Dr. Vu’s research explores how biological systems respond to stress, infection, and environmental change. Current and past projects span insect stress tolerance, COVID-19 health disparities, and bacterial pathogenesis, with an emphasis on survival mechanisms, host-pathogen interactions, and the broader biological and community contexts that shape health outcomes.
Students in the lab gain experience with model organism maintenance, experimental setup, survey-based research, and data collection across projects related to environmental stress, infectious disease, and community health.
Insect Projects
The Vu Lab investigates how environmental stressors, particularly extreme temperature fluctuations and seasonal photoperiod cues, shape physiological stress tolerance, cellular protection, and survival across insect species.
1. Seasonal Biological Rhythms & Thermal Plasticity
Poikilothermic insects rely on seasonal environmental cues like photoperiod and temperature to regulate neuroendocrine acclimation pathways, inducing the synthesis of cryoprotective antifreeze proteins (AFPs), antifreeze glycolipids (AFGLs), and polyols (such as glycerol and sorbitol) prior to winter. Our lab discovered a paradoxical seasonal phenomenon: winter-acclimated cold-tolerant larvae exhibit higher upper lethal temperatures (ULTs) in winter than in summer.
- Fire-colored beetle (Dendroides canadensis): Winter larvae achieve a 24-hour upper lethal temperature limit of 40.9°C compared to 36.7°C in summer, expanding their total functional survival range to 64°C in winter versus 41°C in summer.
- Red flat bark beetle (Cucujus clavipes clavipes): Freeze-avoiding larvae maintain over 75% survivorship at 39°C during winter months, compared to 0% survival in spring and summer.
- Cranefly (Tipula trivittata): Freeze-tolerant larvae similarly demonstrate significantly heightened heat tolerance (35°C survival) in winter relative to warm seasons.
2. Antifreeze Proteins & Neuro-Cellular Membrane Stabilization
Thermal stress and seasonal remodeling of cell membrane phospholipids can disrupt inorganic ion homeostasis and cause cellular damage. Our work demonstrates that insect-derived antifreeze proteins (DAFPs), traditionally studied for subzero survival, also serve a thermoprotective role by stabilizing biological membranes and preventing thermal damage. Expressing D. canadensis antifreeze proteins (DAFP-1 and DAFP-4) in transgenic fruit flies (Drosophila melanogaster) significantly elevates their upper lethal temperature limits, demonstrating cross-protective cellular stabilization across broad thermal extremes.
3. Social Neurobiology & Sex-Based Grouping Dynamics
Current projects using Drosophila melanogaster evaluate how social environment and sex-based grouping structures (female-only, male-only, and mixed-sex cohorts) modulate stress survival under temperature challenge. This research links neuro-behavioral interactions, social structure, and physiological resilience to uncover how social context influences stress coping mechanisms.
Benmore, C. J., Gallington, L. C., Vu, H., Duman, J. G., Barnes, B. M., & Sformo, T. L. (2025). Supercooling of Alaskan beetle larvae as a winter survival strategy. Small Science. Link
Compares cold-adaptation strategies in Indiana and Alaskan beetle larvae of the same species.
Brockbank, K. G. M., Duman, J. G., Chen, Z., Greene, E. D., Vu, H. M., & Campbell, L. H. (2020). Cell, tissue, and organ preservation with insect-derived antifreeze peptides. In H. Ramløv & D. S. Friis (Eds.), Antifreeze proteins volume 2 (pp. 261-285). Springer. Details efforts using insect-derived recombinant antifreeze proteins for short- and long-term mammalian cell, tissue, and organ storage strategies.
Vu, H. M., Pennoyer, J. E., Ruiz, K. R., Portmann, P., & Duman, J. G. (2019). Beetle, Dendroides canadensis, antifreeze proteins increased high temperature survivorship in transgenic fruit flies, Drosophila melanogaster. Journal of Insect Physiology. Link
Examines whether antifreeze proteins from cold-tolerant beetles can also improve high-temperature survival in transgenic fruit flies.
Vu, H. M., & Duman, J. G. (2017). Upper lethal temperatures in three cold-tolerant insects are higher in winter than in summer. Journal of Experimental Biology. Link
Shows that several cold-tolerant insects survive higher temperatures in winter than in summer, suggesting seasonal changes in broader temperature tolerance.
Some insect larvae tolerate high temperatures better during winter. Journal of Experimental Biology, 2017. Link
A research highlight summarizing Vu and Duman’s finding that cold-tolerant insect larvae can show unexpectedly higher heat tolerance during winter.
COVID-19 Health Disparities & Long COVID Cognitive Outcomes
This community-based survey project examines how COVID-19 and Long COVID impact the Michiana region, with a strong focus on health equity in vulnerable populations.
As our research expands into neuro-behavioral frameworks, we are specifically investigating the prevalence and severity of lingering cognitive symptoms, such as persistent brain fog, executive dysfunction, and memory difficulties. By pairing epidemiological survey data with a neuroscience-focused lens, we aim to understand how systemic social disparities influence post-viral neurological recovery.
Bacteria Projects
The lab also studies host-pathogen interactions, with a focus on how bacteria interact with human biological systems during infection. Projects examine how Group A Streptococcus survives within fibrin clots, accesses human plasminogen, and contributes to clot breakdown, wound-site changes, and bacterial dissemination. This work helps clarify mechanisms of bacterial survival and spread while connecting microbiology, inflammation, coagulation, and infectious disease.
Vu, H. M., Moran, T. E., Liang, Z., Bao, Y.-J., Carles, P. G., Keane, J. C., Cerney, M. G., Dahnke, C. N., Flores-Mireles, A. L., Ploplis, V. A., Castellino, F. J., & Lee, S. W. (2025). Group A Streptococcus remains viable inside fibrin clots and gains access to human plasminogen for subsequent fibrinolysis and dissemination. Microbiology Spectrum. Link
Investigates how Group A Streptococcus can remain viable within fibrin clots before activating plasminogen-mediated clot breakdown and dissemination.
Vu, H. M., Hammers, D. E., Liang, Z., Nguyen, G. L., Benz, M. E., Moran, T. E., Higashi, D. L., Park, C. J., Ayinuola, Y. A., Donahue, D. L., Flores-Mireles, A. L., Ploplis, V. A., Castellino, F. J., & Lee, S. W. (2021). Group A Streptococcus-induced activation of human plasminogen is required for keratinocyte wound retraction and rapid clot dissolution. Frontiers in Cardiovascular Medicine. Link
Uses wound and fibrin clot models to study how Group A Streptococcus activates human plasminogen during clot dissolution and wound-site dissemination.
Fields, F. R., Manzo, G., Hind, C. K., Janardhanan, J., Foik, I. P., Silva, P. D. C., Balsara, R. D., Clifford, M., Vu, H. M., Ross, J. N., Kalwajtys, V. R., Gonzalez, A. J., Bui, T. T., Ploplis, V. A., Castellino, F. J., Siryaporn, A., Chang, M., Sutton, J. M., Mason, A. J., & Lee, S. (2020). Synthetic antimicrobial peptide tuning permits membrane disruption and interpeptide synergy. ACS Pharmacology & Translational Science, 3, 418-424. Link Explores ribosomally produced bacterial antimicrobial peptides as an unexplored source of membrane-active antibiotics by demonstrating tunable pore-formation dynamics.
Kane, T., Carothers, K. E., Bao, Y., Yeo, W.-S., Bae, T., Park, C., Fields, F. R., Vu, H. M., Hammers, D. E., Ross, J. N., Ploplis, V. A., Castellino, F. J., & Lee, S. W. (2019). Discovery of genes encoding a Streptolysin S-like toxin biosynthetic cluster in a select highly pathogenic methicillin resistant Staphylococcus aureus JKD6159 strain. bioRxiv. Link Identifies a Streptolysin S-like biosynthetic gene cluster in a highly virulent community-acquired MRSA isolate.