 following an outbreak in poultry on approximately 255 farms. One death was recorded – a veterinarian who had been testing chickens for the virus – and all infected flocks were culled. Most affected people had mild symptoms including https://en.wikipedia.org/wiki/Conjunctivitis - conjunctivitis . https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H7N7#cite_note-1 - [1] https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H7N7#cite_note-2 - [2] Antibodies were found in over half of 500 people tested according to the final official report by the Dutch government
DJ, Immunity against most know types of "human" flu may offer only limited protection-at best- against other kinds of flu...H7 is "new" for as good as all human hosts !
|