上海交通大学：《医学微生物》课程教学资源（PPT课件讲稿）英文版 Respiratory viruses

Respiratory Viruses

1 Respiratory viruses

Categories of Respiratory Viruses Orthomyxoviridae: Influenza virus Paramyxoviridae: Parainfluenza virus, Mumps virus; Measles, Respiratory syneytical virus Togaviridae: Rubella virus Coronaviridae: corona virus sais virus Adenoviridae humanAdenovirus picornaviridae: Rhino virus, Reoviridae:

2 Categories of Respiratory Viruses • Orthomyxoviridae: Influenza virus • Paramyxoviridae : Parainfluenza virus; Mumps virus; Measles; Respiratory syneytical virus • Togaviridae: Rubella Virus • Coronaviridae: Corona Virus; SARS virus • Adenoviridae : human Adenovirus • picornaviridae: Rhino Virus; • Reoviridae:

Influenza virus Orthomyxoviridae: Infuenza virus Influenza is a disease caused by Influenza virus a member of the Orthomyxoviridae

3 Influenza virus Orthomyxoviridae: Influenza virus Influenza is a disease caused by Influenza virus ,a member of the Orthomyxoviridae

Genome of Influenza virus 8 negative sense RNA nucleocapsid segments The RNP(RNA nucleoprotein) is in a helical form with the 3 polymerase polypeptides associated with each segment The segmented genome promotes genetic diversity caused by mutation and reassortment of segments on infection with two different strains

4 Genome of Influenza virus • 8 negative sense RNA nucleocapsid segments • The 'RNP' (RNA + nucleoprotein) is in a helical form with the 3 polymerase polypeptides associated with each segment. • The segmented genome promotes genetic diversity caused by mutation and reassortment of segments on infection with two different strains

Virion sphericallovoid 80 120nm diameter, The inner side of the envelope is lined by the matrix protein, stable type specIfIc

5 Virion • spherical/ovoid, 80 - 120nm diameter, • The inner side of the envelope is lined by the matrix protein, stable type - specific

Virion The outer surface of the particle consists of a lipid envelope from which project prominent glycoprotein spikes of two types, the haemagglutinin, -135A trimer (HA), and neuraminidase, -60A tetramer (NA)

6 Virion • The outer surface of the particle consists of a lipid envelope from which project prominent glycoprotein spikes of two types, the haemagglutinin, ~135Å trimer (HA), and neuraminidase, ~60Å tetramer (NA)

Haemagglutinin (HA) Encoded by rna segment #4 Can agglutinate red blood cells- hence the nomenclature Cleavage by host-cell protease is required(resulting in Hal and HA2) for infection to occur Hemagglutinin glycoprotein is the viral attachment protein and fusion protein, and it elicits neutralizing, protective antibody responses

7 Haemagglutinin (HA) • Encoded by RNA segment #4 • Can agglutinate red blood cells - hence the nomenclature • Cleavage by host-cell protease is required (resulting in HA1 and HA2) for infection to occur • Hemagglutinin glycoprotein is the viral attachment protein and fusion protein , and it elicits neutralizing , protective antibody responses

Neuramindase (NA) Encoded by rNa segment #6 Enzyme that uses neuraminic (sialic) acid as a substrate Important in releasing mature virus from cells

8 Neuraminadase (NA) • Encoded by RNA segment #6 • Enzyme that uses neuraminic (sialic) acid as a substrate • Important in releasing mature virus from cells

ORTHOMYXOVIRUSES HA- hemagglutinin NA- neuraminidase helical nucleocapsid (RNA plus NP protein) lipid bilayer membrane -polymerase complex MI protein type A, B, C: NP, M1 protein sub-types: HA or NA protein

9 ORTHOMYXOVIRUSES M1 protein helical nucleocapsid (RNA plus NP protein) HA - hemagglutinin polymerase complex lipid bilayer membrane NA - neuraminidase type A, B, C : NP, M1 protein sub-types: HA or NA protein

Influenza virus A

10 Influenza virus A