COMPARISON OF RECOMBINANT VACCINIA AND ALDRITHIOL-2 INACTIVATED SIV VACCINES

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。我们比较了“初免-加强”免疫方案的保护效果，使用重组牛痘病毒（rVV）进行初免，使用重组SIV蛋白或灭活SIV病毒粒子进行加强。用表达SIVmne CL 8 Env或Gag/Pol蛋白的两种rVV引发三组猪尾猕猴（7只/组），一年后用明矾/MPL佐剂中的重组gp 160和Gag/Pol病毒样颗粒（组1）、仅用佐剂（组2）或用2，2 '-二硫代二吡啶（醛硫醇-2）-灭活的SIVmne（AT-2 SIV）（组3）加强。四周后，所有动物用未克隆的SIVmne静脉内攻击。虽然所有动物在攻击后均被感染，但与对照组相比，免疫动物的血浆病毒血症显著降低。病毒血症的减少与疫苗诱导的高水平SIV抗体和IFN-γ ELISPOT应答相关。为了进一步了解保护机制，我们分析了未克隆的攻击病毒包膜区的核苷酸序列，并将其与攻击后2-4周收集的感染动物PBMC中的核苷酸序列进行比较。来自未克隆的攻毒病毒的约50%的V1序列与制备疫苗的分子克隆CL 8相同（CL 8型），其余的含有几个保守的变化（变体型）。纳乌感染该未克隆病毒的5只对照动物具有不同比例的两种类型的V1序列，其平均值（38.4%的CL 8和61.6%的变体类型）与攻毒储备中的相似。另一方面，分析的16/17只免疫动物在感染后早期主要（96.6 +/-8.3%）具有变异型V1序列。这些结果支持了我们早期的发现，表明引起的保护性免疫主要限于同源病毒，针对包膜蛋白V1区的免疫应答可能在保护中发挥作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We compared protective efficacy of 'prime-boost' immunization regimens using recombinant vaccinia virus (rVV) for priming and recombinant SIV proteins or inactivated SIV virions for boosting. Three groups of pig-tailed macaques (7/group) were primed with two rVV expressing SIVmne CL8 Env or Gag/Pol proteins and boosted a year later with recombinant gp160 and Gag/Pol virus-like particles in Alum/MPL adjuvant (Group 1), with adjuvant only (Group 2), or with 2,2'-dithiodipyridine (aldrithiol-2)-inactivated SIVmne (AT-2 SIV) (Group 3). Four weeks later, all animals were challenged intravenously with an uncloned SIVmne. While all animals were infected after challenge, immunized animals had significantly reduced plasma viremia compared with controls. Reduction of viremia correlated with high levels of vaccine-induced SIV antibody and IFN-gamma ELISPOT responses at challenge. To gain further insight into the protective mechanism, we analyzed nucleotide sequences in the envelope region of the uncloned challenge virus and compared them with those present in the PBMC of infected animals collected between 2-4 weeks after challenge. Approximately 50% of the V1 sequences from the uncloned challenge virus was identical to the molecular clone CL8 from which the vaccines were made (CL8 type), with the remainder containing several conserved changes (variant type). Na¿ve control animals infected with this uncloned virus had both types of V1 sequences in varying proportions, the mean of which (38.4% of CL8 and 61.6 % of variant type) is similar to that in the challenge stock. On the other hand, 16/17 immunized animals analyzed had predominantly (96.6 +/- 8.3 %) the variant type V1 sequence early after infection. These results support our earlier findings, indicating that the protective immunity elicited is primarily restricted to the homologous virus and that immune responses directed to the V1 region of the envelope protein may play a role in protection.