Axon Initial Segment in Mammalian Brain Function / Nanomaterials for Inducing Antigen-Specific IT
Wednesday, October 21, 2020
9:00 AM-10:30 AM
BIOMED Dual Seminar
Title Seminar #1:
Roles of the Axon Initial Segment in Mammalian Brain Function Under Physiological and Pathological Conditions
Dr. Shuijin He
School of Life Science and Technology
A neuron has specialized structures that consist of the dendrite, the axon and the axon initial segment (AIS). The AIS is the site that connects the soma and the distal axon, and responsible for generating an action potential in a neuron by integration of all information that the dendrite receives from other neurons. Then the action potential propagates along the axon to the axonal terminals, which make connections with the dendrite of other neurons by releasing neurotransmitters. Recently, super-resolution imaging uncovered a periodic arrangement of AIS cytoskeletal proteins, exhibiting rings spaced approximately 190 nm apart. During normal development, the AIS undergoes dynamic changes in the length and location in response to synaptic inputs. This activity-dependent AIS plasticity is crucial for shaping neural networks of the nervous system. Likewise, the AIS cytoskeleton undergoes rapid and irreversible disruption prior to cell death after injury, and loss of AIS integrity can produce profound neurological effects on the nervous system. In this presentation, I will talk about how AIS diameter is regulated in the mammalian neocortex and what roles AIS diameter likely plays in brain functions under physiological conditions. Then I will further discuss the mechanism for an ischemia-induced alteration in AIS integrity.
Shuijin He, PhD, is an assistant professor in the School of Life Science and Technology at ShanghaiTech University. Dr. He received a BS in biochemistry from the Lanzhou University in 2000, an MS in biophysics from the University of Science and Technology of China in 2003, and a PhD in neuroscience from Uniformed Services University in the USA in 2010. Following a research fellowship at the Memorial Sloan Kettering Cancer Center in New York City, Dr. He established his lab at ShanghaiTech University in 2015. His lab is interested in elucidating how neural circuits precisely assemble during development at both the molecular and cellular levels using electrophysiological methods, combined with super-resolution imaging, single cell sequencing, and genetic tools.
Title Seminar #2:
Nanomaterials for Inducing Antigen-Specific Immune Tolerance
Hao Cheng, PhD
Department of Materials Science and Engineering (MSE)
Induction of antigen-specific immune tolerance, which reduces autoreactive immune cells and generates antigen-specific regulatory T cells in patients, is a promising strategy for curing autoimmune diseases. Systemic administration of poly(lactic-co-glycolic acid) (PLGA) nanoparticles with auto-antigen peptides have been demonstrated to induce antigen-specific immune tolerance in experimental autoimmune encephalitis (EAE), a murine model of multiple sclerosis. However, the same nanoparticles failed to alleviate the disease after subcutaneous (s.c.) injection. S.c. administration has the potential advantage in spatiotemporally modulating immune cells in a well-controlled microenvironment. It is unknown what material properties are necessary for inducing tolerance via s.c. administration. Addressing this question will advance nanomaterial design for immune tolerance. We have found PLGA nanoparticles induced inflammatory responses after s.c. injection in mice. After reducing the complement activation of nanoparticles, we show that nanoparticles encapsulating MOG peptide can induce antigen-specific immune tolerance in EAE after disease onset via s.c. administration of the nanomaterials.
Hao Cheng, PhD, is an associate professor in the Department of Materials Science and Engineering (MSE) at Drexel University. He received his BE and MS degrees in Chemical Engineering from Tsinghua University in 1999 and 2001, respectively. Dr. Cheng completed his PhD in Materials Science and Engineering at Northwestern University in 2005. Prior to joining Drexel University in 2012, he was a postdoctoral associate at Northwestern University and MIT. Dr. Cheng's laboratory focuses on cell membrane-derived hydrogels, long circulating nanoparticles, and biomaterials/biological materials for inducing antigen-specific immune tolerance. As a corresponding or co-corresponding author, Dr. Cheng has published in journals, such as ACS Nano, Advanced Materials, Nano Letters, Nature Communications, and Advanced Drug Delivery Reviews. He was a recipient of the inaugural Nano Research Young Innovators Award in Nanobiotechnology in 2018.