Stem cell transplantation has been shown to improve functional outcome in degenerative and ischemic disorders. However, low in vivo survival and differentiation potential of the transplanted cells limits their overall effectiveness and thus clinical usage. Here we show that, after in vitro induction of neuronal differentiation and dedifferentiation, on withdrawal of extrinsic factors, mesenchymal stem cells (MSCs) derived from bone marrow, which have already committed to neuronal lineage, revert to a primitive cell population (dedifferentiated MSCs) retaining stem cell characteristics but exhibiting a reprogrammed phenotype distinct from their original counterparts. Of therapeutic interest, the dedifferentiated MSCs exhibited enhanced cell survival and higher efficacy in neuronal differentiation compared to unmanipulated MSCs both in vitro and in vivo, with significantly improved cognition function in a neonatal hypoxic-ischemic brain damage rat model. Increased expression of bcl-2 family proteins and micro-RNA-34a appears to be the important mechanism giving rise to this previously undefined stem cell population that may provide a novel treatment strategy with improved therapeutic efficacy.

These observations emphasize and extend the potential of the human HSP70 gene as adjuvant for DNA vaccines, and the vaccine based on PSCA and HSP70 is of potential value for treating prostate cancer.

Epidemic methicillin-resistant Staphylococcus aureus (MRSA) imposes an increasing impact on public health. Due to multi-antibiotics resistance in MRSA strains, there is an urgent need to develop novel therapeutics such as effective monoclonal antibodies (mAbs) against MRSA infections. Staphylococcus aureus surface protein A (SasA), a large surface-located protein (~240 kDa), is one of MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) and a potential target for immunotherapeutic approaches against S. aureus infections. In the present study, we analyzed the sequence of SasA with bioinformatics tools and generated a protective monoclonal antibody (2H7) targeting the conserved domain of SasA. 2H7 was shown to recognize wild-type S. aureus and promote opsonophagocytic killing of S. aureus. In both sepsis and peritoneal infection models, prophylactic administration of 2H7 improved the survival of BALB/c mice challenged by S. aureus strain USA300 and ST239 (prevalent MRSA clones in North America and Asian countries, respectively) and enhanced bacterial clearance in kidneys. Additionally, 2H7 prophylaxis prevented the formation of intraperitoneal abscess in a murine model of peritoneal infection and therapeutic administration of 2H7 showed protective efficacy in a murine sepsis model. Our results presented here provide supporting evidences that an anti-SasA mAb might be a potential component in an antibody-based immunotherapeutic treatment of MRSA infections.

BackgroundEbola viruses (EBOVs) cause severe hemorrhagic fever with a high mortality rate. At present, there are no licensed vaccines or efficient therapies to combat EBOV infection. Previous studies have shown that both humoral and cellular immune responses are crucial for controlling Ebola infection. CD8+ T cells play an important role in mediating vaccine-induced protective immunity. The objective of this study was to identify H-2d-specific T cell epitopes in EBOV glycoproteins (GPs).ResultsComputer-assisted algorithms were used to predict H-2d-specific T cell epitopes in two species of EBOV (Sudan and Zaire) GP. The predicted peptides were synthesized and identified in BALB/c mice immunized with replication-deficient adenovirus vectors expressing the EBOV GP. Enzyme-linked immunospot assays and intracellular cytokine staining showed that the peptides RPHTPQFLF (Sudan EBOV), GPCAGDFAF and LYDRLASTV (Zaire EBOV) could stimulate splenoctyes in immunized mice to produce large amounts of interferon-gamma.ConclusionThree peptides within the GPs of two EBOV strains were identified as T cell epitopes. The identification of these epitopes should facilitate the evaluation of vaccines based on the Ebola virus glycoprotein in a BALB/c mouse model.

Chronic hepatitis B virus (HBV) infection is an independent risk factor for the development of hepatocellular carcinoma (HCC). The HBV HBx gene is frequently identified as an integrant in the chromosomal DNA of patients with HCC. HBx encodes the X protein (HBx), a putative viral oncoprotein that affects transcriptional regulation of several cellular genes. Therefore, HBx may be an ideal target to impede the progression of HBV infection-related HCC. In this study, integrated HBx was transcriptionally downregulated using an artificial transcription factor (ATF). Two three-fingered Cys2-His2 zinc finger (ZF) motifs that specifically recognized two 9-bp DNA sequences regulating HBx expression were identified from a phage-display library. The ZF domains were linked into a six-fingered protein that specified an 18-bp DNA target in the Enhancer I region upstream of HBx. This DNA-binding domain was fused with a Krüppel-associated box (KRAB) transcriptional repression domain to produce an ATF designed to downregulate HBx integrated into the Hep3B HCC cell line. The ATF significantly repressed HBx in a luciferase reporter assay. Stably expressing the ATF in Hep3B cells resulted in significant growth arrest, whereas stably expressing the ATF in an HCC cell line lacking integrated HBx (HepG2) had virtually no effect. The targeted downregulation of integrated HBx is a promising novel approach to inhibiting the progression of HBV infection-related HCC.

Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 10 8 infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD 50 ) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax.

The pandemic 2009 H1N1 influenza virus broke out in North America and spread rapidly throughout the world. The type I interferon (IFN) response represents one of the first lines of defense against influenza virus infections. In this study, the protective potential of human exogenous IFN-ω against pandemic 2009 A (H1N1) influenza virus was assessed both in vitro and in guinea pigs. The viral loads of pandemic 2009 A (H1N1) influenza virus strains A/California/04/2009 and A/Beijing/501/2009 were reduced by up to 5000-fold in Caco-2 cells by the addition of human IFN-ω. With daily intranasal treatment with human IFN-ω the viral load of pandemic 2009 A (H1N1) influenza virus strain A/California/04/2009 decreased by 1000-fold in lung tissues of guinea pigs. These results provide strong support for the application of human IFN-ω pretreatment to human influenza control.

To optimize Chinese hamster ovary (CHO) cell culture to recombinant protein therapeutic production, we stably overexpressed survivin and cyclin D1 in three CHO DG44-derived cell lines. The modifications conferred increases of 56-94% in S-phase fractions and decreases of 33-43% in early-stage apoptosis fractions. Clone 6.3, which expressed the highest levels of survivin and cyclin D1, reached significantly greater cell densities in suspension (2.7 × 10(6) cells/ml) following serum deprivation. Nude mice inoculated with the modified cells showed no tumorigenesis suggesting that the CHO DG44-derived cell lines are viable candidates for biopharmaceutical production.