Chronic Viral Infections

Chronic viral infection underlies a wide variety of medically important diseases that either follow directly from primary infection or may require months, years or even decades to develop. Pathogens associated with significant disease, such as human immunodeficiency virus (HIV), hepatitis C virus (HCV) and a number of herpes viruses remain uncontrolled. The success of recent antiviral therapies offers hope by opening new avenues of vaccine and therapy research. The chronic nature of the underlying infection, however, complicates antiviral strategies and favors selection of drug resistant progeny within the chronically infected host.  As the list of chronic diseases associated with long-term viral infection grows, experimental models suggest that chronic virus infection contributes to certain cancers, as well as to diabetes and atherosclerosis. 

Scientists at the Emory Vaccine Center engage in aggressive research programs aimed at understanding and abrogating chronic infections and developing novel vaccines against such persistent infections. The Center’s Director, Dr. Rafi Ahmed, has been a long- standing pioneer of studying the creation and survival of T  immune memory cells. Unlocking these mechanisms is a crucial step in the development of vaccines for HIV and other infectious agents. In addition to his pivotal contributions to vaccine science, Dr. Ahmed’s findings are being applied to developing and testing therapies for the treatment of cancer and the prevention of organ rejection.

Dr. Rama Rao Amara’s lab investigates new HIV/AIDS therapeutic vaccines, while Dr. Eric Hunter aims to elucidate the virus-cell interactions involved in the assembly and the entry of retroviruses. In collaboration with Dr. Cynthia Derdeyn, the Hunter lab is examining how a newly transmitted HIV adapts to its new host-defined immune environment so as to evade detection and destruction in a discordant cohort population in Zambia. Dr. Francois Villinger and his team model human infectious diseases in relevant nonhuman primate models. Dr. Guido Silvestri’s lab also contributes to this work by studying the pathogenesis of HIV infection and AIDS using the comparative nonhuman primate model of SIV infection in rhesus macaques and sooty mangabeys. By increasing our understanding of the pathogenesis of the AIDS virus, Dr. Silvestri and Mirko Paiardini work to develop new immune-based therapies for HIV to be used in addition to antiretroviral therapy.

Dr. Bali Pulendran’s lab explores the efficacy of various molecules such as Flt3-Ligand, GM-CSF, G-CSF, and other factors that modulate dendritic cell numbers or function, as immune modulators or vaccine adjuvants. This is done within the context of HIV and other infectious diseases, in both non human primates and in patients. In addition, Dr. Jerry Blackwell’s approach is to optimize components of the HIV vaccine, namely the vector, the antigen and the immunological response, to increase its efficacy and safety properties.

The paucity of efficacious anti-HCV therapeutic options highlights the need for effective interventions aimed at augmenting or supplementing the natural immune response Dr. Arash Grakoui’s laboratory investigates the host immune response to HCV in order to better facilitate vaccine development. Dr. Ed Mocarski studies the replication, latency and host response to herpes viruses, specializing in cytomegalovirus, an important opportunistic pathogen in immunocompromised hosts. Dr. Samuel Speck’s work on Epstein-Barr virus and murine gammaherpesvirus-68 examines the molecular mechanisms by which these viruses establish persistent, chronic infections.  Additional projects characterize the host response to viral infection and address the control of viral latency and persistent infection.