Defending the fort: a role for defensin-2 in limiting Rickettsia montanensis infection of Dermacentor variabilis.
The importance of tick defensins is evidenced by their expression in a wide variety of tick tissues and prevalence across many tick genera. To date, the functional and biological significance of defensin-2 as a rickettsiastatic or rickettsiacidal antimicrobial peptide has not been addressed. In a previous study, defensin-2 transcription was shown to increase in Dermacentor variabilis ticks challenged with Rickettsia montanensis. In the present study, the hypothesis that defensin-2 is functional as a rickettsiastatic and/or rickettsiacidal antimicrobial peptide is tested. We show that defensin-2 plays a role in reducing burden after acquisition of Rickettsia montanensis through capillary feeding. Moreover, defensin-2 is shown to associate with R. montanensis in vitro and in vivo, causing cytoplasmic leakiness.
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA.
R S
RS
Pelc
J C
JC
McClure
K T
KT
Sears
A
A
Chung
M S
MS
Rahman
S M
SM
Ceraul
D000818:Animals; D000890:Anti-Infective Agents / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides; D002463:Cell Membrane Permeability; D023082:Defensins / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D003870:Dermacentor / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D007113:Immunity, Innate / Q000276:immunology*; D012281:Rickettsia / Q000276:immunology / Q000502:physiology*; D012282:Rickettsia Infections / Q000503:physiopathology
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D023082:Defensins
defensin; innate immunity; rickettsia.; tick