Paramyxoviridae

Question 1

Henipavirus genus

Answer 1

However, of concern are paramyxoviruses in the Henipavirus genus whose natural host is the fruit bat but are highly infectious for swine and humans

Question 2

Most of the paramyxoviridae have ______ and this is why we do not worry about them.

Answer 2

Vaccines.

Question 3

Bovine Parainfluenza virus 3

Answer 3

host: cattle, sheep, other mammals
causes: respiratory disease in cattle and sheep

• Parainfluenza virus-3 is extremely widespread in cattle and 80-90% have antibody
• Isolatesvaryinvirulence
• Cessation of ciliary beating and epithelial necrosis predispose to secondary bacterial infections and coughing.

Question 4

Peste de petits rumiants virus

Answer 4

Host: sheep and goats

Disease: severe generalized disease like rinderpest

Trying to get eradicated in the world

Rinderpest has been eradicated
PPR is a disease listed in the OIE Terrestrial Animal Health Code, and countries are obligated to report the disease Occurrence: North Africa to Tanzania, and in nearly all Middle Eastern countries up to Turkey-

Question 5

Bovine respiratory syncytial virus

Answer 5

host: cattle, sheep, goats

Disease: respiratory disease

Question 6

There are several other members of the Paramyxoviridae that are still waiting classification to existing genera

Answer 6

• Paramyxvovirus of reptiles
• Salem virus of equine
• Viruses of peguins
• Atlantic Salmon paramyxoviruses

Question 7

turkey rhinotracheitis virus

Answer 7

in turkeys and chickens

severe respiratory disease in turkeys, swollen head syndrome of chickens

Question 8

Virion properties

Answer 8

• Virions are P L E O M O R P H I C – spherical or filamentous (similar to Ebola)

• 150-350 nm in diameter
• Enveloped with large glycoprotein spikes (8-14 nm)
• Contain a “herringbone shaped” nucleocapsid- characterisitic

• The genome consist of linear, negative sense, single stranded RNA (13-19 kb in size)

• There is no 5’ cap or 3’ polyadenylation
• However, there are non-coding regions at both 5’ and 3’

Question 9

Number of genes in respective genera

Answer 9

• The Respirovirus, Avulavirus, Henipavirus and Morbilivirus genera have 6 genes each

The Rubulaviruses have 7 genes

The Pneumoviruses have 10 genes

The Metapneumoviruses have 8 genes

The genome of the Paramyxovirinae encode at least 9-12 proteins

• The Pneumovirinae encode only 8-10 proteins

Question 10

L gene encodes

Answer 10

Transcriptase for replication

Question 11

Most of the gene products are found

Answer 11

Most of the gene products are found within the lipid envelope or complexed with the virion RNA

Question 12

Virion structure

Answer 12

• Lipid bilayer

Virion structure

• 3 nucleocapsid proteins referred to as RiboNucleoProteins (RNP)

• RNA-binding protein (N)
• Phosphoprotein (P)
• Large polymerase (L)

3 membrane proteins:

• Unglycosylated matrix protein (M)
• Two glycosylated envelope proteins

————-Fusion protein (F)

————-Attachment protein hemagglutinin (H)

Question 13

attachment proteins

Answer 13

A hemagglutinin-neuraminidase (HN) OR glycoprotein (G) - attachment proteins

Question 14

Variably conserved proteins include

Answer 14

Variably conserved proteins include non-structural proteins (C, NS1 and NS2), cystein rich protein V, small integral membrane (SH), transcription factors M2-1 and M2-2

Question 15

The envelope spikes of Paramyxoviridae are composed of 2

Answer 15

The envelope spikes of Paramyxoviridae are composed of 2 glycoproteins F and G or F and HN or F and H

Question 16

The spike glycoproteins play an important role in

Answer 16

The spike glycoproteins play an important role in the pathogenesis of paramyxovirus

Question 17

(HN, H or G)

Answer 17

One glycoprotein (HN, H or G) is responsible for attachment

Question 18

F protein

Answer 18

F protein mediates fusion of the viral envelope with the cell membrane

Question 19

neutralizing antibodies

Answer 19

The antibodies directed against the these proteins are usually neutralizing antibodies – important in protection against paramyxovirus infection

help with vaccine development

Question 20

Where do paramyxoviruses replicate?

Answer 20

Paramyxoviruses replicate in the cytoplasm of infected cells

Question 21

Pneumovirus do not encoded

Answer 21

Hemagglutaination, which makes it harder to find

Question 22

What is interesting about replication?

Answer 22

Replication can also take place in the presence of a_ctinomycin D(cancer drug) or in enucleated cells_ – THUS, no nuclear function is required for replication

Question 23

How does replication begin?

Answer 23

HN, H, or G attaches to compatible ligands (receptors) on the target

cells

This is different for each type of virus

Question 24

Where is the replication receptor for Rubulaviruses, Respiroviruses and Avulaviruses ?

Answer 24

For Rubulaviruses, Respiroviruses and Avulaviruses the HN molecule binds to sialic acid residue – either glycolipids or glycoproteins

Question 25

For Morbilliviruses, where is the receptor located for replication?

Answer 25

For Morbiliviruses, the receptor is located on lymphocytes, dendritic cells or macrophages – CD150

Question 26

For Heniparviruses, where is the receptor for replication?

Answer 26

Fro Henipaviruses, the receptor is ephrin B2 and B3 cell surface proteins on endothelial cells or on brain stem neurons

Question 27

For pneumonviruses, where is the receptor for replication?

Answer 27

For Pneumoviruses, the receptor is heparan sulfate(common for most viruses

Question 28

After the attachement to the receptor what happens?

Answer 28

The F protein mediates fusion of the viral envelope lipid membrane with the target cell membrane

Question 29

RNA-dependent RNA polymerase

Answer 29

The RNA-dependent RNA polymerase complex (transcriptase L) initiates RNA synthesis at a single site on the 3’ end of the genomic RNA

Question 30

Replication of paramyxoviruses leads to

Answer 30

Replication of paramyxoviruses leads to lysis of infected cells or formation of syncytia

Question 31

Paramyxoviruses produce

Answer 31

Paramyxoviruses produce inclusion bodies – cytoplasmic acidophilic, composed of ribonucleoprotein structures

Question 32

Morbiliviruses produce

Answer 32

Morbiliviruses produce acidophilic intranuclear inclusion bodies composed of nuclear elements and protein N

Question 33

What is a distinctive feature of Paramyxoviruses?

Answer 33

**Hemoadsorption is a distinctive feature of Paramyxoviruses that express the H or HN proteine** **PLEASE REMEMBER**