Project Grant F32AI197522

The National Institute of Allergy and Infectious Diseases awarded The Johns Hopkins University $152,600 on October 15, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to investigate the neural basis of spatial repellency in the malaria mosquito Anopheles gambiae.

The research identifies active ingredients in lemongrass oil species (Cymbopogon citratus, Cymbopogon flexuosus, and Cymbopogon pendulus) that drive spatial repellency and determines the underlying neural mechanisms. Work in Aim 1 characterizes the repellency and mode of action for individual chemical components across the three lemongrass species. Aim 2 investigates which olfactory sensory neurons respond to these active ingredients using transgenic mosquitoes expressing a calcium-sensing fluorescent marker, then identifies the odorant receptors expressed by olfactory receptor neurons via microdissection and RNA-seq and evaluates their individual responses.

The project addresses the limited options for spatial repellents—which act at distance to prevent mosquitoes from entering areas such as homes—by clarifying chemosensory pathways that enable screening and optimization of repellent candidates. Understanding spatial repellency mechanisms supports synergistic use of repellents alongside other mosquito-control strategies to prevent transmission of mosquito-borne diseases.

Performance takes place in Baltimore, Maryland. The period of performance runs from October 15, 2026 through August 31, 2029. The assistance type is a Project Grant.