Immunoprotection of chickens against Eimeria acervulina by recombinant α-tubulin protein

Tubulins are heterodimeric molecules responsible for the polymerization of microtubules in apicomplexan parasites. The alpha-tubulin, a subcellular structural protein of Eimeria acervulina, was cloned and expressed in Escherichia coli as an alpha-tubulin-GST fusion protein. Immunogenicity of the recombinant protein was studied in chickens by subcutaneous injection of 50, 100, or 150 mu g of the protein with or without Freund's adjuvant. Immunization with 150 mu g alpha-tubulin-GST protein in combination with Freund's adjuvant conferred partial protection against E. acervulina oocyst challenge, as shown by a 36% reduction in oocyst shedding, a marked decrease in intestinal lesion score and a significant increase in body weight gain in comparison with the nonimmunized controls. The results suggest that alpha-tubulin protein may be used as an effective vaccine antigen for the control of Eimeria infection.