Recombinant DNA/MVA/ChAdV-63-elicited T cells specific for conserved regions of the HIV-1 proteome recognize HIV-1 infected cells and suppress HIV-1

Results HIV-1 infection kinetics is influenced by the multiplicity of infection (MOI) used to infect autologous CD4+ cells, with rapid kinetics observed at higher MOIs. For HIV-1 BaL optimal infection of autologous CD4+ cells was achieved at MOI of 0.05. In the VSA, HIV-1 BaL virus replication was shown to be sensitive to the chemokines MIP-1a and RANTES added in the absence of effector cells. Pre-activated effector cells indicated increased nonspecific background suppression in healthy controls, which was reduced following a prolonged rest before coculture with autologous CD4+ targets, but led to marked proliferation of the CD8+ T cell effectors. Preliminary investigations in vaccinees show that HIV-1 suppression mediated by CD8+ T cells can be detected in vitro following vaccination and that P24 ELISA has higher sensitivity than flow cytometry. As an alternative to the VSA, an IFN-g ELISpot assay has also been optimized for the use of autologous HIV-1-infected CD4+ cells. Using both of the above assays, preliminary characterization of T cell responses induced in volunteers receiving pSG2.HIVconsv DNA, MVA.HIVconsv and ChAdV63.HIVconsv vaccines will be shown.