Drs. Gail Ferstandig Arnold and Eddy Arnold, AIDS researchers and professors in Rutgers University’s Chemistry and Chemical Biology Department, have published a study in the Journal of Virology. With the support of the National Institutes of Health, the Arnolds and their research team have identified a portion of the AIDS virus that is important to its viability, something the virus needs in order to complete its life cycle, then targeted this crucial part of the virus. They have been able to take a piece of HIV that is involved with helping the virus enter cells and put it on the surface of a common cold virus. They then immunize animals with it and realize that the animals make antibodies that can stop an unusually diverse set of HIV isolates or varieties.
In previous instances, certain researchers were able to bring forth effective antibodies, but only against a very limited number of HIV types. Since HIV is known to mutate, antibodies developed against one local strain may not recognize and fight mu-tant varieties somewhere else, which is one of the great challenges to finding a broad spectrum vaccine able to protect against the myriad of HIV varieties.
Unlike most vaccines which are actually made from the pathogen itself, HIV is just too dangerous to use as the basis for a vaccine vehicle. The Arnolds and their research team have attached the target portion of the HIV using the relatively innocuous cold-causing rhinovirus. This must maintain the HIV part’s shape so that when the immune system sees it, it will actually mount an immune response as it would to the real HIV. Dr. Eddy Arnold stated that the idea is to trick the immune system into thinking it is acting upon HIV before the virus appears. To achieve this is a dilemma in engineering. The goal was to take a small piece of the HIV out of its native context, put it in a completely different system (rhinovirus), and have it look the same and act the same.
Using recombinant engineering, the researchers developed a method to systematically test millions of varied presentations of the HIV segment with the rhinovirus. They tried millions of different variations on how to graft (or splice) one onto the other, creating what are called combinatorial libraries.
“The really exciting part is that we were able to find viruses that could elicit antibodies against a huge variety of isolates of HIV. That is an immense step and a very important step,” said Dr. Gail Ferstandig Arnold.
Dr. Eddy Arnold said that the quantity of response is not huge, but it is significant. This is the first demonstration of this particular flaw being presented in a way to generate a relevant immune response. He said, “It is probably not potent enough by itself to be the vaccine or a vaccine, but it is a proof of principle that what we are trying to do is a very sound idea.”
(Source: Science Daily Web site, March 13, 2009. Adapted from Rutgers University’s materials)
