Histone H3K27 methylation modulates the dynamics of FANCD2 on chromatin to facilitate NHEJ and genome stability.

Dysregulation of the homeostatic balance of histone H3 di- and tri-methyl lysine 27 (H3K27me2/3) levels caused by the mis-sense mutation of histone H3 (H3K27M) is reported to be associated with various types of cancers. In this study, we found that reduction in H3K27me2/3 caused by H3.1K27M, a mutation of H3 variants found in patients with diffuse intrinsic pontine glioma (DIPG), dramatically attenuated the presence of 53BP1 (also known as TP53BP1) foci and the capability of non-homologous end joining (NHEJ) in human dermal fibroblasts. H3.1K27M mutant cells showed increased rates of genomic insertions/deletions and copy number variations, as well as an increase in p53-dependent apoptosis. We further showed that both hypo-H3K27me2/3 and H3.1K27M interacted with FANCD2, a central player in the choice of DNA repair pathway. H3.1K27M triggered the accumulation of FANCD2 on chromatin, suggesting an interaction between H3.1K27M and FANCD2. Interestingly, knockdown of FANCD2 in H3.1K27M cells recovered the number of 53BP1-positive foci, NHEJ efficiency and apoptosis rate. Although these findings in HDF cells may differ from the endogenous regulation of the H3.1K27M mutant in the specific tumor context of DIPG, our results suggest a new model by which H3K27me2/3 facilitates NHEJ and the maintenance of genome stability.This article has an associated First Person interview with the first author of the paper.

Immunogenicity, safety, and immune persistence of a novel inactivated human enterovirus 71 vaccine: a phase II, Randomized, double-blind, placebo-controlled Trial.

BACKGROUND: Vaccination is considered a top priority for the control of human enterovirus 71 (EV71) infection outbreaks. METHODS: On the basis of phase I trial results, we conducted a double-blind, randomized, controlled trial to evaluate the optimal dose, immunogenicity, safety and immune persistence of the vaccine. A total of 480 healthy infants were randomly assigned to receive 2 injections of 100 U of vaccine, 200 U of vaccine, 400 U of vaccine, or placebo. Solicited adverse events (AEs) within 7 days and unsolicited AEs within 28 days after each vaccination were collected for safety evaluation. Blood samples were collected for neutralizing antibody assay. RESULTS: EV71 vaccine was well tolerated, and no dose-related safety concerns were observed. Two doses of the vaccine yielded seropositivity frequencies of 92.3%, 95.9%, and 99.0% (with titers ≥1:8) in the 100 U, 200 U, and 400 U groups, respectively. Geometric mean titers measured by neutralizing antibody assay increased to 60.2 (95% confidence interval [CI], 41.9-86.4), 72.8 (95% CI, 50.8-104.3), and 252.1 (95% CI, 180.8-351.6) for the 100 U, 200 U, and 400 U groups, respectively. The dose-response relationship, with the 400 U dose showing higher immunogenicity than the 100 U and 200 U doses, remained until 13 months after the second vaccination, despite waning antibody levels. CONCLUSIONS: The 400 U dose was recommended as the optimal dose for the phase III trial because of its good safety profile and higher immunogenicity.

[The roles of Kupffer cells in the development and regression of liver fibrosis].

Hepatic fibrosis results from iterative hepatic injury with sustained inflammation, formation of scar tissue, loss of tissue architecture and organ failure. There is no doubt, from both human and animal studies, that too much or too protracted inflammation in the liver leads to excess scarring. During liver injury, Kupffer cells can quickly flood the hepatic milieu with soluble mediators, including oxidants, cytokines, and proteinases, which can affect stellate cell proliferation, migration, and differentiation. On the other hand, the contribution of Kupffer cells to regression of hepatic fibrosis has been demonstrated. These findings underscore the potential importance of hepatic macrophages in regulating both stellate cell biology and extracellular material degradation during regression of hepatic fibrosis. Therefore, biological characterization of Kupffer cells, their interactions with stellate cells in the cytokine environment are essential to understand the mechanisms underlying the progressive development of excessive scarring in the liver as well as the ability of the liver for tissue repair and recovery.

Fast evaluation of oxidative DNA damage by liquid chromatography-electrospray tandem mass spectrometry coupled with precision-cut rat liver slices.

OBJECTIVE: To establish a fast and sensitive method for the detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in precision-cut rat liver slices by HPLC-MS/MS and to investigate isoniazid (INH) -induced oxidative DNA damage. METHODS: Precision-cut liver slices (300 microm) were prepared from male rats, and incubated with INH (0.018 mol/L) for 2 h after 1 h preincubation. DNA in the slices was extracted and digested into free nucleosides at 37 degrees C. The samples were injected into HPLC-MS/MS after the proteins were removed. The level of oxidative DNA damage was estimated using the ratio of 8-OHdG to deoxyguanosine (dG). RESULTS: The limit of detection of 8-OHdG was 1 ng/mL (S/N=3) and the intra-assay relative standard variation was 3.38% when one transition 284.3/168.4 was used as a quantifier and another two transitions 284.3/140.2, 306.1/190.2 as qualifiers. 8-OHdG and dG were well separated, as indicated by elution at 10.02 and 7.37 min, respectively. INH significantly increased the ratio of 8-OHdG to dG in rat liver slices (P<0.05). CONCLUSION: 8-OHdG in precision-cut liver slices could be sensitively determined by HPLC-MS/MS. HPLC-MS/MS coupled with precision-cut tissue slices is a fast and reliable analytical technique to evaluate oxidative DNA damage of target tissues caused by procarcinogens and cytotoxins.

Review of 10 years of clinical experience with Chinese domestic trivalent influenza vaccine Anflu®.

Influenza viruses cause annual winter epidemics globally and influenza vaccination is most effective way to prevent the disease or severe outcomes from the illness, especially in developing countries. However, the majority of the world's total production capacity of influenza vaccine is concentrated in several large multinational manufacturers. A safe and effective preventive vaccine for the developing countries is urgent. Anflu®, a Chinese domestic preservative-free, split-virus trivalent influenza vaccine (TIV), was introduced by Sinovac Biotech Ltd. in 2006. Until now, 20.6 million doses worldwide of Anflu® were sold. Since 2003, 13 company-sponsored clinical studies investigating the immunogenicity and safety of Anflu® have been completed, in which 6642 subjects participated and were vaccinated by Anflu®. Anflu® was generally well tolerated in all age groups, and highly immunogenic in healthy adults and elderly and exceeded the licensure criteria in Europe. This review presents and discusses the experience with Anflu® during the past decade. A new Chinese domestic, preservative-free, unadjuvanted, inactivated split-virus trivalent influenza vaccine (TIV), Anflu®, was introduced into human clinical trials in 2003 and then licensed in China in 2006. The vaccine contains 15 µg/0.5 ml hemagglutinin from each of the 3 influenza virus strains (including an H1N1 influenza A virus subtype, an H3N2 influenza A virus subtype, and an influenza B virus) that are expected to be circulating in the up-coming influenza season. The clinical data pertaining to Anflu® will be reviewed and compared with other TIVs available at present.

Review of 10 years of marketing experience with Chinese domestic inactivated hepatitis A vaccine Healive®.

In 2002, the first Chinese domestic preservative-free inactivated hepatitis A vaccine, Healive®, was introduced in China. It is highly immunogenic, and provides lasting protection in healthy individuals and generates protective levels of antibodies in other at-risk individuals. Over 10 years since its first licensure, postmarketing surveillance data have confirmed the outstanding safety profile of the vaccine. Comparative clinical trials indicated that Healive® induce equal or similar immunogenicity with other currently available inactivated hepatitis A vaccines and are interchangeable for the course of HAV immunization in Chinese children. The vaccine is effective in curbing outbreaks of hepatitis A due to rapid seroconversion and the long incubation period of the disease. Additional issues surrounding the use of the vaccine are also reviewed.

Interchangeability and tolerability of two inactivated hepatitis A vaccines in Chinese children.

In China, no data are available to evaluate the interchangeability between Chinese domestic inactivated hepatitis A vaccines (Healive) and imported inactivated hepatitis A vaccines (Havrix). A double-blind, randomized controlled study was to compare interchangeability and safety of Healive and Havrix among Chinese children. Vaccine was administered to 303 healthy children at 0 and 6 months in one of four vaccine regimens: Healive-Healive; Healive-Havrix; Havrix-Healive or Havrix-Havrix. We collected sera samples at 0 (before vaccination), 6 (before second dose) and 7 months (after second dose), and compared groups in terms of proportion of sero-conversions which is defined as ≥ 20 mIU/ml, and geometric mean concentrations (GMCs) of anti-hepatitis A virus (HAV) antibody. Seroconversion rates were 133/133 (100%) for those received one dose of Healive and 105/131 (80.2%) for those received one dose of Havrix at 6 months, respectively (P<0.001), GMCs for Healive and Havrix were 126.1 and 40.9 mIU/ml (P<0.001), respectively. At 7 months, the seroconversion rate was 100% among all groups. The GMC after two doses of Healive was 8905.5 mIU/ml compared with 1900.9 mIU/ml after two doses of Havrix (P<0.001). The GMC in the Healive-Havrix group was 3275.8 mIU/ml compared with 4165.8 mIU/ml in the Havrix-Healive group (P=0.058). There is not different of reported adverse reactions across the groups. The present study indicated that both vaccines can be recommended for interchangeable using of immunization among Chinese healthy children.