In vivo persistence of donor cells following adoptive transfer of allogeneic dendritic cells in HIV-infected patients

Peripheral blood samples from HIV-seropositive individuals enrolled in a pi lot clinical trial investigating the use of allogeneic dendritic cell thera py were evaluated for mixed chimerism. In this study, dendritic cells from HLA-identical, HIV-seronegative siblings were used. Patients received an in fusion of dendritic cells pulsed with HIV MN gp160 protein or with peptides from HLA-A2 restricted epitopes of env, gag, and pol proteins every month for 6-9 months. Of the five allogeneic dendritic cell recipients, two showe d increases in HIV antigen-specific immune responses. Allele specific polym orphisms were identified in three sib-pairs that allowed infused donor cell s to be detected using sensitive PCR-based molecular methods. Analysis of b lood samples from patients showed similar patterns of donor cell persistenc e after the first infusion, in that cells were detectable for at least 1 we ek. Also, differences were observed in the kinetics of cell survival betwee n the first and subsequent infusion cycles in all three patients. This sugg ests variation in HIV-specific immune responses detected among these three patients was not due to differences in persistence of infused donor cells.