Morbilliviruses (Distemper) Flashcards
what viral family are morbilliviruses a part of
paramyxoviridae
morbillivirus structure
- enveloped
- negative sense ssRNA
- large glycoprotein spikes
- spherical/filamentous virions
- helically symmetric capsid
what are the main surface proteins in morbilliviruses
H: hemagglutinin
F: fusion protein
used as vaccine targets to prevent ability of viruses to attach and enter into host cells
hemagglutinin
binds surface glycoproteins on host cells to attach virus
wide variety of receptors that hemagglutinin can bind to –> wide variety of disease presentations
SLAM
signaling lymphocyte activation molecule
pro-inflammatory surface protein on leukocytes that hemagglutinin can bind to attach to host cells
what tropism do morbilliviruses have due to SLAMs on host cells
lymphocytes
leads to immunosuppression
nectin-4
receptor for measles virus found on polarized epithelial cells in respiratory epithelium
fusion protein
surface protein used to fuse the viral envelope with the host cell membrane
nucleoprotein
protects the genome
transcriptase
used for transcription of the RNA genome
matrix protein (M)
used for virion stability
how do morbilliviruses attach and enter cells
- hemagglutinin binds host cell surface receptor
- fusion proteins drive fusion of viral envelope and cell membrane
- fusion can cause syncytial formation (creates large multinucleate cells)
where does morbillivirus replication occur
in the cytoplasm
- replication can still occur if the cell nucleus is dead
- causes intracytoplasmic and intranuclear inclusions
environmental resistance of morbilliviruses
weak - has a lipid envelope
most disinfectants work well because key attachment proteins (H and F) are on the envelope surface, so destroying the envelope will kill the virulence of the virus
control of morbilliviruses
vaccination
- highly successful LAV and modified/killed vaccines
