Antibody Repertoires Identify β-Tubulin as a Host Protective Parasite Antigen in Mice Infected With Trypanosoma cruzi

Abstract

Few studies investigate the major protein antigens targeted by the antibody diversity of infected mice with <i>Trypanosoma cruzi</i>. To detect global IgG antibody specificities, sera from infected mice were immunoblotted against whole <i>T. cruzi</i> extracts. By proteomic analysis, we were able to identify the most immunogenic <i>T. cruzi</i> proteins. We identified three major antigens as pyruvate phosphate dikinase, Hsp-85, and β-tubulin. The major protein band recognized by host IgG was <i>T. cruzi</i> β-tubulin. The <i>T. cruzi</i> β-tubulin gene was cloned, expressed in <i>E. coli</i>, and recombinant <i>T. cruzi</i> β-tubulin was obtained. Infection increased IgG reactivity against recombinant <i>T. cruzi</i> β-tubulin. A single immunization of mice with recombinant <i>T. cruzi</i> β-tubulin increased specific IgG reactivity and induced protection against <i>T. cruzi</i> infection. These results indicate that repertoire analysis is a valid approach to identify antigens for vaccines against Chagas disease.