The Potentially Useful Varicella Zoster Viruss

Al-Anazi KA¹* and Al-Jasser AM²

¹Department of Hematology and Hematopoietic Stem Cell Transplantation, King Fahad Specialist Hospital, Saudi Arabia

²Department of Research and Studies, Ministry of Health, Saudi Arabia

*Corresponding author: Khalid Ahmed Al-Anazi, Department of Hematology and Hematopoietic Stem Cell Transplantation, Oncology Center, King Fahad Specialist Hospital, P.O. Box: 15215, Dammam 31444, Saudi Arabia

Received: October 24, 2019; Accepted: November 01, 2019; Published: November 08, 2019

Editorial

Varicella Zoster Virus (VZV), a double-stranded DNA virus that belongs to the alpha group of herpes viruses, is a highly contagious human neurotropic virus [1-4]. Primary infection or chickenpox occurs in childhood then the virus becomes latent in the nerve ganglia [4,5]. Immunosuppression predisposes to reactivation of VZV to cause herpes zoster decades later [4-8].

VZV behaves differently from other herpes viruses as it has the following characteristic features: having the smallest viral genome; losing almost all the genes that are not essential for its survival; being cell-associated and highly fusogenic; lacking inhibitors of autophagy; being an exclusively human pathogen; having a species-specific cytokine profile; and having an inverse relationship with glioma [1-4,8-14]. Additionally, it has recently being reported to have: association with Graft Versus Host Disease (GVHD) in recipients of Hematopoietic Stem Cell Transplantation (HSCT); having Bone Marrow (BM) stimulatory effects in patients with cytopenias and BM failure; and having antitumor actions in patients with Hematologic Malignancies (HMs) and solid tumors [2,15-22].

Recently, there is growing evidence suggesting several beneficial effects of the virus in immunocompromised hosts and these effects are translated into prolongation of survival [15,16]. The reported beneficial effects of VZV include: (1) stimulation of BM activity in patients with HMs and BM failure syndromes, (2) antitumor effects in various HMs and solid tumors, and (3) association with GVHD which has anticancer effects [2,14-23]. In addition, there are several reports on the safety of the live-attenuated VZV vaccine even in immune suppressed individuals and on the emerging role of the virus in cancer immunotherapy [24-33]. The reported beneficial effects may occur through several direct or indirect immunological mechanisms including: (1) alterations in BM microenvironment due to stress-induced hematopoiesis; (2) cells that are involved in the immunobiology and pathogenesis of the virus such as: Mesenchymal Stem Cells (MSCs), dendritic cells, Natural Killer (NK) cells, T-cells and mononuclear cells; (3) cellular proteins such as open reading frames, glycoproteins, promyelocytic leukemia protein, chaperons, and small ubiquitin-like modifier proteins; (4) extracellular vesicles, exosomes, and micro-RNAs; and (5) signaling pathways, cytokines, chemokines, and interferons [23,34-67].

The beneficial effects of VZV deserve further evaluation and should encourage scientists and researchers to give this potentially useful virus enough attention [2,23,67]. The antitumor effects as well as the stimulatory effect exerted by the virus on the 3 cell lines in the BM can be explained by one or more of the suggested mechanisms or may be due to a new mechanism that needs elucidation [2,15,23,67]. Ultimately, the virus itself; modified or engineered versions of the virus; or specific elements obtained from the serum of patients infected with VZV such as certain cytokines (e.g. interleukin-6 and tumor necrosis factor-a) and cells (e.g. MSCs and NK cells) may become novel therapeutic modalities in the management of patients with BM failure syndromes, HMs and solid tumors.

The Potentially Useful Varicella Zoster Viruss

Editorial

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