Characterization and Stability of Trypanosoma cruzi 24-C4 (Tc24-C4), a Candidate Antigen for a Therapeutic Vaccine Against Chagas Disease

J Pharm Sci. 2018 May;107(5):1468-1473. doi: 10.1016/j.xphs.2017.12.014. Epub 2017 Dec 21.


Chagas disease due to chronic infection with Trypanosoma cruzi is a neglected cause of heart disease, affecting approximately 6-10 million individuals in Latin America and elsewhere. T. cruzi Tc24, a calcium-binding protein in the flagellar pocket of the parasite, is a candidate antigen for an injectable therapeutic vaccine as an alternative or a complement to chemotherapy. Previously, we reported that a genetically engineered construct from which all cysteine residues had been eliminated (Tc24-C4) yields a recombinant protein with reduced aggregation and improved analytical purity in comparison to the wild-type form, without compromising antigenicity and immunogenicity. We now report that the established process for producing Escherichia coli-expressed Tc24-C4 protein is robust and reproducibly yields protein lots with consistent analytical characteristics, freeze-thaw, accelerated, and long-term stability profiles. The data indicate that, like most proteins, Tc24-C4 should be stable at -80°C, but also at 4°C and room temperature for at least 30 days, and up to 7-15 days at 37°C. Thus, the production process for recombinant Tc24-C4 is suitable for Current Good Manufacturing Practice production and clinical testing, based on process robustness, analytical characteristics, and stability profile.

Keywords: Tc24; Tc24-C4; biotechnology; proteins; stability; target product profile; vaccines.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Protozoan / chemistry*
  • Antigens, Protozoan / immunology
  • Calcium-Binding Proteins / chemistry*
  • Calcium-Binding Proteins / immunology
  • Chagas Disease / immunology
  • Chagas Disease / prevention & control
  • Freezing
  • Humans
  • Protein Stability
  • Protozoan Proteins / chemistry*
  • Protozoan Proteins / immunology
  • Protozoan Vaccines / chemistry*
  • Protozoan Vaccines / immunology
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / immunology
  • Temperature
  • Trypanosoma cruzi / chemistry*
  • Trypanosoma cruzi / immunology


  • Antigens, Protozoan
  • Calcium-Binding Proteins
  • Protozoan Proteins
  • Protozoan Vaccines
  • Recombinant Proteins