Laboratoire d'immuno-virologie, Université Paul Sabatier, UFR/SVT, 31062 Toulouse, France.
J Pept Sci. 2010 Jan;16(1):48-57. doi: 10.1002/psc.1193.
The objective of this study was to analyze the immunogenicity and antigenicity of the V3 domain (Cys313-Cys346) of the external envelope glycoprotein gp125 of SIVmac251. The corresponding peptide was synthesized and characterized as linear and cyclic peptides. Our results showed that this region, as for HIV-1, contained an immunodominant epitope. The antigenicity was similar for the linear and cyclic peptides when tested against a panel of 15 sera from SIV infected macaques. Similarly, both peptide structures presented similar immunogenicity as shown by the characterization of the anti-peptide antibodies produced in rabbits against the cyclic and linear forms. But, unexpectedly, the antibodies produced against linear peptides recognized with a relatively higher intensity the native envelope gp140 than those produced against the cyclic structure. Furthermore, we showed that these antibodies recognized better the deglycosylated form of the glycoprotein. But, in contrast to the neutralizing activity obtained with anti-V3 peptides from HIV-1, no antiviral activity was obtained with antibodies generated against linear or cyclic SIVmac V3 peptides.
本研究旨在分析 SIVmac251 外膜糖蛋白 gp125 的 V3 结构域（Cys313-Cys346）的免疫原性和抗原性。该相应的肽段已被合成并被鉴定为线性和环状肽段。我们的结果表明，这一区域与 HIV-1 一样，包含一个免疫优势表位。当用来自感染 SIV 的猕猴的 15 份血清进行检测时，线性和环状肽的抗原性相似。同样，两种肽结构都表现出相似的免疫原性，这是通过对兔抗环状和线性肽产生的抗肽抗体进行鉴定而显示的。但是，出乎意料的是，针对线性肽产生的抗体对天然包膜 gp140 的识别强度相对较高，而针对环状结构产生的抗体则较低。此外，我们还表明，这些抗体对糖蛋白的去糖基化形式具有更好的识别能力。但是，与从 HIV-1 获得的抗 V3 肽的中和活性不同，针对线性或环状 SIVmac V3 肽产生的抗体没有抗病毒活性。
