Meghan E. Hermance, PhD
Dr. Meghan Hermance joined the Department of Microbiology and Immunology in 2020. She received her Baccalaureate Degree from Texas A&M University and her Ph.D. from The University of Texas Medical Branch. Her training provided significant experience in conducting biosafety level 3 research with emerging arthropod-borne viruses (arboviruses), including maintenance of infected tick and mosquito colonies in biocontainment facilities, and arthropod-host-virus transmission systems in animal models.
Vector Biology and Emerging Arthropod-borne Viruses
The emergence of certain arboviruses is exemplified, but not limited to, the recent outbreaks of Zika virus in the Western Hemisphere; therefore, it is critical to improve our understanding of the factors that contribute to virus emergence and transmission. The Hermance lab uses tick-host-virus models to elucidate the determinants of tick-borne virus transmission and pathogenesis. Within this framework, the research team seeks to discover biological weak links in arbovirus transmission cycles that can be targeted for novel disease control strategies.
Ability of Invasive Tick Species to Transmit North American Arboviruses
The invasive Asian Longhorned tick, Haemaphysalis longicornis, is native to eastern Asia but recently established populations in the United States and continues to expand its geographic range. This is a public health threat, because in its native range, H. longicornis is an established vector of viruses closely related to Heartland virus (HRTV) and Deer tick virus (DTV), which are the two main North American tick-borne viruses. Dr. Hermance’s lab is assessing the ability of H. longicornis to acquire, maintain, and transmit North American tick-borne viruses. Their ongoing studies are evaluating the vector competence of H. longicornis for HRTV and DTV, and investigating whether non-viremic transmission of these viruses occurs between infected native tick species co-feeding on the same host as uninfected H. longicornis. With access to state-of-the-art arthropod biocontainment level-2 and level-3 (ACL-2/3) research facilities, the Hermance lab is uniquely poised to conduct additional vector competence assessments for emerging tick- and mosquito-borne viruses.
Tick-Virus-Host Interactions at the Cutaneous Interface
Skin is the interface between an attached, feeding tick and a host; consequently, it serves as the first line of defense against invading pathogens delivered to a host via tick saliva. The rapid transmission of tick-borne viruses from tick saliva to mammalian host during the process of tick blood feeding underscores the importance of investigating the initial cutaneous immunomodulation and virus transmission. Expanding on her previous research examining the role of Ixodes scapularis tick feeding on the early host cutaneous immune response and transmission of the tick-borne flavivirus, Powassan virus, Dr. Hermance and her research team are currently investigating the cutaneous host immunomodulation caused by virus-infected H. longicornis tick feeding while examining components of the H. longicornis sialome implicated in facilitating virus transmission and dissemination. They hypothesize that expression of key secreted H. longicornis salivary proteins during the early stages of virus-infected tick feeding creates an immunologically privileged micro-environment in the host’s skin, facilitating virus transmission. A long-term goal for the research team is to generate a transmission blocking vaccine for H. longicornis-borne viruses based on antigenic combinations of H. longicornis salivary proteins that facilitate virus transmission from tick to the mammalian host.
Neuroinvasion and Neuropathogenesis of Emerging Arboviruses
During feeding, ticks inoculate pathogens, including neurotropic flaviviruses such as Powassan virus (POWV), into the highly innervated host skin. It is well documented that neuroinvasive POWV cases are associated with neurological complications of both the central and peripheral nervous systems, including acute encephalitis, aseptic meningitis, acute flaccid paralysis, seizures, and other peripheral neuropathies. What remains lacking, however, is an understanding of whether neurotropic flaviviruses can infect cutaneous peripheral neurons adjacent to the vector feeding site, resulting in modulation of neuron-immune cell interactions and/or virus dissemination. Ongoing studies in the Hermance lab are investigating potential mechanisms of flavivirus neuroinvasion and neuro-immune crosstalk at the skin site of vector feeding. The goal of this research is to further understanding of the neuropathogenesis of flavivirus infections and to develop novel therapeutic interventions for these diseases.