- Scientists unveil the difficulty behind designing Hepatitis C vaccines.
- Flexible nature of protein target in vaccines is a deciding factor for making HCV vaccines.
- Further research is carried out for designing newer versions of proteins for eliciting virus-neutralizing antibodies.
A research team from The Scripps Research Institute (TSRI) has recently discovered a reason which pose difficulty in making Hepatitis C vaccines.
Around 130 -150 million people are affected by HCV infections worldwide. These infections occur silently without any symptoms and the use of anti-viral drugs for treating the infections are found to be expensive.
‘Hepatitis C Vaccines can be designed by targeting the flexible nature of proteins.’
Scientists analyzed a lab-made form of a viral protein in HCV vaccines to initiate antibody response to the virus.They found that protein part of the vaccine was found to be flexible.
The flexibility of the vaccine is responsible for the different shapes in the immune system. This would inturn result in a wide variety of antibodies which cannot block the viral infections.
Mansun Law, Associate professor and senior author TSRI said "Because of that flexibility, using this particular protein in HCV vaccines may not be the best way to go."
Ian A. Wilson, TSRI's Hansen Professor of Structural Biology and a member of the Skaggs Institute for Chemical Biology at TSRI and co-senior author also said, "We may want to engineer a version that is less flexible to get a better neutralizing response to the key target site and not so many off-target responses."
Law and Wilson Laboratories worked together over years for designing successful vaccines. The team found that the receptor binding site E2 is the prime candidate for designing HCV vaccine.
They teamed up with Professor Andrew Ward TSRI and analysed the nature of recombinant HCV E2 protein. The findings suggested that the recombinant E2 proteins were made of strong disulfide bonds, structural stability and had a high melting point of 85℃.
TSRI scientist also studied that in highly strengthened conditions the receptor binding portion was found to be extraordinarily loose and flexible. They also found that vaccines with high levels of antibodies against these conformations would help in treating HCV.
Researchers continue to study E2 receptors and find new versions of E2 or a completely different protein for stabilizing conformations and producing virus- neutralizing antibodies.