Effects of anti-tick cocktail vaccine against Rhipicephalus appendiculatus.
Rhipicephalus appendiculatus serpin-3 (RAS-3), R. appendiculatus serpin-4 (RAS-4) and a 36-kDa immuno-dominant protein of R. appendiculatus (RIM36) were reported as candidate antigens for the anti-tick vaccine to control ixodid ticks. In the present study, we generated recombinant proteins of RAS-3 (rRAS-3), RAS-4 (rRAS-4) and RIM36 (rRIM36), and assessed their potency as an anti-tick cocktail vaccine in cattle model. RT-PCR analysis showed that RAS-3, RAS-4 and RIM36 transcripts were detected in both adult male and female ticks during feeding. Immunization of cattle with the combination of rRAS-3, rRAS-4 and rRIM36 had raised antibodies against all recombinants and anti-sera had reacted with the molecules from the tick salivary gland extract. Tick infestation challenge demonstrated protective immunity against female ticks, resulting in mortality rates of 39.5 and 12.8% for the vaccinated and control groups, respectively. Moreover, the mortality rate of Theileria parva-infected female ticks was 48.5 and 10.8% in the vaccinated and control group, respectively. In order to evaluate the levels of pathogen transmission capacity by T. parva-infected ticks fed on immunized cattle, the occurrence of T. parva in the bovine parotid lymph node and peripheral blood was also determined and quantified by real-time PCR. Although the infection with T. parva could not be protected by the vaccine, the occurrence of pathogen in peripheral blood was delayed 1 to 2 days after the infestation challenge in vaccinated group. These results suggest that this cocktail vaccine plays a role in the prevention of tick infestation.
Imamura
Saiki
S
Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Sapporo 060-0818, Japan.
Konnai
Satoru
S
Vaz
Itabajara da Silva Júnior
Ida S
Yamada
Shinji
S
Nakajima
Chie
C
Ito
Yuko
Y
Tajima
Tomoko
T
Yasuda
Jun
J
Simuunza
Martin
M
Onuma
Misao
M
Ohashi
Kazuhiko
K
D000818:Animals; D002417:Cattle; D018076:DNA, Complementary / Q000302:isolation & purification; D005247:Feeding Behavior; D005260:Female; D007300:Insect Control; D019476:Insect Proteins / Q000276:immunology*; D008297:Male; D011489:Protein Denaturation; D011994:Recombinant Proteins; D048494:Rhipicephalus / Q000276:immunology*; D015843:Serpins / Q000276:immunology*; D016797:Theileria parva; D013984:Tick Infestations / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*
D018076:DNA, Complementary; D019476:Insect Proteins; D011994:Recombinant Proteins; D015843:Serpins; D014614:Vaccines, Synthetic