(PHILADELPHIA) Creating vaccines to protect people against viral diseases like AIDS, cervical cancer and infectious hepatitis is a delicate balancing act: If the immune systems response to the vaccine is too strong, toxic side effects can kill the patient. If its not strong enough, the virus will spread faster than the immune system can kill it.
A new vaccine design strategy developed by scientists at The Wistar Institute Vaccine Center could be the answer. The secret is using a herpes simplex protein called glycoprotein D to block a specific receptor molecule on antigen-presenting cells, or APCs. These sentinel cells monitor the body for foreign antigens molecules that can stimulate an immune response from invading viruses.
When they detect viral antigens, APCs signal the bodys immune system to activate T cells to attack and destroy cells infected with the virus. At the same time, they also send inhibitory signals to prevent overreaction by the immune system. One of thee inhibitory signals is blocked by glycoprotein D from herpes virus.
In a study that will be published February 6 in Nature Medicine and is available online, Wistar scientists showed that vectors, which are vaccine delivery systems, made by fusing the glycoprotein D with genes from target antigens increase the immune systems response to those antigens in cell cultures and laboratory mice. The researchers used antigens from HIV, the virus that causes AIDS, and from HPV-16, a human papilloma virus that causes cervical cancer.
Hildegund C.J. Ertl, M.D., director of The Wistar Institute Vaccine Center and senior author of the study, says using glycoprotein D to deliver antigens has a major advantage over other vaccine approaches. It allows us to lower the dose but still get a stronger immune response, she says.
Glycoprotein D is part of the herpes viral envelope and is expressed on the surface of cells infected with the herpes simplex virus. Glycoprot
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| Contact: Abbey Porter aporter@wistar.org 215-898-3943 The Wistar Institute Source:Eurekalert |