title: Antimicrobial activity of mosquito cecropin peptides against Francisella.
abstract: Francisella tularensis is the cause of the zoonotic disease tularemia. In Sweden and Scandinavia, epidemiological studies have implicated mosquitoes as a vector. Prior research has demonstrated the presence of Francisella DNA in infected mosquitoes but has not shown definitive transmission of tularemia from a mosquito to a mammalian host. We hypothesized that antimicrobial peptides, an important component of the innate immune system of higher organisms, may play a role in mosquito host-defense to Francisella. We established that Francisella sp. are susceptible to two cecropin antimicrobial peptides derived from the mosquito Aedes albopictus as well as Culex pipiens. We also demonstrated induced expression of Aedes albopictus antimicrobial peptide genes by Francisella infection C6/36 mosquito cell line. We demonstrate that mosquito antimicrobial peptides act against Francisella by disrupting the cellular membrane of the bacteria. Thus, it is possible that antimicrobial peptides may play a role in the inability of mosquitoes to establish an effective natural transmission of tularemia.
authors.affiliation: Department of Biology, George Mason University, Manassas, VA, USA.
authors.forename: Akanksha
authors.initials: A
authors.lastname: Kaushal
authors.affiliation: College of Science, George Mason University, Fairfax, VA 22030, USA.
authors.forename: Kajal
authors.initials: K
authors.lastname: Gupta
authors.affiliation: Thomas Jefferson School of Science and Technology, Alexandria, VA, USA.
authors.forename: Ruhee
authors.initials: R
authors.lastname: Shah
authors.affiliation: School of Systems Biology, George Mason University, Manassas, VA, USA; National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA 20110, USA. Electronic address: mvanhoek@gmu.edu.
authors.forename: Monique L
authors.initials: ML
authors.lastname: van Hoek
mesh_terms: D000330:Aedes / Q000276:immunology; D000818:Animals; D001433:Bacteriolysis; D054807:Cecropins / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D003465:Culex / Q000276:immunology; D004199:Disease Vectors; D005604:Francisella tularensis / Q000276:immunology*; D007109:Immunity; D019476:Insect Proteins / Q000276:immunology / Q000378:metabolism*; D013548:Sweden; D014406:Tularemia / Q000276:immunology*
chemical_list: D054807:Cecropins; D019476:Insect Proteins
keywords: Antimicrobial peptides; Depolarization; Francisella; Innate immunity; Mosquitoes; Tularemia