Prime-boost immunization generates a high frequency, high-avidity CD8 cytotoxic T lymphocyte population

Abstract

Development and expansion of high-avidity T cell populations may be important for the success of immunization strategies against HIV and other pathogens that have presented major problems for vaccine development. We have used tetrameric-MHC complexes ex vivo and lytic assays to show that 'prime-boost' immunization with DNA vaccines and recombinant poxvirus vectors generates high frequencies of cytotoxic T lymphocytes (CTL) that recognize target cells expressing very low levels of specific antigen. These cells persist for at least 6 months at levels representing ∼10% of the CD8+ T cell population. Using a novel in vivo assay, we also found that prime-boost immunized animals were capable of el..