Monitoring of naturally acquired and artificially induced immunity toAmblyomma variegatumandRhipicephalus appendiculatusticks under field and laboratory conditions

Autor: Jongejan, F., Pegram, R., Zivkovic, D., Hensen, E., Mwase, E., Thielemans, M., Cossé, A., Niewold, T., Said, Ashrafel, Uilenberg, G.
Zdroj: Experimental and Applied Acarology; August 1989, Vol. 7 Issue: 3 p181-199, 19p
Abstrakt: The ability of rabbits, goats and cattle to acquire immunity to the ixodid ticksAmblyomma variegatumandRhipicephalus appendiculatuswas studied under laboratory and field conditions. Rabbits were successfully immunized with crude salivary gland extract (SGE) and midgut extract (ME) obtained from flat or partly fed femaleR. appendiculatusticks. The lowest numbers of larvae were produced by females fed on rabbits immunized with unfed midgut extract. Similar reductions in larval production could be induced after three infestations of rabbits with adultR. appendiculatus. Also, successive feedings of nymphs ofR. appendiculatuson rabbits resulted in significantly reduced engorgement weights. Skin testing with SGE induced delayed-type hypersensitivity reactions, which could be correlated with immunity toR. appendiculatusin rabbits. Moreover, circulating antibodies were detected in rabbits with an ELISA using SGE ofR. appendiculatus. Immunity toA. variegatumnymphs could be induced in rabbits by repeated infestations, but this failed in goats. Immunization of goats with midgut extract from adultA. variegatumdid not protect against subsequent nymphal challenge, but strong skin reactions were noticed when adults ticks fed on immunized goats. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of SGE and ME fromA. variegatumrevealed the presence of 48 protein bands in SGE and 29 bands in midgut extract. Western blotting employing serum from a rabbit immune toR. appendiculatusrecognized a number of bands in SGE fromR. appendiculatus, but also in SGE ofA. variegatum. Immunity acquired by cattle to ixodid tick infestations under field conditions was monitored by skin testing with SGE and western blot analysis. In general, cattle with the lowest tick numbers manifested the strongest delayed-type hypersensitivity responses. Finally, western blot analysis employing sera from tick-infested and tick-naive cattle could not be related to actual immune status.
Databáze: Supplemental Index
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