Choque-Guevara Ricardo, Poma-Acevedo Astrid, Montesinos-Millán Ricardo, Sernaque-Aguilar Yacory, Ygnacio Freddy, Ríos-Matos Dora, Montalván-Ávalos Ángela, Isasi-Rivas Gisela, Lulo Milagros, Fernández-Vera Roque, Ticona Julio, Fernández-Sánchez Manolo, Fernández-Díaz Manolo
Laboratorios de Investigación y Desarrollo, FARVET SAC, Chincha, Ica, Peru; Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Peru.
Laboratorios de Investigación y Desarrollo, FARVET SAC, Chincha, Ica, Peru.
Vaccine. 2025 Jun 19;61:127404. doi: 10.1016/j.vaccine.2025.127404.
Rabies remains a lethal zoonotic disease, affecting approximately 50,000 people annually, underscoring the need for new and cost-effective vaccines capable of elicit robust immunity. Baculoviruses have emerged as promising vaccine vectors due to their ability to display antigens on their surface, making pseudotyping with rabies virus glycoprotein G (gG) a viable strategy for vaccine development. However, strategies to optimize baculovirus pseudotyping remain underexplored. In this study, we evaluated three chimeric gG designs and found that fusion to the gp64 transmembrane domain via a flexible linker significantly enhanced both baculovirus pseudotyping and the resulting immune response. The chimeras consisted of the gG ectodomain fused to the gp64 transmembrane domain either directly (gG-AN) or via a flexible linker (gG-FL), along with a variant retaining its native transmembrane domain (gG-TM). Notably, baculoviruses pseudotyped with gG-FL and gG-AN achieved the highest levels of gG incorporation into viral particles, while gG-TM impaired baculovirus replication. All pseudotyped baculoviruses elicited neutralizing antibodies against rabies virus; however, gG-FL induced the strongest immune response, as evidenced by full activation of bone marrow-derived dendritic cell markers, higher neutralizing antibody titers, and increased IFN-γ production. This enhanced immunogenicity correlated with greater protection following rabies virus challenge, with gG-FL baculovirus-immunized mice achieving the highest survival rates. Moreover, an adjuvanted gG-FL formulation showed an immunological potency of 4.65 IU/dose. These findings highlight the importance of transmembrane domain selection and flexible linker incorporation in optimizing baculovirus pseudotyping with gG and enhancing its immunogenicity against rabies virus. This strategy could inform the design of future baculovirus-based vaccines.
狂犬病仍然是一种致命的人畜共患疾病，每年影响约5万人，这凸显了开发能够引发强大免疫力的新型且具有成本效益的疫苗的必要性。杆状病毒已成为有前景的疫苗载体，因为它们能够在其表面展示抗原，使得用狂犬病病毒糖蛋白G（gG）进行假型化成为疫苗开发的可行策略。然而，优化杆状病毒假型化的策略仍未得到充分探索。在本研究中，我们评估了三种嵌合gG设计，发现通过柔性接头与gp64跨膜结构域融合可显著增强杆状病毒假型化以及由此产生的免疫反应。嵌合体由gG胞外结构域直接（gG-AN）或通过柔性接头（gG-FL）与gp64跨膜结构域融合组成，还有一个保留其天然跨膜结构域的变体（gG-TM）。值得注意的是，用gG-FL和gG-AN假型化的杆状病毒实现了gG掺入病毒颗粒的最高水平，而gG-TM损害了杆状病毒的复制。所有假型化的杆状病毒都引发了针对狂犬病病毒的中和抗体；然而，gG-FL诱导了最强的免疫反应，这通过骨髓来源的树突状细胞标志物的完全激活、更高的中和抗体滴度以及增加的IFN-γ产生得以证明。这种增强的免疫原性与狂犬病病毒攻击后的更大保护相关，用gG-FL杆状病毒免疫的小鼠存活率最高。此外，一种佐剂化的gG-FL制剂显示出4.65 IU/剂量的免疫效力。这些发现突出了跨膜结构域选择和柔性接头掺入在优化用gG进行杆状病毒假型化以及增强其对狂犬病病毒的免疫原性方面的重要性。该策略可为未来基于杆状病毒的疫苗设计提供参考。
