The present study was conducted to identify new target immunogenic molecules from the larval stage of the cattle tick, Boophilus annulatus (Acari: Ixodidae). Two specific larval glycoproteins (GLPs) were isolated by two-step affinity chromatography. The larval immunogens were first purified with CNBr-Sepharose coupled to rabbit anti-larval immunoglobulins, and the glycoproteins were then purified with Con-A Sepharose. These glycoproteins have molecular weights of approximately 32 and 15 kDa with isoelectric points between 6.8 and 7.2. Antibodies against the two GLPs, labeled I and II, were detected in the anti-whole tick, -whole larval, and -gut antigens through immunoblot analysis. These results suggest that these GLPs are good immunogens and can be useful in the vaccination of cattle against tick infestation.
Amino Acid Sequence ; Animals ; Cattle ; Cattle Diseases/immunology/*parasitology/prevention & control ; Chromatography, Affinity ; Electrophoresis, Polyacrylamide Gel ; Glycoproteins/immunology/*isolation & purification ; Immunoblotting ; Isoelectric Focusing ; Ixodidae/chemistry/*immunology ; Male ; Molecular Weight ; Rabbits ; Sequence Analysis, Protein ; Tick Infestations/immunology/parasitology/prevention & control/*veterinary

In order to identify antigens that can help prevent camel tick infestations, three major glycoproteins (GLPs) about 97, 66 and 40 kDa in size were purified from adult and larval Egyptian ticks, Hyalomma (H.) dromedarii, using a single-step purification method with Con-A sepharose. The purified GLPs were evaluated as vaccines against camel tick infestation in rabbits. The rabbits received three intramuscular inoculations of GLPs (20 microg/animal) on days 0, 14, and 28. In the immunoblot analysis, Sera from the immunized rabbits recognized the native GLPs and other proteins from larval and adult H. dromedarii ticks along with those from other tick species such as Rhipicephalus sanguineus but not Ornithodoros moubata. The effects of immunity induced by these GLPs were determined by exposing rabbits to adult H. dromedarii ticks. These results demonstrated that GLP immunization led to a slightly decreased reproductive index and significantly reduced rates of egg hatchability. These results demonstrated that immunization with the purified GLPs can provide protection against infestation by H. dromedarii and some other tick species. Further studies are needed to confirm the effectiveness of immunization with GLPs against other tick species.
Animals ; Antigens/immunology/isolation & purification ; Argasidae/immunology ; Chromatography, Affinity/veterinary ; Electrophoresis, Polyacrylamide Gel/veterinary ; Female ; Glycoproteins/*immunology/isolation & purification ; Immunoblotting/veterinary ; Injections, Intramuscular/veterinary ; Ixodidae/growth & development/*immunology ; Life Cycle Stages ; Male ; Rabbits/*immunology/parasitology ; Reproduction ; Species Specificity ; Tick Infestations/immunology/prevention & control/*veterinary