Monoclonal antibodies against Hepatitis C genotype 3a virus like particle inhibit virus entry in cell culture system.
The envelope protein (E1-E2) of Hepatitis C virus (HCV) is a major component of the viral structure. The glycosylated envelope protein is considered to be important for initiation of infection by binding to cellular receptor(s) and also known as one of the major antigenic targets to host immune response. The present study was aimed at identifying mouse monoclonal antibodies which inhibit binding of virus like particles of HCV to target cells. The first step in this direction was to generate recombinant HCV-like particles (HCV-LPs) specific for genotypes 3a of HCV (prevalent in India) using the genes encoding core, E1 and E2 envelop proteins in a baculovirus expression system. The purified HCV-LPs were characterized by ELISA and electron microscopy and were used to generate monoclonal antibodies (mAbs) in mice. Two monoclonal antibodies (E8G9 and H1H10) specific for the E2 region of envelope protein of HCV genotype 3a, were found to reduce the virus binding to Huh7 cells. However, the mAbs generated against HCV genotype 1b (D2H3, G2C7, E1B11) were not so effective. More importantly, mAb E8G9 showed significant inhibition of the virus entry in HCV JFH1 cell culture system. Finally, the epitopic regions on E2 protein which bind to the mAbs have also been identified. Results suggest a new therapeutic strategy and provide the proof of concept that mAb against HCV-LP could be effective in preventing virus entry into liver cells to block HCV replication.
Department of Biochemistry, Indian Institute of Science, Bangalore, India.
Soma
S
Das
Rohini K
RK
Shetty
Anuj
A
Kumar
Radhika Nagamangalam
RN
Shridharan
Ranjitha
R
Tatineni
Giriprakash
G
Chi
Anirban
A
Mukherjee
Saumitra
S
Das
Shaila Melkote
SM
Subbarao
Anjali Anoop
AA
Karande
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000494:pharmacology; D018929:Cell Culture Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D018604:Epitope Mapping; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects / Q000235:genetics* / Q000276:immunology / Q000502:physiology*; D006508:Hepatitis Antibodies / Q000276:immunology; D006526:Hepatitis C / Q000276:immunology / Q000821:virology; D006801:Humans; D051379:Mice; D011485:Protein Binding / Q000187:drug effects; D014771:Virion / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure; D053586:Virus Internalization / Q000187:drug effects
D000911:Antibodies, Monoclonal; D006508:Hepatitis Antibodies