Recombinant interferon-gamma promotes immunoglobulin G and cytokine memory responses to cathepsin L-like cysteine proteinase of Hyalomma asiaticum and the efficacy of anti-tick

Among bloodsucking arthropods, hard tick is a vector of transmitting the most diverse human and animal pathogens, leading to an increasing number of manifestations worldwide. The development of the anti-tick vaccine has the potential to be an environmentally friendly and cost-effective option for tick management. We have previously demonstrated the induction of both humoral and cellular response against Hyalomma asiaticum (H. asiaticum) following immunization with recombinant cathepsin L-like cysteine protease from H. asiaticum tick (rHasCPL), and could control tick infestations. Interferon-gamma (IFN-?), is an immunomodulatory factor that plays an important role in the regulation of adaptive immunity against infection. In the present study, recom-binant BALB/c mouse IFN-? (rMus-IFN-?) was cloned and expressed using a prokaryotic expression system, and verified by Western blotting and IFN-?-ELISA kit analysis. Female BALB/c mice (n = 12) were used for immu-nization using rHasCPL (100 ?g) plus IFN-? as adjuvant (10 ?g). In immunized female BALB/c mice, the levels of anti-CPL antibodies as well as cytokines were determined using ELISA analysis. Protective efficacy of immuni-zation was evaluated by larvae H. asiaticum challenge of immunized female BALB/c mice. Using rMus-IFN-? as an adjuvant to rHasCPL vaccine (CPL + IFN-?) promoted specific antibody IgG (IgG1 > IgG2a) and increased production of IFN-? and IL-4 compared to immune rHasCPL group (CPL). The protected rate of immunized mice from tick challenge was significantly higher after immunization with CPL + IFN-? (85.11 %) than with CPL (63.28 %). Immunization using CPL + IFN-? promoted the activation of anti-HasCPL humoral and cellular im-mune responses, and could provide better protection against H. asiaticum infestation. This approach may could help develop a candidate vaccine for control tick infestations.