Biologic Therapy Carries a Very Low Risk of Reactivation in Hepatitis B Surface Antigen-Negative Phase of Hepatitis B.

BACKGROUND: The risk of hepatitis B reactivation in hepatitis B surface antigen-negative phase of hepatitis B virus-infected patients exposed to biologic agents is not clear. We aimed to investigate the reactivation rate in hepatitis B surface antigen-negative phase of hepatitis B virus-infected patients after biologic therapy. METHODS: Patients followed at gastroenterology, rheumatology, and dermatology clinics with a diagnosis of immune-mediated inflam matory diseases were screened. Immune-mediated inflammatory diseases patients exposed to biologic agents with a negative hepatitis B surface antigen and positive hepatitis B core immunoglobulin G antibody were included in the study. RESULTS: We screened 8266 immune-mediated inflammatory disease patients, and 2484 patients were identified as exposed to biologic agents. Two hundred twenty-one patients were included in the study. The mean age was 54.08 ± 11.69 years, and 115 (52.0%) patients were female. The median number of different biologic subtype use was 1 (range: 1-6). The mean biologic agent exposure time was 55 (range: 2-179) months. One hundred and fifty-two (68.8%) patients used a concomitant immunomodulatory agent, and 84 (38.0%) patients were exposed to corticosteroids during biologic use. No hepatitis B reactivation with a reverse seroconversion of hepatitis B surface antigen positivity was seen. Antiviral prophylaxis for hepatitis B was applied to 48 (21.7%) patients. Hepatitis B virus-DNA was screened in 56 (25.3%) patients prior to the biologic exposure. Two patients without antiviral prophylaxis had hepatitis B virus-DNA reactivation with a negative hepatitis B surface antigen during exposure to the biologic agent. CONCLUSION: We found 2 reactivations and no hepatitis B surface antigen seroconversion in our cohort. Antiviral prophylaxis for patients exposed to biologic agents may need to be discussed in more detail.

Histone deacetylase inhibition reduces deleterious cytokine release induced by ingenol stimulation.

Latency reversing agents (LRAs), such as protein kinase C (PKC) agonists, constitute a promising strategy for exposing and eliminating the HIV-1 latent reservoir. PKC agonists activate NF-κB and induce deleterious pro-inflammatory cytokine production. Adjuvant pharmacological agents, such as ruxolitinib, a JAK inhibitor, have previously been combined with LRAs to reduce deleterious pro-inflammatory cytokine secretion without inhibiting HIV-1 reactivation in vitro. Histone deacetylase inhibitors (HDACi) are known to dampen pro-inflammatory cytokine secretion in the context of other diseases and synergize with LRAs to reactivate latent HIV-1. This study investigates whether a panel of epigenetic modifiers, including HDACi, could dampen PKC-induced pro-inflammatory cytokine secretion during latency reversal. We screened an epigenetic modifier library for compounds that reduced intracellular IL-6 production induced by the PKC agonist Ingenol-3,20-dibenzoate. We further tested the most promising epigenetic inhibitor class, HDACi, for their ability to reduce pro-inflammatory cytokines and reactivate latent HIV-1 ex vivo. We identified nine epigenetic modulators that reduced PKC-induced intracellular IL-6. In cells from aviremic individuals living with HIV-1, the HDAC1-3 inhibitor, suberohydroxamic acid (SBHA), reduced secretion of pro-inflammatory cytokines TNF-α, IL-5, IL-2r, and IL-17 but did not significantly reactivate latent HIV-1 when combined with Ingenol-3,20-dibenzoate. Combining SBHA and Ingenol-3,20-dibenzoate reduces deleterious cytokine production during latency reversal but does not induce significant viral reactivation in aviremic donor PBMCs. The ability of SBHA to reduce PKC-induced pro-inflammatory cytokines when combined with Ingenol-3,20-dibenzoate suggests SBHA can be used to reduced PKC induced pro-inflammatory cytokines but not to achieve latency reversal in the context of HIV-1.

Safety, tolerability of ES16001, a novel varicella zoster virus reactivation inhibitor, in healthy adults.

PURPOSE: Herpes zoster (HZ), or shingles, is a clinical syndrome resulting from the reactivation of latent varicella zoster virus (VZV) within the sensory ganglia. We evaluated the safety and tolerability of ES16001 (ethanol extract of Elaeocarpus sylvestris var. ellipticus), a novel inhibitor of varicella zoster virus reactivation in healthy adults. METHOD: Single-center, randomized, double-blind, placebo-controlled, single and multiple ascending dose (SAD and MAD, respectively) studies were conducted in 20- to 45-year-old healthy adults without chronic disease. In the SAD study (n = 32), subjects randomly received a single oral dose of 240, 480, 960, or 1440 mg ES16001 or a placebo. In the MAD study (n = 16), subjects randomly received once daily doses of 480 or 960 mg ES16001 or a placebo for 5 days. The safety and tolerability of the drug were evaluated by monitoring participants' treatment emergent adverse events (TEAEs) and vital signs, electrocardiograms (ECGs), physical examinations, and clinical laboratory tests. RESULTS: In the SAD study, 11 adverse reactions were seen in 5 subjects, and in the MAD study, 8 adverse reactions were seen in 6 subjects. All adverse reactions were mild, and no serious adverse reactions occurred. The most common adverse reaction was an increase in alanine aminotransferase (ALT), but all test values were in the clinically non-significant range, and their clinical significance was judged to be small considering the fact that most of the test values returned to normal immediately after the end of drug administration. CONCLUSION: ES16001 has good safety and tolerability when administered both once and repeatedly to healthy subjects. Further research is needed to identify any possible drug-induced hepatotoxicity, which appears infrequently. Our findings provide a rationale for further clinical investigations of ES16001 for the prevention of HZ. TRIAL REGISTRATION: CRIS, KCT0006066. Registered 7 April 2021-Retrospectively registered, https://cris.nih.go.kr/cris/search/detailSearch.do/19071 ).

An extract of Stephania hernandifolia, an ethnomedicinal plant, inhibits herpes simplex virus 1 entry.

Stephania hernandifolia (Nimukho), an ethnomedicinal herb from rural Bengal, has been used traditionally for the management of nerve, skin, urinary, and digestive ailments. Here, we attempted to confirm the antiviral potential of aqueous, methanol, and chloroform extracts of S. hernandifolia against herpes simplex virus type 1 (HSV-1), the causative agent of orolabial herpes in humans, and decipher its underlying mechanism of action. The bioactive extract was standardized and characterized by gas chromatography-mass spectroscopy, while cytotoxicity and antiviral activity were evaluated by MTT and plaque reduction assay, respectively. Two HSV strains, HSV-1F and the clinical isolate VU-09, were inhibited by the chloroform extract (CE) with a median effective concentration (EC50) of 4.32 and 4.50 µg/ml respectively, with a selectivity index (SI) of 11. Time-of-addition assays showed that pre-treatment of virus-infected cells with the CE and its removal before infection reduced the number of plaques without lasting toxicity to the cell, indicating that the CE affected the early stage in the viral life cycle. The number of plaques was also reduced by direct inactivation of virions and by the addition of CE for a short time following attachment of virions. These results together suggest that modification of either the virion surface or the cell surface by the CE inhibits virus entry into the host cell.

Discovery of Ethyl Ketone-Based Highly Selective HDACs 1, 2, 3 Inhibitors for HIV Latency Reactivation with Minimum Cellular Potency Serum Shift and Reduced hERG Activity.

We describe the discovery of histone deacetylase (HDACs) 1, 2, and 3 inhibitors with ethyl ketone as the zinc-binding group. These HDACs 1, 2, and 3 inhibitors have good enzymatic and cellular activity. Their serum shift in cellular potency has been minimized, and selectivity against hERG has been improved. They are also highly selective over HDACs 6 and 8. These inhibitors contain a variety of substituted heterocycles on the imidazole or oxazole scaffold. Compounds 31 and 48 stand out due to their good potency, high selectivity over HDACs 6 and 8, reduced hERG activity, optimized serum shift in cellular potency, and good rat and dog PK profiles.

The Efficacy of Natural Bioactive Compounds for the Treatment of Nasopharyngeal Carcinoma.

The death toll associated with cancer worldwide is constantly on the increase. Efforts to combat and treat the different forms of this disease is also evolving. Nasopharyngeal carcinoma (NPC) is a lethal form of cancer, which is prevalent in Southern China, that is normally treated by using radiotherapy. Here, we will review products obtained from natural sources that have potential cytotoxic and apoptotic properties against NPC. These include grifolin, dihydroartemisinin, luteolin, honokiol, indole-3-carbinol, caffeic acid phenethyl ester, 6-O-angeloylenolin, cucurbitacin E, genistein, helenalin, celastrol, coronarin D, quercetin, trans-cinnamaldehyde, 5'-epimer episilvestrol, silvestrol, arnicolide D, brevilin A, and baicalin hydrate. Ethyl acetate extracts of Wedelia chinensis and aqueous extracts of Ajuga bracteosa are also included although the bioactive compounds involved have yet to be identified. The known mechanism of action of these products is discussed. It is anticipated that one or more of these substances may provide the general population with alternative and cost-effective ways to combat this fatal disease.

Evaluation of Hepatitis B Reactivation Among Patients With Chronic Myeloid Leukemia Treated With Tyrosine Kinase Inhibitors.

Hepatitis B reactivation (HBVr) in cancer patients is a well-established complication due to chemotherapy-induced immunosuppression. Studies have reported HBVr associated with immunosuppressive medications, such as rituximab, methotrexate, and high dose steroids. There are different risks for different types of chemotherapy with rituximab carrying one of the highest risks for hepatitis B reactivation. Tyrosine kinase inhibitors (TKIs) are the standard of care in patients with chronic myeloid leukemia (CML). The risk of HBVr in chronic myeloid leukemia has been reported in many studies, but to this date, there are no clear guidelines or recommendations regarding screening and monitoring of HBV in CML patients receiving TKIs. We conducted this review to identify the risk of HBVr in patients with CML who are treated with tyrosine kinase inhibitors. We recommend testing for HBV status in patients who are to be treated with TKIs and to consider giving prophylaxis in those who are positive for HBsAg at baseline. More studies are needed to assess the risk of reactivation in patients with Hepatitis B core antibody positive receiving TKIs. Currently, monitoring such patients for reactivation may be the best strategy.

[Functional immunoassays in the setting of infectious risk and immunosuppressive therapy of non-HIV immunocompromised patients]. / Place des tests immunitaires fonctionnels dans la prise en charge du risque infectieux et de la gestion des thérapies immunosuppressives chez les patients immunodéprimés non-VIH.

The holistic approach of the human immune system is based on the study of its components collectively driving a functional response to an immunogenic stimulus. To appreciate a specific immune dysfunction, a condition is mimicked ex vivo and the immune response induced is assessed. The application field of such assays are broad and expanding, from the diagnosis of primary and secondary immunodeficiencies, immunotherapy for cancer to the management of patients at-risk for infections and vaccination. These assays are immune monitoring tools that may contribute to a personalised and precision medicine. The purpose of this review is to describe immune functional assays available in the setting of non-HIV acquired immune deficiency. First, we will address the use of theses assays in the diagnosis of opportunistic infections such as viral reactivation. Secondly, we will report the usefulness of these assays to assess vaccine efficacy and to manage immunosuppressive therapies.

Universal hepatitis B screening and management in patients with cancer who received immunosuppressive chemotherapy.

BACKGROUND: Clinical data to guide management of patients with cancer and hepatitis B virus (HBV) infection who are treated with immunosuppressive chemotherapy are lacking. The purpose of this study was to describe HBV+ rates in a population of patients with cancer and evaluate a risk-stratified management protocol for the prevention of HBV reactivation (HBVr). METHODS: This was a descriptive study conducted in an integrated healthcare delivery system. Patients with cancer and hepatitis B virus infection who received immunosuppressive chemotherapy between 1 January 2014 and 31 January 2016 were included. A risk-stratified management protocol that continued for six months after chemotherapy completion or 12 months after completion of B-cell targeted chemotherapy was assessed. Outcomes included the proportion of patients who were HBV+ and amongst patients who initiated immunosuppressive therapy, proportions who received hepatitis B virus monitoring or anti-hepatitis B virus prophylaxis, or experienced HBVr or hepatitis B virus-related complications. RESULTS: There were 2463 patients with cancer screened for hepatitis B virus with 114 (4.6%) HBV+ of whom 59 (51.8%) initiated chemotherapy. Included patients were primarily older, male, and white with gastrointestinal or hematologic cancers and initiated intermediate/low-risk cytotoxic chemotherapy. During follow-up, 41 (69.5%) received hepatitis B virus DNA monitoring and 17 (28.8%) initiated anti-hepatitis B virus prophylaxis. No HBVr was observed. ALT and AST abnormalities were common but mostly Grade 1 and primarily related to the patient's malignancy or medications. CONCLUSIONS: Universal hepatitis B virus screening coupled with a risk-stratified management strategy utilizing HBVr monitoring and anti-hepatitis B virus prophylaxis in HBV+ patients receiving immunosuppressive chemotherapy for cancer may prevent HBVr.

Identification of new antiviral agents against Kaposi's sarcoma-associated herpesvirus (KSHV) by high-throughput drug screening reveals the role of histamine-related signaling in promoting viral lytic reactivation.

Kaposi's sarcoma-associated herpesvirus (KSHV) causes several human cancers, such as Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). Current treatment options for KSHV infection and virus associated diseases are sometimes ineffective, therefore, more effectively antiviral agents are urgently needed. As a herpesvirus, lytic replication is critical for KSHV pathogenesis and oncogenesis. In this study, we have established a high-throughput screening assay by using an inducible KSHV+ cell-line, iSLK.219. After screening a compound library that consisted of 1280 Food and Drug Administration (FDA)-approved drugs, 15 hit compounds that effectively inhibited KSHV virion production were identified, most of which have never been reported with anti-KSHV activities. Interestingly, 3 of these drugs target histamine receptors or signaling. Our data further confirmed that antagonists targeting different histamine receptors (HxRs) displayed excellent inhibitory effects on KSHV lytic replication from induced iSLK.219 or BCBL-1 cells. In contrast, histamine and specific agonists of HxRs promoted viral lytic replication from induced iSLK.219 or KSHV-infected primary cells. Mechanistic studies indicated that downstream MAPK and PI3K/Akt signaling pathways were required for histamine/receptors mediated promotion of KSHV lytic replication. Direct knockdown of HxRs in iSLK.219 cells effectively blocked viral lytic gene expression during induction. Using samples from a cohort of HIV+ patients, we found that the KSHV+ group has much higher levels of histamine in their plasma and saliva than the KSHV- group. Taken together, our data have identified new anti-KSHV agents and provided novel insights into the molecular bases of host factors that contribute to lytic replication and reactivation of this oncogenic herpesvirus.

Asymptomatic reactivation of hepatitis B virus after prolonged treatment with etanercept.

Etanercept is an anti-tumor necrosis factor ɑ (anti-TNFɑ) drug used for treating immunomediated inflammatory diseases. It is least associated with hepatitis B virus (HBV) reactivation. We present a 71-year-old man with psoriasis refractory to phototherapy and acitretin, which led to etanercept monotherapy. Before anti-TNFɑ treatment, past contact with HBV was elicited; antibodies to HBc and HBs were positive whereas HBsAg was negative. Seven years after treatment initiation, while the patient was completely asymptomatic, a transaminase elevation was found and a reactivation of HBV was documented, with a high viral load of the virus. He started entecavir therapy and, after a 14-month follow-up, the viral load is still detectable at a low level, as well as HBsAg. We emphasize the late and asymptomatic reactivation of HBV associated with soluble anti-TNFɑ monotherapy. This case reinforces the importance of current recommendations for periodic monitoring of viral load and HBV markers in all patients that have had prior contact with HBV (positive anti-HBc), with or without indication for treatment of HBV (HBsAg and HBV-DNA negative).

Quercetin Synergistically Inhibit EBV-Associated Gastric Carcinoma with Ganoderma lucidum Extracts.

Mycotherapy has been shown to improve the overall response rate during cancer treatment and reduce some chemotherapy-related adverse events. Ganoderma lucidum is a traditional mushroom used for pharmaceutical purposes. G. lucidum extracts (GLE) showed potential antitumor activities against several cancers. These tumor inhibitory effects of GLE were attributed to the suppression of the proliferation and metastasis of cancer cells. Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) is defined as the monoclonal proliferation of carcinoma cells with latent EBV infection. The inhibitory effects of GLE against EBVaGC are questionable. The aim of this study was to investigate GLE as potential antitumor agents and a counterpart of quercetin (QCT) for the cotreatment in suppressing EBVaGC development. Therefore, this study conducted antitumor assays using a EBVaGC xenograft mice model and found that GLE could suppress tumor development. These inhibitory effects were significantly augmented by the low concentration of the quercetin (QCT) cotreatment in the xenograft mice. The addition of GLE in low concentrations synergistically reinforced QCT-induced apoptosis and EBV lytic reactivation. GLE contains various polysaccharides and triterpenes, such as ganoderic acid. Interestingly, the addition of ganoderic acid A (GAA) could produce similar bioactive effects like GLE in QCT-mediated antitumor activity. The GAA addition in low concentrations synergistically reinforced QCT-induced apoptosis and EBV lytic reactivation. GAA was sufficiently effective as much as GLE. Therefore, our results suggested that QCT-supplemented GLE could be a potential food adjunct for the prevention of EBVaGC development.

Epstein-Barr virus (EBV) reactivation and therapeutic inhibitors.

Epstein-Barr virus (EBV) is a ubiquitous human virus which infects almost all humans during their lifetime and following the acute phase, persists for the remainder of the life of the individual. EBV infects B lymphocytes leading to their immortalisation, with persistence of the EBV genome as an episome. In the latent phase, EBV is prevented from reactivating through efficient cytotoxic cellular immunity. EBV reactivates (lytic phase) under conditions of psychological stress with consequent weakening of cellular immunity, and EBV reactivation has been shown to occur in a subset of individuals with each of a variety of cancers, autoimmune diseases, the autoimmune-like disease, chronic fatigue syndrome/myalgic encephalitis and under other circumstances such as being an inpatient in an intensive care unit. Chronic EBV reactivation is an important mechanism in the pathogenesis of many such diseases, yet is rarely tested for in immunocompetent individuals. This review summarises the pathogenesis of EBV infection, EBV reactivation and its role in disease, and methods which may be used to detect it. Known inhibitors of EBV reactivation and replication are discussed, including drugs licensed for treatment of other herpesviruses, licensed or experimental drugs for various other indications, compounds at an early stage of drug development and nutritional constituents such as vitamins and dietary supplements.

Dual effects of the novel ingenol derivatives on the acute and latent HIV-1 infections.

The latent reservoir of HIV-1 in resting memory CD4+ T cells serves as a major barrier to curing HIV-1 infection. Reactivation of latent HIV-1 is proposed as a promising strategy for the clearance of the viral reservoirs. Because of the limitations of current latency reversal agents (LRAs), identification of new LRAs is urgently required. Here, we analyzed Euphorbia kansui extracts and obtained three ingenol derivative compounds named EK-1A, EK-5A and EK-15A. We found that ingenol derivatives can effectively reactivate latent HIV-1 at very low (nanomolar) concentrations in HIV latency model in vitro. Furthermore, ingenol derivatives exhibited synergy with other LRAs in reactivating latent HIV-1. We verified that EK-15A can promote latent HIV-1 reactivation in the ex vivo resting CD4+ T cells isolated from the peripheral blood of HIV-infected individuals on suppressive antiretroviral therapy. In addition, ingenol derivatives down-regulated the expression of cell surface HIV co-receptors CCR5 and CXCR4, therefore potentially preventing new infection of HIV-1. Our results indicated that the ingenol derivatives extracted from Euphorbia kansui have dual functions: reactivation of latent HIV-1 and inhibition of HIV-1 infection.

Reactivation of latent HIV-1 in vitro using an ethanolic extract from Euphorbia umbellata (Euphorbiaceae) latex.

Euphorbia umbellata (E. umbellata) belongs to Euphorbiaceae family, popularly known as Janauba, and its latex contains a combination of phorbol esters with biological activities described to different cellular protein kinase C (PKC) isoforms. Here, we identified deoxi-phorbol esters present in E. umbellata latex alcoholic extract that are able to increase HIV transcription and reactivate virus from latency models. This activity is probably mediated by NF-kB activation followed by nuclear translocation and binding to the HIV LTR promoter. In addition, E. umbellata latex extract induced the production of pro inflammatory cytokines in vitro in human PBMC cultures. This latex extract also activates latent virus in human PBMCs isolated from HIV positive patients as well as latent SIV in non-human primate primary CD4+ T lymphocytes. Together, these results indicate that the phorbol esters present in E. umbellata latex are promising candidate compounds for future clinical trials for shock and kill therapies to promote HIV cure and eradication.

Dual TLR2 and TLR7 agonists as HIV latency-reversing agents.

The presence of a reservoir of latently infected cells in HIV-infected patients is a major barrier towards finding a cure. One active cure strategy is to find latency-reversing agents that induce viral reactivation, thus leading to immune cell recognition and elimination of latently infected cells, known as the shock-and-kill strategy. Therefore, the identification of molecules that reactivate latent HIV and increase immune activation has the potential to further these strategies into the clinic. Here, we characterized synthetic molecules composed of a TLR2 and a TLR7 agonist (dual TLR2/7 agonists) as latency-reversing agents and compared their activity with that of the TLR2 agonist Pam2CSK4 and the TLR7 agonist GS-9620. We found that these dual TLR2/7 agonists reactivate latency by 2 complementary mechanisms. The TLR2 component reactivates HIV by inducing NF-κB activation in memory CD4+ T cells, while the TLR7 component induces the secretion of TNF-α by monocytes and plasmacytoid dendritic cells, promoting viral reactivation in CD4+ T cells. Furthermore, the TLR2 component induces the secretion of IL-22, which promotes an antiviral state and blocks HIV infection in CD4+ T cells. Our study provides insight into the use of these agonists as a multipronged approach targeting eradication of latent HIV.

Mesenchymal stem cells are attracted to latent HIV-1-infected cells and enable virus reactivation via a non-canonical PI3K-NFκB signaling pathway.

Persistence of latent HIV-1 in macrophages (MACs) and T-helper lymphocytes (THLs) remain a major therapeutic challenge. Currently available latency reversing agents (LRAs) are not very effective in vivo. Therefore, understanding of physiologic mechanisms that dictate HIV-1 latency/reactivation in reservoirs is clearly needed. Mesenchymal stromal/stem cells (MSCs) regulate the function of immune cells; however, their role in regulating virus production from latently-infected MACs & THLs is not known. We documented that exposure to MSCs or their conditioned media (MSC-CM) rapidly increased HIV-1 p24 production from the latently-infected U1 (MAC) & ACH2 (THL) cell lines. Exposure to MSCs also increased HIV-1 long terminal repeat (LTR) directed gene expression in the MAC and THL reporter lines, U937-VRX and J-Lat (9.2), respectively. MSCs exposed to CM from U1 cells (U1-CM) showed enhanced migratory ability towards latently-infected cells and retained their latency-reactivation potential. Molecular studies showed that MSC-mediated latency-reactivation was dependent upon both the phosphatidyl inositol-3-kinase (PI3K) and nuclear factor-κB (NFκB) signaling pathways. The pre-clinically tested inhibitors of PI3K (PX-866) and NFκB (CDDO-Me) suppressed MSC-mediated HIV-1 reactivation. Furthermore, coexposure to MSC-CM enhanced the latency-reactivation efficacy of the approved LRAs, vorinostat and panobinostat. Our findings on MSC-mediated latency-reactivation may provide novel strategies against persistent HIV-1 reservoirs.

High-dose zinc oral supplementation after stem cell transplantation causes an increase of TRECs and CD4+ naïve lymphocytes and prevents TTV reactivation.

INTRODUCTION: Zinc plays an important role in thymic function and immune homeostasis. We performed a prospective clinical trial using a high-dose zinc oral supplementation to improve the immune reconstitution after hematopoietic stem cell transplant (HSCT). PATIENTS AND METHODS: We enrolled 18 patients undergoing autologous HSCT for multiple myeloma. Nine patients were randomized to receive only a standard antimicrobial prophylaxis; whereas, nine patients received in addition 150 mg/day of zinc from day +5 to day +100 after transplant. RESULTS: CD4+ naïve lymphocytes and TRECs showed a significant increase from day +30 until day +100 only in the zinc-treated group. Moreover, the load of Torquetenovirus, a harmless virus that replicates in course of immunedepression, increased at day +100 only in the control group. No severe adverse events were reported during the zinc consumption. CONCLUSION: First data from the ZENITH trial suggest that high-dose zinc supplementation is safe and may enhance the thymic reconstitution after HSCT. Registered: http://Clinicaltrials.gov (NCT03159845); and EUDRACT: 2014-28 004499-47.

Triterpenoids from Ocimum labiatum Activates Latent HIV-1 Expression In Vitro: Potential for Use in Adjuvant Therapy.

Latent HIV reservoirs in infected individuals prevent current treatment from eradicating infection. Treatment strategies against latency involve adjuvants for viral reactivation which exposes viral particles to antiretroviral drugs. In this study, the effect of novel triterpenoids isolated from Ocimum labiatum on HIV-1 expression was measured through HIV-1 p24 antigen capture in the U1 latency model of HIV-1 infection and in peripheral blood mononuclear cells (PBMCs) of infected patients on combination antiretroviral therapy (cART). The mechanism of viral reactivation was determined through the compound's effect on cytokine production, histone deacetylase (HDAC) inhibition, and protein kinase C (PKC) activation. Cytotoxicity of the triterpenoids was determined using a tetrazolium dye and flow cytometry. The isolated triterpene isomers, 3-hydroxy-4,6a,6b,11,12,14b-hexamethyl-1,2,3,4,6,6a,6b,7,8,8a,9,10,11,12,12a,14,14a,14b-octadecahydropicene-4,8a-dicarboxylic acid (HHODC), significantly (p < 0.05) induced HIV-1 expression in a dose-dependent manner in U1 cells at non-cytotoxic concentrations. HHODC also induced viral expression in PBMCs of HIV-1 infected patients on cART. In addition, the compound up-regulated the production of interleukin (IL)-2, IL-6, tumour necrosis factor (TNF)-α, and interferon (IFN)-γ but had no effect on HDAC and PKC activity, suggesting cytokine upregulation as being involved in latency activation. The observed in vitro reactivation of HIV-1 introduces the adjuvant potential of HHODC for the first time here.