Wyatt Linda S, Earl Patricia L, Vogt Jennifer, Eller Leigh Anne, Chandran Dev, Liu Jinyan, Robinson Harriet L, Moss Bernard
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892-3210, USA.
Vaccine. 2008 Jan 24;26(4):486-93. doi: 10.1016/j.vaccine.2007.11.036. Epub 2007 Dec 3.
The purpose of the present study was to correlate the in vitro level of HIV Env expression by recombinant modified vaccinia virus Ankara (rMVA) with immunogenicity in mice. A 5-fold difference in Env synthesis was achieved at the translational level by the presence or absence of an out-of-frame initiation codon upstream of the env gene. This perturbation had no effect on the size or processing of Env. In contrast to the variation in Env synthesis, the rMVAs produced similar amounts of HIV Gag, which were expressed from identical cassettes. Mice immunized with the higher Env expressing rMVAs had about 15-fold higher titers of Env antibodies and several fold higher frequencies of Env-specific CD8+ and CD4+ T cells than mice immunized with the low expresser. The greater immune response achieved by high expression was maintained over a 100-fold dose range. Importantly, enhanced Env immune responses did not come at the expense of lower Gag T cell responses. These data suggest that for high immunogenicity, rMVAs should be engineered to produce the most recombinant protein that can be achieved without compromising the growth and stability of the rMVA.
本研究的目的是将重组改良安卡拉痘苗病毒（rMVA）在体外表达HIV Env的水平与在小鼠体内的免疫原性相关联。通过env基因上游有无框外起始密码子，在翻译水平上实现了Env合成5倍的差异。这种干扰对Env的大小或加工没有影响。与Env合成的变化相反，rMVA产生的HIV Gag量相似，这些Gag由相同的盒式结构表达。用高表达Env的rMVA免疫的小鼠产生的Env抗体效价比用低表达rMVA免疫的小鼠高约15倍，Env特异性CD8+和CD4+ T细胞频率高几倍。高表达所实现的更强免疫反应在100倍剂量范围内得以维持。重要的是，增强的Env免疫反应并未以降低Gag T细胞反应为代价。这些数据表明，为了获得高免疫原性，rMVA应进行工程改造，以产生在不损害rMVA生长和稳定性的情况下所能达到的最多重组蛋白。
