Characterisation of the antigenic and immunogenic properties of bacterially expressed, sexual stage antigens of the coccidian parasite, Eimeria maxima

Vaccine. 2004 Oct 22;22(31-32):4316-25. doi: 10.1016/j.vaccine.2004.04.019.

Abstract

Coccidiosis in poultry is caused by the intestinal parasite Eimeria; it causes significant financial losses to the commercial poultry industry worldwide. CoxAbic is the first commercially available subunit vaccine against coccidiosis. The vaccine consists of affinity purified sexual stage (gametocyte) antigens (APGA) isolated from Eimeria maxima. Production of this vaccine is time-consuming and laborious and, therefore, a recombinant subunit vaccine substitute for CoxAbic is desirable. The genes encoding the two immunodominant components of CoxAbic, gam56 and gam82, were cloned into the bacterial expression vector, pTRCHisB, and the proteins expressed and purified. Both recombinant proteins were recognised by protective chicken antibodies that were raised to APGA, by immunoblotting. In a competitive ELISA, a combination of the recombinant proteins inhibited the binding of anti-APGA antibodies to APGA by 76%, which was comparable to the inhibition of 98% observed when APGA was used as the competing protein in the assay. In two breeds of chicken (Australorp and Cobb500), the recombinant proteins alone, or in combination, elicited a dose-dependent, antibody response that recognised APGA by ELISA, and gametocytes by immunoblotting. Together, the results suggested that the development of a recombinant subunit vaccine that maintains the antigenic and immunogenic properties of the native protein vaccine, CoxAbic, is feasible.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Protozoan / analysis
  • Antibodies, Protozoan / biosynthesis
  • Antibodies, Protozoan / immunology
  • Antigen-Antibody Reactions
  • Antigens, Protozoan / biosynthesis
  • Antigens, Protozoan / immunology*
  • Antigens, Protozoan / isolation & purification
  • Chickens
  • Coccidiosis / immunology*
  • Eimeria / immunology*
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme-Linked Immunosorbent Assay
  • Escherichia coli / metabolism
  • Glycoproteins / biosynthesis
  • Glycoproteins / immunology
  • Glycoproteins / isolation & purification
  • Immunization
  • Immunoblotting
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / immunology
  • Recombinant Proteins / isolation & purification

Substances

  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Glycoproteins
  • Recombinant Proteins