Manton Center Fellows

Erin Janssen MD PhD
Dr. Erin Janssen graduated with a B.S. in Biology from the Massachusetts Institute of Technology. She received her M.D. and Ph.D. degrees through the Medical Scientist Training Program at Duke University. Her graduate studies focused on signaling through the T and B cell receptors and their roles in lymphocyte development. In 2005, she joined the Boston Combined Residency Program for her pediatrics residency. After residency, Dr. Janssen remained at Boston Children's Hospital to pursue a clinical fellowship in Pediatric Rheumatology. She joined Dr. Raif Geha's laboratory in 2009 as an Immunology Research Fellow.

A focus of the Geha laboratory is elucidating the molecular basis of primary immunodeficiencies. Recently, DOCK8 deficiency has been identified as a cause of autosomal recessive hyper-IgE syndrome (AR-HIES). DOCK8 belongs to the DOCK180 superfamily of guanine nucleotide exchange factors. Beyond this, very little is known about DOCK8 function. Patients with DOCK8 deficiency have recurrent infections, especially chronic or recurrent viral skin infections, severe atopy, develop autoimmune phenomena, and appear to be at high risk for the development of malignancies. Dr. Janssen is developing a murine model of AR-HIES. She has devised two strategies to mimic both a point mutation and large deletions seen in AR-HIES patients. She plans to begin characterization of these mouse models in the coming year. Her focus will be on determining the roles of DOCK8 in lymphocyte development and the responses of the innate and adaptive immune systems to antigens. These studies will provide critical insight into the immune systems of patients with DOCK8 deficiency and may guide potential avenues for treatment.

Duyu Nie MD PhD
Dr. Duyu Nie received his medical degree from Xiang-ya School of Medicine (formerly Hunan Medical University) in China. He did his PhD training in neuroscience at National University of Singapore (NUS) Yong Loo Lin School of Medicine. His graduate research projects focused on understanding the role and molecular mechanism of axon-glia interactions during myelin development as well as for rewiring neural network after lesions to the central nervous system. He joined Dr. Mustafa Sahin’s laboratory at F. M. Kirby Neurobiology Center and Department of Neurology in 2007.

Dr. Nie continued his interests in studying the axon development and neuronal connectivity. The disease models that are extensively investigated in Dr. Mustafa Sahin’s laboratory include Tuberous Sclerosis Complex (TSC) and Spinal Muscular Atrophy (SMA). Particularly, they focus on dissecting the identity and regulation of mRNA transport and translation that governs all aspects of the axonal development, neuronal connectivity and synaptic plasticity, with a combination of biochemistry, genetic approach and imaging techniques. In particular, Dr. Nie has discovered that the local mRNA translation within the axonal growth cone is fine-tuned in response to a specific extracellular cue, namely ephrins. Dysregulated protein translation has emerged as a common defect in several genetic disorders characterized by intellectual disability and autism. Dr. Nie proposes to look into the mRNA profiling in neuronal models of TSC deficiency with an un-biased approach and further investigate axonal specification, growth cone dynamics and pre-synaptic differentiation regulated by specific mRNAs. This study has the potential to offer novel targets of treatment for patients with TSC and other related neurodevelopmental disorders.

Diane H Cho PhD
Dr. Diane H. Cho received her B.A. at Princeton University majoring in molecular biology, and her Ph.D. at the Univeristy of Washington’s Molecular and Cellular Biology Program. Her graduate training came from Dr. Stephen Tapscott’s laboratory at the Fred Hutchinson Cancer Research Center in Seattle, Washington where she studied the role of bidirectional transcription across an unstable repeat human disease locus, and demonstrated how local boundary elements and RNAi pathways are involved in establishing differential gene transcription and chromatin structure. She joined Dr. Suneet Agarwal’s laboratory in December 2011 to pursue her postdoctoral studies.

Dr. Cho will investigate how specific telomerase mutations can lead to dyskeratosis congenita by studying patient cells that have been reprogrammed into stem cells. Dyskeratosis congenita is a disease that is characterized by premature aging, increased cancer development and high rates of mortality through bone marrow failure. This disease can be attributed to genetic mutations affecting telomerase, a protein complex that is essential for establishing the interminable self-renewal capacity of stem cells. The latest technology in human genome engineering will be applied to correct the genetic defects and restore telomerase function in the patient iPS cells with the hopes that these studies will eventually have direct clinical impact.