virus replication hsiao-sheng liu 劉校生 國立成功大學微生物暨免疫學研究所
TRANSCRIPT
Virus Replication
Hsiao-Sheng Liu 劉校生
國立成功大學微生物暨免疫學研究所
The objectives:
• How to calculate virus titer?
• One step growth curve
• The general stages of viral replication cycle
• Attachment, penetration and release of the viruses
How to measure virus titer?
Baculovirus plaques
Zones of clearing (plaques) are generated by infection of insect (Sf9} cells with individual baculovirus particles. Uninfected Sf9 cells surrounding the plaque are stained pink with neutral red.
10-6 10-7
PFU: plaque forming unit 1 PFU = 1 plaque = 1 bacterial phageCount : plaque 數量 x 稀釋倍數 x 10/9 = PFU/ml
Ex: 211 x 107 x 10/9 = 2.34 x 109 PFU/ml
211 plaques
What is one step growth curve?
陰蔽期潛伏期
What are the general stages in viral replication cycles?
General replicationprocedure
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© 2005 Elsevier
Complicated replicationprocedure (e.g. Herpes virus)
How the viral replication cycle is known?
Attachment: receptor, tissue tropism
HA: Hemagglutinine
Trimmers of HA on influenza virus membrane
Coreceptor: CCR5 CRCX4
CCR5: macrophage-tropic HIV
CXCR4: lymphocyte-tropic HIV
How does the virus enter the cell?
Endocytosis
Fusion
Pinocytosis (Viropexis)
Paramyxovirus fusion Syncytia
Togavirus
How is the virus released from the cell?
Orthomyxoviruswith M protein Herpes virus
Respiratory syncytial virus budding
Brooks et al, 1998