21 research outputs found
Fludarabine Modulates Immune Response and Extends In Vivo Survival of Adoptively Transferred CD8 T Cells in Patients with Metastatic Melanoma
Adoptive T cell therapy involving the use of ex vivo generated antigen-specific cytotoxic T lymphocytes provides a promising approach to immunotherapy. It has become increasingly apparent that anti-tumor efficacy using adoptively transferred T cells is linked to their duration of in vivo persistence and can only be achieved when combined with some form of pre-infusion patient conditioning regimen. An optimal conditioning regimen that provides a positive benefit without serious toxicities has yet to be defined. We have established a unique clinical model that allows for evaluation of a given conditioning regimen on adoptively transferred T cells in humans. In this first-in-human study (FHCRC #1796), we evaluate the use of fludarabine, an FDA-approved reagent with predictable lymphodepleting kinetics and duration of action, as a conditioning regimen that promotes homeostatic upregulation of cytokines and growth signals contributing to in vivo T cell persistence.We conducted a phase I study in patients with refractory metastatic melanoma. Patients received two infusions of a single tumor-reactive antigen-specific CTL clone expanded to 10(10)/m(2); the first infusion was given without fludarabine conditioning, and the second CTL infusion was given after a course of fludarabine (25 mg/m(2)/dayx5 days). This design permits intra-patient comparison of in vivo T cell persistence pre- and post-fludarabine. Nineteen CTL infusions were administered to ten patients. No serious toxicities were observed. Three of nine evaluable patients experienced minor response or stable disease for periods of 5.8-11.0 months with two additional patients demonstrating delayed disease stabilization. The median overall survival in this heavily pre-treated population was 9.7 months. Fludarabine led to a 2.9 fold improvement in the in vivo persistence of transferred CTL clones from a median of 4.5 days (range 0-38+) to 13.0 days (range 2-63+) (p<0.05). Fludarabine lymphodepletion increased plasma levels of the homeostatic cytokines IL-7 and IL-15. Surprisingly, fludarabine also increased the relative percentage of CD4+ T cells expressing the regulatory protein Foxp3.Lymphodepletion with fludarabine enhances transferred T cell persistence but suggest that additional improvements to optimize T cell survival and address regulatory T cells are critical in providing anti-tumor efficacy.ClinicalTrials.gov NCT00317759
Impaired Thymic Export and Apoptosis Contribute to Regulatory T-Cell Defects in Patients with Chronic Heart Failure
Animal studies suggest that regulatory T (T(reg)) cells play a beneficial role in ventricular remodeling and our previous data have demonstrated defects of T(reg) cells in patients with chronic heart failure (CHF). However, the mechanisms behind T(reg-)cell defects remained unknown. We here sought to elucidate the mechanism of T(reg-)cell defects in CHF patients.We performed flow cytometry analysis and demonstrated reduced numbers of peripheral blood CD4(+)CD25(+)FOXP3(+)CD45RO(-)CD45RA(+) naïve T(reg) (nT(reg)) cells and CD4(+)CD25(+)FOXP3(+)CD45RO(+)CD45RA(-) memory T(reg) (mT(reg)) cells in CHF patients as compared with non-CHF controls. Moreover, the nT(reg)/mT(reg) ratio (p<0.01), CD4(+)CD25(+)FOXP3(+)CD45RO(-) CD45RA(+)CD31(+) recent thymic emigrant T(reg) cell (RTE-T(reg)) frequency (p<0.01), and T-cell receptor excision circle levels in T(reg) cells (p<0.01) were lower in CHF patients than in non-CHF controls. Combined annexin-V and 7-AAD staining showed that peripheral T(reg) cells from CHF patients exhibited increased spontaneous apoptosis and were more prone to interleukin (IL)-2 deprivation- and CD95 ligand-mediated apoptosis than those from non-CHF individuals. Furthermore, analyses by both flow cytometry and real-time polymerase chain reaction showed that T(reg)-cell frequency in the mediastinal lymph nodes or Foxp3 expression in hearts of CHF patients was no higher than that of the non-CHF controls.Our data suggested that the T(reg)-cell defects of CHF patients were likely caused by decreased thymic output of nascent T(reg) cells and increased susceptibility to apoptosis in the periphery
Effective DNA/RNA Co-Extraction for Analysis of MicroRNAs, mRNAs, and Genomic DNA from Formalin-Fixed Paraffin-Embedded Specimens
Background: Retrospective studies of archived human specimens, with known clinical follow-up, are used to identify predictive and prognostic molecular markers of disease. Due to biochemical differences, however, formalin-fixed paraffinembedded (FFPE) DNA and RNA have generally been extracted separately from either different tissue sections or from the same section by dividing the digested tissue. The former limits accurate correlation whilst the latter is impractical when utilizing rare or limited archived specimens. Principal Findings: For effective recovery of genomic DNA and total RNA from a single FFPE specimen, without splitting the proteinase-K digested tissue solution, we optimized a co-extraction method by using TRIzol and purifying DNA from the lower aqueous and RNA from the upper organic phases. Using a series of seven different archived specimens, we evaluated the total amounts of genomic DNA and total RNA recovered by our TRIzol-based co-extraction method and compared our results with those from two commercial kits, the Qiagen AllPrep DNA/RNA FFPE kit, for co-extraction, and the Ambion RecoverAll TM Total Nucleic Acid Isolation kit, for separate extraction of FFPE-DNA and-RNA. Then, to accurately assess the quality of DNA and RNA co-extracted from a single FFPE specimen, we used qRT-PCR, gene expression profiling and methylation assays to analyze microRNAs, mRNAs, and genomic DNA recovered from matched fresh and FFPE MCF10A cells. These experiments show that the TRIzol-based co-extraction method provides larger amounts of FFPE-DNA and –RNA tha
A different immunologic profile characterizes patients with HER-2-overexpressing and HER-2-negative locally advanced breast cancer: implications for immune-based therapies
INTRODUCTION: The clinical efficacy of trastuzumab and taxanes is at least partly related to their ability to mediate or promote antitumor immune responses. On these grounds, a careful analysis of basal immune profile may be capital to dissect the heterogeneity of clinical responses to these drugs in patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy. METHODS: Blood samples were collected from 61 locally advanced breast cancers (36 HER2- and 25 HER2+) at diagnosis and from 23 healthy women. Immunophenotypic profiling of circulating and intratumor immune cells, including regulatory T (Treg) cells, was assessed by flow cytometry and immunohistochemistry, respectively. Serum levels of 10 different cytokines were assessed by multiplex immunoassays. CD8+ T cell responses to multiple tumor-associated antigens (TAA) were evaluated by IFN-γ-enzyme-linked immunosorbent spot (ELISPOT). The Student's t test for two tailed distributions and the Wilcoxon two-sample test were used for the statistical analysis of the data. RESULTS: The proportion of circulating immune effectors was similar in HER2+ patients and healthy donors, whereas higher percentages of natural killer and Treg cells and a lower CD4+/CD8+ T cell ratio (with a prevalence of naïve and central memory CD8+ T cells) were observed in HER2- cases. Higher numbers of circulating CD8+ T cells specific for several HLA-A*0201-restricted TAA-derived peptides were observed in HER2+ cases, together with a higher prevalence of intratumor CD8+ T cells. Serum cytokine profile of HER2+ patients was similar to that of controls, whereas HER2- cases showed significantly lower cytokine amounts compared to healthy women (IL-2, IL-8, IL-6) and HER2+ cases (IL-2, IL-1β, IL-8, IL-6, IL-10). CONCLUSIONS: Compared to HER2- cases, patients with HER2-overexpressing locally advanced breast cancer show a more limited tumor-related immune suppression. This may account for the clinical benefit achieved in this subset of patients with the use of drugs acting through, but also promoting, immune-mediated effects
Enhancement of Trigonopsis variabilis D-Amino Acid Oxidase Overproduction in Fed-batch Cultivation of Escherichia coli
D-Amino acid oxidase is a key enzyme in the production of semisynthetic cephalosporins. The Trigonopsis variabilis D-amino acid oxidase with 12- amino-acid peptide at N-terminus was expressed in Escherichia coli BL21(DE3), in a series of short fed-batch cultivations. The strategy of gradual induction and gradual feeding with D-methionine during expression resulted in active enzyme production twice as high as that in which the inducer and methionine were added all at once at the expression start. In optimal conditions during 14 h of aerobic cultivation, 350 mg L–1 of active enzyme was produced
Uptake of iron by yeast cells and its impact on biomass production
Procedures for the production of Saccharomyces cerevisiae biomass enriched with iron and the effects of the iron ions addition into the molasses medium on the yeast growth and the production of ethanol were studied. The growth of the yeast S. cerevisiae and the ethanol production in media with different concentrations of Fe were monitored in the batch process under semiaerobic and anaerobic conditions. The highest biomass concentration and ethanol production were achieved in the medium with 0.6-0.8 g l-1 of Fe under both (semiaerobic and anaerobic) conditions. Kinetics of the iron ions accumulation in yeast cells during 24 h of growth in the batch process under semiaerobic and anaerobic conditions were monitored. In anaerobic conditions the maximum uptake (10 mg g-1 d.m. yeast biomass) was obtained after 12 h of fermentation, while in semiaerobic conditions a four times lower uptake (2.5 mg g-1 d.m. yeast biomass) was obtained after 16 h of fermentation
Effect of treatment by non-thermal plasma jet on the growth of various food spoilage bacteria in superfluous
The efficiency of gas phase plasma at atmospheric pressure by using an electrical discharge in gas argon on the inactivation of microorganisms was examined. The gas phase plasma was applied to suspensions of pure cultures Escherichia coli 3014, Staphylococcus aureus 3048, Salmonella sp. 3064, Listeria monocytogenes ATCC 23074 and Bacillus cereus 30. The experiments were planned and performed according to a statistical experimental design, specifically central composite design, which considered three independent variables: volume (2, 3 and 4 mL), gas flow (0.75, 1 and 1.25 L/min) and treatment time (3, 4 and 5 min). Two studied parameters, volume and treatment time, substantially affected the inactivation. For plasma treatment, the inactivation can be attributed to UV radiation and plasma reactive oxygen species (ROS). It was found that Gram-negative bacteria were more susceptible to the plasma treatment than Gram-positive bacteria, and that the susceptibility of Gram-positive bacteria was remarkably species-dependent. Complete inactivation of Escherichia coli, Salmonella sp., and Listeria monocytogenes was achieved when optimal combination of parameters was applied