A DNA prime-oral Listeria boost vaccine in rhesus macaques induces a SIV-specific CD8 T cell mucosal response characterized by high levels Of α4β7 integrin and an effector memory phenotype

in this study in Rhesus macaques, we tested whether IL-12 or IL-15 in a DNA prime-oral Listeria boost amplifies the SIV-Gag-specific CD8 mucosal response. SIV-specific CD8 T cells were demonstrated in the peripheral blood (PB) in all test vaccine groups, but not the control group. SIV-Gag-specific CD8 T cells in the PB expressed alpha(4)beta(7) integrin, the gut-homing receptor; a minor subset co-express alpha(E)beta(7) integrin. SIV-Gag-specific CD8 T cells were also detected in the gut tissue, intraepithelial (IEL) and lamina propria lymphocytes (LPL) of the duodenum and ileum. These cells were characterized by high levels of 7 integrin expression and a predominance of the effector memory phenotype. Neither I1-12 nor IL-15 amplified the frequency of SIV-specific CD8 T cells in the gut. Thus, the DNA prime-oral Listeria boost strategy induced a mucosal SIV-Gag-specific CD8 T cell response characterized by expression of the alpha(4)beta(7) integrin gut-homing receptor. (c) 2006 Elsevier Inc. All rights reserved.