User-Friendly Replication-Competent MAdV-1 Vector System with a Cloning Capacity of 3.3 Kilobases

• Published in: Viruses Vol. 16; no. 5; p. 761
• Main Authors: Zhang, Zhichao, Guo, Xiaojuan, Hou, Wenzhe, Zou, Xiaohui, Wang, Yongjin, Liu, Shuqing, Lu, Zhuozhuang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-05-2024
• Subjects: Adenoviridae - genetics; Adenoviruses; Analysis; Animals; Backup software; Cloning; Cloning vectors; Cloning, Molecular; Control; Enzymes; Ethylenediaminetetraacetic acid; Expression vectors; Genes, Reporter; Genetic vectors; Genetic Vectors - genetics; Genomes; Health aspects; Identification and classification; infectious plasmid; Laboratory animals; Mice; mouse adenovirus 1; Mutation; NIH 3T3 Cells; packaging capacity; Pathogenesis; Plasmids; Plasmids - genetics; Rabies; Replication; replication competent; transgene; Transgenes; Vaccines; vector; Viral proteins; Virus Replication; Viruses; China; Beijing China; United States > US; infectious plasmid; transgene; mouse adenovirus 1; packaging capacity; Gibson assembly; replication competent; vector
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v16050761

Mouse adenoviruses (MAdV) play important roles in studying host-adenovirus interaction. However, easy-to-use reverse genetics systems are still lacking for MAdV. An infectious plasmid pKRMAV1 was constructed by ligating genomic DNA of wild-type MAdV-1 with a PCR product containing a plasmid backbone through Gibson assembly. A fragment was excised from pKRMAV1 by restriction digestion and used to generate intermediate plasmid pKMAV1-ER, which contained E3, fiber, E4, and E1 regions of MAdV-1. CMV promoter-controlled GFP expression cassette was inserted downstream of the pIX gene in pKMAV1-ER and then transferred to pKRMAV1 to generate adenoviral plasmid pKMAV1-IXCG. Replacement of transgene could be conveniently carried out between dual BstZ17I sites in pKMAV1-IXCG by restriction-assembly, and a series of adenoviral plasmids were generated. Recombinant viruses were rescued after transfecting linearized adenoviral plasmids to mouse NIH/3T3 cells. MAdV-1 viruses carrying GFP or firefly luciferase genes were characterized in gene transduction, plaque-forming, and replication in vitro or in vivo by observing the expression of reporter genes. The results indicated that replication-competent vectors presented relevant properties of wild-type MAdV-1 very well. By constructing viruses bearing exogenous fragments with increasing size, it was found that MAdV-1 could tolerate an insertion up to 3.3 kb. Collectively, a replication-competent MAdV-1 vector system was established, which simplified procedures for the change of transgene or modification of E1, fiber, E3, or E4 genes.