Current Lab Members
Katya Heldwein, PhD
Principal Investigator
Katya received her PhD from Oregon Health Sciences University in Portland, OR, where she studied ligand recognition by bacterial transcription regulators using x-ray crystallography in the laboratory of Richard Brennan. She then did her postdoctoral work at Harvard Medical School in the laboratory of Stephen Harrison, where she initially worked on clathrin adaptor complexes and later delved into herpesvirus cell entry. She opened her own laboratory at Tufts University School of Medicine in the Fall of 2006.
Mohammad Karimian Shamsabadi, PhD
Postdoctoral Fellow
Mohammad earned his PhD in Biomedical Engineering from the University of Massachusetts Dartmouth in 2024. His research focused on the structural mechanisms by which HIV-1 Nef antagonizes SERINC, CD4, and MHC-I, and he developed high-throughput screening assays to identify inhibitors of Nef. He previously obtained his BS and MS in Chemical Engineering from Sharif University of Technology in Iran. Currently, Mohammad’s work investigates the structural basis of the interaction between HCMV glycoprotein B in its prefusion state and antibodies.
Bing Dai, PhD
Postdoctoral Fellow
Bing earned his PhD in Genetic, Molecular, and Cell Biology from Tufts University in 2026. During his doctoral work, he identified and characterized the role of host protein CLCC1 in HSV nuclear egress. He received a Bachelors in Medicinal Chemistry from China Pharmaceutical University in Nanjing, China and a Masters Pharmacology and Drug Development from Tufts. His current project is investigating virally encoded CLCC1 homologs in Malacoherpesviridae and Alloherpesviridae.
Nathalie Lavoie
PhD Student, Molecular Microbiology Program
Nathalie received a Bachelor’s degree in Biology from Boston College and a Master's in Spatial Analysis for Public Health from Johns Hopkins University. She is using quantitative fluorescence microscopy and cryo-electron microscopy to study how the nuclear egress coat (NEC) assembles at the capsid interface.
Nicolas Romero, PhD
Postdoctoral Fellow
Nicolas studied molecular and cellular biology and virology in the laboratory of Dr. Jose Francisco Rodriguez Aguirre at the Spanish National Centre for Biotechnology. He then earned his Ph.D. from Ghent University in Dr. Herman Favoreel's laboratory. He joined Dr. David Knipe’s laboratory at Harvard Medical School as a postdoctoral fellow. Nicolas is currently embarking on his second postdoctoral fellowship in the Heldwein Lab, where he is investigating the molecular determinants of CLCC1-driven HSV-1 nuclear egress.
Maria K. McClave
PhD Student, Molecular Microbiology Program
Maria received her BA in Molecular and Cell Biology from the University of California, Berkeley. Her current project focuses on characterizing the structure of the HCMV fusogen, gB, and its interactions with both new and existing neutralizing antibodies using electron microscopy and by developing HCMV-specific functional assays.
Leah (Chanyoung) Lee
PhD Student, Molecular Microbiology Program
Leah (Chanyoung) earned her Bachelor’s degree in Food Science and her Master’s degree in Food Microbiology from Seoul National University, South Korea. She began her PhD investigating the role of the cytoplasmic domains of HCMV gB and gH in fusion regulation, work now published in mBio. Her current project focuses on determining HCMV gB structure with gH/gL/gO trimer in the context of native membrane using a synthetic polymer.
Ariana Calkwood Calderón-Zavala
PhD Student, Molecular Microbiology Program
Ariana received her Bachelor's in Biochemistry and Molecular Biology at Lawrence University in Appleton, WI. She completed her post-baccalaureate in Cell, Molecular, and Developmental Biology at Tufts University GSBS in Boston, MA. Her project focuses on elucidating the role of the nuclear egress complex in gamma-herpesviruses, such as KSHV.
Adrian Sperl
PhD Student, GMCB
Adrian received his Bachelor’s degree in Chemical Engineering/Biochemistry from Northeastern University. His current project involves determining the structure of host chloride channel CLCC1 and investigating its role in HSV-1 nuclear egress.
Brian Cieslewicz
PhD Student, Molecular Microbiology Program
Brian received his BS in Chemical Engineering from Northeastern University. His project focuses on characterizing pre- and post-fusion conformations of the viral fusogen gB across various human herpesviruses.
Hunter Russell
PhD Student, GMCB
Hunter received a Bachelor’s degree in Biology from the College of the Holy Cross in Worcester, MA. Currently, his project focuses on the entry of Alphaherpesviruses, namely HSV-1 and HSV-2. The main goal of the project is to characterize the structure and interactions of the gD-gHgL complex, using a mAb to help stabilize the complex.
Jacob Grant
PhD Student, Molecular Microbiology Program
Jacob earned his Bachelor's of Science in Biology from Brandeis University. His project focuses on characterizing the effector functions of new monoclonal antibodies targeting HCMV gB and on investigating their combined mechanisms through antibody cocktails.