Antimicrobial activity of human beta-defensins and induction by Francisella.
The ability of human beta-defensins hBD-1, hBD-2, and hBD-3 to exert direct in vitro antimicrobial effects was evaluated using Francisella tularensis Live Vaccine Strain (LVS) and Francisella novicida. While hBD-2 showed some antimicrobial activity in these assays, only hBD-3 demonstrated significant potency against Francisella. Francisella tularensis LVS infection induced elevated levels of hBD-2 mRNA in human airway epithelial (A549) cells, while having no significant impact on the levels of hBD-3 and only a moderate effect on the level of hBD-1 mRNA. Francisella infection avoided stimulating the production of the most potent anti-Francisella host peptide, hBD-3, in A549 cells, although hBD-3 is stimulated by other treatments. The differential induction of beta-defensins in Francisella infected lung epithelial cells suggests a complex dynamic in the expression of antimicrobial peptides and the innate immune response.
Han
Suhua
S
Department of Molecular and Microbiology, National Center for Biodefense and Infectious Diseases, George Mason University, 10910 University Blvd, Manassas, VA 20110, USA.
Bishop
Barney M
BM
van Hoek
Monique L
ML
D002460:Cell Line; D005604:Francisella tularensis / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D008168:Lung / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology*; D012333:RNA, Messenger / Q000378:metabolism; D023083:beta-Defensins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
C406407:DEFB1 protein, human; C422950:DEFB103A protein, human; C106641:DEFB4A protein, human; D012333:RNA, Messenger; D023083:beta-Defensins