The John Schroeder Lab focuses on understanding the role human basophils and mast cells play in allergic reactions, as it relates not only to their secretion of potent inflammatory mediators (e.g., histamine and leukotriene C4) but also to their production of pro-inflammatory cytokines. We have long utilized human cells rather than cell lines in order to address the parameters, signal transduction and pharmacological aspects underlying clinically relevant basophil and mast cell responses. As a result, the lab has established protocols for rapidly isolating large numbers of basophils at high purity from human blood and for growing culture-derived mast cells/basophils from human progenitor cells. A variety of assays and techniques are also in place for concurrently detecting cytokines and mediators following a wide range of stimuli. These have facilitated the in vitro testing of numerous anti-allergic drugs for inhibitory activity on basophil and mast cell activation. The lab also studies counter-regulation between the IgE and innate immune receptors on human immature dendritic cell subtypes.

The Jun O. Liu Laboratory tests small molecules to see if they react in our bodies to find potential drugs to treat disease. We employ high-throughput screening to identify modulators of various cellular processes and pathways that have been implicated in human diseases from cancer to autoimmune diseases. Once biologically active inhibitors are identified, they will serve both as probes of the biological processes of interest and as leads for the development of new drugs for treating human diseases. Among the biological processes of interest are cancer cell growth and apoptosis, angiogenesis, calcium-dependent signaling pathways, eukaryotic transcription and translation.

Dr. Sohn's lab is interested in understanding how biological stress-sensors are assembled, detect danger signals and initiate stress response. Innate immunity is the first line of defense against invading pathogens in higher eukaryotes. We are using in vitro quantitative biochemical assays and mutagenesis and x-ray crystallography to investigate the underlying operating principles of inflammasomes, a component of the innate immune system, to better understand biological stress sensors.

We leverage both yeast and mammalian systems to study the processes of mRNA translation and mRNA stability.

The Phenotyping Core promotes functional genomics and other preclinical translational science at Johns Hopkins. We assist and collaborate in the characterization and use of genetically and phenotypically relevant animal models of disease and gene function.

Researchers in the Center for Cell Dynamics study spatially and temporally regulated molecular events in living cells, tissues and organisms. The team develops and applies innovative biosensors and imaging techniques to monitor dozens of critical signaling pathways in real time. The new tools help them investigate the fundamental cellular behaviors that underlie embryonic development, wound healing, cancer progression, and functions of the immune and nervous systems.

The McCallion Laboratory studies the roles played by cis-regulatory elements (REs) in controlling the timing, location and levels of gene activation (transcription). Their immediate goal is to identify transcription factor binding sites (TFBS) combinations that can predict REs with cell-specific biological control--a first step in developing true regulatory lexicons. As a functional genetic laboratory, we develop and implement assays to rapidly determine the biological relevance of sequence elements within the human genome and the pathological relevance of variation therein. In recent years, we have developed a highly efficient reporter transgene system in zebrafish that can accurately evaluate the regulatory control of mammalian sequences, enabling characterization of reporter expression during development at a fraction of the cost of similar analyses in mice. We employ a range of strategies in model systems (zebrafish and mice), as well as analyses in the human population, to illuminate the genetic basis of disease processes. Our long-term objective is to use these approaches in contributing to improved diagnostic, prognostic and therapeutic strategies in patient care.

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.

Prostate cancer is the most commonly diagnosed malignancy in men in the United States, although our understanding of the molecular basis for this disease remains incomplete. We are interested in characterizing consistent alterations in the structure and expression of the genome of human prostate cancer cells as a means of identifying genes critical in the pathways of prostatic carcinogenesis. We are focusing on somatic genomic alterations occurring in sporadic prostate cancers, as well as germline variations which confer increases in prostate cancer risk. Both genome wide and candidate gene approaches are being pursued, and cancer associated changes in gene expression analyses of normal and malignant prostate cells are being cataloged as a complementary approach in these efforts. It is anticipated that this work will assist in providing more effective methodologies to identify men at high risk for this disease, in general, and in particular, to identify new markers of prognostic and therapeutic significance that could lead to more effective management of this common disease.

The Green Group is the biomaterials and drug delivery laboratory in the Biomedical Engineering Department at the Johns Hopkins University School of Medicine. Our broad research interests are in cellular engineering and in nanobiotechnology. We are particularly interested in biomaterials, controlled drug delivery, stem cells, gene therapy, and immunobioengineering. We are working on the chemistry/biology/engineering interface to answer fundamental scientific questions and create innovative technologies and therapeutics that can directly benefit human health.