Infectivity and growth kinetics of Herpes Simplex Virus type-2 in MOLT4 CCR5+ and CEM CCR5+ T cell lines

Altered HIV-1 Viral Copy Number and Gene Expression Profiles of Peripheral (CEM CCR5+) and Mucosal (A3R5.7) T Cell Lines Co-Infected with HSV-2 In Vitro

Co-infecting pathogens have been speculated to influence Human Immunodeficiency Virus (HIV) disease progression. Herpes Simplex Virus Type-2 (HSV-2), another sexually transmitted pathogen, is commonly observed in individuals with HIV-1. Some clinical studies have observed an increase in HIV-1 viral copy number in HSV-2 co-infected individuals. In vitro studies have also demonstrated an increase in the expression of HIV-1 co-receptors on immune cells infected with HSV-2. Although both the viruses show distinctive persistent infection, the influence of HSV-2 on HIV-1 is poorly understood. Here we present a comparative analysis of primary CD4+ T-cells and four different T-cell lines (PM-1, CEM CCR5+, MOLT4 CCR5+, and A3R5.7) to assess the influence of HSV-2 co-infection on HIV-1 replication in vitro. Cell lines indicating significant changes in HIV-1 viral copy number [CEM CCR5+ (0.61 Log10), A3R5.7 (0.78 Log10)] were further evaluated for the infectivity of HIV-1 virions and the changes in gene expression profiles of HSV-2/HIV-1 co-infected and mono-infected cells, which were further confirmed by qPCR. Significant changes in NUP, MED, and VPS mRNA expression were observed in the gene expression profiles in co-infected CEM CCR5+ and A3R5.7 cells. In both cell lines, it was observed that the WNT signaling, PI3 kinase, apoptosis, and T-cell activation pathways were negatively affected in co-infected cells. The data suggest that HSV-2 infection of T-cells may influence the expression of genes that have been previously shown to affect HIV-1 replication in vitro. This idea needs to be explored further to identify anti-viral targets for HSV-2 and HIV-1.

Host-virus interaction and viral evasion

With each infectious pandemic or outbreak, the medical community feels the need to revisit basic concepts of immunology to understand and overcome the difficult times brought about by these infections. Regarding viruses, they have historically been responsible for many deaths, and such a peculiarity occurs because they are known to be obligate intracellular parasites that depend upon the host's cell machinery for their replication. Successful infection with the production of essential viral components requires constant viral evolution as a strategy to manipulate the cellular environment, including host internal factors, the host's nonspecific and adaptive immune responses to viruses, the metabolic and energetic state of the infected cell, and changes in the intracellular redox environment during the viral infection cycle. Based on this knowledge, it is fundamental to develop new therapeutic strategies for controlling viral dissemination, by means of antiviral therapies, vaccines, or antioxidants, or by targeting the inhibition or activation of cell signaling pathways or metabolic pathways that are altered during infection. The rapid recovery of altered cellular homeostasis during viral infection is still a major challenge. Here, we review the strategies by which viruses evade the host's immune response and potential tools used to develop more specific antiviral therapies to cure, control, or prevent viral diseases.

In Vitro Study of Multi-Therapeutic Properties of Thymus bovei Benth. Essential Oil and Its Main Component for Promoting Their Use in Clinical Practice

Thymus bovei Benth. (TB) is an important plant in the traditional medicine of the Mediterranean region. This study investigates the health-promoting properties of TB essential oil (TB-EO) for its possible use in clinical practice with regards to its cytotoxic, anti-herpes simplex virus type 2 (HSV-2), and antihypertensive (through inhibition of human angiotensin-converting enzyme; ACE) properties. The phytochemical profile of EO (99.9%) was analyzed by Gas Chromatography with Flame-Ionization Detection (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS). In this study, all biological methods were performed at the level of in vitro studies. The results showed that TB-EO exerted remarked cytotoxic properties against human cervical carcinoma cells, colon cancer cells, and lung adenocarcinoma cells with the half-maximal inhibitory concentration (IC₅₀) values of 7.22, 9.30, and 8.62 µg/mL, respectively, in comparison with that of standard anticancer drug cisplatin with IC₅₀ values of 4.24, 5.21, and 5.43 µg/mL, respectively. Fascinatingly, TB-EO showed very weak cytotoxicity on the healthy human fetal lung fibroblast cells with an IC₅₀ value of 118.34 µg/mL compared with that of cisplatin (IC₅₀ = 10.08 µg/mL). TB-EO, its main component geraniol, TB-EO combined with acyclovir (ACV) along with standard ACV, have displayed pronounced inhibitory properties against the replication of HSV-2 with the half-maximal effective concentration (EC₅₀) values of 2.13, 1.92, 0.81 and 1.94 µg/mL, respectively, with corresponding selectivity indices (SI) 98.59, 109.38, 259.26 and 108.25, respectively. TB-EO and geraniol at a concentration of 15 µg/mL showed prominent inhibitory activities against ACE with % of inhibition 95.4% and 92.2%, respectively, compared with that of standard inhibitor captopril (99.8%; 15 µg/mL). Molecular docking studies were performed to unveil the mechanism of action of geraniol as well as structural parameters necessary for anti-HSV-2 activity (through the inhibition of HSV-2 protease) and ACE inhibition. This is the first report on the chemical composition of Egyptian TB-EO along with the above-mentioned biological activities. Our results may be considered as novel findings in the course of a search for new and active anticancer, anti-HSV-2 and antihypertensive agents, and expand the medicinal value of this plant and its phytochemicals in clinical practice.