The Balagopal Lab has adapted high-resolution tools to study viruses in situ. Specifically, we were the first to quantify hepatitis C virus (HCV) infection in single hepatocytes by developing single-cell laser capture microdissection (scLCM) and integrating this tool with highly sensitive quantitative real-time PCR. We reported that HCV infects a minority of hepatocytes that are found in geospatial clusters. More recently, we (PIs Balagopal and Thio) integrated scLCM with droplet digital PCR (ddPCR) to reveal the first observations of hepatitis B virus (HBV) infection at single cell resolution in the liver. We found that HBV infects nearly all hepatocytes prior to antiviral therapy. However, during antiviral therapy, HBV infection is diminished while viral transcription is markedly attenuated. Our lab has also focused on HIV-1 infection and immune activation for over a decade. Most recently, we have studied type 1 interferon responses to HIV-1 using RNA sequencing (RNAseq). Using this technology, we identified novel interferon-stimulated genes (ISGs) that are associated with HIV-1 restriction in vivo.

Work in the Joel Blankson Lab explores the mechanism of control of HIV-1 replication in a cohort of patients known as elite controllers or elite suppressors. These patients are HIV-1 seropositive but maintain levels of viremia that are below the limit of detection of standard clinical assays. We feel that elite suppressors represent a potential model for a therapeutic HIV vaccine. Our central hypothesis is that many of these patients are infected with fully replication-competent HIV-1 isolates that are held in check by the immune system. To test this hypothesis, we are studying many different host and viral factors in these patients.

Research in the Robert Siliciano Laboratory focuses on HIV and antiretroviral therapy (ART). ART consists of combinations of three drugs that inhibit specific steps in the virus life cycle. Though linked to reduced morbidity and mortality rates, ART is not curative. Through our research related to latently infected cells, we've shown that eradicating HIV-1 infection with ART alone is impossible due to the latent reservoir for HIV-1 in resting CD4+ T cells. Our laboratory characterized the different forms of HIV-1 that persist in patients on ART. Currently, we are searching for and evaluating drugs that target the latent reservoir. We are also developing assays that can be used to monitor the elimination of this reservoir. We are also interested in the basic pharmacodynamic principles that explain how antiretroviral drugs work. We have recently discovered why certain classes of antiretroviral drugs are so effective at inhibiting viral replication. We are using this discovery along with experimental and computational approaches to develop improved therapies for HIV-1 infection and to understand and prevent drug resistance. Finally, we are studying the immunology of HIV-1 infection, and in particular, the ability of some patients to control the infection without ART.

Research in the Janet Siliciano lab focuses on HIV. Areas of study include CD4-positive T lymphocytes, virus latency and highly active antiretrovirals. We recently explored the challenges of detecting HIV persistence during potentially curative interventions and the multifactorial nature of HIV-1 latency.

The Stivers Lab is broadly interested in the biology of the RNA base uracil when it is present in DNA. Our work involves structural and biophysical studies of uracil recognition by DNA repair enzymes, the central role of uracil in adapative and innate immunity, and the function of uracil in antifolate and fluoropyrimidine chemotherapy. We use a wide breadth of structural, chemical, genetic and biophysical approaches that provide a fundamental understanding of molecular function. Our long-range goal is to use this understanding to design novel small molecules that alter biological pathways within a cellular environment. One approach we are developing is the high-throughput synthesis and screening of small molecule libraries directed at important targets in cancer and HIV-1 pathogenesis.

Dr. Christine Durand, assistant professor of medicine and oncology and member of the Johns Hopkins Kimmel Cancer Center, is involved in clinical and translational research focused on individuals infected with HIV and hepatitis C virus who require cancer and transplant therapies. Her current research efforts include looking at outcomes of hepatitis C treatment after solid organ transplant, the potential use of organs from HIV-infected donors for HIV-infected solid organ transplant candidates, and HIV cure strategies including bone marrow transplantation. Dr. Durand is supported by multiple grants: • R01 from the National Institute of Allergy and Infectious Diseases (NIAID) to study HIV-to-HIV organ transplantation in the US. • K23 from the National Cancer Institute (NCI) to study antiretroviral therapy during bone marrow transplant in HIV-1 infection. • U01 from the NIAID to study HIV-to-HIV deceased donor kidney transplantation. U01 from the NIAID to study HIV-to-HIV deceased donor liver transplantation.