The Johns Hopkins Center for Epithelial Disorders focuses on research into the physiology and pathophysiology of epithelial cells (cells that line the cavities and interior surfaces of the body) of the gastrointestinal (GI) tract, liver, pancreas and kidney. Specifically, the center’s research seeks to: -Understand the mechanisms regulating the activity of transport proteins (including channels) of epithelial cells Characterize the mechanisms by which polarity of epithelial cells are maintained -Investigate the mechanisms controlling transcription of epithelial-specific genes Understand the pathophysiological basis of GI and renal diseases that involve the preceding three components -The center also provides a framework for training fellows in gastroenterology and hepatology to become independent investigators. The center is funded primarily through individual investigator-initiated extramural research grant support from the National Institutes of Health (NIH) as well as multi-investigator grants including RO1, PO1, UO1 and R24.

The Greider lab uses biochemistry to study telomerase and cellular and organismal consequences of telomere dysfunction. Telomeres protect chromosome ends from being recognized as DNA damage and chromosomal rearrangements. Conventional replication leads to telomere shortening, but telomere length is maintained by the enzyme telomerase. Telomerase is required for cells that undergo many rounds of divisions, especially tumor cells and some stem cells. The lab has generated telomerase null mice that are viable and show progressive telomere shortening for up to six generations. In the later generations, when telomeres are short, cells die via apoptosis or senescence. Crosses of these telomerase null mice to other tumor prone mice show that tumor formation can be greatly reduced by short telomeres. The lab also is using the telomerase null mice to explore the essential role of telomerase stem cell viability. Telomerase mutations cause autosomal dominant dyskeratosis congenita. People with this disease die of bone marrow failure, likely due to stem cell loss. The lab has developed a mouse model to study this disease. Future work in the lab will focus on identifying genes that induce DNA damage in response to short telomeres, identifying how telomeres are processed and how telomere elongation is regulated.

We study human B cells and neutralizing antibody responses against hepatitis C virus (HCV), hepatitis B virus (HBV), SARS-CoV-2, and respiratory syncytial virus (RSV). Our overarching hypothesis is that understanding the B cell response in individuals who naturally control infections, and those who have been vaccinated, can help us to understand the basic biology behind successful immune responses, leading to design of more effective vaccines. A particular technical strength of our laboratory is high dimensional flow cytometric analysis of antigen-specific B cells, which allows us to phenotype these rare cells, and also to sequence B cell receptor (BCR) repertoires and isolate virus-neutralizing monoclonal antibodies (mAbs).

Research in the Jeremy Sugarman Lab focuses on biomedical ethics—particularly, the application of empirical methods and evidence-based standards to the evaluation and analysis of bioethical issues. Our contributions to medical ethics and health policy include work on the ethics of informed consent, umbilical cord blood banking, stem cell research, international HIV prevention research, global health and research oversight.

Current projects include: The evaluation of mechanisms of immune tolerance to cancer in mouse models of breast and pancreatic cancer. We have characterized the HER-2/neu transgenic mouse model of spontaneous mammary tumors. This model demonstrates immune tolerance to the HER-2/neu gene product. This model is being used to better understand the mechanisms of tolerance to tumor. In addition, this model is being used to develop vaccine strategies that can overcome this tolerance and induce immunity potent enough to prevent and treat naturally developing tumors. More recently, we are using a genetic model of pancreatic cancer developed to understand the early inflammatory changes that promote cancer development. The identification of human tumor antigens recognized by T cells. We are using a novel functional genetic approach developed in our laboratory. Human tumor specific T cells from vaccinated patients are used to identify immune relevant antigens that are chosen based on an initial genomic screen of overexpressed gene products. Several candidate targets have been identified and the prevelence of vaccine induced immunity has been assessed . This rapid screen to identify relevant antigenic targets will allow us to begin to dissect the mechanisms of tumor immunity induction and downregulation at the molecular level in cancer patients. More recently, we are using proteomics to identify proteins involved in pancreatic cancer development. We recently identified Annexin A2 as a molecule involved in metastases. The analysis of antitumor immune responses in patients enrolled on vaccine studies. The focus is on breast and pancreatic cancers. We are atttempting to identify in vitro correlates of in vivo antitumor immunity induced by vaccine strategies developed in the laboratory and currently under study in the clinics.