The St. John lab research program focuses on understanding host immune responses to virulent pathogens:
Innate and adaptive immune responses to dengue: Dengue is a mosquito-borne virus infection. We use immune competent mouse models to identify the ways the host immune system responds to dengue infection.
Mast cell responses to viral pathogens: Mast cells are best known for their involvement in conditions such as asthma, allergy and anaphylaxis, however, they also can provide immune surveillance for viral pathogens such as dengue virus. We are learning that MC responses to different viruses are highly unique. Several projects in the lab focus on understanding how mast cells contribute to immune protection and pathology during viral infection.
Flavivirus-induced vascular pathology: Many flaviviral pathogens induce immune pathology involving vascular and/or blood brain barrier leakage. We are particularly interested in the role of mast cell derived proteases in inducing vascular permeability or blood brain barrier permeability.
Vertical transmission of allergic and infectious diseases: Zika virus is able to cross the placenta from mother to developing fetus. Members of our lab are investigating the mechanisms of vertical transmission of infection with emphasis on understanding how components of the immune system influence fetal infection. We are also investigating how maternal antibodies can induce or promote allergic diseases in their offspring.
Developing novel vaccination strategies, diagnostics, and therapeutics for infectious diseases: Highly host-adapted pathogens require specialized vaccine strategies for effective immune protection. We apply the knowledge gained in our basic research studies to develop novel vaccine strategies. We are also translating our findings that mast cell stabilizing drugs can limit dengue severity in animal models by working with collaborators at multiple institutions in Singapore to test whether mast cell stabilizing drugs can limit vascular leakage in dengue patients.