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.

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.

The David Graham Lab studies the consequences of HIV interactions with the immune system, the resulting pathogenesis and how to sabotage these interactions. We apply advanced technologies like mass spectrometry to dissect processes at the molecular level. We are also actively involved in cardiovascular research and studies the ways proteins are organized into functional units in different cell types of the heart. Major projects in our lab are organized into three major areas: (1) H/SIV pathogenesis and neuropathogenesis, (2) Cardiovascular disease, and (3) High technology development

The Zhu lab is focused on characterizing the activities of large collection of proteins, building signaling networks for better understanding the mechanisms of biological processes, and identifying biomarkers in human diseases and cancers. More specifically, our group is interested in analyzing protein posttranslational modifications, and identifying important components involved in transcription networks and host-pathogen interactions on the proteomics level, and biomarkers in human IBD diseases.

Work in the William B. Guggino Lab focuses on the structure of the cystic fibrosis transmembrane conductance regulator (CFTR) and water channels; the molecular structure of transport proteins in epithelial cell membranes; and gene therapies to treat cystic fibrosis (CF) patients. We are also working to identify CF’s specific defect in chloride channel regulation. One recent study showed that insulin-like growth factor 1 (IGF-1) enhances the protein expression of CFTR.

Work in the Wei Dong Gao Lab primarily focuses on heart failure and defining molecular and cellular mechanisms of contractile dysfunction. We use molecular biology and proteomic techniques to investigate the changes that myofilament proteins undergo during heart failure and under drug therapy. We're working to determine the molecular nature of nitroxyl (HNO) modification of tropomyosin.

The Landon King Lab studies aquaporins water-specific membrane channel proteins. We hope to understand how these proteins contribute to water homeostasis in the respiratory tract and how their expression or function may be altered in disease states.

The Krummey Lab is a part of the Department of Pathology at the Johns Hopkins School of Medicine.

Our research prioritizes understanding the cellular mechanisms of alloimmunity, with a concentration on manipulating various cosignaling receptors and antigen recognition pathways to restrain the key lymphocytes principally involved in graft rejection. With the use of MHC tetramers, transgenic mouse models, and high-dimensional flow cytometry, we focus on mouse- and human-graft specific CD8+ T cells, CD4+ T cells, and B cells.

Transplantation is a life-saving procedure against a variety of diseases. Despite technical advances vastly improving early outcomes after transplant, long-term survival of transplanted organs has remained stagnant for the better part of three decades. A major cause of graft loss is immune-mediated rejection, which traditionally has be classified as acute or chronic based on its occurrence early or late after transplantation. Recently, this consensus has shifted to defining a graft rejection by its immunologic characteristics, either antibody-mediated or T cell-mediated (cellular rejection). This is because modern discoveries have identified the true major contributor to graft failures that occur many years after transplantation: not chronic rejection, but rather the cumulative impact of T cell-mediated acute rejection as a risk factor for later graft loss. Thus, original approaches to specifically prohibit and/or treat T cell-mediated acute rejection are of major significance for improving post-transplant outcomes.

HLA compatibility has also proven to be paramount for graft rejection. Originally, this was believed to be at the cellular level, then the single HLA protein level, and now at the epitope or molecular mismatch level. Specifically, HLA class II epitope-level mismatch has been identified as a risk factor for graft rejection, and multiple studies have identified specific epitopes within HLA class II peptides that are thought to be highly pathogenic. Few techniques directly measure antibody responses against specific regions of HLA proteins, but such measurements could provide both new information about the strength and character of alloimmunity and serve as an important new tool to study allogeneic B cells and antibody-secreting cells.

The Tom Woolf Lab studies the quarter of the genome devoted to membrane proteins. This rapidly growing branch of bioinformatics, which includes computational biophysics, represents the main research direction of our group. We aim to provide insight into critical issues for membrane systems. In pursuit of these goals, we use extensive computer calculations to build an understanding of the relations between microscopic motions and the world of experimental measurements. Our calculations use our own Beowulf computer cluster as well as national supercomputer centers. An especially strong focus has been on the computed motions of proteins and all-atom models of the lipid bilayers that mediate their influence. To compute these motions, we use the molecular dynamics program CHARMM. We hope to use our understanding of the molecular motions for the prediction of membrane protein structures using new computational methods.

The nervous system has extremely complex RNA processing regulation. Dysfunction of RNA metabolism has emerged to play crucial roles in multiple neurological diseases. Mutations and pathologies of several RNA-binding proteins are found to be associated with neurodegeneration in both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). An alternative RNA-mediated toxicity arises from microsatellite repeat instability in the human genome. The expanded repeat-containing RNAs could potentially induce neuron toxicity by disrupting protein and RNA homeostasis through various mechanisms. The Sun Lab is interested in deciphering the RNA processing pathways altered by the ALS-causative mutants to uncover the mechanisms of toxicity and molecular basis of cell type-selective vulnerability. Another major focus of the group is to identify small molecule and genetic inhibitors of neuron toxic factors using various high-throughput screening platforms. Finally, we are also highly interested in developing novel CRISPR technique-based therapeutic strategies. We seek to translate the mechanistic findings at molecular level to therapeutic target development to advance treatment options against neurodegenerative diseases.