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Microbes & Immunity

REVIEW ARTICLE
The application of a herpes simplex virus Type I

vector for transgenic therapy

Chunfu Zheng*
Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary,
Canada

Abstract
The key to successful gene therapy is to effectively transfer genes to target cells and
control the effective expression of genes to avoid expression in non-target tissues.
At present, there are two common methods of gene therapy: non-replicating viruses
and viral vectors. The use of non-replicating viruses as vectors often limits the
efficiency of gene transfer and is unsatisfactory for clinical application. In contrast,
replicative viral vectors can deliver genes from a small number of cells to neighboring
cells, significantly improve the efficiency of gene delivery, and stably and persistently
express exogenous genes. As a result, the investigation and application of viral vectors
are recommended. Herpes simplex virus Type I-derived vectors have gradually
become important biological treatments due to their wide host range, integration of
long fragments of exogenous DNA, neurotropism, and various animal models.

Keywords: Herpes simplex virus Type I; Gene therapy; Vectors; Transgenic technology

*Corresponding author:
Chunfu Zheng
(chunfu.zheng2@ucalgary.ca) 1. Introduction
Citation: Zheng C. The application of
a herpes simplex virus Type I vector Herpesvirus is a type of virus that is widely distributed in nature. Most animals carry
for transgenic therapy. Microbes & at least one herpesvirus in their body, and therefore, the host is often found to carry
Immunity. 2025;2(2):16-33. several different herpesviruses at the same time. Herpesviruses seldom infect more
doi: 10.36922/mi.7947
than one type of host naturally; therefore, more than 200 herpesviruses are likely to be
Received: December 18, 2024 identified. At present, eight human herpesviruses have been identified, which can be
Revised: February 13, 2025 divided into three subfamilies: α-herpesvirinae (herpes simplex virus [HSV]-1, HSV-2
Accepted: February 19, 2025 and varicella-zoster virus [VZV]), β-herpesvirinae (human cytomegalovirus HCMV,
human herpesvirus types 6 and 7) and γ-herpesvirinae (Epstein-Barr virus and human
Published online: March 4, 2025 herpesvirus 8 [Kaposi’s sarcoma-associated herpesvirus]).
Copyright: © 2025 Author(s).
This is an Open-Access article The herpesvirus family has four significant biological characteristics: (1) these
distributed under the terms of the viruses encode a large number of enzymes related to nucleic acid metabolism, DNA
Creative Commons Attribution synthesis and post-translational modification of proteins, although different species of
License, permitting distribution,
and reproduction in any medium, herpesviruses may encode different enzymes. (2) The synthesis of viral DNA and the
provided the original work is assembly of capsids are completed in the nucleus, but the final assembly of virions occurs
properly cited. in the cytoplasm. (3) Destruction of infected cells often accompanies the production
Publisher’s Note: AccScience of infectious progeny viruses. (4) All herpesviruses detected thus far can cause latent
Publishing remains neutral with infection in natural hosts. When the virus undergoes latent infection in cells, the viral
regard to jurisdictional claims in
published maps and institutional genome appears in a closed circle form, and only a small portion of viral genes are
affiliations. expressed. The genome of the latent virus retains its ability to replicate and can cause

Volume 2 Issue 2 (2025) 16 doi: 10.36922/mi.7947