Engineering, decoding and systems-level characterization of chimpanzee cytomegalovirus

Area of Science:

• Virology
• Genomics
• Comparative Biology

Background:

• Chimpanzee cytomegalovirus (CCMV) is highly conserved with human cytomegalovirus (HCMV).
• Human cells support CCMV replication, making CCMV a potential model for HCMV.
• CCMV's genetic tractability is limited, hindering its use as a model.

Purpose of the Study:

• To create a BAC-cloned CCMV for precise genetic manipulation.
• To characterize the CCMV genome, transcriptome, and proteome.
• To investigate CCMV's functional genomics and host interactions.

Main Methods:

• CCMV genomic DNA was cloned into a bacterial artificial chromosome (BAC).
• BAC clones were reconstituted into infectious CCMV, and viral growth was assessed.
• Whole-genome sequencing, transcriptome, and proteome analyses were performed.
• Functional studies, including UL128 frameshift repair, were conducted.

Main Results:

• BAC-CCMV clones were successfully generated and produced infectious virus with high titers.
• Genomic analysis revealed polymorphic loci and a deletion-prone region.
• Novel ORFs, splice variants, and regulatory RNAs were identified.
• CCMV gene expression followed five temporal classes, and host responses mirrored HCMV infection.
• Repairing a UL128 frameshift mutation restored CCMV tropism for endothelial and epithelial cells.

Conclusions:

• BAC-cloned CCMV provides a versatile platform for genetic manipulation and functional genomics.
• This system enhances CCMV's utility as a model for HCMV research.
• The findings facilitate comparative studies leveraging the CCMV-HCMV relationship.