Analysis of two potential shuttle vectors containing herpes simplex virus defective DNA

Area of Science:

• Molecular Biology
• Virology
• Biotechnology

Background:

• Herpes simplex virus type 1 (HSV-1) defective DNA (dDNA) is a component of viral particles.
• Shuttle vectors are engineered DNA molecules capable of replicating in different host systems, such as bacteria and eukaryotic cells.
• The stability and efficiency of shuttle vectors are critical for their utility in molecular cloning and gene transfer.

Purpose of the Study:

• To evaluate the stability and efficiency of two distinct shuttle vectors containing HSV-1 dDNA when propagated in eukaryotic cells.
• To compare the performance of a bacteriophage lambda-based vector versus a plasmid-based vector for HSV-1 dDNA cloning.

Main Methods:

• Construction of two chimeric shuttle vectors: lambda gtWES::12-7 (bacteriophage lambda-based) and pBR325::12-7 (plasmid-based), both containing an HSV-1 dDNA fragment (HSV12-7).
• Transfection of these vectors into African green monkey kidney cells, followed by infection with wild-type HSV-1 helper virus.
• Analysis of vector replication, packaging into HSV-1 virions, and recovery of functional DNA from the virions.

Main Results:

• Both lambda gtWES::12-7 and pBR325::12-7 were replicated and packaged into HSV-1 virions.
• The lambda gtWES::12-7 vector exhibited significant deletion and rearrangement of its DNA regions.
• The pBR325::12-7 vector showed less rearrangement, and the recovered DNA was capable of transforming E. coli, indicating functional utility.

Conclusions:

• The choice of prokaryotic DNA origin significantly impacts the stability of HSV-1 dDNA-based shuttle vectors in eukaryotic systems.
• Plasmid-based vectors appear more suitable for accommodating and propagating HSV-1 dDNA compared to bacteriophage lambda-based vectors.
• Further considerations are needed when designing HSV-1 dDNA vectors for efficient cloning of large DNA fragments.