Cutting edge: Immunity against a "silent" salivary antigen of the Lyme vector Ixodes scapularis impairs its ability to feed.
Ixodes scapularis ticks transmit the Lyme disease agent in the United States. Although strong antitick immunity mediates tick rejection by certain vertebrates, only a few Ags have been molecularly characterized. We show that guinea pig vaccination against a secreted tick salivary immunomodulator, sialostatin L2, can lead to decreased feeding ability of I. scapularis nymphs. Increased rejection rate, prolonged feeding time, and apparent signs of inflammation were observed for nymphs attached to vaccinated animals, indicating a protective host immune response. Interestingly, sialostatin L2 humoral recognition does not take place upon repeated tick exposure in control animals, but only in the vaccinated animals that neutralize sialostatin L2 action. Therefore, we demonstrate an essential sialostatin L2 role upon nymphal infestation that can be blocked by vertebrate immunity and propose the discovery of similarly "silent" Ags toward the development of a multicomponent vaccine that will protect against tick bites and the pathogens they transmit.
Kotsyfakis
Michalis
M
Vector Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA. mkotsyfakis@mail.nih.gov
Anderson
Jennifer M
JM
Andersen
John F
JF
Calvo
Eric
E
Francischetti
Ivo M B
IM
Mather
Thomas N
TN
Valenzuela
Jesus G
JG
Ribeiro
José M C
JM
D000818:Animals; D000917:Antibody Formation / Q000276:immunology*; D001096:Arachnid Vectors / Q000276:immunology*; D015891:Cystatins / Q000276:immunology*; D005247:Feeding Behavior; D006168:Guinea Pigs; D018884:Ixodes / Q000276:immunology*; D008193:Lyme Disease / Q000276:immunology / Q000635:transmission*; D009758:Nymph; D012471:Salivary Proteins and Peptides / Q000276:immunology*; D014611:Vaccination
D015891:Cystatins; D012471:Salivary Proteins and Peptides; C515505:sialostatin L, Ixodes scapularis