Biolistic DNA vaccination against Trypanosoma infection.

Immunization to protect against Trypanosoma cruzi infection has the potential to greatly decrease the burden of Chagas' disease in the Americas. Several target antigens have been explored by multiple investigators and show promise, but given that this parasite has multiple stages within the mammalian host, with both intracellular and extracellular forms, a multivalent vaccine will probably be necessary to provide complete immunity and prevent disease. Therefore, DNA immunization is an attractive method for efficient and effective delivery of multiple target antigens. In addition, the target population for a T. cruzi vaccine lives predominately in poorer rural areas in South America, making the stable DNA-gold precipitate, which does not require a cold-chain, used in biolistic immunization an attractive method for vaccination. Here we describe a biolistic immunization protocol that is capable of generating high titer antibody responses to recombinant T. cruzi vaccine targets and the in vitro preparation of T. cruzi for use in experimental vaccine challenge studies.