Tripartite Motif Containing 52 (TRIM52) Promotes Cell Proliferation in Hepatitis B Virus-Associated Hepatocellular Carcinoma.

BACKGROUND Chronic hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC). HBV X protein (HBx) plays a crucial role in the development of HCC. Moreover, many tripartite motif (TRIM) family proteins exert diverse biological functions in hepatocarcinogenesis. However, as a novel member of this family, the specific effect of TRIM52 is still largely obscure. In the present study, we investigated the expression and function of TRIM52 in HBV-associated HCC. MATERIAL AND METHODS Fluorescence quantitative polymerase chain reaction (FQ-PCR) was performed to detect the HBV DNA levels in the peripheral blood of HCC patients. Quantitative real-time PCR (qRT-PCR) and Western blot analysis were performed to detect the expression of TRIM52, HBx, and NF-κB p65. HBx-pcDNA3.1 and TRIM52-shRNA were used to induce HBx ectopic expression and TRIM52 silencing, respectively. Pyrrolidine dithiocarbamate (PDTC) was used to block the activation of NF-κB. Cell proliferation was detected using the Cell Counting Kit-8 (CCK-8) assay. RESULTS TRIM52 expression was up-regulated together with HBx in HBV-associated HCC tissues. Ectopic expression of HBx elevated TRIM52 expression in HepG2 cells. TRIM52 silencing repressed the proliferation of HepG2.2.15 cells. Moreover, NF-κB p65 expression was increased in HCC cell lines. Blocking NF-κB activation with PDTC suppressed TRIM52 expression and attenuated the viability of HepG2.2.15 cells. CONCLUSIONS These findings indicate that TRIM52 can promote cell proliferation and HBx may regulate TRIM52 expression via the NF-κB signaling pathway in HBV-associated HCC.

Round pneumonia in an adult.

Round pneumonia is an uncommon form of pulmonary infection usually found in children. It may resemble pulmonary neoplasm on radiographs. We present a case of round pneumonia in a 43-year-old male with a history of smoking and a family history of lung cancer. The patient was treated with antibiotics for more than two weeks, after which the infection resolved completely both clinically and radiologically. Clinicians should consider this uncommon type of pneumonia in the differential diagnosis of spherical pulmonary masses to avoid unnecessary diagnostic tests.

Life's essential 8 and risk of subclinical atherosclerosis progression: a prospective cohort study.

BACKGROUND: Previous studies have demonstrated the benefits of ideal cardiovascular health (CVH) in reducing cardiovascular risk. However, its role in subclinical atherosclerosis (SA) progression remains unclear. We aim to examine the association of CVH, estimated by the American Heart Association's new Life's Essential 8 (LE8), with the progression of SA. METHODS: This prospective cohort study was conducted among 972 asymptomatic Chinese participants and followed up for 5.7 years. The LE8 score (range, 0-100) consisted of blood pressure, lipids, glucose, body mass index, smoking status, diet health, physical activity and sleep health was evaluated in 1998 and 2008-2009. Progression of SA was determined by carotid plaque and coronary artery calcification (CAC) in 2008-2009 and 2013-2014. Log-binomial regression model was used to estimate the association of LE8 score with SA progression. RESULTS: Each 10 points increment in LE8 score was associated with 15.2% (RR: 0.848, 95% CI: 0.797-0.902), 17.7% (RR: 0.823, 95% CI: 0.766-0.884) and 12.0% (RR: 0.880, 95% CI: 0.845-0.916) lower risks of carotid plaque, CAC and overall SA progression, respectively. Compared with participants with non-ideal CVH at both visits, the participants with ideal CVH at both visits had 39.1% (RR: 0.609, 95% CI: 0.494-0.752), 41.0% (RR: 0.590, 95% CI: 0.456-0.764) and 29.7% (RR: 0.703, 95% CI: 0.598-0.825) lower risks of carotid plaque, CAC and overall SA progression, respectively. CONCLUSIONS: Higher LE8 scores were associated with lower risks of SA progression. Besides, long-term maintenance of optimal CVH was more beneficial to prevent SA progression.

Inhibition of hepatitis B virus production in vitro by proteasome inhibitor MG132.

BACKGROUND/AIMS: To investigate the suppressive effects of proteasome inhibitor MG132 on hepatitis B virus production. METHODOLOGY: HepG2 2.2.15 hepatoblastoma cells, which constitutively produce HBV particles, were used in the present study. MTT assay was used to evaluate the cytotoxicity of MG132. A Proteasome-Glo chymotrypsin-like cell-based assay was used to access the proteasome activity. Quantitative PCR were performed to analyze HBV-DNA. Secreted HBV antigens in the culture medium were measured by ELISA. Western blot and immunofluorescent staining of HBV antigen were also performed. RESULTS: After 6 days of MG132 treatment, proteasome activity was greatly decreased to 64.3 ± 7.8% and 36.4 ± 7.7% of untreated cells by 0.1µM and 0.3µM of MG132, respectively. The levels of HBsAg and HBeAg, and the copy number of extracellular HBV-DNA, were decreased to nearly half of the control group by 0.1µM MG132. The HBV replicative intermediates were also suppressed by MG132. Western blot and immunofluorescent staining clearly showed the lower levels of the expression of HBV proteins induced by MG132. CONCLUSIONS: MG132 could effectively inhibit the HBV replication in vitro. Ubiquitin-proteasome pathway plays an important role in HBV life cycle and could be a promising therapeutic target for anti-HBV drugs.

Cryptococcal osteomyelitis of the scapula and rib in an immunocompetent patient.

Cryptococcal osteomyelitis is extremely rare and almost always occurs in immunocompromised patients. We describe a case of osteomyelitis due to Cryptococcus neoformans involving both scapula and rib in an immunocompetent and previously healthy patient. The patient received treatment with amphotericin B deoxycholate and flucytosine for 4 weeks, followed by oral fluconazole 400 mg per day for 8 weeks and 200 mg per day for 9 months. The 12-month course of antifungal therapy resulted in complete clinical recovery and undetectable serum cryptococcal antigen. Cryptococcal osteomyelitis should be suspected in any immunocompetent patient with osteolytic lesions on radiological images.

Astragalus polysaccharide alleviated hepatocyte senescence via autophagy pathway.

Aging is characterized by inevitable organ function decline over time, with consequent body deterioration and increased susceptibility to death. Astragalus polysaccharide (APS) has been reported to have anti-oxidative, anti-apoptotic, and anti-inflammatory properties. We investigated the potential protective effects of APS on hydrogen peroxide (H2 O2 ) induced hepatocyte senescence and identified related mechanisms in L02, Huh7, and LM3 cell lines. Aged female C57BL/6 mice were given APS for 1 week by intraperitoneal injection, and APS provided the strongest protective effect against H2 O2 -induced damage at 100 µM. APS reduced the expression of cell senescence markers and alleviated pathological damage in aged mouse liver. APS treatment decreased oxidative stress, apoptosis, NOD-like receptor protein-3-mediated pyroptosis, and maintained mitochondrial homeostasis. Notably, the protective effect of APS was weakened in the presence of chloroquine. APS might enrich autophagy by activating AMP-activated protein kinase (AMPK) and inhibiting mammalian target of rapamycin (mTOR). In conclusion, APS reduced reactive oxygen species levels, inhibited apoptosis and pyroptosis, and promoted mitophagy via AMPK/mTOR pathway to alleviate hepatocyte senescence in vitro and in vivo.

HOXA10 knockdown inhibits proliferation, induces cell cycle arrest and apoptosis in hepatocellular carcinoma cells through HDAC1.

BACKGROUND: Homeobox A10 (HOXA10) has been implicated in the development and progression of various human cancers. However, the precise biological functions of HOXA10 in hepatocellular carcinoma (HCC) have not been defined. METHODS: In this study, we examined mRNA expression by quantitative real-time PCR (qRT-PCR) of HOXA10 as well as histone deacetylase (HDAC) and protein levels by Western blot of HOXA10, HDAC1, Cyclin D1, proliferating cell nuclear antigen (PCNA), Survivin and p53 acetylation in HCC tissues and cell lines. We also assessed cell proliferation using Cell Counting Kit-8 (CCK-8) and analyzed cell cycle by flow cytometry. Furthermore, tumor growth of HCC cells in vivo was monitored using the nude mouse xenograft model. Finally, HDAC1 promoter activity and binding in HCC cell lines were detected by luciferase reporter assay and chromatin immunoprecipitation (ChIP), respectively. RESULTS: We uncovered the elevated expression of HOXA10 in HCC tissues compared to adjacent normal liver tissues. RNA interference-mediated knockdown of HOXA10 inhibited HCC cell proliferation both in vitro and in vivo. HOXA10 knockdown also induced cell cycle arrest at G0/G1 phase and apoptosis, which were accompanied with the reduced expression of Cyclin D1, PCNA and Survivin. Notably, HOXA10 knockdown enhanced p53 acetylation (Lys382), which is crucial to the activation of p53. Likewise, HOXA10 knockdown suppressed the transcription of HDAC1, a potential deacetylase for p53. In line with these observations, HDAC1 downregulation abrogated the effects of HOXA10 overexpression on proliferation, cell cycle progression, apoptosis and p53 acetylation, indicating the role of HDAC1 in mediating HOXA10 functions. CONCLUSION: Our results demonstrate that HOXA10 knockdown inhibits proliferation, induces cell cycle arrest and apoptosis in HCC cells by regulating HDAC1 transcription.

Prevalence and clinical significance of SEN virus infection in patients with non A-E hepatitis and volunteer blood donors in Shanghai.

AIM: To explore the prevalence of SEN virus (SENV) in patients with non A-E hepatitis and volunteer blood donors in Shanghai. METHODS: According to the published gene sequences, primers from the conserved region were designed. Then, the prevalence of SEN virus in 30 samples from healthy voluntary blood donors and 30 samples from patients with non A-E hepatitis were detected by nested-PCR of SENV-D/H. Some PCR products were cloned and sequenced. RESULTS: The specificity of genotype-specific PCR was confirmed by sequencing, the SENV DNA was detected in 53.3% of the patients with non A-E hepatitis and 10% of the blood donors. The prevalence of SENV-D/H viremia was significantly higher in patients with non A-E hepatitis than in blood donors (P = 0.0002). SENV-H subtype and SENV-D subtype were found in 2 and 1 samples, respectively from blood donors. SENV-H subtype, SENV D subtype, mixed SENV-D and SENV-H subtype were found in 8, 6 and 2 samples, respectively, from patients with non A-E hepatitis. CONCLUSION: The gene type of SENV in patients with non A-E hepatitis and blood donors in shanghai is D or H subtype, and transfusion is not the only transmitting form of SENV.

TRIM52 up-regulation in hepatocellular carcinoma cells promotes proliferation, migration and invasion through the ubiquitination of PPM1A.

BACKGROUND: Many tripartite motif (TRIM) family proteins have been reported to be of great importance in the initiation and progression in hepatocellular carcinoma (HCC). However, the biological role and regulatory mechanism of tripartite motif containing 52 (TRIM52) in HCC development and progression are poorly defined. METHODS: Immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR) or Western blot analysis was used to detect TRIM52, p21, matrix metalloproteinase 2 (MMP2), protein phosphatase, Mg2+/Mn2+ dependent 1A (PPM1A), p-Smad2/3 and Smad2/3 levels in HCC tissues and cell lines. HCC cell proliferation and cell cycle were measured by Cell Counting Kit-8 (CCK-8) and flow cytometry analysis, respectively. HCC cell migration and invasion were measured by Transwell assay. Tumor growth of HCC cells in vivo was measured using the nude mouse xenograft model. The correlation between TRIM52 and PPM1A was measured by co-immunoprecipitation (Co-IP) and ubiquitination analysis in vitro. RESULTS: TRIM52 was significantly up-regulated in the HCC tissues in comparison with the adjacent non-tumor hepatic tissues. TRIM52 was also up-regulated in HCC cell lines (MHCC-97H and MHCC-97L cells) compared with normal human liver cell line LO2. TRIM52 down-regulation by RNA interfering in MHCC-97H cells enhanced inhibition of cell proliferation, migration and invasion. TRIM52 down-regulation also induced MHCC-97H cells arrest in G0-G1 phase cell cycle and inhibited MHCC-97H cell growth in the nude mice. However, TRIM52 up-regulation in MHCC-97L cells promoted cell proliferation, migration and invasion. Furthermore, TRIM52 down-regulation significantly increased p21 and PPM1A expression, but inhibited MMP2 expression and induced Smad2/3 dephosphorylation in MHCC-97H cells, which were reversed by TRIM52 up-regulation in MHCC-97L cells. TRIM52 was found interacted with PPM1A and TRIM52 down-regulation inhibited the ubiquitination of PPM1A. Importantly, PPM1A up-regulation in MHCC-97L cells significantly suppressed TRIM52-mediated enhancement on cell proliferation, invasion and migration. CONCLUSIONS: Our findings suggest that TRIM52 up-regulation promotes proliferation, migration and invasion of HCC cells through the ubiquitination of PPM1A.

Expression of ICAM-1, HLA-DR, and CD80 on peripheral circulating CD1 alpha DCs induced in vivo by IFN-alpha in patients with chronic hepatitis B.

AIM: To explore the effects of interferon-alpha (IFN-alpha) application on peripheral circulating CD1alpha dendritic cells (DCs)in patients with chronic hepatitis B, and the expression of HLA-DR, CD80, and ICAM-1 on CD1alpha DCs in order to explore the mechanism of immune modulation of IFN-alpha. METHODS: By flow cytometry technique, changes of CD1alpha DCs were monitored in 22 patients with chronic hepatitis B treated with IFN-alpha and in 16 such patients not treated with IFN-alpha within three months. Meanwhile, the expression of HLA-DR, CD80, and ICAM-1 on CD1alpha DCs was detected. RESULTS: In the group of IFN-alpha treatment, the percentage of CD1alpha DCs in peripheral blood mononuclear cells was increased after three months of therapy. In patients who became negative for HBV-DNA after IFN-alpha treatment, the increase of DCs was more prominent, while in control, these changes were not observed. Increased expression of HLA-DR, CD80,and ICAM-1 on CD1alpha DCs was also observed. CONCLUSION: CD1alpha DCs can be induced by IFN-alpha in vivo, and the immune related molecules such as HLA-DR, CD80,and ICAM-1 are up-regulated to some degree. This might be an important immune related mechanism of IFN-alpha treatment for chronic hepatitis B.

[Expression of anti-HBc single-chain variable fragment mediated by recombinant replication defective adenovirus in vitro].

OBJECTIVES: To define the expression of single-chain variable fragment (ScFv) against hepatitis B virus core protein (HBc) mediated by recombinant replication defective adenovirus carrying the anti-HBc ScFv gene in vitro and to define the activity of anti-HBc ScFv combining HBcAg. METHODS: The recombinant adenoviruses carrying anti-HBc ScFv gene generated by homologous recombination in bacteria and packaged in 293 cells were transfected into HepG2 cells, and the anti-HBc ScFv was detected using SDS-PAGE and Western blot. RESULTS: Green fluorescent protein (GFP) was observed in HepG2 cells after the transfection. SDS-PAGE displayed a protein strap about 2.7 x 10(4), and the result of Western blot displayed a positive reactive strap. CONCLUSION: Anti-HBc ScFv can be expressed in cells mediated by recombinant replication defective adenovirus carrying the anti-HBc ScFv gene.

TUBERCULOSIS INFECTION MIGHT INCREASE THE RISK OF INVASIVE CANDIDIASIS IN AN IMMUNOCOMPETENT PATIENT.

Deep Candida infections commonly occur in immunosuppressed patients. A rare case of a multiple deep organ infection with Candida albicans and spinal tuberculosis was reported in a healthy young man. The 19-year-old man complained of month-long fever and lower back pain. He also had a history of scalded mouth syndrome. Coinfection with Mycobacterium tuberculosis and Candida albicans was diagnosed using the culture of aspirates from different regions. Symptoms improved considerably after antifungal and antituberculous therapy. This case illustrates that infection with tuberculosis might impair the host's immune system and increase the risk of invasive candidiasis in an immunocompetent patient.

Curative effects of interferon-alpha and HLA-DRB1 -DQA1 and -DQB1 alleles in chronic viral hepatitis B.

AIM: To investigate the association between curative effects of interferon-alpha and partial human leucocyte antigen (HLA) II alleles in chronic viral hepatitis B. METHODS: Sixty patients with chronic viral hepatitis B in Shanghai were treated with a standard course of treatment with interferon-alpha for 6 mo. HLA-DRB1, -DQA1, and -DQB1 alleles were detected by polymerase chain reaction-sequence specific primer (PCR-SSP) method. RESULTS: Frequencies of HLA-DRB1*04 (P<0.025) and HLA-DQA1*0303 (P<0.01) in non-responders were significantly higher than those in partial and complete responders. Frequencies of HLA-DQA1*0505 (P<0.025) and HLA-DQB1*0301 (P<0.005) in partial and complete responders were significantly higher than those in non-responders. CONCLUSION: Non-response to interferon-alpha therapy is positively correlated with HLA-DRB1*04 and HLA-DQA1*0303, and negatively correlated with HLA-DQA1*0505 and -DQB1*0301 in patient with chronic viral hepatitis B. HLA II genes of the identification alleles provide a method for evaluating outcome of interferon-alpha treatment.

The Fusion Protein of CTP-HBcAg18-27-Tapasin Mediates the Apoptosis of CD8(+)T Cells and CD8(+) T Cell Response in HLA-A2 Transgenic Mice.

BACKGROUND: HBV-specific cytotoxic T lymphocyte (CTL) activity is believed to play a critical role in controlling HBV infection. The phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway manipulates cell fate decisions in many different cell types by regulating the activity of downstream effectors. We have previously testified that the fusion protein of CTP-HBcAg18-27--Tapasin could enter the cytoplasm of dendritic cells and efficiently induce robust specific CTL response in vitro. OBJECTIVES: In the present study, we evaluated specific CTL response and the level of apoptosis of CD8+ T cells induced by CTP-HBcAg18-27-Tapasin in HLA-A2 transgenic mice (H-2Kb). Meanwhile, we preliminary investigated PI3K, phosphorylation level of Akt, and mammalian target of rapamycin (mTOR) as positive regulator of the magnitude and effector function of the hepatitis B virus-specific cytotoxic T lymphocytes in HLA-A2 transgenic mice. MATERIALS AND METHODS: HLA-A2 transgenic mice were immunized by intramuscular injection in the hind legs three times at one-week intervals with PBS, CTP-HBcAg18-27-Tapasin (50 µg), CTP-HBcAg18-27 (50 µg), HBcAg18-27-Tapasin (50 µg), and HBcAg18-27 (50 µg). One week after the last immunization, mice were sacrificed and splenocytes were harvested in strile condition. The specific CTL response was analyzed by flow cytometry and enzyme linked immunosorbent assay (ELISA); the expression of (PI3K)/Akt signaling was detected by RT-PCR and western blot. RESULTS: The results showed that CTP-HBcAg18-27-Tapasin significantly increased the percentages of IFN-γ(+) CD8α(+) T cells, the numbers of these polyfunctional triple-cytokine-producing (IFN-γ, TNF-α, and IL-2) CD8(+)T cells, the secretion of cytokine IFN-γ, IL-2, and TNF-α, while in comparison to control group, it significantly decreased the percentage of apoptotic CD8(+) T cells in HLA-A2 transgenic mice. Moreover, the expression of PI3K, P-Akt, and P-mTOR was significantly upregulated in CTP-HBcAg18-27-Tapasin group compared with control groups. CONCLUSIONS: In conclusion, CTP-HBcAg18-27-Tapasin could reduce apoptosis of CD8(+) T cells, increase the percentages of IFN-γ(+) CD8α(+) T cells, and elicit cell-mediated immunity in HLA-A2 transgenic mice; these processes were associated with activation of the PI3K/Akt signaling pathway.

Lentivirus-mediated silencing of rhomboid domain containing 1 suppresses tumor growth and induces apoptosis in hepatoma HepG2 cells.

Rhomboids were identified as the first intramembrane serine proteases about 10 years ago. Since then, the study of the rhomboid protease family has blossomed. Rhomboid domain containing 1 (RHBDD1), highly- expressed in human testis, contains a rhomboid domain with unknown function. In the present study, we tested the hypothesis that RHBDD1 was associated with proliferation and apoptosis in hepatocellular carcinoma using recombinant lentivirus-mediated silencing of RHBDD1 in HepG2 cells. Our results showed that down-regulation of RHBDD1 mRNA levels markedly suppressed proliferation and colony formation capacity of HepG2 human hepatoma cancer cells in vitro, and induced cell cycle arrest. We also found that RHBDD1 silencing could obviously trigger HepG2 cell apoptosis. In summary, it was demonstrated that RHBDD1 might be a positive regulator for proliferative and apoptotic characteristics of hepatocellular carcinoma.

Listeria monocytogenes meningitis in an immunocompetent adult: a case report.

Listeria monocytogenes (L. monocytogenes) is an uncommon cause of bacterial meningitis in immunocompetent adults. Patients with immunosuppression are at increased risk of developing serious invasive diseases, particularly meningitis. We describe a case of meningitis caused by L. monocytogenes in an immunocompetent and previously healthy 34-year-old adult. The patient received treatment with intravenous ampicillin plus amikacin and made a full recovery. L. monocytogenes should be suspected in immunocompetent adults with bacterial meningitis who fail to respond to empirical antibiotic treatment.

Inhibition of Csn3 expression induces growth arrest and apoptosis of hepatocellular carcinoma cells.

PURPOSE: Csn3 (or CSN3) encodes the third subunit of an eight-subunit complex, the COP9 signalosome (CSN), which acts as a protein kinase and a deneddylase in mammalian cells. Previous studies have shown that Csn3 is essential for maintenance of cell proliferation in the mouse embryonic epiblast and associated with the tumorigenesis process in osteosarcoma. However, its correlation with hepatocellular carcinoma (HCC) has not been explored yet. METHODS: The expression of Csn3 in HCC (n = 30), cirrhosis (n = 30), and normal tissues (n = 30) was detected using immunohistochemical analysis. The impacts of lentivirus-mediated inhibition of Csn3 on HCC cells were detected using MTT, BrdU incorporation assay, and flow cytometric analysis. In addition, the colony formation and tumor growth ability in nude mice were detected to define the role of Csn3 in tumorigenesis. RESULTS: Knockdown of Csn3 expression in HCC cell lines (SMMC-7721 and Hep3B) significantly inhibits the tumor growth both in vitro and in vivo. Further investigation indicates that this growth inhibition effect may be mediated through cell cycle arrest in G0/G1 phase and inductions of pro-apoptotic proteins BIK and Caspase-8. In addition, knockdown of Csn3 expression evidently suppresses tumor growth in a xenograft nude mice model. CONCLUSION: Collectively, this study demonstrates Csn3 as an oncogene that regulates the tumorigenesis process in HCC cells.

Enhancement of CTLs induced by DCs loaded with ubiquitinated hepatitis B virus core antigen.

AIM: To investigate whether hepatitis B virus (HBV) could induce a hepatitis B virus core antigen (HBcAg)-specific cytotoxic T lymphocyte (CTL) response in vitro by dendritic cells (DCs) transduced with lentiviral vector-encoding ubiquitinated hepatitis B virus core antigen (LV-Ub-HBcAg). METHODS: Recombinant LV-Ub-HBcAg were transfected into highly susceptible 293 T cells to obtain high virus titres. Bone marrow-derived DCs isolated from BALB/c mice were cultured with recombinant granulocyte-macrophage colony-stimulating factor and recombinant interleukin (IL)-4. LV-Ub-HBcAg, lentiviral vector-encoding hepatitis B virus core antigen (LV-HBcAg), lentiviral vector (LV) or lipopolysaccharide were added to induce DC maturation, and the DC phenotypes were analyzed by flow cytometry. The level of IL-12 in the supernatant was detected by enzyme-linked immunosorbent assay (ELISA). T lymphocytes were proliferated using Cell Counting Kit-8. DCs were cultured and induced to mature using different LVs, and co-cultured with allogeneic T cells to detect the secretion levels of IL-2, IL-4, IL-10 and interferon-γ in the supernatants of T cells by ELISA. Intracellular cytokines of proliferative T cells were analyzed by flow cytometry, and specific CTL activity was measured by a lactate dehydrogenase release assay. RESULTS: LV-Ub-HBcAg-induced DCs secreted more IL-12 and upregulated the expression of CD80, CD86 and major histocompatibility class II. DCs sensitised by different LVs effectively promoted cytokine secretion; the levels of IL-2 and interferon-γ induced by LV-Ub-HBcAg were higher than those induced by LV-HBcAg. Compared with LV-HBcAg-transduced DCs, LV-Ub-HBcAg-transduced DCs more efficiently stimulated the proliferation of T lymphocytes and generated HBcAg-specific cytotoxic T lymphocytes. CONCLUSION: LV-Ub-HBcAg effectively induced DC maturation. The mature DCs efficiently induced T cell polarisation to Th1 and generated HBcAg-specific CTLs.

Photoluminescence properties of Re(I) complex doped composite submicron fibers prepared by electrospinning.

In this paper, a Re(I) complex of Re(CO)3(Bphen)Br, where Bphen=4,7-diphenyl-1,10-phenanthroline is synthesized, and doped into poly(vinylpyrrolidone) submicron fibers through electrospinning technique. Their morphology, absorption, and emission spectra are investigated in detail. The composite fibers exhibit smooth and uniform morphology on the substrate, with an average diameter of ∼800 nm. A bright yellow emission peaking at 543 nm is observed from these composite fibers, and this emission is attributed to the triplet emissive state of Re(CO)3(Bphen)Br. When doped into poly(vinylpyrrolidone) matrix, the emission shows a blue-shift tendency compared with that of bulk sample, correspondingly, the photostability is also largely improved. Detailed analysis suggests that Re(CO)3(Bphen)Br occupies a homogeneous site within poly(vinylpyrrolidone) matrix, and the matrix provides a rigid environment for Re(CO)3(Bphen)Br.

Ubiquitin conjugation of hepatitis B virus core antigen DNA vaccine leads to enhanced cell-mediated immune response in BALB/c mice.

BACKGROUND: Nearly 350 million persons worldwide are chronically infected with hepatitis B virus (HBV). Ubiquitin (Ub) is a highly conserved small regulatory protein, ubiquitous in eukaryotes, that usually serves as a signal for the target protein that is recognised and degraded in proteasomes . The Ub-mediated processing of antigens is rapid and efficient and stimulates cell-mediated immune responses. Accordingly, Ub-mediated processing of antigens has been widely used in chronic-infection and cancer studies to improve immune response. OBJECTIVES: Many clinical trials have shown that DNA vaccine potency needs to be greatly enhanced. Here, we report a new strategy for designing an HBV DNA vaccine using the ubiquitin (Ub) sequence. The aim of this study was to investigate a novel DNA vaccination, based on the expression of HBV core antigen (HBcAg), fused to Ub to enhance DNA vaccine potency. MATERIALS AND METHODS: Mouse ubiquitin fused to the HBcAg gene and cloned into the eukaryotic vector pcDNA3.1 (-). BALB/c mice were immunized with recombinant pUb-HBcAg or pHBcAg DNA vaccine. Lymphocyte proliferation assay, intracellular IFN-γ assay, CTL cytotoxicity assay, and antibody assay were performed to analyze the cellular and humoral immune responses to our DNA constructs. RESULTS: HBcAg was expressed effectively in the COS-7 cells that were transiently transfected with pUb-HBcAg. Strong anti-HBc IgG responses were elicited in mice that were immunized with pUb-HBcAg. The endpoint titers of anti-HBc peaked at 1:656100 on the 42nd day after the third immunization. pUb-HBcAg stimulated greater lymphocyte proliferation and induced higher levels of IL-2 and IFN-γ and a greater percentage of HBcAg-specific CD8+ T cells in mice than pHBcAg. In the CTL assay, the specific lysis rate reached 56.5% at an effector:target ratio of 50:1 in mice that were immunized with pUb-HBcAg. CONCLUSIONS: pUb-HBcAg elicits specific anti-HBc responses and induces HBc-specific CTL responses in immunized BALB/c mice. Our results imply that Ub can be used as a molecular adjuvant that enhances the potency of DNA vaccines.