Artificial immunization of pigeons against Argas polonicus (Ixodoidea, Argasidae)

Two subcutaneous injections of salivary gland antigen (SGA) or larval homogenate (LH) at 2-week intervals induced a resistance in pigeons to Argas (Argas) polonicus Siuda, Hoogstraal, Clifford and Wassef larvae and induced anti-tick antibodies. The number of larvae rejected after LH immunization was significantly higher compared to SGA immunization but lower than the number of larvae rejected after two natural infestations at 2-week intervals. The antibody titre reached a peak on day 6 following the first inoculation of LH, and 11-13 days after SGA inoculation. The maximum antibody titre was recorded 6 days after a second challenge for both antigens. The highest antibody titre was reached after the first inoculation with LH but only after the second inoculation with SGA. The sera of pigeons immunized either with SGA or LH cross-reacted with the other antigen as demonstrated by ELISA. SDS-PAGE and immunoblot studies demonstrated several differences in the protein profiles of these antigens, the presence of 34 and 35 kdal proteins in SGA and their absence in LH.