The impact of gene knock-down and vaccination against salivary metalloproteases on blood feeding and egg laying by Ixodes ricinus

• Published in: International journal for parasitology Vol. 38; no. 5; pp. 549 - 560
• Main Authors: Decrem, Yves, Mariller, Marcel, Lahaye, Kathia, Blasioli, Virginie, Beaufays, Jérôme, Zouaoui Boudjeltia, Karim, Vanhaeverbeek, Michel, Cérutti, Martine, Brossard, Michel, Vanhamme, Luc, Godfroid, Edmond
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2008; [Oxford; New York]: Elsevier Science; Elsevier Science
• Subjects: Amino Acid Sequence; Animals; anti-tick vaccine; antibody formation; Biological and medical sciences; complementary DNA; Feeding Behavior; Female; Fibrinolysis; Fundamental and applied biological sciences. Psychology; gene expression; Gene Library; Gene Silencing; hematophagy; Ixodes - enzymology; Ixodes - genetics; Ixodes - immunology; Ixodes ricinus; Ixodidae; Life cycle. Host-agent relationship. Pathogenesis; Male; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Metalloprotease; Metalloproteases - genetics; Metalloproteases - immunology; Metalloproteases - metabolism; metalloproteinases; Metis; Molecular Sequence Data; Multigene Family; Oviposition; Protozoa; Rabbits; recombinant antigens; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA Interference; saliva; salivary glands; Salivary Glands - enzymology; Salivary Proteins and Peptides - genetics; Salivary Proteins and Peptides - immunology; Sequence Alignment; Tick; Tick Infestations - immunology; Tick Infestations - prevention & control; ticks; vaccination; Vaccination - methods; vaccine development; Vectors. Intermediate hosts; Weight Gain; Metalloprotease; Tick; RNA interference; Ixodes ricinus; Parasitiformes; RNA; Vaccination; Interference; Parasite; Blood feeding; Arachnida; Acari; Gene; Ixodida; Arthropoda; Egg laying; Invertebrata; Ixodidae
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2007.09.003

Two cDNAs coding homologous putative metalloproteases (Metis 1 and Metis 2, expected molecular weights of 55.6 and 56.0 kDa, respectively) were identified from the hard tick Ixodes ricinus. The expression of Metis genes was induced in salivary glands during tick blood meal. RNA interference was used to assess the role of both Metis 1 and Metis 2 in tick feeding. It was found that salivary gland extracts lacking Metis 1–2 had a restricted ability to interfere with fibrinolysis. RNAi against Metis 1–2 also induced a high mortality rate. An immune reaction was raised in repeatedly bitten animals against Metis 1 and 2. Vaccination of hosts with the recombinant Metis 1 protein produced in a eukaryotic system partially interfered with completion of the blood meal. Although vaccination did not alter the survival rate or feeding time of ticks, their weight gain and oviposition rate were reduced. This will affect their reproductive fitness in the field. We believe this is the first report of an anti-tick vaccine trial using a metalloprotease derived from I. ricinus.