Hope for HIV Vaccine Found in Miller School Researcher’s SIV Study
Offering hope for an HIV vaccine, Eckhard Podack, M.D., Ph.D., professor and chair of microbiology and immunology, has demonstrated that a vaccine he developed with a novel heat-shock technology provides significant protection against the Simian Immunodeficiency Virus (SIV), a non-human virus closely related to the HIV virus that causes AIDS. Published March 15 in The Journal of Immunology, the results of the proof-of-concept study he led showed a highly significant 73 percent reduction in the risk of SIV infection among macaques treated with the vaccine.
“To our knowledge, with this study we achieved a degree of protection against SIV that is among the best ever seen and invites further development to achieve full protection,” Podack said of the study conducted with colleagues from his department, the Department of Medicine and the Miami Center for AIDS Research (CFAR). “Vaccine-induced protection against infection by HIV or SIV has been limited. And while HIV can be controlled with an intensive drug regimen, the required medication is life-long and may have unpleasant side effects, so this presents a significant advance.”
Funded primarily by a grant from the National Institutes of Health and conducted with researchers at the Animal Models and Retroviral Vaccines Section of the National Cancer Institute, the study, “Cutting Edge: Novel Vaccination Modality Provides Significant Protection against Mucosal Infection by Highly Pathogenic Simian Immunodeficiency Virus,” marks another milestone for the ImPACT technology developed by Heat Biologics, a clinical-stage immunotherapy company focused on developing therapeutic vaccines to combat a wide range of diseases, including cancers and infectious diseases.
“This research further validates the significant potential that the ImPACT therapeutic vaccine platform holds,” said Jeffrey Wolf, President and CEO of Heat Biologics, which is currently conducting Phase II trials for a vaccine Podack developed for non-small cell lung cancer. “It is an exciting addition to Dr. Podack’s groundbreaking work with the ImPACT Therapy, which has already generated encouraging results in the treatment of other life-threatening diseases.”
The company’s ImPACT Therapy exploits the natural ability of antigens to activate the immune system by utilizing live, off-the-shelf, genetically modified cells injected into a patient to elicit a powerful immune response against the disease target. Heat’s ImPACT Therapy is based upon heat shock protein gp-96, a chaperone protein found in all human cells and normally tethered to cells with a leash called the KDEL sequence. ImPACT Therapy removes this KDEL leash, transforming allogeneic living cells into powerful machines that continually pump out gp-96 and their chaperoned antigens to activate the immune system against the full spectrum of antigens expressed by a patient’s disease.
Other Miller School co-authors on the SIV study are first author Natasa Strbo, M.D., Ph.D., assistant scientist in the Department of Microbiology and Immunology; Savita Pahwa, M.D., Director of the Miami CFAR and professor of microbiology and immunology, pediatrics and medicine; Michael A. Kolber, M.D., Ph.D., professor of medicine, Director of the Comprehensive AIDS Program and Clinical Director of the Adult HIV Section for Infectious Diseases; Eva Fisher, research associate in microbiology and immunology; and Louis Gonzalez, graduate student in microbiology and immunology.