Epstein-Barr virus (EBV) is typically found in a latent, asymptomatic state in immunocompetent individuals. Perturbations of the host immune system can stimulate viral reactivation. Furthermore, there are a myriad of EBV-associated illnesses including various cancers, post-transplant lymphoproliferative disease, and autoimmune conditions. A thorough understanding of this virus, and the interplay between stress and the immune system, is essential to establish effective treatment. This review will provide a summary of the interaction between both psychological and cellular stressors resulting in EBV reactivation. It will examine mechanisms by which EBV establishes and maintains latency and will conclude with a brief overview of treatments targeting EBV.
Viral pathogens often exploit host cell regulatory and signaling pathways to ensure an optimal environment for growth and survival. Several studies have suggested that 5′-adenosine monophosphate-activated protein kinase (AMPK), an intracellular serine/threonine kinase, plays a significant role in the modulation of infection. Traditionally, AMPK is a key energy regulator of cell growth and proliferation, host autophagy, stress responses, metabolic reprogramming, mitochondrial homeostasis, fatty acid β-oxidation and host immune function. In this review, we highlight the modulation of host AMPK by various viruses under physiological conditions. These intracellular pathogens trigger metabolic changes altering AMPK signaling activity that then facilitates or inhibits viral replication. Considering the COVID-19 pandemic, understanding the regulation of AMPK signaling following infection can shed light on the development of more effective therapeutic strategies against viral infectious diseases.
Ginkgolic acids (GA) are alkylphenol constituents of the leaves and fruits of Ginkgo biloba. GA has shown pleiotropic effects in vitro, including: antitumor effects through inhibition of lipogenesis; decreased expression of invasion associated proteins through AMPK activation; and potential rescue of amyloid-β (Aβ) induced synaptic impairment. GA was also reported to have activity against Escherichia coli and Staphylococcus aureus. Several mechanisms for this activity have been suggested including: SUMOylation inhibition; blocking formation of the E1-SUMO intermediate; inhibition of fatty acid synthase; non-specific SIRT inhibition; and activation of protein phosphatase type-2C. Here we report that GA inhibits Herpes simplex virus type 1 (HSV-1) by inhibition of both fusion and viral protein synthesis. Additionally, we report that GA inhibits human cytomegalovirus (HCMV) genome replication and Zika virus (ZIKV) infection of normal human astrocytes (NHA). We show a broad spectrum of fusion inhibition by GA of all three classes of fusion proteins including HIV, Ebola virus (EBOV), influenza A virus (IAV) and Epstein Barr virus (EBV). In addition, we show inhibition of a non-enveloped adenovirus. Our experiments suggest that GA inhibits virion entry by blocking the initial fusion event. Data showing inhibition of HSV-1 and CMV replication, when GA is administered post-infection, suggest a possible secondary mechanism targeting protein and DNA synthesis. Thus, in light of the strong effect of GA on viral infection, even after the infection begins, it may potentially be used to treat acute infections (e.g. Coronavirus, EBOV, ZIKV, IAV and measles), and also topically for the successful treatment of active lesions (e.g. HSV-1, HSV-2 and varicella-zoster virus (VZV)).
There is a significant body of research examining the role of human papillomavirus (HPV) in the pathogenesis of cervical cancer, with a particular emphasis on the oncogenic proteins E5, E6, and E7. What is less well explored, however, is the relationship between cervical cancer and herpes simplex virus (HSV). To date, studies examining the role of HSV in cervical cancer pathogenesis have yielded mixed results. While several experiments have determined that HPV/HSV-2 coinfection results in a higher risk of developing cervical cancer, others have questioned the validity of this association. However, clarifying the potential role of HSV in the pathogenesis of cervical cancer may have significant implications for both the prevention and treatment of this disease. Should this relationship be clarified, treating and preventing HSV could open another avenue with which to prevent cervical cancer. The importance of this is highlighted by the fact that, despite the creation of an effective vaccine against HPV, cervical cancer still impacts 604,000 women and is responsible for 342,000 deaths annually. This review provides an overview of HSV and HPV infections and then delves into the possible links between HPV, HSV, and cervical cancer. It concludes with a summary of preventive measures against and recent treatment advances in cervical cancer.
Epstein–Barr virus (EBV) is one of eight known herpesviruses with the potential to infect humans. Globally, it is estimated that between 90–95% of the population has been infected with EBV. EBV is an oncogenic virus that has been strongly linked to various epithelial malignancies such as nasopharyngeal and gastric cancer. Recent evidence suggests a link between EBV and breast cancer. Additionally, there are other, rarer cancers with weaker evidence linking them to EBV. In this review, we discuss the currently known epithelial malignancies associated with EBV. Additionally, we discuss and establish which treatments and therapies are most recommended for each cancer associated with EBV.
Herpes simplex virus type 1 (HSV-1) causes a lifelong latent infection with an estimated global prevalence of 66%. Primary and recurrent HSV infections are characterized by a tingling sensation, followed by an eruption of vesicles, which can cause painful erosions. Commonly used antiviral drugs against HSV infection are nucleoside analogues including acyclovir (ACV), famciclovir, and valacyclovir. Although these nucleoside analogues reduce morbidity and mortality in immunocompetent individuals, ACV-resistant HSV strains (ACVR-HSV) have been isolated from immunocompromised patients. Thus, ACVR-HSV infection poses a critical emerging public health concern. Recently, we reported that ginkgolic acid (GA) inhibits HSV-1 by disrupting viral structure, blocking fusion, and inhibiting viral protein synthesis. Additionally, we showed GA affords a broad spectrum of fusion inhibition of all three classes of fusion proteins, including those of HIV, Ebola, influenza A and Epstein Barr viruses. Here we report GA’s antiviral activity against HSV-1 skin infection in BALB/cJ mice. GA-treated mice demonstrated a significantly reduced mortality rate and decreased infection scores compared to controls treated with dimethylsulfoxide (DMSO)-vehicle. Furthermore, GA efficiently inhibited ACVR-HSV-1 strain 17+ in vitro and in vivo. Since GA’s mechanism of action includes virucidal activity and fusion inhibition, it is expected to work alone or synergistically with other anti-viral drugs, and we anticipate it to be effective against additional cutaneous and potentially systemic viral infections.