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.

Engineered Hydroxyapatite Nanoadjuvants with Controlled Shape and Aspect Ratios Reveal Their Immunomodulatory Potentials.

Hydroxyapatite (HAP) has been formulated as adjuvants in vaccines for human use. However, the optimal properties required for HAP nanoparticles to elicit adjuvanticity and the underlying immunopotentiation mechanisms have not been fully elucidated. Herein, a library of HAP nanorods and nanospheres was synthesized to explore the effect of the particle shape and aspect ratio on the immune responses in vitro and adjuvanticity in vivo. It was demonstrated that long aspect ratio HAP nanorods induced a higher degree of cell membrane depolarization and subsequent uptake, and the internalized particles elicited cathepsin B release and mitochondrial reactive oxygen species generation, which further led to pro-inflammatory responses. Furthermore, the physicochemical property-dependent immunostimulation capacities were correlated with their humoral responses in a murine hepatitis B surface antigen immunization model, with long aspect ratio HAP nanorods inducing higher antigen-specific antibody productions. Importantly, HAP nanorods significantly up-regulated the IFN-γ secretion and CD107α expression on CD8+ T cells in immunized mice. Further mechanistic studies demonstrated that HAP nanorods with defined properties exerted immunomodulatory effects by enhanced antigen persistence and immune cell recruitments. Our study provides a rational design strategy for engineered nanomaterial-based vaccine adjuvants.

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.

Quantification, epitope mapping and genotype cross-reactivity of hepatitis B preS-specific antibodies in subjects vaccinated with different dosage regimens of BM32.

BACKGROUND: Chronic hepatitis B virus (HBV) infections are a global health problem. There is a need for therapeutic strategies blocking continuous infection of liver cells. The grass pollen allergy vaccine BM32 containing the preS domain of the large HBV surface protein (LHBs) as immunogenic carrier induced IgG antibodies in human subjects inhibiting HBV infection in vitro. Aim of this study was the quantification, epitope mapping and investigation of HBV genotype cross-reactivity of preS-specific antibodies in subjects treated with different dosage regimens of BM32 METHODS: Hundred twenty eight grass pollen allergic patients received in a double-blind, placebo-controlled trial five monthly injections of placebo (aluminum hydroxide, n= 34) or different courses of BM32 (2 placebo + 3 BM32, n= 33; 1 placebo + 4 BM32, n= 30; 5 BM32, n= 31). Recombinant Escherichia coli-expressed preS was purified. Overlapping peptides spanning preS and the receptor-binding sites from consensus sequences of genotypes A-H were synthesized and purified. Isotype (IgM, IgG, IgA, IgE) and IgG subclass (IgG1-IgG4) responses to preS and peptides were determined by ELISA at baseline, one and four months after the last injection. IgG1 and IgG4 subclass concentrations specific for preS and the receptor-binding site were measured by quantitative ELISA. FINDINGS: Five monthly injections induced the highest levels of preS-specific IgG consisting mainly of IgG1 and IgG4, with a sum of median preS-specific IgG1 and IgG4 concentrations of >135 µg/ml reaching up to 1.8 mg/ml. More than 20% of preS-specific IgG was directed against the receptor-binding site. BM32-induced IgG cross-reacted with the receptor-binding domains from all eight HBV genotypes A-H. INTERPRETATION: BM32 induces high levels of IgG1 and IgG4 antibodies against the receptor binding sites of all eight HBV genotypes and hence might be suitable for therapeutic HBV vaccination. FUNDING: This study was supported by the PhD program IAI (KPW01212FW), by Viravaxx AG and by the Danube-ARC funded by the Government of Lower Austria. Rudolf Valenta is a recipient of a Megagrant of the Government of the Russian Federation, grant No 14.W03.31.0024.

Structure guided maturation of a novel humanized anti-HBV antibody and its preclinical development.

We have reported that E6F6, a mouse monoclonal antibody, is a promising treatment option for patients with chronic hepatitis B (CHB). A humanized E6F6 antibody B11 with affinity loss was obtained by CDR-grafting approach. To address this issue, in silico affinity maturation through scanning mutagenesis using CHARMM force field methods was performed on an predicted immune complex model of the B11:HBsAg. We chose four variants with top increased interaction energy for further characterization. The antibody huE6F6-1 within two point mutations (Heavy Chain: Asp65Val; His66Leu) was identified to restore the parental antibody's high binding affinity, neutralization activity, and potent efficacy of viral suppression in vivo. Crystal structure (1.8 Å resolution) based molecular docking proved more stabilized and compact hydrogen bond interactions formed in huE6F6-1.The smaller and dispersed HBV immune complexes of huE6F6-1 by electron microscopy suggested it will have the same therapeutic efficacy as the parental E6F6 mAb. Preclinical study and pharmacokinetics of huE6F6-1 demonstrated that it is a stable and desirable lead candidate to improve the clinical management of CHB. Notably, our structure guided approach may facilitate the humanization and affinity maturation of other rodent antibody candidates during drug development.

Lipopolysaccharide derived alginate coated Hepatitis B antigen loaded chitosan nanoparticles for oral mucosal immunization.

Mucosal administration of vaccine can produce a strong immune response. Antigens adhere to "M-cells", present at the intestinal mucosa and the M-cells produce immunity after actively transporting luminal antigens to the underlying immune cells. The objective of the present study was to prepare and characterize alginate coated chitosan nanoparticles (ACNPs) loaded with HBsAg as an antigen to produce immunity; additionally anchored with lipopolysaccharide (LPS) as an adjuvant. Ionic gelation method was used to prepare chitosan nanoparticles (CNPs) which were loaded with HBsAg and stabilized by alginate coating to protect from gastric environment. Results showed that the prepared LPS-HB-ACNPs were small and spherical with mean particle size 605.23 nm, polydispersity index 0.234 and Zeta potential -26.2 mV and could effectively protect antigen at GIT in acidic medium. HB-ANCPs were stable during storage at 4 ± 1 and 27 ± 2 °C. Anchoring with LPS showed increased immunity as compared to other formulations. Additionally, NPs elicited significant sIgA at mucosal secretions and IgG antibodies in systemic circulation. Thus, the prepared LPS anchored alginate coated chitosan NPs may be a promising approach as a vaccine delivery system for oral mucosal immunization.

Effects of traditional Chinese medicine formula Le-Cao-Shi on hepatitis B: In vivo and in vitro studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Formula Le-Cao-Shi (LCS) is a traditional Chinese medicine (TCM), which has long been used as a folk remedy against hepatitis B in China. The present study was conducted to evaluate the anti-hepatitis B effects of aqueous extract of LCS in vivo and in vitro. MATERIALS AND METHOD: we investigated the anti-HBV effects of LCS in vivo and in vitro with duck hepatitis B model and HepG2.2.15 cell line model, respectively. The serologic and cellular biomarkers and the histopathological changes were examined. RESULTS: By a duck hepatitis B model, the extract of LCS was found to restrain the expressions of duck hepatitis B surface antigen (DHBsAg), hepatitis B e antigen (DHBeAg), and HBV-DNA (DHBV-DNA). Moreover, LCS could decrease the levels of aspartate and alanine aminotransferases (AST and ALT) and ameliorate duck liver histological lesions. Correspondingly, in a HepG2.2.15 cellular model, LCS could also significantly inhibit the secretions of HBsAg and HBeAg. CONCLUSION: LCS exerted potent anti-hepatitis effects against the infection of HBV. The above results demonstrated the first-hand experimental evidences for the anti-hepatitis B efficiency of LCS. Our study provides a basis for further exploration and development of this promising compound prescription to treat hepatitis B disease.

Protamine Nanocapsules for the Development of Thermostable Adjuvanted Nanovaccines.

One of the main challenges in the development of vaccine has been to improve their stability at room temperature and eliminate the limitations associated with the cold chain storage. In this paper, we describe the development and optimization of thermostable nanocarriers consisting of an oily core with immunostimulating activity, containing squalene or α tocopherol surrounded by a protamine shell. The results showed that these nanocapsules can efficiently associate the recombinant hepatitis B surface antigen (rHBsAg) without compromising its antigenicity. Furthermore, the freeze-dried protamine nanocapsules were able to preserve the integrity and bioactivity of the associated antigen upon storage for at least 12 months at room temperature. In vitro studies evidenced the high internalization of the nanocapsules by immunocompetent cells, followed by cytokine secretion and complement activation. In vivo studies showed the capacity of rHBsAg-loaded nanocapsules to elicit protective levels upon intramuscular or intranasal administration to mice. Overall, our data indicate that protamine nanocapsules are an innovative thermostable nanovaccine platform for improved antigen delivery.

Anti-hepatitis B virus effects of the traditional Chinese herb Artemisia capillaris and its active enynes.

ETHNOPHARMACOLOGICAL RELEVANCE: Artemisia capillaris (Yin-Chen) is a famous traditional Chinese medicine (TCM) for treating acute and chronic hepatitis in China. Enynes are one type of characteristic constituents in this herb, while their anti-hepatitis B virus (anti-HBV) properties have not been systemically investigated. AIM OF THE STUDY: This study is to reveal the active part of A. capillaris, and systemically investigate the enynes and their anti-HBV activity. MATERIALS AND METHODS: The total extract and each fraction of A. capillaris were assayed for the anti-HBV activity to reveal the active part. Bioassay-guided fractionation using various chromatographic techniques yielded the enynes, whose structures were elucidated by spectroscopic analyses and ECD calculations. The anti-HBV properties inhibiting HBsAg and HBeAg secretions and HBV DNA replication were evaluated on HepG 2.2.15 cell line in vitro. RESULTS: ACT-2 and ACT-3 was revealed to be the respective active and toxic part of A. capillaris. Twelve enynes (1-12) involving four new ones (1-4) and two unusual enyne analogs (13-14) were isolated from the active part (ACT-2). All the isolates were assayed for their anti-HBV activity, and the preliminary structure-activity relationships were summarized based on the structural features. In particular, compound 4 could significantly inhibit the secretions of HBsAg and HBeAg, and HBV DNA replication with IC50 values of 197.2 (SI > 5.1), 48.7 (SI > 20.5) and 9.8 (SI > 102) µM. CONCLUSIONS: Enynes are responsible for the anti-HBV effects of A. capillaris. Hydroxyl and glycosyl groups are preferable for maintaining activity. This is the first time to systematically investigate the anti-HBV activity of enynes in A. capillaris, which provides valuable information for understanding the ethnopharmacological application of Yin-Chen.

Safety and efficacy of immunotherapy with the recombinant B-cell epitope-based grass pollen vaccine BM32.

BACKGROUND: BM32 is a grass pollen allergy vaccine based on recombinant fusion proteins consisting of nonallergenic peptides from the IgE-binding sites of the 4 major grass pollen allergens and the hepatitis B preS protein. OBJECTIVE: We sought to study the safety and clinical efficacy of immunotherapy (allergen immunotherapy) with BM32 in patients with grass pollen-induced rhinitis and controlled asthma. METHODS: A double-blind, placebo-controlled, multicenter allergen immunotherapy field study was conducted for 2 grass pollen seasons. After a baseline season, subjects (n = 181) were randomized and received 3 preseasonal injections of either placebo (n = 58) or a low dose (80 µg, n = 60) or high dose (160 µg, n = 63) of BM32 in year 1, respectively, followed by a booster injection in autumn. In the second year, all actively treated subjects received 3 preseasonal injections of the BM32 low dose, and placebo-treated subjects continued with placebo. Clinical efficacy was assessed by using combined symptom medication scores, visual analog scales, Rhinoconjunctivitis Quality of Life Questionnaires, and asthma symptom scores. Adverse events were graded according to the European Academy of Allergy and Clinical Immunology. Allergen-specific antibodies were determined by using ELISA, ImmunoCAP, and ImmunoCAP ISAC. RESULTS: Although statistical significance regarding the primary end point was not reached, BM32-treated subjects, when compared with placebo-treated subjects, showed an improvement regarding symptom medication, visual analog scale, Rhinoconjunctivitis Quality of Life Questionnaire, and asthma symptom scores in both treatment years. This was accompanied by an induction of allergen-specific IgG without induction of allergen-specific IgE and a reduction in the seasonally induced increase in allergen-specific IgE levels in year 2. In the first year, more grade 2 reactions were observed in the active (n = 6) versus placebo (n = 1) groups, whereas there was almost no difference in the second year. CONCLUSIONS: Injections of BM32 induced allergen-specific IgG, improved clinical symptoms of seasonal grass pollen allergy, and were well tolerated.

Analysis of immunological mechanisms exerted by HBsAg-HBIG therapeutic vaccine combined with Adefovir in chronic hepatitis B patients.

An HBsAg-HBIG therapeutic vaccine (Yeast-derived Immune Complexes, YIC) for chronic hepatitis B (CHB) patients has undergone a series of clinical trials. The HBeAg sero-conversion rate of YIC varied from 21.9% to 14% depending on the immunization protocols from 6 to 12 injections. To analyze the immunological mechanisms exerted by 6 injections of YIC, 44 CHB patients were separately immunized with YIC, alum as adjuvant control or normal saline as blank control, with add on of antiviral drug Adefovir in all groups. Kinetic increase in Th1 and Th2 cells CD4+ T cell sub-populations with association in decrease in Treg cells and increase of Tc1 and Tc17 cells in CD8+ T cells were observed in YIC immunized group. No such changes were found in the other groups. By multifunctional analysis of cytokine profiles, significant increase of IL-2 levels was observed, both in CD4+ and CD8+ T cells in the YIC immunized group, accompanied by increase in IFN-gamma and decrease of inhibitory factors (IL-10, TGF-ß and Foxp3) in CD4+ T cells. In the alum immunized group, slight increase of IL-10, TGF-ß and Foxp3 in CD4+ T cells was found after the second injection, but decreased after more injections, suggesting that alum induced early inflammatory responses to a certain extent. Similar patterns of responses of IL-17A and TNF-α in CD8+T cells were shown between YIC and the saline group. Results indicate that add on of Adefovir, did not affect host specific immune responses.

Systems Pharmacology-based strategy to screen new adjuvant for hepatitis B vaccine from Traditional Chinese Medicine Ophiocordyceps sinensis.

Adjuvants are common component for many vaccines but there are still few licensed for human use due to low efficiency or side effects. The present work adopted Systems Pharmacology analysis as a new strategy to screen adjuvants from traditional Chinese medicine. Ophiocordyceps sinensis has been used for many years in China and other Asian countries with many biological properties, but the pharmacological mechanism has not been fully elucidated. First in this study, 190 putative targets for 17 active compounds in Ophiocordyceps sinensis were retrieved and a systems pharmacology-based approach was applied to provide new insights into the pharmacological actions of the drug. Pathway enrichment analysis found that the targets participated in several immunological processes. Based on this, we selected cordycepin as a target compound to serve as an adjuvant of the hepatitis B vaccine because the existing vaccine often fails to induce an effective immune response in many subjects. Animal and cellular experiments finally validated that the new vaccine simultaneously improves the humoral and cellular immunity of BALB/c mice without side effects. All this results demonstrate that cordycepin could work as adjuvant to hepatitis b vaccine and systems-pharmacology analysis could be used as a new method to select adjuvants.

A Pre-Clinical Safety Evaluation of SBP (HBsAg-Binding Protein) Adjuvant for Hepatitis B Vaccine.

Although adjuvants are a common component of many vaccines, there are few adjuvants licensed for use in humans due to concerns about their toxic effects. There is a need to develop new and safe adjuvants, because some existing vaccines have low immunogenicity among certain patient groups. In this study, SBP, a hepatitis B surface antigen binding protein that was discovered through screening a human liver cDNA expression library, was introduced into hepatitis B vaccine. A good laboratory practice, non-clinical safety evaluation was performed to identify the side effects of both SBP and SBP-adjuvanted hepatitis B vaccine. The results indicate that SBP could enhance the HBsAg-specific immune response, thus increasing the protection provided by the hepatitis B vaccine. The safety data obtained here warrant further investigation of SBP as a vaccine adjuvant.

Oral administration of synthetic selenium nanoparticles induced robust Th1 cytokine pattern after HBs antigen vaccination in mouse model.

Hepatitis B virus (HBV) infection is known as a life-threatening liver infection and leads to chronic liver disease if left untreated. Nevertheless, the prevalence of HBV infection has been reduced by an approved vaccination approach using recombinant Hepatitis B surface Antigen (HBsAg) and Alum, known as the HBV vaccine. Alum can be used as an adjuvant to increase HBsAg immunogenicity as a strong Th2 stimulator. There is a vital need to stimulate Th1 immunity by HBsAg vaccination; however, the present vaccine does not induce a prophylactic immune response in some groups. The main aim of the present study was to induce a Th1 cytokine pattern and stimulate an immune response after HBsAg vaccination. Experimental mice were fed selenium nanoparticles (SeNPs) and were later immunized with 5µg of Hepatitis B Vaccine. After a period of 30 days, the experimental animals were given two booster doses of SeNPs during their vaccination course. Group one, i.e., the control vaccine group, was only administered the HBsAg vaccine. The two treated groups, Groups 2 and 3, were daily fed different doses of SeNPs (100µg and 200µg, respectively) via gavage. Group four was considered the control group and was only given phosphate buffered saline (PBS). Lymphocyte proliferation, IFN-γ and IL-4 levels, total antibody and the isotypes of IgG1, IgG2a, IgG2b, and IgM were measured by Enzyme Linked Immunosorbent Assay (ELISA). The administration of SeNPs and the HBs antigen vaccine affected the lymphocyte proliferation; moreover, the total antibody responses also increased the IFN-γ level and induced a Th1 response. CONCLUSIONS: The present study proposed that the administration of SeNPs with a conventional HBs antigen vaccine induces a better immune response with a Th1 bias.

Improvement of chronic hepatitis B by iron chelation therapy in a patient with iron overload: A case report.

RATIONALE: This report describes seroconversion of hepatitis B surface antigen (HBsAg) in a patient with marked iron overload caused by chronic hepatitis B (CHB) after receiving iron chelation therapy and discusses the role of iron chelation therapy in CHB. PATIENT CONCERNS: Increased serum ferritin level for 2 months. DIAGNOSIS: Secondary iron overload and CHB. INTERVENTION: To relieve iron load of the body, the patient underwent regular phlebotomy therapy and deferoxamine (DFO) therapy. During the therapy, serum ferritin and hepatitis B virus (HBV) were monitored and the iron concentration of the liver and heart were followed by T2* of magnetic resonance imaging (MRI) scan. OUTCOMES: Serum ferritin gradually decreased. Approximately 1 year after the therapy, HBsAg turned persistently negative. LESSONS: Iron chelation therapy may attenuate HBV infection.

Immunotherapy With the PreS-based Grass Pollen Allergy Vaccine BM32 Induces Antibody Responses Protecting Against Hepatitis B Infection.

BACKGROUND: We have constructed and clinically evaluated a hypoallergenic vaccine for grass pollen allergy, BM32, which is based on fusion proteins consisting of peptides from the IgE binding sites of the major grass pollen allergens fused to preS (preS1+preS2), a domain of the hepatitis B virus (HBV) large envelope protein which mediates the viral attachment and entry. Aim of this study was the characterization of the HBV-specific immune response induced by vaccination of allergic patients with BM32 and the investigation of the vaccines' potential to protect against infection with HBV. METHODS: Hepatitis B-specific antibody and T cell responses of patients vaccinated with BM32 were studied using recombinant preS and synthetic overlapping peptides spanning the preS sequence. The specificities of the antibody responses were compared with those of patients with chronic HBV infection. Furthermore, the capacity of BM32-induced antibodies, to inhibit HBV infection was investigated using HepG2-hNTCP cell-based in vitro virus neutralization assays. FINDINGS: IgG antibodies from BM32-vaccinated but not of HBV-infected individuals recognized the sequence motif implicated in NTCP (sodium-taurocholate co-transporting polypeptide)-receptor interaction of the hepatitis B virus and inhibited HBV infection. INTERPRETATION: Our study demonstrates that the recombinant hypoallergenic grass pollen allergy vaccine BM32 induces hepatitis B-specific immune responses which protect against hepatitis B virus infection in vitro.

Maternal zinc supplementation improves hepatitis B antibody responses in infants but decreases plasma zinc level.

PURPOSE: The World Health Report identifies zinc deficiency as one of the major causes of disease in developing countries, and infants are at particular risk. We aimed to investigate the effect of maternal zinc supplementation on the infant's immune function in a population at risk of deficiency. METHODS: In a randomized, double-blind placebo-controlled trial, mothers were supplemented either with 20 mg/day of elemental zinc (n = 20) or placebo (n = 19) at the beginning of second trimester, which continued until 6 months postpartum. Indicators of the infants' immune function measured included interleukin (IL)-7, thymic size and response to hepatitis B vaccination. RESULTS: Infants born from mothers receiving zinc supplements during pregnancy and postpartum had significantly lower plasma zinc (p < 0.05) but marginally higher IL-7 and antibody responses to hepatitis B vaccination (p < 0.10) than infants born from mothers not receiving zinc. Maternal zinc supplementation showed no negative impact on copper status of mothers or their infants. Maternal zinc supplementation did not influence infant thymic size, but cord blood IL-7 was found positively associated with thymus size at 1 month of age (r = 0.392) and with hepatitis B vaccine response at 6 months of age (r = 0.386). CONCLUSION: Prenatal and postnatal zinc supplementation marginally improved T cell-dependent antibody responses in infants along with IL-7, a cytokine involved in human T cell development and maintaining homeostasis.

Three new anti-HBV active constituents from the traditional Chinese herb of Yin-Chen (Artemisia scoparia).

ETHNOPHARMACOLOGICAL RELEVANCE: Yin-Chen is a famous traditional Chinese medicine (TCM) in China for the treatment of acute and chronic hepatitis. Two species, namely Artemisia scoparia and Artemisia capillaris, are documented in Chinese Pharmacopoeia as the authentic resources for Yin-Chen. Previous investigation has proved that chlorogenic acid analogs and phenolic acids are two main types of the anti-HBV active constituents of A. capillaris. However, there is no investigation concerned with the anti-HBV components of A. scoparia. AIM OF THE STUDY: The aim of the present study is to recognize the new anti-HBV constituents of A. scoparia by detailed LCMS analyses. MATERIALS AND METHODS: LCMS and bioassay-guided fractionation on the active part of A. scoparia led to the isolation of three new compounds. Their structures were determined by detailed spectroscopic analyses. Anti-HBV assay involving inhibition on HBsAg and HBeAg secretions and HBV DNA replication were performed in virto on HepG 2.2.15 cell line. RESULTS: The 90% ethanol extract of A. scoparia was revealed with anti-HBV activity for the first time, which was further separated into several fractions by column chromatography. Fr. D-4 was revealed with the highest anti-HBV activity, from which three new compounds including one unusual 4-pyridone glucoside (1) and two polyacetylene glucosides (2-3) were isolated under the guidance of LCMS analyses. Compounds 1-3 exhibited activity against the secretions of HBsAg and HBeAg, and HBV DNA replication. In particular, compounds 2 and 3 inhibited HBV DNA replication with IC50 values of 0.07 ± 0.04 and 0.012 ± 0.05 mM, with SI values of 23.6 and 17.1, respectively. Based on the MS/MS experiment, the fragmentation pathways of 1 in both positive and negative modes, and 2 and 3 in negative mode were proposed. The ion pairs of 388-208 (positive) and 432-206 (negative) for 1, 503-341 (negative) for 2, and 503-203 (negative) for 3, could be recognized as their respective diagnostic ions. CONCLUSIONS: The first time investigation on the anti-HBV constituents of A. scoparia yielded three new active compounds, which will provide valuable information for understanding the ethnopharmacological usage of Yin-Chen, as well as the chemical difference with A. capillaris.

Protamine-based nanoparticles as new antigen delivery systems.

The use of biodegradable nanoparticles as antigen delivery vehicles is an attractive approach to overcome the problems associated with the use of Alum-based classical adjuvants. Herein we report, the design and development of protamine-based nanoparticles as novel antigen delivery systems, using recombinant hepatitis B surface antigen as a model viral antigen. The nanoparticles, composed of protamine and a polysaccharide (hyaluronic acid or alginate), were obtained using a mild ionic cross-linking technique. The size and surface charge of the nanoparticles could be modulated by adjusting the ratio of the components. Prototypes with optimal physicochemical characteristics and satisfactory colloidal stability were selected for the assessment of their antigen loading capacity, antigen stability during storage and in vitro and in vivo proof-of-concept studies. In vitro studies showed that antigen-loaded nanoparticles induced the secretion of cytokines by macrophages more efficiently than the antigen in solution, thus indicating a potential adjuvant effect of the nanoparticles. Finally, in vivo studies showed the capacity of these systems to trigger efficient immune responses against the hepatitis B antigen following intramuscular administration, suggesting the potential interest of protamine-polysaccharide nanoparticles as antigen delivery systems.