FIG 1.
Vaccination of macaques with SIVmac251 DNA-protein coimmunization vaccine regimens. (A) Indian rhesus macaques were vaccinated three times (0, 2, and 6 months) with SIVmac251-derived env plasmids (SIVmac239 and T/F M766) coadministered with monomeric M766 gp120 protein adjuvanted with TLR4+7 (n = 12) or TLR4+QS21 (n = 12). The DNA mixtures also contained SIVmac239 gag DNA and rmIL-12 DNA. Five months after the 3rd vaccination, the animals were subjected to weekly intrarectal exposures using a titrated dose of the heterologous SIVsmE660 virus, and the infected animals were monitored for 6 months. (B) Schematic representation of the DNA-protein vaccine comprising RNA/DNA-optimized expression vectors producing SIVmac251-derived membrane-bound gp120e-TM and the soluble trimeric gp140 Env proteins. The vaccine contained monomeric M766 gp120 Env. Amino acid positions follow SIVmac239 numbering. (C) HEK293T cells were transfected with SIV M766 env plasmid DNAs (pDNAs) expressing gp150 (lane 1), gp140 (lane 2), gp120e-TM (lane 3), and gp120-TM (lane 4). Proteins from the cell-associated and extracellular (1/200 of each sample) fractions were analyzed by Western immunoblotting and detected using a mouse anti-gp120 Ab. Equal loading of the blot with the cell-associated fractions was controlled by probing the membrane with an antiactin antibody. (D) Histogram overlay showing the membrane localization of mac239 and M766 gp120e-TM proteins on transfected HEK293 cells using a mouse anti-gp120 Ab followed by an APC-conjugated goat anti-mouse Ab. The mock-transfected cells are shown (gray histogram).