Magnesium Oxide Nanoparticles: A New Frontier in Antiviral Therapy Against Herpes Simplex Virus Type 1

Enhanced synergistic antiviral effects of thermally expanded graphite and copper oxide nanosheets in the form of a novel nanocomposite against herpes simplex virus type 1

This systematic review aimed to evaluate existing randomized controlled trials (RCT) and cohort studies on the efficacy of mouthwashes in reducing SARS-CoV-2 viral loads in human saliva.Searches with pertinent search terms were conducted in PubMed, MEDLINE, Scopus, and Web of Science databases for relevant records published up to Oct 15, 2022. Google Scholar and ProQuest were searched for grey literature. Manual searches were conducted as well for any pertinent articles. The protocol was prospectively registered at PROSPERO (CRD42022324894). Eligible studies were critically appraised for risk of bias and quality of evidence to assess the efficacy of mouthwash in reducing the SARS-CoV-2 viral load in human saliva.Eleven studies were included. The effect on viral load using various types of mouthwash was observed, including chlorhexidine (CHX), povidone-iodine (PI), cetylpyridinium chloride (CPC), hydrogen peroxide (HP), ß-cyclodextrin-citrox mouthwash (CDCM), and Hypochlorous acid (HCIO). Eight articles discussed CHX use. Five were found to be significant and three did not show any significant decrease in viral loads. Eight studies reviewed the use of PI, with five articles identifying a significant decrease in viral load, and three not showing a significant decrease in viral load. HP was reviewed in four studies, two studies identified significant viral load reductions, and two did not. CPC was reviewed in four studies, two of which identified significant viral load reductions, and two did not. CDCM was reviewed in one article which found a significant decrease in viral load reduction. Also, HCIO which was evaluated in one study indicated no significant difference in CT value.The current systematic review indicates that based on these eleven studies, mouthwashes are effective at reducing the SARS-CoV-2 viral load in human saliva. However, further studies should be performed on larger populations with different mouthwashes. The overall quality of evidence was high.

Herpes Simplex Virus Type 1 (HSV-1) has been found to present many therapeutic challenges due to the problem of drug resistance and the low efficacy of antiviral compounds. Recently, the photocatalytic property and biocompatibility of graphitic carbon nitride (g-C3N4) nanosheets have been found to be promising for antiviral therapy. The antiviral efficacy and biocompatibility of the g-C3N4 nanosheets are assessed in this study. g-C3N4 nanosheets were prepared and characterized by X-ray diffraction (XRD), Fourier Transform InfraRed Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and zeta potential measurements to confirm the properties. Antiviral efficacy was determined by the ability of g-C3N4 to block the infection of Vero cells by HSV-1 using two different methods: the virucidal assay and the post-treatment assay. The Real-Time PCR measured viral replication. The cytotoxic effect of the g-C3N4 nanosheets was evaluated using a neutral red uptake assay. g-C3N4 nanosheets exhibited a pure graphitic structure, high colloidal stability, and a porous, flake-like morphology. They achieved dose-dependent HSV-1 inhibition rates of 94.9-99.2% (virucidal) and 92.3-96.0% (post-treatment) at 600-800µg/mL (P < 0.001). No cytotoxic effects were seen in the g-C3N4 nanosheets; however, increased cell viability by nearly 40% was seen when tested at a concentration of 800µg/mL. g-C3N4 nanosheets possess excellent biocompatibility and the ability to inhibit HSV-1 greatly, and are promising alternatives to conventional treatment regimens. There is a need to study further the mechanism of the antiviral properties of g-C3N4 nanosheets and the efficacy of g-C3N4 nanosheets in vivo.

Herpes simplex virus type 1 (HSV‐1) is responsible for the majority of cold sores, herpetic keratitis‐induced blindness, profound skin lesions, and encephalitis that can be fatal. Currently, acyclovir and its derivatives are the first‐line therapy for the treatment of HSV‐1 infection. But there are drawbacks to these treatments: limited efficacy against drug‐resistant strains of the virus. Hence, it is of critical importance to explore and develop new antiviral drugs for HSV‐1. In the present study, we explored whether tungsten oxide nanoparticles (WO3NPs) were potent inhibitors of HSV‐1 infection as a new class of agent. WO3NPs were characterized by X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FE‐SEM), Fourier transform infrared (FTIR) spectroscopy, and zeta potential analysis. Cytotoxicity of Vero cells caused by WO3NPs was determined by methyl thiazolyl tetrazolium (MTT) assay. The quantitative real‐time polymerase chain reaction (qRT‐PCR) assay was utilized for further verification of the action of the WO3NPs on HSV‐1. The cytotoxicity test showed low toxicity (<20%) of the rod‐shaped WO3NPs when they were assayed on Vero cells at concentrations of up to 700 μg/mL. When HSV‐1 was treated with WO3NPs at 700 µg/mL [20% cytotoxicity concentration (CC20); the concentration causing 20% cytotoxicity, ~80% cell viability] and 1000 µg/mL [50% cytotoxicity concentration (CC50); the concentration causing 50% cytotoxicity, ~50% cell viability] for 3 h, the viral load was significantly reduced, achieving inhibition rates of 99.4% and 99.9%, respectively. Additionally, experiments conducted after HSV‐1 infection of Vero cells (post‐treatment assays) indicated that WO3NPs at concentrations of 250, 500, and 750 µg/mL significantly suppressed viral replication, with inhibition rates of 82%, 87.5%, and 96.5%, respectively. WO3NPs have potent inhibitory effects on HSV‐1. Therefore, they can be considered potential candidates for therapeutic development against infections caused by this virus.

Commentary on 'Fast anterograde transport of herpes simplex virus: role for the amyloid precursor protein of Alzheimer's disease' by Prasanna Satpute-Krishnan et al. Aging Cell Vol. 2, Issue 6, 305-318 (2003).

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are among the most common coinfections seen in individuals infected with HIV-1. Most research on HSV-HIV coinfection has focused on HSV-2, and in particular, on its impact on HIV transmission. HSV-2 is associated with micro- and macroulcerations in genital mucosal surfaces, increased numbers of HIV target cells in genital mucosal tissue and increases in plasma HIV viral load of up to 0.5 log(10) copies/mL, such that HSV-2 infection increases the risk of both HIV acquisition and transmission. Because plasma HIV RNA levels are a major determinant of rates of CD4 cell decline, HSV-2 coinfection may also adversely affect the progression of HIV disease. Anti-HSV medications have in fact been associated with reciprocal decreases in HIV viral load in short-term studies. These findings have led to the development of several clinical trials of HSV-2 suppression as strategies for preventing HIV transmission and slowing the rate of HIV disease progression. HSV-1 coinfection has largely been ignored from this growing body of research, yet there are several reasons that this coinfection remains an important issue for study. First, the seroprevalence of HSV-1 is consistently higher than that of HSV-2 among both HIV-infected and HIV-uninfected populations, underscoring the relevance of HSV-1 coinfection to the majority of HIV-infected persons. Second, pre-existing HSV-1 antibodies in individuals may modulate the course of subsequently acquired HSV-2 infection; the implications of such changes on HSV-HIV coinfection remain unexplored. Third, HSV-1 and HSV-2 are closely related viruses that share 83% genetic homology. Their virological and pathobiological similarities suggest that their implications on HIV pathogenesis may be similar as well. Finally, HSV-1 is becoming increasingly relevant because the incidence of genital HSV-1 has risen. Although genital herpes is traditionally associated with HSV-2, recent studies have shown that the majority of serologically confirmed primary genital herpes in some settings is attributable to HSV-1. Because the genital tract is an important site of biological interaction between HSV and HIV, this epidemiological change may be clinically important.

Objective To evaluate the anti- herpes simplex virus type 1 (HSV-1) activity of KPC-rg1, a water extract from Cinnamomum cassia, and explore its potential function of broad-spectrum antivirus effect. Methods In vitro, the changes of morphology of Vero cells were assessed and viral loads were detected after cells were infected with HSV-1 alone and HSV-1 pre-treated with KPC-rg1 respectively. The corneal lesions of mouse and tree shrew corneal infection model were evaluated after they were infected with HSV-1 alone and HSV-1 pre-treated with KPC-rg1 respectively. The antiviral activity of KPC-rg1 against 9 viruses were measured by CPE and GFP reduction assays. Results The virus replication of HSV-1 infected cells was moderately inhibited by KPC-rg1 in a dose range of 0.0001-1.0 mg/ml, while the cells were completely protected when they were infected with HSV-1 pre-treated with KPC-rg1 (0.001-1.0 mg/ml). The corneal lesions of animals were improved in both mouse and tree shrews models infected with HSV-1 after the treatment of KPC-rg1, while animals were completely protected from infection when HSV-1 pre-treated with KPC-rg1. KPC-rg1 had a potential anti-virus effect on the enveloped viruses such as HSV-1, HCMV, RSV alone and HIV-1. Conclusions KPC-rg1 is a collosol (Tyndall effect) which would immediately form a stable super-nanoparticle structure of KPC-rg1/virus when encounter virus, and thus the virus coated by KPC-rg1 lost its ability of infection. KPC-rg1 can reduce the suffering by newly or latent virus infection because its encapsulation of virus and inhibition of further infection. Our study added additional proofs of the anti-viral property of the water extract from Cinnamomum cassia, and provided a further basis to develop KPC-rg1 as a drug which could be potentially applied in clinic to treat HSV-1 infection. Key words: Cinnamon water extract KPC-rg1; Herpes simplex virus type 1; Antiviral activity

The T-cell-mediated resolution of herpes simplex virus type 2 (HSV-2) genital infections is not fully understood. In these studies, the mechanisms by which CD8+ T cells clear virus from the genital epithelium were examined. Ovalbumin (OVA)-specific CD8+ T cells from OT-I transgenic mice cleared a thymidine kinase-deficient, ovalbumin-expressing HSV-2 virus (HSV-2 tk- OVA) from the genital epithelium of recipient mice, and clearance was abrogated by in vivo neutralization of gamma interferon (IFN-gamma). Further, CD8+ OT-I T cells deficient in IFN-gamma were unable to clear HSV-2 tk- OVA from the vaginal epithelium. The requirement for cytolytic mechanisms in HSV-2 tk- OVA clearance was tested in radiation chimeras by adoptive transfer of wild-type or perforin-deficient OT-I T cells to irradiated Fas-defective or wild-type recipients. Although a dramatic decrease in viral load was observed early after challenge with HSV-2 tk- OVA, full resolution of the infection was not achieved in recipients lacking both perforin- and Fas-mediated cytolytic pathways. These results suggest that IFN-gamma was responsible for an early rapid decrease in HSV-2 virus titer. However, either perforin- or Fas-mediated cytolytic mechanisms were required to achieve complete clearance of HSV-2 from the genital epithelium.

Isolates from a total of 228 patients with clinical herpes simplex were included in this study: 92 were from patients in their first episode and 136 were from patients with recurrent genital herpes...

In search of new potent treatment of herpes simplex keratitis (HSK), inhibitory effect of oridonin (Ori) on herpes simplex virus type 1 (HSV-1) was validated by experiments. For evaluating inhibitory effect of oridonin on herpes simplex virus type 1, a series of in-vivo and in-vitro studies were carried out. Mouse HSV-1 infection model was used in the in-vivo experiments. Experimental mice were classified infivedifferentgroups: Mock (mock-infected), HSV-1+ DMSO, HSV-1+ Ori, HSV-1+ ACV, combined Ori and ACV+HSV-1. Corneas of Mock, HSV-1+ DMSO, HSV-1+ Ori group were sent formRNA-sequencing after 3 days post infection (dpi). The expression of virus and host-related genes was evaluated by quantitative real-time polymerase chain reaction (qPCR). Vero cells HSV-1 infection models were used in the in-vitro experiments. The application of ACV, Oridonin alone or a combination of both could alleviate HSV-1 severity and inhibit HSV-1 virus replication in C57BL/6 mice models. qPCR showed that compared with mock group, the expression of interleukin-6 (il-6), interleukin-1α (il-1α), and Tumor-necrosis factor-alpha (tnf-α) was up-regulated in DMSO+HSV-1 group and suppressed in other three group. Moreover, the expression of nod-like receptor protein (nlrp3), caspase 1 and interleukin-1β (il-1β) were depressed in the oridonin-treated group. Oridonin significantly inhibits HSV-1 replication, HSV-1 related gene expression, and the production of progeny HSV-1 viruses in vitro. Besides, oridonin affect the replication phase but not HSV-1 entry or penetration and cannot inactivate HSV-1. Oridonin alleviates herpes simplex keratitis infection in mouse, which may be attributed to inhibition of the NLRP3-inflammasome-IL-1β pathway. Our study illustrates that Oridonin has potential promise for application in treating HSK and other diseases caused by HSV-1 infection.

Objective: To evaluate the antiviral activity of pure compounds against herpes simplex virus type 1 (HSV-1) from the rhizome of Anemarrhena asphodeloides. Methods: Bioassay-guided isolation was conducted to separate the active compound and its chemical structure was elucidated by spectral analysis. In vitro antiviral efficacy of active compound was detected by Cell Counting Kit-8 assay, plaque reduction assay, and fluorescence observation. RT-PCR was used to determine the viral load and the cytokine-related gene expression after HSV-1 infection. In vivo study was also conducted to further determine antiviral efficacy of an active compound against HSV-1. Results: An active compound was isolated and elucidated as mangiferin. Mangiferin significantly inhibited the replication of HSV-1 in Vero cells with a half maximal inhibitory concentration (IC50) of 64.0 mg/L. Time-of-addition and time-of-removal assays demonstrated that mangiferin could effectively inhibit the replication of HSV-1 in the early stage (8 h). UL12, UL42, and UL54 gene expression levels of HSV-1 in the 64 mg/L mangiferin-treated group were markedly reduced as compared with the HSV-1 group (P&lt;0.01). Fluorescence observation showed that mangiferin attenuated the mitochondrial damage maintaining ΔΨm induced by HSV-1 in Vero cells. The expression of inflammatory factors TNF-α, IL- 1β, and IL-6 was remarkably increased in the virus-infected group as compared with that in the normal group (P&lt;0.05), the levels of these inflammatory factors dropped after treatment with mangiferin. Mangiferin significantly decreased the viral load and attenuated the HSV-1-induced up-regulation of TNF-α, IL1β, and IL-6. The relative protection rate of HSV-1-infected mice could reach up to 55.5% when the concentration of mangiferin was 4 g/kg. Conclusions: Mangiferin exhibits promising antiviral activity against HSV-1 in vitro and in vivo and could be a potential antiviral agent for HSV-1.

CROI OVERVIEW The 13th Conference on Retroviruses and Opportunistic Infections (CROI) was held in Denver, Colorado, on February 5-8, 2006. This conference served as a backdrop for reflecting on the 25th anniversary of acquired immunodeficiency syndrome ([AIDS] first described in June 1981) and the 10th anniversary of highly active antiretroviral therapy ([HAART] first widely available in 1996). This year, approximately 4000 leading researchers and clinicians from 85 countries (54% from North America) were able to attend 6 plenary lectures, 7 roundtable symposia, 5 thematic research overviews, 122 original oral abstract presentations, 734 poster presentations, 9 poster discussions, and late breakers. In this month's Snapshots, we review some highlights of the conference. Abstracts, webcasts, and podcasts are accessible through the conference website (www.retroconference.org/2006). TEN YEARS OF HAART John G. Bartlett from Johns Hopkins University gave a plenary lecture covering the most important advances in the therapy of human immunodeficiency virus (HIV) infection over the past decade. He outlined the method of doing HIV clinical trials (including the Food and Drug Administration's approval of HIV RNA as the first laboratory marker accepted as an end point for any infectious disease) and a series of clinical trials which have led to current guidelines. He concluded by looking forward to the soon to be completed head-to-head study of efavirenz and lopinavir/ritonavir (ACTG 5142), the marketing of the first once daily coformulation of tenofovir/emtricitabine/efavirenz (the single HAART pill), the availability of new salvage agents (the TMC114 Expanded Access Program and others in the near future), the potential for multidrug induction followed by single boosted protease inhibitor (PI) maintenance (lopinavir/ritonavir and atazanavir/ritonavir), and the continued development of new antiretroviral classes (to be discussed later). DIAGNOSIS AND TRANSMISSION Since 2002, North Carolina's Screening & Tracing Active Transmission (STAT) program has used a combined HIV antibody and RNA testing algorithm to identify cases of primary HIV in the antibody "window" period. Patterson et al (abstract 370) demonstrated that the standard antibody test missed 4% of the pregnant women in North Carolina who are infected with HIV. They were able to prevent vertical transmission despite high viremia in the mother by initiating antiretroviral therapy. Following reports from New York City and San Francisco, that there might be excessive false-positive oral fluid rapid HIV tests (OraQuick Advance HIV1/2 Rapid Antibody Test approved in March 2004), the Centers for Disease Control and Prevention (CDC) initiated an investigation (abstract 34LBb) that confirmed the reliability of the test and identified site-specific factors associated with high false-positives. The CDC is in the process of revising recommendations for HIV testing with a goal of increasing the proportion of HIV-infected Americans who know their infection status (abstract 164). One proposal is for a voluntary "opt-out" consent procedure for HIV testing as part of the consent for general care and expanded rescreening in the third trimester for women found to be HIV-negative early in pregnancy. The CDC also presented data (abstract 27) on trends in HIV/AIDS among non-Hispanic blacks (NHBs) in the United States. Between 2001 and 2004, 156,000 newly diagnosed cases of HIV infection were reported in 33 states; NHBs accounted for 51% of cases (although they constitute only 13% of the US population). Among NHBs, trends in transmission remained stable or declined in all categories analyzed except in men who have sex with men (MSM). The National Cancer Institute (abstract 26) reported that the presence of HLA-B Bw4 alleles was associated with a decreased risk of HIV transmission from infected hemophiliac men to their female sex partners and speculated that there might be a decreased seminal HIV RNA load in this setting. A multicenter adolescent trials network study (ATN029, abstract 21) provided evidence for transmitted resistance (genotypic in 18% and phenotypic in 22%) among recently infected youth aged 16 to 24 years. These data are very disturbing and represent the highest prevalence of primary HIV resistance in the United States. Thomas Quinn (abstract 120) gave an entertaining plenary lecture entitled "Circumcision and HIV Transmission: The Cutting Edge." He reviewed the evidence supporting male circumcision for the prevention of HIV transmission, including epidemiology (countries with high rates of circumcision have low HIV rates and vice versa), cohort studies (demonstrating a 44%-80% reduction in transmission), biologic mechanisms (9-fold fewer HIV targets in stratified epithelium vs. mucosal inner foreskin), and clinical trials (3 prospective clinical trials in Africa). A group from the University of Washington in Seattle (abstract 163) reported that "serosorting" (the practice in which people who know their HIV status search for partners of the same status) is common and can lead either to decreased HIV transmission (as has been seen among MSM in San Francisco) or to superinfection, a generally rare event but the topic of several abstracts (91, 92, 293). A European group (abstract 33LB) demonstrated in the first randomized controlled trial that active herpes simplex virus type 2 (HSV-2) infection is causally related to increased HIV genital shedding and that HSV-2 suppression with valacyclovir decreased genital HIV RNA by 25% and plasma HIV RNA by 40%. This obviously could have an impact on HIV transmission. CURRENT ANTIRETROVIRAL THERAPY Several posters (525, 529, 530, 769) offered new insights into the timing of initiating HAART, each favoring treating patients earlier (ie, at a higher CD4 lymphocyte count nadir); the HIV Outpatient Study even demonstrated decreased long-term toxicity (peripheral neuropathy, lipoatrophy, and renal insufficiency) if this strategy is used. Another multinational study (abstract 351) supported earlier use of antiretrovirals to decrease the risk of HIV encephalopathy. Several studies looked at compartmentalization of antiretroviral agents. Oral abstract 74 showed the best central nervous system penetration among nucleoside reverse transcriptase inhibitors ([NRTIs] zidovudine and abacavir), non-NRTIs ([NNRTIs] nevirapine), and PI (all boosted including fosamprenavir, lopinavir, atazanavir, and indinavir but not saquinavir). Oral abstract 129 explored genital tract pharmacokinetics of antiretrovirals and potential implications for preexposure and postexposure prophylaxis. In addition to previous studies on tenofovir, agents with the greatest ratio of genital tract-to-plasma drug levels included emtricitabine, zidovudine, and lamivudine followed by atazanavir and didanosine. Structured treatment interruptions have been the subject of numerous studies in various cohorts (eg, primary HIV infection and those seeking a "drug holiday"). At this conference, both time-based and CD4-guided treatment interruption studies were presented. The results of these studies (abstracts 102, 103, 104, 105LB, and 106LB) provided some mixed messages, but certain strategies were definitely associated with poor outcomes. The most important data came from the Strategies for Management of Anti-Retroviral Therapy (SMART) study presented by Wafaa El-Sadr. Patients in this huge study (N = 5472) were randomized to a continuous HAART arm (viral suppression [VS]) or to a discontinuation arm (the drug-conservation group [DC], stopping when the CD4 >350 and resuming when the CD4 <250). On January 10, 2006, the Drug Safety and Monitoring Board recommended stopping further enrollment because of a significantly increased risk of disease progression (AIDS or death) in the DC arm. Another trial from West Africa (ANRS 1269 Trivacan Trial) using the same CD4 targets as SMART demonstrated a 2-fold higher rate of serious morbidity (mainly invasive bacterial diseases) in the discontinuation/resumption arm. In contrast, the multinational STACCATO trial (using a CD4 of 350 to stop and resume therapy) showed similar rates of treatment failure and complications in both arms. Although a great deal of further analysis is needed, it would be prudent to resume HAART at the higher CD4 level of 350 if CD4-based treatment interruption is used. Time-based interruptions (eg, the ongoing FOTO study using 5 days on/2 days off) seek to decrease exposure to antiretrovirals, adverse effects, and overall cost. The Window-ANRS 106 trial demonstrated that a fixed structured interruption of 8 weeks off/8 weeks on appeared clinically and immunologically safe over 96 weeks while sparing 48.5% of drug exposure. The 48-week data reported on the use of tipranavir/ritonavir in antiretroviral therapy-experienced patients (combined data from RESIST 1 and 2 studies [abstract 520]). Treatment response (≥1 log reduction in HIV RNA) with tipranavir/ritonavir was achieved at approximately twice the rate of comparator PI/ritonavir. The rate of virological suppression to a viral load of less than 50 copies/mL occurred in 22.8% and 10.2% of tipranavir/ritonavir- and comparator PI/ritonavir-treated patients, respectively. Responses to tipranavir/ritonavir were greater in patients with a lower baseline viral load or higher baseline CD4 count. The 48-week data were also presented comparing atazanavir with or without ritonavir in antiretroviral-naive patients (abstract 107LB). Virological response rates were similar in the 2 groups; 75% and 70% achieved an HIV RNA of less than 50 copies/mL in the boosted and unboosted groups, respectively. However, virological failure because of viral rebound was greater in the unboosted group. Furthermore, whereas no PI mutations were identified in the boosted group, 3 patients in the unboosted group developed the I50L mutation. Adverse events were more common in the boosted group, leading to more discontinuations (8% vs. 1%). Specifically, jaundice occurred in 22% of patients in the boosted group compared with 7% in the unboosted group. A growing area of research involves simplifying the therapy with only a boosted PI. One such study presented at CROI assessed simplification to ritonavir-boosted atazanavir in 34 patients. Patients enrolled were receiving their first PI plus 2 NRTIs and had documented virological suppression for at least 48 weeks. Thirty-one patients maintained virological suppression at 24 weeks after simplification. Of the 3 patients who experienced virological failure, 2 patients had undetectable atazanavir concentrations. No PI mutations were detected upon genotyping studies. FUTURE ANTIRETROVIRAL THERAPY Twenty-one antiretroviral agents are currently marketed in the United States; only 1, enfuvirtide, acts extracellularly. New names have emerged for some of the second-generation compounds of the NRTI (dexelvucitabine [D-d4FC]), NNRTI (etravirine [TMC125]), and PI (darunavir [TMC114] and brecanavir [GW640385]) classes. Numerous agents from novel classes were discussed, including entry inhibitors, integrase inhibitors, and maturation inhibitors. Two new entry inhibitors (TRI-1144 and TRI-999) show activity against enfuvirtide-resistant HIV, and pharmacokinetic data suggest once weekly dosing is feasible. Research is ongoing with co-receptor inhibitors. Vicriviroc, a CCR5 co-receptor antagonist, was studied with zidovudine/lamivudine in a phase 2 study (abstract 161LB). The Data Safety Monitoring Board terminated the study prematurely because of virological breakthrough. Such data suggest that more research is necessary to define the role of co-receptor inhibitors. The orally bioavailable CXCR4 co-receptor inhibitors KRH-3955 and KRH-3140 were introduced and showed promising results in animal studies (abstract 49LB). Clinical trial data were presented for 2 integrase inhibitors in development (abstracts 159LB and 160LB). Both MK-0518 and GS-9137 (JTK-303), along with an optimized background regimen, exhibited substantial antiviral activity. MK-0518 was studied at 3 doses in patients with HIV resistant to all 3 classes of oral antiretrovirals. At week 8, approximately two thirds of patients had HIV RNA of less than 50 copies/mL. PA-457 is a first-in-class maturation inhibitor that was studied as monotherapy in HIV-positive patients (abstract 52). Although the primary goal of the study was to determine pharmacokinetics, there was a 1.1 log reduction in the HIV RNA after 10 days of treatment at the highest dose, and no resistance to PA-457 was detected. An in vitro study showed that PA-457 has wild-type activity against drug-resistant HIV-1 isolates, and synergy was demonstrated with currently approved antiretroviral classes (abstract 509). Data were presented on 2 novel NRTIs in development. GS9148 is an adenosine analogue similar to tenofovir (abstract 45). In vitro assays showed minimal potential for metabolic toxicity. GS9148 was active against HIV with multiple NRTI mutations, including strains with up to 5 thymidine analogue mutations (TAMs). The Q151M resistance complex was the only mutation that significantly affected GS9148. The peripheral blood mononuclear cell half-life was greater than 24 hours in an animal model, suggesting that once daily dosing is possible. The second novel NRTI presented is 1-(β-D-dioxolane)thymine, a thymidine kinase-dependent NRTI (abstract 46). It also has considerable activity against NRTI-resistant HIV. The presence of TAMs and/or the M184V mutation did not affect susceptibility. However, the 69 insertion mutation and the Q151M complex produced 1-(β-D-dioxolane)thymine resistance. Another new class of antiretrovirals is the nucleotide-competing reverse transcriptase inhibitors, which form a dead-end complex with reverse transcriptase after pyrimidine incorporation (abstract 47). The class representative nucleotide-competing reverse transcriptase inhibitor type 1 displayed antiviral activity, but resistance was seen with the M184V mutation, whereas the K65R mutation caused hypersusceptibility. Lastly, a PI in development called SPI-256 demonstrated greater in vitro potency than currently approved PIs and was similarly active against wild-type and multidrug-resistant HIV-1 isolates (abstract 501). DRUG-DRUG INTERACTIONS Among the drug interaction studies at CROI, there was a focus on potential dual-PI therapies and on an investigational NNRTI called TMC125 currently in phase 3 clinical trials. In the first of 3 studies with TMC125, no significant interaction was detected when TMC125 was administered with the investigational PI TMC114/ritonavir (abstract 575c). In a similar study, no significant interaction was found between TMC125 and either saquinavir or lopinavir/ritonavir (abstract 575b). However, when administered with tipranavir 500 mg and ritonavir 200 mg, TMC125 concentrations were reduced to less than 30% of those with TMC125 alone (abstract 583). Investigators recommend avoiding this antiretroviral combination. Previous studies have also shown that tipranavir significantly reduces lopinavir concentrations when administered with lopinavir/ritonavir. This interaction was studied in patients given 1 of 2 investigational dosing regimens (abstract 584). All patients received standard twice daily dosing of lopinavir/ritonavir. One group also received 500 mg tipranavir plus 200 mg ritonavir, both BID, whereas another group received 500 mg tipranavir plus 133 mg lopinavir/33 mg ritonavir plus 100 mg ritonavir, all BID. In both groups, median trough concentrations of lopinavir were comparable with standard dosing of lopinavir/ritonavir; however, there was significant interpatient variability. The authors recommend therapeutic drug monitoring if one of these regimens is prescribed. In another dual-PI study, concentrations of saquinavir were measured when given with either ritonavir or atazanavir (abstract 586). The regimen of 1500 mg saquinavir plus 200 mg atazanavir, both BID, resulted in potentially therapeutic concentrations of both PI. However, the boosting effect of atazanavir was not as strong as ritonavir (saquinavir Cmin 599 ng/mL vs. 129 ng/mL). A third dual-PI study found favorable concentrations when 300 mg/day atazanavir is combined with standard dosing lopinavir/ritonavir (abstract 585). Finally, a study of once daily 1400 mg fosamprenavir plus 400 mg atazanavir found a 2-way interaction that resulted in a 57% reduction in the Cmin of atazanavir but a 283% increase in the Cmin of amprenavir (abstract 587). The authors of this study were unable to speculate on the clinical utility of this combination. PHARMACOKINETICS OF PROTEASE INHIBITORS IN PREGNANCY The US Food and Drug Administration recently issued warnings of lopinavir concentrations in women lopinavir/ritonavir the third trimester of pregnancy. Two studies were presented at CROI that this concentrations were measured in a cohort of 16 women in the third trimester of (abstract All patients received 3 of lopinavir/ritonavir twice trough concentrations were detected in and of had an undetectable HIV was in the 2 with a viral In a similar study, a higher of lopinavir/ritonavir was studied the third twice daily (abstract Of the women with available lopinavir concentrations were achieved at the higher however, excessive concentrations were achieved with the higher at 2 weeks Another group of measured trough concentrations in pregnant patients receiving a of mg or mg (abstract Patients in this study were not in the third trimester of pregnancy. of patients had a trough the of 1 The was increased to 1500 mg in 8 patients, but only 6 achieved the The data presented in these studies further the utility of therapeutic drug monitoring pregnancy. Two novel nucleoside analogue mutations were described at this In the mutation was among of patients receiving the NRTI of tenofovir, and The mutation is also by and the investigational NRTI which is an adenosine analogue similar to tenofovir Investigators found that the mutation resistance by (abstract However, to thymidine in the presence of suggesting that this mutation is to the development of similar to is seen with the K65R mutation. The mutation is another novel reverse transcriptase (abstract This mutation a increase in resistance to zidovudine and but at a of reduced to study the of mutations, such as of TAMs greater resistance to than lamivudine (abstract Of isolates with 3 to TAMs and no M184V mutation, were resistant to emtricitabine, whereas only were resistant to Another study confirmed that the presence of both and to efavirenz (abstract was significantly reduced with on an analysis of the this mutation was found to in with in is with both Two studies documented the of thymidine if resistance is associated with the K65R mutation. Among 3 patients virological failure associated with the K65R mutation, zidovudine resulted in viral load to less than 50 the strains were resistant to all the in the regimen (abstract A similar analysis of isolates with the K65R mutations found that of a thymidine analogue in the salvage regimen a virological response (abstract No CROI would be without a of resistance associated with investigational antiretroviral agents. The investigational NNRTI TMC125 was found to activity against HIV with baseline NNRTI however, the viral load reduction was significantly less in the presence of 3 or more baseline NNRTI mutations and HIV RNA with 1 and mutations, (abstract associated with the investigational PI TMC114/ritonavir was also An analysis of 2 studies of TMC114/ritonavir in patients 1 and was The analysis certain mutations associated with reduced response to TMC114/ritonavir (abstract The presence of or at baseline was associated with a lower decrease in viral Virological rebound was associated with the development of mutations or OF THERAPY AND each conference, we more metabolic and complications of long-term antiretroviral all from studies in developed Although has been in the United because of as compared with it a in the in fixed A study from (abstract looking at the use of and widely available as another from The Data on Adverse of study demonstrated that increased PI exposure was associated with an increased risk of by However, both the SMART and HIV Outpatient Study data found that increased disease risk was associated with risk factors of disease risk was reduced by and agents. The ongoing Study concluded that the metabolic syndrome as of the and blood or is more common in than men The CDC data from patients and reported on the of in HIV which were significantly higher in HIV infection and their risk when compared with a included the 3 and and 7 disease and was no increased risk of or renal and a decreased risk of and is the of HIV-infected patients and can be more and more in this setting. researchers used in HIV-infected patients with and found that they were able to early in 75% of the test was and The in with viral was a prospective study the role of in virus in the HAART for HAART, was associated with a decrease in the risk of transmission of risk (abstract In a study of patients, ratio was used to significant ratio were found in of patients with HIV infection of patients with 22% of patients with virus and of patients with risk factors associated with significant were CD4 and HAART (abstract A study of patients with of infection by undetectable viral showed that patients are at risk for of Of patients of viral occurred in 6 of HIV-infected patients but in of 16 HIV-negative patients for a median of viral load testing be for patients with of infection (abstract Two studies demonstrated that high risk and mucosal factors are associated with transmission of infection in factors included and including with and activity the of (abstracts and A CD4 cell response in patients with has been of patients demonstrated no significant in CD4 response in patients after of viral suppression in compared with HIV However, the study found that with 2 or 3 had a CD4 response compared with 1 or (abstract In an study of 24 patients 1, or plus to therapy for 48 weeks was compared with dosing with induction of for the first for the and for weeks. No significant in virological response was seen with vs. in the induction arm = treatment resulted in a reduction in in one third of patients in the induction arm compared with in the treatment group (abstract A study to the of alone compared with plus was in all patients were with monotherapy for weeks. Patients with undetectable RNA at weeks continued treatment with monotherapy to 48 whereas those with RNA were with therapy with the addition of The rate in patients who received monotherapy for 48 weeks was compared with in patients who did not viral suppression at weeks. The study the of viral load with to treatment outcomes. This strategy be in patients with or a for use (abstract An analysis of the trial data demonstrated similar in patients with 1 of baseline RNA 13% achieved rapid virological response and had an (abstract A study looking at the impact of the of treatment for patients to weeks in patients who achieved undetectable RNA levels at 24 weeks did not show any significant in between the 2 rate in the 48-week treatment group vs. in the group = (abstract a study showed a significant decrease in after treatment in patients who achieved (abstract In patients, CD4 were not of response to Patients who have had have similar response rates compared with patients with high baseline CD4 (abstract was found to be higher in patients vs. in HIV were most associated with HIV of patients of disease (abstract In a study, patients were found to have similar infection rates compared with patients receiving The count did not with infection rates (abstract A study demonstrated more in patients compared with patients. The was not caused by drug use and be from infection (abstract of viral response at week of treatment was in 2 and 3 patients with or in with response rates were for and for of treatment virological and rate were and in patients who achieved RNA levels less than 100 after weeks compared with and in patients with RNA levels greater than 100 at weeks to be a to of treatment (abstract is a strong of Among patients the of patients with was greatest with NNRTI greater than PI greater than boosted PI greater than NRTI (abstract In contrast, a study of patients to determine the risk of in patients concluded that patients on HAART were not at increased risk of compared with patients of HAART risk vs. = drug patients to be at higher risk for (abstract New therapies for are very for the and are inhibitors of the These have demonstrated rapid and in viral but resistance is a In a study of a log was achieved at In a study of with plus of patients with 1 had undetectable levels at mutations associated with resistance and level resistance and or high level resistance of of PIs be used in therapy with and inhibitors are nucleoside and viral inhibitors. to inhibitors also for resistance mutations and and be used in with agents (abstracts and Lastly, there were several plus lamivudine was to tenofovir or alone for the treatment of patients at 24 weeks (abstract was also for treatment of infection in significant in and no virological (abstract infection with was seen in to of patients. would that all HIV-infected patients be for infection given the implications for the of infection was not greater in patients compared with patients (abstracts and A study the of demonstrated that occurred in 34 cases in patients compared with cases in patients against factors for failure after for and CD4 count were not receiving HAART and (abstract A review such as this to the that CROI such a each the to website for further and

Herpes simplex virus type 1 (HSV-1), a member of the herpesviridae, causes a variety of human viral diseases globally. Although a series of antiviral drugs are available for the treatment of infection and suppression of dissemination, HSV-1 remains highly prevalent worldwide. Therefore, the development of novel antiviral agents with different mechanisms of action is a matter of extreme urgency. During the proliferation of HSV-1, capsid assembly is essential for viral growth, and it is highly conserved in all HSV-1 strains. In this study, small interfering RNAs (siRNAs) against the HSV-1 capsid protein were screened to explore the influence of silencing capsid expression on the replication of HSV-1. We designed and chemically synthesized siRNAs for the capsid gene and assessed their inhibitory effects on the expression of target mRNA and the total intracellular viral genome loads by quantitative real-time PCR, as well as on the replication of HSV-1 via plaque reduction assays and electron microscopy. Our results showed that siRNA was an effective approach to inhibit the expression of capsid protein encoding genes including UL18, UL19, UL26, UL26.5, UL35 and UL38 in vitro. Interference of capsid proteins VP23 (UL18) and VP5 (UL19) individually or jointly greatly affected the replication of clinically isolated acyclovir-resistant HSV-1 as well as HSV-1/F and HSV-2/333. Plaque numbers and intracellular virions were significantly reduced by simultaneous knockdown of UL18 and UL19. The total intracellular viral genome loads were also significantly decreased in the UL18 and UL19 knockdown groups compared with the viral control. In conclusion, interfering with UL18 and UL19 gene expression could inhibit HSV-1 replication efficiently in vitro. Our research offers new targets for an RNA interference-based therapeutic strategy against HSV-1.

PurposeSARS-CoV-2 virus dynamics in different hosts and different samples and their relationship with disease severity have not been clearly revealed. The aim of this study is to evaluate the viral loads of 6 different sample types (nasopharyngeal/oropharyngeal combined, oral cavity, saliva, rectal, urine, and blood) of patients with different ages and clinics, to reveal the relationship between disease course and SARS-CoV-2 viral load, and differences in viral loads of asymptomatic and symptomatic patients.MethodsNasopharyngeal/oropharyngeal, oral cavity, saliva, rectal, urine, and blood samples are collected from patients who were hospitalized with diagnosis of COVID-19 on admission. Laboratory analysis were carried out at Public Health Institute of Turkey Virology Reference and Research Laboratory.ResultsA total of 360 samples from 60 patients were obtained on admission. Fifteen (25%) of the patients were asymptomatic while 45 (75%) were symptomatic. A significant difference was found between mean ages of asymptomatic vs symptomatic patients (26.4 and 36.4, respectively, p = 0.0248). No PCR positivity were found in blood. Only one asymptomatic patient had positive PCR result for urine sample. Viral loads of asymptomatic patients were found to be significantly higher (p = 0.0141) when compared with symptomatic patients. Viral load had a significant negative trend with increasing age. A significant decrease in viral load was observed with increasing disease severity.ConclusionIn conclusion, this study demonstrates that asymptomatic patients have higher SARSCoV-2 viral loads than symptomatic patients and unlike in the few study in the literature, a significant decrease in viral load of nasopharyngeal/oropharyngeal samples was observed with increasing disease severity. Factors associated with poor prognosis are found to be significantly correlated with low viral load.

The cell that a virus replicates in i.e., the producer cell, can alter the macromolecular composition and infectious capacity of the virions that are produced. Herpes Simplex virus type 1 (HSV-1) primarily infects keratinocytes of the epidermis or oral mucosa prior to establishing latency in neurons of the peripheral nervous system, where the virus can persist for the lifetime of the host. Many cell lines that are used to amplify HSV-1 are derived from species and tissue types that are less physiologically relevant to HSV-1 disease. To understand if the producer cell type influences HSV-1 infection, we tested the infectivity of HSV-1 derived from immortalized African green monkey kidney cells (vero), immortalized human keratinocytes (HaCaT), and primary human foreskin fibroblasts (HFF-1). We observed that the producer cell type alters the capacity of HSV-1 to produce viral proteins and infectious virions from infected cells and susceptibility to inhibition of replication by interferon treatment. HaCaT-derived HSV-1 consistently exhibited enhanced replication over HFF-1 or vero-derived virus. To determine if the producer cell type changes the protein composition of virions, we performed an untargeted LC/MS-MS analysis of virions purified from each cell line. Comparison of virion associated proteins revealed quantitative differences in composition of both cellular and viral proteins including ICP0, pUL24 and pUL42. These results highlight the influence that the producer cell-type has on HSV-1 infection outcomes and suggest that cell type specific factors can alter HSV-1 and impact viral replication.ImportanceApproximately 67% of the human population harbors HSV-1 infection. To study HSV-1 infection, laboratories utilize several different cell lines to propagate HSV-1 for downstream experiments. The type of cell used to produce a virus, i.e. the producer cell type, can alter the macromolecular composition, immunogenicity, and infectivity of the virions that are produced across several virus families. We found that the producer cell type of HSV-1 alters virion infectivity and virion protein composition. Therefore, the producer cell type may have implications in the spread of HSV-1 and subsequent disease outcomes in humans. Our results also raise concerns about how the use of different ceil types to propagate HSV-1 may alter the outcome, interpretation, and reproducibility of experimental results.