T cells activated to fight HIV basis for dendritic cell therapeut...( Toronto Aug. 12 -- Having their immun...),Health

Toronto, Aug. 12 -- Having their immune system cells go through a laboratory version of boot camp may help patients win their battle against HIV, believe University of Pittsburgh researchers. In essence, that's the concept behind the development of a novel therapeutic vaccine loaded with a patient's own souped up dendritic cells, which have been galvanized to rally other cells of the immune system in fighting the virus unique to that individual.

At the XVI International AIDS Conference (AIDS 2006), University of Pittsburgh researchers will describe one of the steps that is key to the approach's success modifying the dendritic cells in such a way that they will get the attention of killer T cells. Results of these studies will be incorporated into the protocol for a clinical trial of the vaccine, which is expected to begin later this year.

"The goal of the approach is to teach killer T cells to more efficiently find, detect and destroy HIV infected cells. Our vaccine, as an immunotherapy, is custom-designed to target the unique virus that has evolved in each individual being treated. A patient's own dendritic cells together with their unique viral antigens comprise the main elements of the vaccine," said Charles R. Rinaldo, Jr., Ph.D., professor and chairman of the department of infectious diseases and microbiology at Pitt's Graduate School of Public Health (GSPH) and the study's senior author.

In particular, the approach aims to activate a type of T cell called a CD8, or cytotoxic, T cell, also known as a killer T cell. In a typical immune response, CD8 cells are called to action by dendritic cells. Persons infected with HIV and being treated with antiretroviral drugs can control but not eliminate HIV infection. If the drug therapy is discontinued, the virus comes roaring back. Dr. Rinaldo and others have hypothesized that this is because the drug therapy does not completely restore CD8 cell immunity to the virus. So, in trying to f
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Contact: Lisa Rossi
RossiL@upmc.edu
412-647-3555
University of Pittsburgh Medical Center
12-Aug-2006