A study of the antigenicity and immunogenicity of a new hepatitis B vaccine using a panel of monoclonal antibodies

Synthesis, chemo-informatics, and anticancer evaluation of fluorophenyl-isoxazole derivatives

The current study aimed to design and synthesize a novel series of fluorophenyl-isoxazole-carboxamide derivatives and evaluate their antiproliferative activities. Anticancer activities of the novel compounds were evaluated by MTS assay against four cancer cell lines, including liver (Hep3B, HepG2), cervical (HeLa), and breast (MCF-7), and α-fetoprotein tumor marker, cell cycle analysis, and annexin V tests. Chemo-informatics analysis showed that all synthesized derivatives 2a–2f obeyed Lipinski’s rule. Compound 2f was the most potent compound against Hep3B and Hep-G2 cancer cell lines with IC50 values of 5.76 and 34.64 µg/mL, respectively. Moreover, compounds 2a–2c and 2e showed potent inhibitory activity against Hep3B with an IC50 value range of 7.66–11.60 µg/mL. Hep3B secretions of α-fetoprotein (α-FP) results showed that compound 2f reduced the secretion of Hep3B to 168.33 ng/mL and compound 2d reduced the secretion to value approximately 598.33 ng/mL, in comparison with untreated cells’ value of 1116.67 ng/mL. Furthermore, cell cycle analysis showed that the 2f compound induced arrest in the G2-M phase in 6.73% of the total cells and that was lower than the activity of the positive control doxorubicin (7.4%). Moreover, 2b and 2f compounds reduced the necrosis rate of Hep3B to 4-folds and shifted the cells to apoptosis.

The impact of filtered water-pipe smoke on healthy versus cancer cells and their neurodegenerative role on AMPA receptor

Water pipe smoking is highly prevalent in developing countries, especially in Eastern Mediterranean regions. Research finds that more than 100 million people smoke a water pipe. Furthermore, tobacco smoking is one of the leading behavioral factors related to an increased risk of cancer, a leading cause of death globally. We aim to introduce a novel filtration system for water-pipe smoking and evaluate cytotoxic effects of common water pipe condensed smoke in comparison with our novel filtration system on normal (HEK293t) and cancer cell lines (Hep3B and MCF7) by MTS assay, alpha-fetoprotein (aFP), and apoptosis/necrosis effects. More so, the smoke substituents' neurotoxicity effect was evaluated by analyzing the depressive property on AMPA receptors (AMPARs). Our results showed that the silica filtration system was more effective than the water filtration system. The number of toxic compounds was reduced from 145 mg in distilled water extract (DWE) to 57.5 mg in silica solution extract (SSE). The SSE method also showed lower toxicity impacts on normal and cancerous cell lines (HEK293t, Hep3B, and MCF7) with CC₅₀ values 149.9, 10.14, and 8.9 µg/ml, relative to the DWE method (CC₅₀ values 77.1, 3.1, and 5.24 µg/ml, respectively). SSE extraction also reduced the α-FP (tumor marker test) to 2273.3 ng/ml which was closer in value to untreated cells (4066.7 ng/ml) in comparison with DWE which reduced it greatly to 1658.7 ng/ml, and the biophysical properties of AMPAR subunits demonstrate a reduced effect on desensitization rates of GluA2 homomer and GluA1/2 heteromer, using SSE relative to DWE. In conclusion, the condensed smoke of ordinary water pipe (DWE) has cytotoxic and neurotoxic impacts on various cell lines, while our newly developed system (SSE) was less toxic.

Synthesis and Biological Evaluation of Novel Isoxazole-Amide Analogues as Anticancer and Antioxidant Agents

Cancer now is one of the leading causes of mortality in the world. There has been a lot of effort to discover new anticarcinogenic agents that allow treatment with fewer side effects. A series of isoxazole-carboxamide derivatives (2a–2g) were synthesised and evaluated for their cytotoxic activity against breast (MCF-7), cervical (HeLa), and liver (Hep3B) cancer cell lines and their antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The results showed that 2d and 2e were the most active compounds against Hep3B cells, with a half-maximal inhibitory concentration (IC₅₀) of around 23 μg/ml; 2d showed the highest activity against HeLa cells, with an IC₅₀ 15.48 μg/ml. However, 2a had the lowest IC₅₀ (39.80 μg/ml) against MCF-7 cells. By contrast, compound 2g was inactive against all cancer cell lines, with IC₅₀ values >400 μg/ml. Both 2d and 2e reduced Hep3B secretion of alpha-fetoprotein (to 1829.33 ± 65.91 ng/ml and 1758.66 ± 54.04 ng/ml, respectively). Furthermore, in cell cycle analysis, 2d and 2e induced a delay in the G2/M phase of 18.07%, which is similar to the doxorubicin positive control. Moreover, 2d and 2e reduced the necrosis rate of Hep3B threefold and instead shifted the cells to apoptosis. Our results indicate that 2d and 2e have potent and promising anticancer activity. However, compound 2a was the most active as antioxidant agent (IC₅₀ = 7.8 ± 1.21 μg/ml) compared with Trolox as a positive control (IC₅₀ 2.75 μg/ml).

Synthesis and Biological Evaluation of Benzodioxole Derivatives as Potential Anticancer and Antioxidant agents

a series of benzodioxole compounds were synthesized and evaluated for their cytotoxic activity against cervical (Hela), colorectal (Caco-2), and liver (Hep3B) cancer cell lines. Compounds 5a, 5b, 6a, 6b, 7a and 7b showed very weak or negligible anticancer activity with IC50 3.94-9.12 mM. On the contrary, carboxamide containing compounds 2a and 2b showed anticancer activity. Both 2a and 2b reduced Hep3B secretions of α-fetoprotein (α-FP) to 1625.8 ng/ml and 2340 ng/ml, respectively, compared to 2519.17 ng/ml in untreated cells. The results also showed that compound 2a has potent anticancer activity against Hep3B cancer cell line. Furthermore, in cell cycle analysis, compound 2a induced arrest in the G2-M phase in value of 8.07% that was very close to the activity of doxorubicin (7.4%). These results indicate that compound 2a has a potent and promising antitumor activity. However, benzodiazepine derivatives (7a and 7b) showed moderate antioxidant activity with IC50 values of 39.85 and 79.95 μM, respectively compared with the potent antioxidant agent Trolox (IC50 = 7.72 μM).

Evaluating functional antibodies in rhesus monkeys immunized with hepatitis B virus surface antigen vaccine with novel adjuvant formulations

Effective and safe novel adjuvants are of great interest to the vaccine research community. In this study, we describe our evaluation of adjuvant formulations containing a TLR9 agonist adjuvant (ISS1018) or ISCOMATRIX™ adjuvant for a two-dose regimen of hepatitis B virus surface antigen virus-like particle vaccine in mice and rhesus macaques. Our results show a 10-20 fold improvement in Ab binding titers determined in an antigen-sandwich assay for adjuvant formulations with ISCOMATRIX™ adjuvant, in comparison to routine aluminum formulation. Furthermore, we optimized a competition assay to evaluate a functional component of immune sera, using a conformation-dependent and protective mAb, RFHBs1, as the probe. Although good correlation was observed between Ab binding titers from the antigen-sandwich assay and functional titers from the in-solution competition against RFHBs1, the latter assessment provided a much more stringent ranking of adjuvant formulations than the former. These results indicate the importance of evaluating functional Abs when assessing and comparing novel adjuvant formulations, as it provides another angle to investigate the effects of change in adjuvant composition on antigenic integrity of the testing vaccines.

Hepatitis B vaccines

Yeast-derived hepatitis B vaccines, containing the small HBV envelope protein SHBAg, are immunogenic, safe and cost-effective in prevention of hepatitis B virus infection in neonates, children and adults. Newly developed pre-S/S hepatitis B vaccines may play a role in inducing fast and augmented seroconversion rates in special risk groups.

Fine-mapping of the B-cell epitope domain at the N-terminus of the preS2 region of the hepatitis B surface antigen

In this study, we report the exact localization and substitutional characterization of a B-cell epitope domain at the N-terminus of the preS2 region of the hepatitis B surface antigen. A set of deletion variants containing preS2 sequences of different length was generated on the basis of frCP as a carrier. It was found after Western blot analysis that three monoclonal antibodies (MAbs) (2-11B1, 3-11C2, HB.OT10) recognized the linear preS2 sequence within the amino acid (aa) stretch 3-WNSTTFHQTLQDP-13. The importance of each aa residue of the epitope was proved by comparison of antibody binding to alanine-substituted peptides in both free-peptide and Pepscan variants.

Analysis of the relationship between immunogenicity and immunity for viral subunit vaccines

The prevention of viral infection by vaccination relies on stimulating an appropriate immune response in order to reduce the probability with which a virus can establish an infection. Post-vaccination antibody responses have therefore been associated with reducing the probability with which an individual can be infected (i.e., the vaccine's "impact"). Quantifying this relationship is essential in evaluating new vaccines, especially since comparisons between vaccines, and vaccine licensure, may be dependent on antibody responses alone. In this paper two principal questions are identified which need to be addressed in the evaluation of subunit vaccines: i) how do specific antibody levels relate to complete protection from infection or disease and ii) how do antigenic subunits interact in developing protection when combined together in a single vaccine. The aim is to identify explicitly certain assumptions that are frequently made implicitly in the discussion of vaccine action. First, antibody levels are related to levels of protection through a novel statistical analysis of incidence data from a published hepatitis B vaccine trial. The antibody response observed after influenza A virus infection is discussed in relation to the selection of neutralisation escape variants. Finally, by way of example, a theoretical situation is examined and three simple models of subunit vaccine action are constructed in order to describe how antibody levels may be related to population level phenomena such as the elimination of an infection by mass vaccination.

Liver disease in the elderly

Despite several morphologic and functional changes that have been described in the aging liver, most relevant studies fail to identify a significant age-related deficit in liver function in humans. One of the important age-related changes is a decrease in regenerative capacity, which may partly explain the impaired recovery after severe viral and toxic injury in the elderly. Nevertheless, livers from older subjects are used successfully for transplantation. Substantial morbidity and mortality in the elderly is attributable to liver diseases, and the number of patients older than 65 years of age with chronic liver disease is increasing rapidly. Although there are no liver diseases specific to advanced age, the presentation, clinical course and management of liver diseases in the elderly may differ in important respects from those of younger individuals.

Anti-HBs characteristics after hepatitis B immunisation with plasma-derived and recombinant DNA-derived vaccines

Hepatitis B surface antigen derived from chronic hepatitis B carriers has been replaced almost completely by recombinant DNA-derived HBsAg for use as hepatitis B vaccine. Similarly, recombinant DNA-derived HBsAg is replacing plasma-derived HBsAg in standard anti-HBs assays. We analysed the influence of a change from plasma-derived HBsAg to recombinant DNA-derived HBsAg on antigen presentation in immunoassays and the characteristics of the anti-HBs antibodies after immunisation. Antigens and/or antibodies were subjected to three types of experiments: (a) binding of 'a'-loop specific monoclonal (anti-S) antibody conjugates to immobilised vaccine-HBsAg; (b) binding of post-vaccination anti-HBs to immobilised (vaccine-)HBsAg and (c) inhibition of HBsAg binding to immobilised monoclonal anti-HBs after pre-incubation with post-vaccination antibodies. Our results show that, in both antigen presentation and anti-HBs binding properties, yeast recombinant HBsAg and related antibodies could be clearly distinguished from plasma-derived HBsAg and related antibodies. Divergent results were also obtained in the inhibition assay with recombinant DNA-derived HBsAg but not with serum HBsAg from the vaccine HBsAg subtype. It is concluded that both antigen presentation in vaccines and in anti-HBs assays can markedly influence the quantitation anti-HBs response. It is suggested that a challenge with an heterologous hepatitis B virus may encounter reduced efficacy of vaccine antibodies.

Viral hepatitis A, B, and C

Mankind probably has known viral hepatitis for many centuries; however, the major and most dramatic developments in our knowledge of these diseases have taken place during the second half of the 20th century. During this relatively short period of time, the infectious nature of hepatitis A, B, and C has been proven, leading to their identification and description. The advent of serologic markers has provided the means for establishing the diagnosis. Epidemiologic studies have provided important information that led to exciting achievements in detection and prevention of transmission. Molecular biology studies and cell culture techniques have established our knowledge of the viral genomes, and led to the development of specific vaccines for hepatitis A and B. Anti-viral therapy has been developed and aggressive combination therapy has emerged as a promising strategy for chronic hepatitis B and C. This article reviews some of the main fields of progress and achievement related to viral hepatitis A, B, and C in the 20th century.

Viral hepatitis

Viral hepatitis is still one of the most common causes of acute and chronic liver disease worldwide. Major advances have been made in our knowledge of these diseases, many during the past year. Molecular biology and clinical studies have improved our understanding of the mechanisms of antiviral drugs, as well as viral resistance to therapy. The risks of hepatitis A in patients with chronic liver disease have been confirmed, and the efficacy of hepatitis A vaccines in these patients has been proven. Aggressive combination therapy has emerged as a promising strategy for chronic hepatitis B and C, and techniques for immune prophylaxis for hepatitis B are being improved. Liver transplantation has become routine for end-stage hepatitis B virus liver disease, and new strategies to prevent and treat recurrence are being explored. This review discusses the recent advances in our knowledge of hepatitis viruses A through G, focusing on the literature of the past year.