Anti-infectivity of camel polyclonal antibodies against hepatitis C virus in Huh7.5 hepatoma
1 Antibody Laboratory, Protein Research Dept., Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technology Applications, New Borg EL-Arab, Alexandria, 21394, Egypt
2 Botany and Microbiology Dept., Faculty of Science, Alazhar University, Cairo, Egypt
3 Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoz, Miguel Servet 177, Zaragoza, 50013, Spain
4 Biological Sciences Dept., Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Kingdom of Saudi Arabia
Virology Journal 2012, 9:201 doi:10.1186/1743-422X-9-201Published: 16 September 2012
To extend the study of the camel milk proteins which have antiviral activity against HCV, camel naïve polyclonal IgGs, α-lactalbumin were purified from camel milk and their anti-HCV effect was examined using PBMCs and Huh7.5 cell-lines. They were compared with the activity of human polyclonal IgGs and camel lactoferrin and casein.
Material and methods
Three types of experiments were performed on PBMCs and HuH7.5 cell. HCV was directly incubated with the purified proteins and then mixed with both cell types, or the proteins were incubated with the cells and then exposed to HCV, or the HCV pre-infected cells were treated with the proteins to inhibit intracellular replication. The proteins were added to cells or virus at different concentrations and time intervals.
Pretreated PBMCs and Huh7.5 cells with milk proteins were not protected when exposed to HCV infection. The direct interaction between HCV and camel IgGs and camel lactoferrin (cLf) led to a complete inhibition of HCV entry into cells, while casein, α-lactalbumin and human IgGs failed to inhibit HCV entry at any tested concentration. Camel IgGs showed ability to recognize HCV peptides with a significant titer (12 × 103) in comparison with human IgGs which failed to do it. Camel lactoferrin was capable of inhibiting the intracellular HCV replication at concentrations of 0.25-1.25 mg/ml.
Camel milk naïve polyclonal IgGs isolated from camel milk could inhibit the HCV infectivity and demonstrated strong signal against its synthetic peptides. Lactoferrin inhibit the HCV infectivity started from 0.25 mg/ml. However, α-lactalbumin, human IgGs and casein failed to demonstrate any activity against HCV infectivity.