Legrand Fatema A, Verardi Paulo H, Jones Leslie A, Chan Kenneth S, Peng Yue, Yilma Tilahun D
International Laboratory of Molecular Biology for Tropical Disease Agents, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
J Virol. 2004 Mar;78(6):2770-9. doi: 10.1128/jvi.78.6.2770-2779.2004.
Vaccinia virus (VV) has been effectively utilized as a live vaccine against smallpox as well as a vector for vaccine development and immunotherapy. Increasingly there is a need for a new generation of highly attenuated and efficacious VV vaccines, especially in light of the AIDS pandemic and the threat of global bioterrorism. We therefore developed recombinant VV (rVV) vaccines that are significantly attenuated and yet elicit potent humoral and cell-mediated immune responses. B13R (SPI-2) and B22R (SPI-1) are two VV immunomodulating genes with sequence homology to serine protease inhibitors (serpins) that possess antiapoptotic and anti-inflammatory properties. We constructed and characterized rVVs that have the B13R or B22R gene insertionally inactivated (vDeltaB13R and vDeltaB22R) and coexpress the vesicular stomatitis virus glycoprotein (v50DeltaB13R and v50DeltaB22R). Virulence studies with immunocompromised BALB/cBy nude mice indicated that B13R or B22R gene deletion decreases viral replication and significantly extends time of survival. Viral pathogenesis studies in immunocompetent CB6F(1) mice further demonstrated that B13R or B22R gene inactivation diminishes VV virulence, as measured by decreased levels of weight loss and limited viral spread. Finally, rVVs with B13R and B22R deleted elicited potent humoral, T-helper, and cytotoxic T-cell immune responses, revealing that the observed attenuation did not reduce immunogenicity. Therefore, inactivation of immunomodulating genes such as B13R or B22R represents a general method for enhancing the safety of rVV vaccines while maintaining a high level of immunogenicity. Such rVVs could serve as effective vectors for vaccine development and immunotherapy.
痘苗病毒（VV）已被有效地用作预防天花的活疫苗以及疫苗开发和免疫治疗的载体。鉴于艾滋病的流行以及全球生物恐怖主义的威胁，对新一代高度减毒且有效的VV疫苗的需求日益增加。因此，我们开发了重组VV（rVV）疫苗，其显著减毒但仍能引发强大的体液免疫和细胞介导的免疫反应。B13R（SPI-2）和B22R（SPI-1）是两个与丝氨酸蛋白酶抑制剂（丝氨酸蛋白酶抑制剂）具有序列同源性的VV免疫调节基因，具有抗凋亡和抗炎特性。我们构建并鉴定了rVVs，它们的B13R或B22R基因通过插入失活（vDeltaB13R和vDeltaB22R）并共表达水疱性口炎病毒糖蛋白（v50DeltaB13R和v50DeltaB22R）。对免疫受损的BALB/cBy裸鼠进行的毒力研究表明，B13R或B22R基因缺失会降低病毒复制并显著延长存活时间。在免疫健全的CB6F(1)小鼠中进行的病毒发病机制研究进一步证明，通过体重减轻水平降低和病毒传播受限来衡量，B13R或B22R基因失活会降低VV毒力。最后，缺失B13R和B22R的rVVs引发了强大的体液免疫、辅助性T细胞和细胞毒性T细胞免疫反应，表明观察到的减毒并未降低免疫原性。因此，使B13R或B22R等免疫调节基因失活是提高rVV疫苗安全性同时保持高水平免疫原性的通用方法。此类rVVs可作为疫苗开发和免疫治疗的有效载体。
