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we used 49 purpose - bred juvenile and adult male rm ( macaca mulatta ) of indian genetic background in this study , including 12 rhcmv and 6 rhcmv rm inoculated with rhcmv / siv vectors , 9 rm that received a gag protein prime followed by ad5(gag ) boost vaccine protocol , and 22 rhcmv rm used as unvaccinated controls .
all rm were free of cercopithicine herpesvirus 1 , d type simian retrovirus , simian t - lymphotrophic virus type 1 and siv infection at the start of the study , and were used with approval of the oregon national primate research center s animal care and use committee , under the standards of the nih guide for the care and use of laboratory animals .
we administered rhcmv / siv vectors subcutaneously at a dose of 10 plaque - forming units ( pfu ) .
the gag protein prime / ad5(gag ) boost protocol consisted of 450 g sivgag protein ( protein sciences ) emulsified in montanide isa-51 carrier ( seppic ) , with or without 1 mg of poly i : c ( invitrogen ) , 3m-12 ( 3 m pharmaceuticals ) , or class c cpg ( pfizer ) adjuvant , at weeks 0 and 10 followed by ad5(gag ) ( 10 particles , from nih vaccine research center ) at week 20 .
we performed sivmac239 challenge by administering 300 focus - forming units ( ffu ) of virus weekly via the intra - rectal route for the first 8 challenges , and then , if necessary , 5 additional weekly challenges at 1000 ffu .
we challenged all of the vaccinated and 12 of the control rm concurrently ; the remaining 4 control rm were challenged as part of titration performed immediately prior to the primary challenge , using the same viral dose and challenge procedure .
we followed plasma viral loads weekly , with challenge being discontinued the week following detection of > 30 copy eq / ml of siv gag rna .
for cd8 cell depletion , we treated rm with 10 , 5 , 5 , and 5 mg / kg of the humanized monoclonal antibody cm - t80730 on days 1 , 3 , 5 and 10 , respectively .
we prepared rhcmv constructs expressing siv proteins ( designated rhcmv / siv viruses ; fig .
1a ) using a bacterial artificial chromosome ( bac ) containing the entire rhcmv strain 68 - 1 genome ( prhcmv / bac - cre ) , as described31,32 ( see supplementary fig .
we confirmed the genomic integrity of the recombinant rhcmv / siv bacs by restriction enzyme digestion and southern analysis , and direct dna sequence analysis of the siv open reading frames ( data not shown ) .
we reconstituted rhcmv / siv viruses by transfection of bac dna into rhcmv permissive rhesus fibroblasts , and confirmed expression of siv antigens by western analysis of rhcmv / siv - infected cell lysates ( supplementary fig
multi - step growth analysis of rhcmv / siv viruses31 showed growth kinetics comparable to wildtype rhcmv ( supplementary fig .
was generated by expanding the sivmac239 clone33 in rm peripheral blood mononuclear cells ( pbmc ) , and was quantified using the smagi cell assay34 and by quantitative rt - pcr for siv genomic rna35 .
we prepared at-2-inactivated sivmac239 ( lot # p4146 ) as described36 , and normalized this stock to the infectious sivmac239 stock by real - time rt - pcr quantification of siv genome copy number .
we centrifuged filter - sterilized ( 0.4 m ) urine at 16,000  g for 1 hr @ 4 c to concentrate virus for co - culture on rf .
after extensive cytopathic effect or 42 days of co - culture , we prepared cell lysates and assessed rhcmv / siv vector replication based on expression of siv antigen - specific epitope tags by western immunoblot .
we measured whole blood rhcmv dna , plasma siv rna , and cell - associated siv dna and rna by real - time pcr and rt - pcr assays24,35,37 , with the cell - associated siv quantification using immunobead - isolated cd4 t cells , before and after 48 hrs stimulation with immobilized anti - cd3 and il-2 , and including rt - pcr analysis of supernatants of the stimulated cells .
we measured rhcmv- and siv - specific cd4 and cd8 t cell responses by flow cytometric intracellular cytokine analysis ( fcica ) of peripheral blood mononuclear cells and bal cells , as described7,24,25,38 ( see supplementary methods ) .
neutralizing abs against sivmac239 and tissue culture adapted sivmac251 were measured in luciferase reporter gene assays using the tzm - bl and m7 luc cell lines , respectively , for sivmac239 and tissue culture adapted sivmac25140 .
we assessed the significance of differences in 1 ) the phenotype or functional properties of rhcmv - specific t cells vs. rhcmv - vectored , siv - specific t cells vs. prime - boost - elicited siv - specific t cells using mixed effects analysis , 2 ) the proportion of rm within the vaccinated vs. control groups that completely controlled siv infection after repeated , limiting dose mucosal challenge using a two - sided fischer s exact test , and 3 ) the peak and mean plateau phase ( day 42 to day 91 ) plasma viral loads of the control vs. vaccinated rm with progressive infection by using general linear models with log10 transformed data . in all analysis , we used a two - sided significance level ( alpha ) of 0.05 , with correction made for multiple comparisons using the bonferroni method .
we used 49 purpose - bred juvenile and adult male rm ( macaca mulatta ) of indian genetic background in this study , including 12 rhcmv and 6 rhcmv rm inoculated with rhcmv / siv vectors , 9 rm that received a gag protein prime followed by ad5(gag ) boost vaccine protocol , and 22 rhcmv rm used as unvaccinated controls .
all rm were free of cercopithicine herpesvirus 1 , d type simian retrovirus , simian t - lymphotrophic virus type 1 and siv infection at the start of the study , and were used with approval of the oregon national primate research center s animal care and use committee , under the standards of the nih guide for the care and use of laboratory animals .
we administered rhcmv / siv vectors subcutaneously at a dose of 10 plaque - forming units ( pfu ) .
the gag protein prime / ad5(gag ) boost protocol consisted of 450 g sivgag protein ( protein sciences ) emulsified in montanide isa-51 carrier ( seppic ) , with or without 1 mg of poly i : c ( invitrogen ) , 3m-12 ( 3 m pharmaceuticals ) , or class c cpg ( pfizer ) adjuvant , at weeks 0 and 10 followed by ad5(gag ) ( 10 particles , from nih vaccine research center ) at week 20 .
we performed sivmac239 challenge by administering 300 focus - forming units ( ffu ) of virus weekly via the intra - rectal route for the first 8 challenges , and then , if necessary , 5 additional weekly challenges at 1000 ffu .
we challenged all of the vaccinated and 12 of the control rm concurrently ; the remaining 4 control rm were challenged as part of titration performed immediately prior to the primary challenge , using the same viral dose and challenge procedure .
we followed plasma viral loads weekly , with challenge being discontinued the week following detection of > 30 copy eq / ml of siv gag rna .
for cd8 cell depletion , we treated rm with 10 , 5 , 5 , and 5 mg / kg of the humanized monoclonal antibody cm - t80730 on days 1 , 3 , 5 and 10 , respectively .
we prepared rhcmv constructs expressing siv proteins ( designated rhcmv / siv viruses ; fig .
1a ) using a bacterial artificial chromosome ( bac ) containing the entire rhcmv strain 68 - 1 genome ( prhcmv / bac - cre ) , as described31,32 ( see supplementary fig .
we confirmed the genomic integrity of the recombinant rhcmv / siv bacs by restriction enzyme digestion and southern analysis , and direct dna sequence analysis of the siv open reading frames ( data not shown ) .
we reconstituted rhcmv / siv viruses by transfection of bac dna into rhcmv permissive rhesus fibroblasts , and confirmed expression of siv antigens by western analysis of rhcmv / siv - infected cell lysates ( supplementary fig .
multi - step growth analysis of rhcmv / siv viruses31 showed growth kinetics comparable to wildtype rhcmv ( supplementary fig .
was generated by expanding the sivmac239 clone33 in rm peripheral blood mononuclear cells ( pbmc ) , and was quantified using the smagi cell assay34 and by quantitative rt - pcr for siv genomic rna35 .
we prepared at-2-inactivated sivmac239 ( lot # p4146 ) as described36 , and normalized this stock to the infectious sivmac239 stock by real - time rt - pcr quantification of siv genome copy number .
we centrifuged filter - sterilized ( 0.4 m ) urine at 16,000  g for 1 hr @ 4 c to concentrate virus for co - culture on rf .
after extensive cytopathic effect or 42 days of co - culture , we prepared cell lysates and assessed rhcmv / siv vector replication based on expression of siv antigen - specific epitope tags by western immunoblot .
we measured whole blood rhcmv dna , plasma siv rna , and cell - associated siv dna and rna by real - time pcr and rt - pcr assays24,35,37 , with the cell - associated siv quantification using immunobead - isolated cd4 t cells , before and after 48 hrs stimulation with immobilized anti - cd3 and il-2 , and including rt - pcr analysis of supernatants of the stimulated cells .
we measured rhcmv- and siv - specific cd4 and cd8 t cell responses by flow cytometric intracellular cytokine analysis ( fcica ) of peripheral blood mononuclear cells and bal cells , as described7,24,25,38 ( see supplementary methods ) .
neutralizing abs against sivmac239 and tissue culture adapted sivmac251 were measured in luciferase reporter gene assays using the tzm - bl and m7 luc cell lines , respectively , for sivmac239 and tissue culture adapted sivmac25140 .
we assessed the significance of differences in 1 ) the phenotype or functional properties of rhcmv - specific t cells vs. rhcmv - vectored , siv - specific t cells vs. prime - boost - elicited siv - specific t cells using mixed effects analysis , 2 ) the proportion of rm within the vaccinated vs. control groups that completely controlled siv infection after repeated , limiting dose mucosal challenge using a two - sided fischer s exact test , and 3 ) the peak and mean plateau phase ( day 42 to day 91 ) plasma viral loads of the control vs. vaccinated rm with progressive infection by using general linear models with log10 transformed data . in all analysis , we used a two - sided significance level ( alpha ) of 0.05 , with correction made for multiple comparisons using the bonferroni method .
the rapid onset of massive , systemic viral replication during primary hiv / siv infection and the immune evasion capabilities of these viruses pose fundamental problems for vaccines that depend upon initial viral replication to stimulate effector t cell expansion and differentiation15 . 
 we hypothesized that vaccines designed to maintain differentiated  effector memory  t cell ( tem ) responses5,6 at viral entry sites might improve efficacy by impairing viral replication at its earliest stage2 , and have therefore developed siv protein - encoding vectors based on rhesus cytomegalovirus ( rhcmv ) , the prototypical inducer of life - long tem responses79 . 
 rhcmv vectors expressing siv gag , rev / nef / tat , and env persistently infected rhesus macaques ( rm ) , regardless of pre - existing rhcmv immunity , and primed and maintained robust siv - specific , cd4 + and cd8 + tem responses ( characterized by coordinate tnf , ifn- and mip-1 expression , cytotoxic degranulation , and accumulation at extra - lymphoid sites ) in the absence of neutralizing antibodies . compared to control rm , these vaccinated rm showed increased resistance to acquisition of progressive sivmac239 infection upon repeated , limiting dose , intra - rectal challenge , including four animals that controlled rectal mucosal infection without progressive systemic dissemination . 
 these data suggest a new paradigm for aids vaccine development : that vaccines capable of generating and maintaining hiv - specific tem might decrease the incidence of hiv acquisition after sexual exposure .