IMMUNE-RESPONSES IN RABBITS IMMUNIZED AGAINST THE TICK, HYALOMMA-ANATOLICUM-ANATOLICUM

Humoral and cell-mediated immune response (CMIR) were investigated in rabbits immunized with semi-engorged female Hyalomma anatolicum anatolicum whole tick extract antigen (WTE Ag). Enzyme-linked immunosorbent assay detected antibody on day 14 and the titre thereafter gradually increased up to day 28 but subsequently started decreasing though remained significantly higher in comparison to control throughout the experimental period (63 days). Double diffusion test detected antibody from 14 to 63 days post-immunization (dpi). The precipitating antibodies started fading out from day 49 onwards. A significantly higher lymphocyte stimulation index (LSI) was observed from days 21 to 42 after first immunization. The LSI was more on day 35. The leucocyte migration index in immunized rabbits was lower on 2 3,35 and 42 dpi, indicating enhanced CMIR. The WTE Ag elicited delayed type hypersensitivity skin reaction in immunized rabbits. Both humoral and CMIR were therefore significantly operational in these immunized rabbits.