Holgado María Pía, Falivene Juliana, Maeto Cynthia, Amigo Micaela, Pascutti María Fernanda, Vecchione María Belén, Bruttomesso Andrea, Calamante Gabriela, Del Médico-Zajac María Paula, Gherardi María Magdalena
Instituto de Investigaciones Biomédicas en Retrovirus y SIDA (INBIRS), Universidad de Buenos Aires-CONICET, Facultad de Medicina, Ciudad de Buenos Aires 1121, Argentina.
Unidad de Microanálisis y Métodos Físicos Aplicados a Química Orgánica (UMYMFOR), Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina.
Viruses. 2016 May 23;8(5):139. doi: 10.3390/v8050139.
MVA is an attenuated vector that still retains immunomodulatory genes. We have previously reported its optimization after deleting the C12L gene, coding for the IL-18 binding-protein. Here, we analyzed the immunogenicity of MVA vectors harboring the simultaneous deletion of A44L, related to steroid synthesis and A46R, a TLR-signaling inhibitor (MVAΔA44L-A46R); or also including a deletion of C12L (MVAΔC12L/ΔA44L-A46R). The absence of biological activities of the deleted genes in the MVA vectors was demonstrated. Adaptive T-cell responses against VACV epitopes, evaluated in spleen and draining lymph-nodes of C57Bl/6 mice at acute/memory phases, were of higher magnitude in those animals that received deleted MVAs compared to MVAwt. MVAΔC12L/ΔA44L-A46R generated cellular specific memory responses of higher quality characterized by bifunctionality (CD107a/b⁺/IFN-γ⁺) and proliferation capacity. Deletion of selected genes from MVA generated innate immune responses with higher levels of determining cytokines related to T-cell response generation, such as IL-12, IFN-γ, as well as IL-1β and IFN-β. This study describes for the first time that simultaneous deletion of the A44L, A46R and C12L genes from MVA improved its immunogenicity by enhancing the host adaptive and innate immune responses, suggesting that this approach comprises an appropriate strategy to increase the MVA vaccine potential.
痘苗病毒天坛株（MVA）是一种减毒载体，仍保留免疫调节基因。我们之前曾报道过在删除编码IL-18结合蛋白的C12L基因后对其进行的优化。在此，我们分析了同时缺失与类固醇合成相关的A44L基因和一种TLR信号抑制剂A46R基因的MVA载体（MVAΔA44L-A46R）的免疫原性；或者还包括删除C12L基因的载体（MVAΔC12L/ΔA44L-A46R）。结果证明了MVA载体中缺失基因的生物学活性不存在。在急性/记忆期对C57Bl/6小鼠的脾脏和引流淋巴结中针对痘苗病毒（VACV）表位的适应性T细胞反应进行评估，结果显示与野生型MVA（MVAwt）相比，接受缺失型MVA的动物中这些反应的强度更高。MVAΔC12L/ΔA44L-A46R产生了更高质量的细胞特异性记忆反应，其特征为具有双功能性（CD107a/b⁺/IFN-γ⁺）和增殖能力。从MVA中删除选定基因产生了先天免疫反应，与T细胞反应产生相关的决定性细胞因子水平更高，如IL-12、IFN-γ以及IL-1β和IFN-β。本研究首次描述了从MVA中同时删除A44L、A46R和C12L基因通过增强宿主适应性和先天免疫反应提高了其免疫原性，表明这种方法是一种提高MVA疫苗潜力的合适策略。
