Insect vectors are critical components of the life cycle of many existing and newly emerging and pandemic infections in the world today, including malaria.
Several JHMRI groups pursue research addressing the population biology of mosquito disease vectors and their molecular interaction with human pathogens such as the Plasmodium parasite that causes malaria and the virus that causes dengue.
Dr. George Dimopoulos team mainly focuses on the mosquito’s innate immune system and the mosquito midgut microbiota, and how they interact with various human pathogens including Plasmodium and dengue virus, using genomics, functional genomics and molecular biology techniques and approaches. The research is largely focused at the basic science level, with a strong translational orientation. The long-term goal is to develop the next generation of novel mosquito-based disease control strategies.
Dr. Douglas Norris and his laboratory focus on genetic diversity within, and the genetic structuring of, arthropod and arthropod-borne pathogen populations. This approach, coupled with observations on vector foraging behavior, especially for malaria vectors, is critical for understanding which arthropod populations are important to disease transmission. The information gathered in these studies aids in the understanding of the evolution and genetic constraints of these vector-pathogen systems and may provide insight into how these cycles of disease may be disrupted. Most recently, his group’s research on fine scale temporal, spatial and foraging heterogeneity of malaria vectors in Zambia may illustrate why vector control has largely failed in that area. Current research activities in the laboratory are focused on malaria in Southern Africa and Asia, Lyme disease, Rickettsia-like and other tick-borne bacteria in the Eastern U.S. and dengue in South America.
Dr. Jennifer Stevenson is based at Macha Research Trust, Southern Zambia, an area targeted for elimination of malaria. She and colleagues study the bionomics of malaria vectors in the area and investigate where residual transmission may be occurring as part of the activities of the International Centers of Excellence in Malaria Research project (ICEMR). She also helps to oversee entomological monitoring and evaluation at two other ICEMR sites, in northern Zambia with highly endemic malaria and in eastern Zimbabwe, an area prone to epidemics. Recently the construction of a semi-field system was completed at Macha. This offers the unique opportunity to study mosquito behavior and response to novel control methods in a more realistic environment. She is also the site PI for a multi-site intervention study examining the protective efficacy of spatial repellents against malaria in eastern Zambia.
Dr. Marcelo Jacobs-Lorena's team focuses on the investigation of molecular mechanisms by which the malaria parasite develops in its vector mosquito thus allowing transmission from one vertebrate host to another. Previously, the laboratory developed a genetically modified mosquito that is impaired for parasite transmission. The team is currently exploring an alternative strategy to genetically modify symbiotic bacteria from the mosquito gut for the production of anti-parasitic substances. Mosquitoes carrying such bacteria are substantially impaired in parasite transmission. Separate projects in the laboratory are investigating 1) molecular interactions between male and female Plasmodium gametes; 2) how the malaria parasite recruits factors from the human host (plasminogen, tissue-type plasminogen activator) to allow it to cross the mosquito midgut; 3) how the mosquito defends itself from the malaria parasite infection (“early” and “late” oocyst death); and 4) how the malaria sporozoite leaves the human circulation to infect the liver.
Dr. Conor McMeniman and his group focus on identifying chemical, molecular and cellular mechanisms driving mosquito attraction to humans. His laboratory employs integrative techniques spanning the fields of chemical ecology, genetics and neurobiology to elucidate how human odorants present in body odor and breath are perceived by the mosquito peripheral nervous system and brain. His research team also seeks to understand how parasitic and microbial infection in both mosquito and human hosts influences mosquito olfactory perception and behavior. With this knowledge his group aims to develop innovative strategies that lure or repel mosquitoes away from humans to eliminate transmission of vector-borne diseases including malaria, dengue, chikungunya and zika.