A Hadassah University Medical Center research team has developed a vaccine that significantly strengthens the body's immune system against the autoimmune aftereffects of HIV infection, a breakthrough that could dramatically make an impact in the treatment of AIDS patients.
The researchers found that although treatment with the widespread AIDS cocktail of medications kills the virus, the immune system continues to kill healthy cells. While the virus disappears in many patients, their immune system remains dangerously ineffective against foreign elements, and many of the patients end up dying due to related complications. This research focuses on developing a vaccine that would arrest this autoimmune destructive process. The results of this study were published in the latest issue of the prestigious Journal of Clinical Virology.
The Hadassah study was conducted between 1998 and 2002 with an additional two-year monitoring period. Seven patients participated in the study; five of the seven patients responded positively to the vaccine developed by the research team.
Lead researcher Dr. Rivka Abulafia-Lapid was assisted by Yael Keren-Zur,at the Human Biology Research Center directed by Prof. Henri Atlan, associated with the Department of Biophysics and Nuclear Medicine, Ein Karem, Jerusalem. The study was conducted in collaboration with Prof. Zvi Bentwich, and Prof. Irun Cohen from the Weizmann Institute of Science.
Initially, the researchers identified CD8 cells which are involved in the autoimmune process and are supposedly responsible for destroying CD4 cells in the immune system. In the laboratory, the scientists isolated the CD8 cells from a sample of the patient's white blood cells and mixed them with CD4 cells, and showed that these CD8 cells were involved in the killing process. At this stage, preparation of the vaccine involved neutralization of these CD8 cells and preparation of portions of ten million cells each to be used by injection under the skin in order to trigger a vaccination against these harmful cells.
Seven patients were treated with the new therapeutic vaccine. Each received between three and four injections in a six-month period. Following treatment, the patients CD4 cell count was continually monitored for another two years from their initial vaccination to determine if the number of CD4 cells increased in the peripheral blood, and subsequently, reinforced the strength of the immune system. In five of the seven vaccinated patients, the CD4 cells increased by more than 50 percent.
"After two years of treatment, we found that the cells had been eliminated or were very low. After three injections of the vaccine, five of the seven patients tested showed an increase in healthy white blood cells, which brought them to a certain level considered good for AIDS patients," said Abulafia-Lapid.
"Our aim was not to prevent infection by the virus but to strengthen the immune system and use our vaccination treatment as a complement to the antiviral medication (HAART)", said Abulafia-Lapid. "Since the autoimmune process continues even after elimination of the virus, the vaccine that we have developed is directed to stop this destructive process. In other words, our vaccine complements the cocktail of medications, to stop the body from continuing to destroy itself."
The researchers are continuing to develop the vaccine funded by a grant from Hadasit, the Hadassah subsidiary that promotes and commercializes the intellectual properties generated at Hadassah and by the Center for the Study of Emerging Diseases.
"Now, we plan to conduct extended clinical trials. We've shown that the vaccine is non-toxic and safe. It's not an easy treatment but we've shown that patients benefit from it," said Abulafia-Lapid. "What I envision is making the disease like a chronic infection - the cocktail treats the virus and we help the immune system to recover and allow the patient to continue his life and have his immune system fight any new invaders."
Courtesy http://www.israel21c.org/