Characterization of Haemaphysalis longicornis recombinant cement-like antigens and preliminary study of their vaccination effects

Two genes encoding immunodominant antigens, hlim2 and hlim3, were obtained from a salivary gland cDNA library of the hard tick, Haemaphysalis longicornis. The recombinant proteins were expressed in Escherichia coli as the GST fusion protein and used for immunization. We observed that the attachment rate of nymphal ticks fed on mice immunized with GST-hlim3 was significantly lower than that in the control group during the initial days of feeding. However, immunization with GST-hlim3 did not affect the engorgement rate of the ticks. In sharp contrast, GST-hlim2 did not influence the attachment rate and feeding period of ticks but had a significant reduction in the engorgement body weight. These data highlight the suitability of the 2 recombinant cement-like proteins for use in a cocktail vaccine.