Benjamin K Chen, MD, PhD
- PROFESSOR | Medicine, Infectious Diseases
- PROFESSOR | Microbiology
- PROFESSOR | Pharmacological Sciences
Research Topics:Antivirals, Cell Adhesion, Cell Motility, Cytoskeleton, HIV/AIDS, Image Analysis, Imaging, Immune Deficiency, Immunology, Infectious Disease, Integrins, Lymphocytes, Lysosomes/endosome, Macrophage, Migration, Molecular Biology, Protein Trafficking & Sorting, RNA Transport & Localization, Retrovirus, Synapses, T Cells, Trafficking, Two-Photon Imaging, Vaccine Development, Viruses and Virology
Benjamin K. Chen, MD, PhD, is a Professor in the Division of Infectious Diseases, Department of Medicine, at the Icahn School of Medicine at Mount Sinai School of Medicine. He currently serves as the Irene and Dr. Arthur M. Fishberg Professor of Medicine, the Vice Chair for Research in the Department of Medicine and as an Associate Director for the Medical Scientist Training Program in the Icahn School of Medicine. He received his MD from Weill Medical College-Cornell University and his PhD at Rockefeller University studying human immunodeficiency virus type 1 (HIV-1) biology with the Nobel Laureate, Dr. David Baltimore. During his post doctoral fellowship at the Whitehead Institute for Biomedical Research with Dr. Peter S. Kim he studied HIV-1 assembly.
Benjamin Chen’s Laboratory studies the pathogenesis of HIV-1 infection and has revealed how cell-to-cell transmission of the virus contributes to disease. His group has used imaging approaches to uncover the formation of transmission-promoting structures called virological synapses. The images have revealed how the virus facilitates its spread by exploiting dynamic exchange of virus between cells. The lab has also revealed how the virological synapses promote immune evasion and allow the virus to maintain high genetic diversity. Recent studies have captured images of infected cells in living hosts measuring the influence of infected cells on the cell movements and interactions with uninfected recipient cells. These studies provide live images of the spread of HIV-1 within living immune tissues. The lab’s work on virological synapses contributes to the development of new drug, vaccine and microbicide approaches.
In The News
Transfer of HIV Between T Cells Captured on Video
Mount Sinai researchers and colleagues have for the first time captured on video the transfer of human immunodeficiency virus (HIV) from infected to uninfected T cells.
Find out more here
Multi-Disciplinary Training AreasImmunology [IMM], Microbiology [MIC], Pharmacology and Therapeutics Discovery [PTD]
BAS, Stanford University
MD, Weill Medical College of Cornell University
PhD, The Rockefeller University
Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology
Avant Garde Award in HIV/AIDS research
Burroughs Wellcome Fund Investigator in the Pathogenesis of Infectious Diseases
Irma T. Hirschl Monique Weill-Caulier Career Scientist Award
National Research Service Award, National Institute for Allergy and Infectious Disease
Graduation with Honors in Biological Sciences
Graduation with Distinction in Philosophy
Current Students: MD/PhD: Chati Zony, Graduate: Natasha Durham, Kenneth Law, Hongru Li
Postdoctoral Fellows: Ray Alvarez, Anthony Esposito, Lili Wang
Research Faculty: Ping Chen, Talia Swartz
Summary of Research Studies:
Mechanisms of HIV cell-cell transmission
The efficiency of HIV spread in culture is greatly facilitated by cell contact between infected and uninfected CD4+ T cells. Infected T cells form adhesive contacts with uninfected CD4+ T cells. These contacts are called virological synapses (VS) because of similarity to other adhesive structures in the immune system call immunological synapses. VS require viral Env proteins to be expressed on the cell surface where they interact with CD4 on target cells. Using infectious, fluorescent virus clones we are able to quantify and visualize the amount of viral transfer that occurs through VS. Live, video rate confocal microscopy allowed us to visualize the changes in cellular distribution of the viral protein Gag that occurs during VS formation. We found that the VS causes the efficient transfer of viral particles into target T cells through an endocytic route that is still being characterized. We are working to understand the viral signals that allow virus assembly to be recruited to the VS and the cellular signaling pathways the work in both the VS donor and target cells.
Neutralization Resistance of VS
The VS-mediated viral infection can be resistant to patient antibodies that are capable of neutralizing homologous cell free virus. We are working to understand how the VS provides a mechanism for HIV to evade humoral immune responses. We found that the cytoplasmic tail of the Env glycoprotein, which is plays an important role in regulating fusion activity of Env, plays a role in the resistance of cell-cell infection to neutralization. We are testing a model whereby the conformational regulation of Env during VS formation is what makes cell-cell transmission more resistant to neutralization. We are studying patient neutralizing responses, and cloning B cells from patients to characterize potent cell-cell neutralizing activities.
Role of cell-cell transmission in vivo
We have been studying humanized mouse models to better understand how this mode of efficient viral dissemination contributes to viral spread in vivo. To overcome the inability of HIV to replicate in mouse cells, researchers have exploited mouse xenograft models that engraft human immune systems into immunocompromised mice. These mouse systems transplant human hematopoietic stem cells into immunodeficient mice and allow diverse lineages of human immune cells to develop. Importantly, the human immune systems are highly susceptible to HIV and can support sustained HIV viral loads in animals that are challenged. In humanized mouse systems, we are using whole animal imaging and intravital microscopy to understand how T cell migration and synapse formation contribute to HIV spread within a living organism.
For more information, please visit the Benjamin K. Chen Laboratory.