Safety and immunogenicity of tyrosinase DNA vaccines in patients with melanoma

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Background: T-cell and antibody responses to self antigens on cancer are usually constrained by immunologic tolerance and ignorance. We found that DNA vaccines encoding xenogeneic differentiation antigens, such as tyrosinase (TYR), can mediate tumor protection and regression in implantable mouse models and dogs with spontaneously arising melanoma. Based on this, we conducted a trial of DNA vaccines encoding mouse and human TYR in patients with AJCC stage III/IV melanoma. Methods: HLA-A*0201+ melanoma patients were randomized to 2 different schedules: one group received 3 injections of mouse TYR DNA followed by 3 injections of human TYR DNA while the other group received 3 injections of human TYR DNA followed by 3 injections with the mouse gene. The study was conducted a three different dose levels: 100, 500 and 1,500 mcg DNA/injection, administered IM every 3 weeks. A total of 18 patients were treated, 6 at each dose level being randomized to one of the two schedules. Anti-TYR antibodies and CD8+ T cells recognizing the native human tyrosinase369-377 (YMDGTMSQV) peptide were measured at fixed time points. T-cell responses were monitored with MHC tetramer and intracytoplasmic IFN-γ staining assays using 10-day in vitro stimulation. Multiparametric flow cytometry was performed to further define the phenotype of responding cells. Results: Most toxicities were transient grade I injection site reactions. Seven patients had CD8+ T cell responses, defined as a >3 standard deviation increase in baseline reactivity to the TYR peptide in either the tetramer or intracellular IFN-γ assay. There was no relationship between dose level or assigned schedule and occurrence of T-cell response. Phenotypic characterization of responding T cells showed that most were consistent with an effector memory phenotype including the expression of granzyme B and surface expression of CD107a. No antibody responses were observed. At a median of 42 months of follow-up, median survival has not been reached and 6/18 patients have died from melanoma (1 in the group of patients who had a T cell response and 5 in the non-responders). Conclusions: Mouse and human TYR DNA vaccines were safe and induced CD8+ T cell responses in 7/18 patients. T cells recognizing a native TYR peptide had a phenotype consistent with that of effector memory cells.

No significant financial relationships to disclose.

Expression analysis of genes putatively involved in chicken gonadal development

In mammals, testis development is initiated by the expression of the sex-determining gene, SRY whereas the genetic trigger for sex determination in birds remains unknown. In the present study, the expression of seven genes implicated in vertebrate sex determination and differentiation were studied in chicken embryonic gonads from day 4 to day 12 of incubation using reverse transcription and the polymerase chain reaction (RT-PCR). Results showed transcription of cLhx9, cGATA4, cVnnl, cPptl, cBrd3 were sexually dimorphic during chicken gonadal development, whereas cEki2, cFog2 were expressed at similar levels in both sexes. Results of comparative studies between mammals and chickens show that vertebrate sex-determining pathways comprise both conserved and divergent elements: expression profiles of cGATA4/cFog2 and cVnnl are similar to those in mammals, while others appear some differences. Possible functions of these genes on chicken gonadal development were analyzed based on their expression profiles.

Notch1 induces cell cycle arrest and apoptosis in human cervical cancer cells: involvement of nuclear factor kappa B inhibition

Notch signaling can serve as a tumor suppressor or tumor promoter in the same kind of cancer, such as human papillomavirus-positive cervical cancer cells. However, the exact mechanisms remain poorly characterized. Our studies demonstrated that constitutively overexpressed active Notch1 via stable transfection with exogenous intracellular domain of Notch1 (ICN) resulted in growth inhibition of the human cervical cancer cell line HeLa by inducing G(2)-M arrest and apoptosis. Moreover, the growth inhibition was correlated with inhibition of nuclear factor kappa B (NF-kappaB) p50 activation, accompanied by a decrease in the nuclear expression of NF-kappaB p50 and an increase in the cytosolic expression of IkappaBalpha. Consistent with these results, downregulation of cyclin D1 and Bcl-2, which are both the downstream genes of NF-kappaB, were observed in ICN-overexpressed cells. Overall, our results suggest that NF-kappaB inhibition may contribute partially to cell cycle arrest and apoptosis induced by Notch1 activation in human cervical cancer cells.

Quantifying the contribution of cross-correlation in stimulus feature discrimination in an ensemble of retinal ganglion cells

Based on Poisson variability, the strength of cross-correlation of two spike trains was quantified by a cross-correlation index (CCI). Discriminant analysis with CCI was used to quantify the contribution of cross-correlation in stimulus feature discrimination in an ensemble of retinal ganglion cells. Compared with simulated Poisson cell pair, it was found that cross-correlation carried useful information for stimulus feature discrimination and with the cross-correlation included in the analysis, the color and the intensity discrimination ability of a cell pair increase 4.2% and 2.7%, respectively.

Low-temperature in situ large strain plasticity of ceramic SiC nanowires and its atomic-scale mechanism

Large strain plasticity is phenomenologically defined as the ability of a material to exhibit an exceptionally large deformation rate during mechanical deformation. It is a property that is well established for metals and alloys but is rarely observed for ceramic materials especially at low temperature ( approximately 300 K). With the reduction in dimensionality, however, unusual mechanical properties are shown by ceramic nanomaterials. In this Letter, we demonstrated unusually large strain plasticity of ceramic SiC nanowires (NWs) at temperatures close to room temperature that was directly observed in situ by a novel high-resolution transmission electron microscopy technique. The continuous plasticity of the SiC NWs is accompanied by a process of increased dislocation density at an early stage, followed by an obvious lattice distortion, and finally reaches an entire structure amorphization at the most strained region of the NW. These unusual phenomena for the SiC NWs are fundamentally important for understanding the nanoscale fracture and strain-induced band structure variation for high-temperature semiconductors. Our result may also provide useful information for further studying of nanoscale elastic-plastic and brittle-ductile transitions of ceramic materials with superplasticity.

Enhanced T-cell immunity induced by dendritic cells with phagocytosis of heat shock protein 70 gene-transfected tumor cells in early phase of apoptosis

The dual role of heat shock protein 70 (HSP70), as antigenic peptide chaperone and danger signal, makes it especially important in dendritic cell (DC)-based vaccination. In this study, we investigated the impacts of apoptotic transgenic MCA/HSP tumor cells expressing HSP70 on DC maturation, T-cell stimulation and vaccine efficacy. We found that DCs with phagocytosis of MCA/HSP in early phase of apoptosis expressed more pMHC I complexes, stimulated stronger cytotoxic T lymphocyte (CTL) responses (40% specific killing at an E:T cell ratio of 50) and induced immune protection in 90% of mice against MCA tumor cell challenge, compared with 25% specific CTL killing activity and 60% immune protection seen in mice immunized with DC with phagocytosis of MCA/HSP in late phase of apoptosis (P<0.05). Similar results were confirmed in another EG7 tumor model also expressing HSP70. Taken together, our data demonstrate that HSP70 on apoptotic tumor cells stimulate DC maturation, and DC with phagocytosis of apoptotic tumor cells expressing HSP70 in early phase of apoptosis more efficiently induced tumor-specific CTL responses and immunity than DCs with phagocytosis of apoptotic tumor cells in late phase of apoptosis. These results may have an important impact in designing DC-based antitumor vaccines.

RTD (residence time distribution) predictions in large mechanically aerated lagoons

Mechanically aerated lagoons (used for wastewater treatment in the pulp and paper industry) are typically very large (>500,000 m3) and have complex three-dimensional fluid flow patterns due to mechanical agitation, sludge accumulation, internal baffling, and confined inlet/outlet flow channels. RTD data is frequently used for evaluation of hydraulic performance, however, obtaining accurate data with traditional dye measurements is a difficult and time-consuming process. Moreover, the mixing impact of factors such as aerator positions, sludge accumulation, and internal baffles would require a significant and costly number of local field measurements. Recent applications of CFD to mechanically aerated lagoons have helped engineers to understand the complex flow interactions. This paper provides a practical method for the evaluation of the hydraulic performance of large mechanically aerated lagoons using CFD. A method, based on random-walk Lagrangian particle tracking, has been developed to significantly shorten the computational time needed to produce RTD curves for these lagoons. Comparison of the particle method with the more conventional scalar transport yields excellent results. These methods allow wastewater engineers to combine their existing knowledge and expertise with the established power of CFD. The results quantify the hydraulic impact of different inlet/outlet configurations, aerator configurations, influent flow rates, and bottom sludge profiles.

In vitro expansion of Ag-specific T cells by HLA-A*0201-transfected K562 cells for immune monitoring

BACKGROUND

Development of a practical and sensitive assay for evaluating immune responses against cancer Ag has been a challenge for immune monitoring of patients. We have established a reproducible method using peptide-pulsed K562-A*0201 cells as APC to expand Ag-specific T cells in vitro. This method may be applied for monitoring T-cell responses in cancer immunotherapy clinical trials.

METHODS

Autologous PBMC from HLA-A*0201+ healthy donors and patients with melanoma were stimulated with peptide-pulsed K562-A*0201 cells under varying conditions. We investigated (1) different culture conditions, including the requirements for serum and cytokines for expansion of CD8+ T lymphocytes; (2) a range of peptide concentrations for Ag loading; (3) phenotypic characterization of responding T cells; and (4) APC:responder ratios and their effects on T-cell expansion. We validated these conditions by ELISPOT and intracellular cytokine staining (ICS) assays using peptides from influenza, Epslein-Barr Virus (EBV) and tyrosinase.

RESULTS

Conditions for optimal T-cell expansion using K562-A*0201 APC included input of 2 x 10(6) PBMC, a 10 microg/mL peptide concentration to pulse K562-A*0201 cells, a 1:30 APC:responder T-cell ratio and culture in 10% autologous plasma supplemented with IL-2 and IL-15. In these conditions, Ag-specific T cells expanded >100-fold over a 10-day culture period (peak at day 12).

DISCUSSION

This bulk culture method is simple and reliable for expanding human Ag-specific T cells using peptide-pulsed K562-A*0201 cells. This HLA-matched APC line can be adapted to other HLA haplotypes, and has advantages for monitoring clinical trials of immunotherapy with limited availability of autologous APC and PBMC from patients.

Relationships between sediment microbial communities and pollutants in two California salt marshes

Salt marshes are important ecosystems whose plant and microbial communities can alter terrestrially derived pollutants prior to coastal water discharge. However, knowledge regarding relationships between anthropogenic pollutant levels and salt marsh microbial communities is limited, and salt marshes on the West Coast of the United States are rarely examined. In this study, we investigated the relationships between microbial community composition and 24 pollutants (20 metals and 4 organics) in two California salt marshes. Multivariate ordination techniques were used to assess how bacterial community composition, as determined by terminal restriction fragment length polymorphism and phospholipid fatty acid analyses, was related to pollution. Sea urchin embryo toxicity measurements and plant tissue metabolite profiles were considered two other biometrics of pollution. Spatial effects were strongly manifested across marshes and across channel elevations within marshes. Utilizing partial canonical correspondence analysis, an ordination technique new to microbial ecology, we found that several metals were strongly associated with microbial community composition after accounting for spatial effects. The major patterns in plant metabolite profiles were consistent with patterns across microbial community profiles, but sea urchin embryo assays, which are commonly used to evaluate ecological toxicity, had no identifiable relationships with pollution. Whereas salt marshes are generally dynamic and complex habitats, microbial communities in these marshes appear to be relatively sensitive indicators of toxic pollutants.

Antepartum immunoprophylaxis of three doses of hepatitis B immunoglobulin is not effective: a single-centre randomized study

To investigate the efficacy of antepartum administration of three doses of hepatitis B immunoglobulin (HBIg), currently being used in China, 250 pregnant women who were seropositive for hepatitis B e antigen (HBeAg) were randomly divided into study (117 cases) and control groups (133 cases). Subjects in the study group received HBIg 400 IU intramuscularly once a month at the third, second and first month before delivery; subjects in the control group received no antepartum treatment. All neonates received passive-active immunization after birth. The maternal hepatitis B virus (HBV) markers, hepatitis B surface antigen (HBsAg) titres and HBV deoxyribonucleic acid (DNA) levels were measured at week 28 of gestation (before the antepartum treatment) and at labour; the neonatal serum HBV markers were detected at birth and at 12 months after birth. No side-effects were found in any of the women or their neonates. No statistical differences were seen between the maternal HBsAg and HBV DNA levels of the study and control groups at labour nor the protective efficacy rates of postnatal immunoprophylaxis at 12 months after birth (P > 0.05, respectively). To conclude, antepartum administration of three doses of HBIg for the HBeAg-positive women is inefficacious.

Histopathological characteristics of a novel knock-in mouse prostate cancer model

Prostate cancer is relatively unique to man. There is no naturally occurring prostate cancer in the mouse. Pre-clinical studies involve the establishment of a genetically engineered mouse prostate cancer model with features close to those of the human situation. A new knock-in mouse adenocarcinoma prostate (KIMAP) model was established, which showed close-to-human kinetics of tumor development. In order to determine if the similar kinetics is associated with heterogeneous tumor architecture similar to the human situation, we utilized a new mouse histological grading system (Gleason analogous grading system) similar to the Gleason human grading system and flow cytometry DNA analysis to measure and compare the adenocarcinoma of the KIMAP model with human prostate cancer. Sixty KIMAP prostate cancer samples from 60 mice were measured and compared with human prostate cancer. Flow cytometry DNA analysis was performed on malignant prostate tissues obtained from KIMAP models. Mice with prostate cancer from KIMAP models showed a 53.3% compound histological score rate, which was close to the human clinical average (50%) and showed a significant correlation with age (P = 0.001). Flow cytometry analyses demonstrated that most KIMAP tumor tissues were diploid, analogous to the human situation. The similarities of the KIMAP mouse model with tumors of the human prostate suggest the use of this experimental model to complement studies of human prostate cancer.

Stable gene silencing of cyclin B1 in tumor cells increases susceptibility to taxol and leads to growth arrest in vivo

Cyclin B1 is the regulatory subunit of cyclin-dependent kinase 1 (Cdk1) and is critical for the initiation of mitosis. Accumulating data indicate that the deregulation of cyclin B1 is tightly linked to neoplastic transformation. To study the phenotype and the potential preclinical relevance, we generated HeLa cell lines stably transfected with the plasmids encompassing short hairpin RNA (shRNA) targeting cyclin B1. We demonstrate that the reduction of cyclin B1 caused inhibition of proliferation by arresting cells in G2 phase and by inducing apoptosis. Cells, entering mitosis, were impaired in chromosome condensation and alignment. Importantly, HeLa cells with reduced cyclin B1 were more susceptible to the treatment of small interfering RNA targeting Polo-like kinase 1 (Plk1) and to the administration of the chemotherapeutic agent taxol. Finally, HeLa cells with reduced cyclin B1 showed inhibited tumor growth in nude mice compared to that of control cells. In summary, our data indicate that cyclin B1 is an essential molecule for tumor cell survival and aggressive proliferation, suggesting that the downregulation of cyclin B1, especially in combination with other molecular targets, might become an interesting strategy for antitumor intervention.

Cellular response to endoplasmic reticulum stress: a matter of life or death

The proper functioning of the endoplasmic reticulum (ER) is critical for numerous aspects of cell physiology. Accordingly, all eukaryotes react rapidly to ER dysfunction through a set of adaptive pathways known collectively as the ER stress response (ESR). Normally, this suite of responses succeeds in restoring ER homeostasis. However, in metazoans, persistent or intense ER stress can also trigger programmed cell death, or apoptosis. ER stress and the apoptotic program coupled to it have been implicated in many important pathologies but the regulation and execution of ER stress-induced apoptosis in mammals remain incompletely understood. Here, we review what is known about the ESR in both yeast and mammals, and highlight recent findings on the mechanism and pathophysiological importance of ER stress-induced apoptosis.

Efficient production of laccases by Trametes sp. AH28-2 in cocultivation with a Trichoderma strain

A biocontrol fungus isolated from rotting wood was identified as a Trichoderma strain (named as Trichoderma sp. ZH1) by internal transcribed spacer (ITS) sequences of rRNA genes. The laccase yield of Trametes sp. AH28-2 in cocultivation with Trichoderma sp. ZH1 reached 6,210 U l(-1), approximately identical to those induced by toxic aromatic inducers. Cocultures maintained 60-70 % of their highest laccase activity obtained at 5 days after inoculation of the biocontrol fungus, at least for 20 days. Furthermore, a novel laccase isozyme (LacC) was obtained through the fungal interactions. The molecular weight of LacC is about 64 kDa, and its isoelectric point is 6.6. The temperature and pH optimum for LacC to oxidize guaiacol are 55 degrees C and 5.0, respectively. LacC is stable both at 60 degrees C and pH 4.0-8.0. Furthermore, the K (m) values of LacC for various substrates were also determined. Our work demonstrates a safe strategy for the production of industrial laccases, instead of the traditional method of chemical induction.

Cytogenetic mapping of 11 functional genes to chicken chromosomes by fluorescence in situ hybridization

With chicken bacterial artificial chromosome (BAC) DNA as probes, 11 non-assigned functional genes were localized to chicken chromosomes 1 or 2 by fluorescence in situ hybridization (FISH). The 11 genes and their chromosomal positions are as follows: ALVEB5, 1p26-24; ACO2, 1p16-14; HSP108, 1p14-13; CD4, 1q11; HSD3B; 1q11; SOD1, 1q14-21; LAMP1, 1q24-31; P2Y5, 1q35-36; EN2, 2p31-24; NPY, 2p14-13 and CA2, 2q31-32. Metaphase chromosome spreads used for hybridization were prepared from embryonic chicken fibroblast cultures. The gene position was identified according to the international standardized G-banded karyotype of chicken by measuring the relative fractional length from the telomere of the p-arm to the hybridization signal (FLpter). The 11 genes mapped newly will enrich the cytogenetic map and serve as additional anchor markers for integrating the cytogenetic map with the genetic map of chicken.

Gain of 1q25–32, 12q23–24.3, and 17q12–22 facilitates tumorigenesis and progression of human squamous cell lung cancer

To explore the genetic changes involved in the stepwise development of lung cancer, we have determined the genetic events associated with the histological progression from normal bronchial epithelium to squamous cell carcinoma. Comparative genomic hybridization was used to identify chromosomal imbalances in 54 microdissected samples, including squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumour derived from 23 patients with squamous cell carcinoma of the lung. Histopathological progression was accompanied by an increased number of chromosomal abnormalities. Gains of 1q25-32, 12q23-24.3, and 17q12-22, in particular, were detected at high frequencies in both carcinoma in situ and invasive tumours and were found more often in the cases with lymph node metastases than in those without. Our previous expression profiling of squamous cell carcinomas had identified overexpression of laminin5 gamma2, a gene located at 1q25-31. Therefore, this was investigated at the protein level by immunohistochemical analysis in 336 samples of squamous cell carcinoma of the lung. Consistent with the genomic data for this region, the expression level of laminin5 gamma2 was higher in the primary tumours with lymph node metastases than in tumours without metastases (p = 0.012). These data suggest that gains of genes from 1q25-32, 12q23-24.3, and 17q12-22 facilitate tumorigenesis and progression of squamous cell carcinoma of the lung, and may serve as potential predictors for this disease.