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 Radiopharmaceutical Therapy and Dosimetry (RTD) Lab has two missions: 1. Support clinical Radiopharmaceutical Therapy (RPT) trials by performing patient-specific dosimetry and developing novel methods that advance this field and illustrate the impact of a precision medicine approach to implementing treatment planning in RPT. This includes radiobiological modeling and microscale dosimetry calculations for alpha-particle emitter RPT. 2. Pre-clinical studies using novel alpha-emitter RPT agents with immune intact transgenic animal models that incorporate modeling and dosimetry to support the translation of novel targeted radionuclide therapy strategies to the clinic. In particular, identifying how to best combine RPT with complementary orthogonal-modality agents while also obtaining a basic understanding of how the treatment works and which variables have the greatest impact on efficacy and toxicity. The underlying objective is to utilize pre-clinical modeling and dosimetry to help identify an optimal therapeutic clinical trial design so as to reduce unnecessary human experimentation.

The Lane laboratory is focused on understanding molecular mechanisms underlying chronic rhinosinusitis, particularly the pathogenesis of nasal polyps, as well as inflammation on the olfactory epithelium. Diverse techniques in molecular biology, immunology, and physiology are utilized to study epithelial cell innate immunity, olfactory loss, and response to viral infection. Ongoing work explores how epithelial cells of the sinuses and olfactory mucosa participate in the immune response and contribute to chronic inflammation. The lab creates and employs transgenic mouse models of chronic nasal/sinus inflammation to support research in this area. Collaborations are in place with the School of Public Health to explore mechanisms of anti-viral immunity in influenza and COVID-19.

Chronic rhinosinusitis (CRS) is a leading cause of morbidity globally and is the single most common self-reported chronic health condition and accounts for billions of dollars in health care costs and lost work days annually. Exposure to air pollutants is thought to be a critical modifier of CRS susceptibility. Despite marked reductions in air pollution levels in the United States, the fine particulate component of air pollution (PM2.5) and ultrafine pollutants secondary to traffic continue to remain a recalcitrant issue globally and in the United States. The Ramanathan Lab focuses on studying the role of air pollution (PM2.5) in CRS. In collaboration with scientists at the Bloomberg School of Public Health, we have utilized a state of the art air pollution exposure system to develop a novel mouse model of air pollution induced rhinosinusitis that mimics many of the features of CRS in humans. Our lab uses transgenic mouse models and novel immunologic/genomic techniques to study the mechanisms by which PM2.5 causes eosinophilic inflammation and sinonasal epithelial barrier dysfunction. We are also interested in the role of the antioxidant transcription factor, Nrf2, which has shown to stabilize the epithelial barrier and reduce eosinophilia in PM induced rhinosinusitis as a potential therapeutic target.

Dr. Ross and his research team have focused on Huntington's disease and Parkinson's disease, and now are using insights from these disorders to approach more complex diseases such as schizophrenia and bipolar disorder. They use biophysical and biochemical techniques, cell models, and transgenic mouse models to understand disease processes, and to provide targets for development of rational therapeutics. These then can provide a basis for developing small molecule interventions, which can be used both as probes to study biology, and if they have favorable drug-like properties, for potential therapeutic development. We have used two strategies for identifying lead compounds. The first is the traditional path of identification of specific molecular targets, such as enzymes like the LRRK2 kinase of Parkinson’s disease. Once structure is known, computational approaches or fragment based lead discovery, in collaboration, can be used. The second is to conduct phenotypic screens using cell models, or in a collaboration, natural products in a yeast model. Once a lead compound is identified, we use cell models for initial tests of compounds, then generate analogs, and take compounds that look promising to preclinical therapeutic studies in animal models. The ultimate goal is to develop therapeutic strategies that can be brought to human clinical trials, and we have pioneered in developing biomarkers and genetic testing for developing strategies.