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1.
Akon Higuchi Makoto Yoshida Takeshi Ohno Tetsuo Asakura Mariko Hara 《Cytotechnology》2000,34(1-2):165-173
Normal human skin (NB1-RGB) cells were cultured in the presenceof polyinosinic and polycytidylic acids, diethylaminoethyldextran, cycloheximide and actinomycin D, which induced humaninterferon-. The simplest induction method, that requiredonly polyinosinic and polycytidylic acids and diethylaminoethyldextran was found to give the highest production ofinterferon- by the cells. The cell growth and productionof interferon- were investigated for NB1-RGB cellscultured on silk fibroin, poly(-methyl-L-glutamate),poly(-benzyl-L-glutamate) and collagen films prepared bythe Langmuir-Blodgett (LB) and casting methods. The cell densityof NB1-RGB cells cultured on the LB films was found to be higherthan that on the cast films made of the same polymer. Thisindicates that not only the chemical structure of the polymersused for the preparation of the films but the preparationmethods of the films, i.e., casting and LB methods, are also astrong factor affecting the cell growth. The production ofinterferon- per unit number of cells was found to behigher on the cast films than that on the LB films made of thesame polymer. This is explained by the fact that the optimalsuppressed growth of NB1-RGB cells on the cast films leads tothe enhanced production of interferon- on the cast filmscompared to those on the LB films prepared by the same polymer. 相似文献
2.
Response of cells on surface-induced nanopatterns: fibroblasts and mesenchymal progenitor cells 总被引:1,自引:0,他引:1
Khor HL Kuan Y Kukula H Tamada K Knoll W Moeller M Hutmacher DW 《Biomacromolecules》2007,8(5):1530-1540
Ultrathin films of a poly(styrene)-block-poly(2-vinylpyrindine) diblock copolymer (PS-b-P2VP) and poly(styrene)-block-poly(4-vinylpyrindine) diblock copolymer (PS-b-P4VP) were used to form surface-induced nanopattern (SINPAT) on mica. Surface interaction controlled microphase separation led to the formation of chemically heterogeneous surface nanopatterns on dry ultrathin films. Two distinct nanopatterned surfaces, namely, wormlike and dotlike patterns, were used to investigate the influence of topography in the nanometer range on cell adhesion, proliferation, and migration. Atomic force microscopy was used to confirm that SINPAT was stable under cell culture conditions. Fibroblasts and mesenchymal progenitor cells were cultured on the nanopatterned surfaces. Phase contrast and confocal laser microscopy showed that fibroblasts and mesenchymal progenitor cells preferred the densely spaced wormlike patterns. Atomic force microscopy showed that the cells remodelled the extracellular matrix differently as they migrate over the two distinctly different nanopatterns. 相似文献
3.
Synthesis and characterization of RGD peptide grafted poly(ethylene glycol)-b-poly(L-lactide)-b-poly(L-glutamic acid) triblock copolymer 总被引:2,自引:0,他引:2
Advances in tissue engineering require biofunctional scaffolds that can provide not only physical support for cells but also chemical and biological cues needed in forming functional tissues. To achieve this goal, a novel RGD peptide grafted poly(ethylene glycol)-b-poly(L-lactide)-b-poly(L-glutamic acid) (PEG-PLA-PGL/RGD) was synthesized in four steps (1) to prepare diblock copolymer PEG-PLA-OH and to convert its -OH end group into -NH(2) (to obtain PEG-PLA-NH(2)), (2) to prepare triblock copolymer PEG-PLA-PBGL by ring-opening polymerization of NCA (N-carboxyanhydride) derived from benzyl glutamate with diblock copolymer PEG-PLA-NH(2) as macroinitiator, (3) to remove the protective benzyl groups by catalytic hydrogenation of PEG-PLA-PBGL to obtain PEG-PLA-PGL, and (4) to react RGD (arginine-glycine-(aspartic amide)) with the carboxyl groups of the PEG-PLA-PGL. The structures of PEG-PLA-PGL/RGD and its precursors were confirmed by (1)H NMR, FT-IR, amino acid analysis, and XPS analysis. Addition of 5 wt % PEG-PLA-PGL/RGD into a PLGA matrix significantly improved the surface wettability of the blend films and the adhesion and proliferation behavior of human chondrocytes and 3T3 cells on the blend films. Therefore, the novel RGD-grafted triblock copolymer is expected to find application in cell or tissue engineering. 相似文献
4.
Vascular smooth muscle cells on polyelectrolyte multilayers: hydrophobicity-directed adhesion and growth 总被引:1,自引:0,他引:1
Polyelectrolyte multilayer films were employed to support attachment of cultured rat aortic smooth muscle A7r5 cells. Like smooth muscle cells in vivo, cultured A7r5 cells are capable of converting between a nonmotile "contractile" phenotype and a motile "synthetic" phenotype. Polyelectrolyte films were designed to examine the effect of surface charge and hydrophobicity on cell adhesion, morphology, and motility. The hydrophobic nature and surface charge of different polyelectrolyte films significantly affected A7r5 cell attachment and spreading. In general, hydrophobic polyelectrolyte film surfaces, regardless of formal charge, were found to be more cytophilic than hydrophilic surfaces. On the most hydrophobic surfaces, the A7r5 cells adhered, spread, and exhibited little indication of motility, whereas on the most hydrophilic surfaces, the cells adhered poorly if at all and when present on the surface displayed characteristics of being highly motile. The two surfaces that minimized cell adhesion consisted of two varieties of a diblock copolymer containing hydrophilic poly(ethylene oxide) and a copolymer bearing a zwitterionic group AEDAPS, (3-[2-(acrylamido)-ethyldimethyl ammonio] propane sulfonate). Increasing the proportion of AEDAPS in the copolymer decreased the adhesion of cells to the surface. Cells presented with micropatterns of cytophilic and cytophobic surfaces generated by polymer-on-polymer stamping displayed a surface-dependent cytoskeletal organization and a dramatic preference for adhesion to, and spreading on, the cytophilic surface, demonstrating the utility of polyelectrolyte films in manipulating smooth muscle cell adhesion and behavior. 相似文献
5.
Paul B. Hatzinger James L. Stevens 《In vitro cellular & developmental biology. Plant》1989,25(2):205-212
Summary A culture system is described in which rat kidney proximal tubule epithelial cells (RPTE) can be prepared with good yield
and high viability and grown in culture under serum-free conditions. The cells require EGF, insulin, cholera toxin and either
1% dialyzed serum or a complex of bovine serum albumin with oleic acid (BSA/OA). The cells can be maintained for long periods
of time and express several markers for RPTE. The cells have both alkaline phosphatase and γ-glutamyltransferase activity
and respond to parathyroid hormone but not vasopressin. The specific activity of γ-glutamyltransferase decreases when the
cells begin to grow, but increases when they reach confluence. Extracellular calcium plays a role in the induction of γ-glutamyltransferase
in confluent cells. Cells grown in media containing low calcium, i.e. less than 0.4 mM, have reduced specific activity of
γ-glutamyltransferase. Extracellular calcium also alters the morphology of the cells in that cells grown in low calcium are
single cells or loose clusters suggesting poor cell-cell contact. When the calcium is raised to 1.0 mM, the cells change their
shape and organization to adopt the morphology of cells maintained continuously in 1.0 mM calcium. The cells can be passaged
onto plastic surfaces which have been coated with collagen but cannot be subcultured on uncoated or serum coated plastic.
This culture system will be a useful model for the investigation of renal carcinogenesis and the role of cell proliferation
in that process.
This work was supported by grants CA48197 and DK38925 from the National Institutes of Health
Editor's Statement This paper reports a method for isolation and, uniquely, multipassage culture of rat proximal tubule epithelial
cells. The authors use this culture system to explore some aspects of the physiology of these cells, demonstrating the value
of the model. 相似文献
6.
A novel synthetic method for poly(L-lactide) (PLLA)-based diblock copolymers was developed by the use of PLLA extended chain crystallites (or crystalline residues) as a solid-state macro-coinitiator. In this study, we showed one example, i.e., a synthesis of diblock copolymer composed of a crystalline PLLA chain and an amorphous poly(DL-lactide) chain by ring-opening polymerization of DL-lactide initiated with stannous octoate (i.e., tin(II) 2-ethylhexanoate) in the presence of PLLA extended chain crystallites. The PLLA extended chain crystallites were prepared by hydrolytic degradation of crystallized PLLA films at 97 degrees C for 70 h. The chains inside the extended chain crystallites are expected to be protected from transesterfication reaction. Gel permeation chromatography, polarimetry, 1H NMR spectroscopy, wide-angle X-ray scattering, and differential scanning calorimetry revealed that the diblock copolymer poly(L-lactide-block-DL-lactide) was successfully prepared without significant transesterification. 相似文献
7.
Sho Kobayashi Yoshitaka Ikeda Yuhei Shigeno Hiroyuki Konno Junichi Fujii 《Amino acids》2020,52(4):555-566
Some γ-glutamylpeptides in blood plasma are putative biomarkers for pathological conditions of the liver. γ-Glutamyltransferase (GGT) and γ-glutamylcysteine synthetase (γ-GCS) are two such potential enzymes that are responsible for the production of γ-glutamylpeptides. GGT produces γ-glutamylpeptides by transferring the γ-glutamyl moiety from glutathione to an amino acid or a peptide. γ-GCS normally catalyzes the production of γ-glutamylcysteine from glutamate and cysteine in the glutathione-synthesizing reaction, but other amino acids can also serve as an acceptor of a γ-glutamyl group, thus resulting in the formation of a variety of γ-glutamylpeptides. Based on liquid chromatography–mass spectrometry analyses, we observed differences in the distribution of γ-glutamylpeptides between the liver and kidney and were able to measure the activities of γ-GCS as well as the GGT reactions by quantifying the resulting γ-glutamylpeptides. The enzymatic characterization of γ-GCS in liver homogenates indicated that several γ-glutamylpeptides including γ-glutamyltaurine are actually produced. Cys showed the lowest Km value (0.06 mM) while other amino acids had much higher Km values (ranging from 21 to 1800 mM). The moderate Km values for these amino acids suggest that they were not the preferred amino acids in this conversion but were utilized as acceptor substrates for the production of the corresponding γ-glutamylpeptides by the γ-GCS reaction under Cys-deficient conditions. Thus, the production of these γ-glutamylpeptides by γ-GCS is directly correlated with a low Cys content, suggesting that their measurement in blood plasma could be useful for predicting the presymptomatic disease state of the liver with a defect in GSH redox balance. 相似文献
8.
Toshihiro Fujimoto Michael A. O’Donnell Akos Szilvasi H. Yang R. B. Duda 《Cancer immunology, immunotherapy : CII》1996,42(5):280-284
Although immunotherapy with bacillus Calmette Guérin (BCG) is an established adjuvant treatment for malignant melanoma, the
mechanism of its role in this process is unclear. To investigate the possible contribution of tumor-inhibitory cytokines induced
by BCG, B16F10 melanoma cell growth in culture was assessed in response to purified cytokines and conditioned media of BCG-stimulated
splenocytes. Interferon-γ (IFNγ) was the most potent single agent (IC50≈50 pg/ml). Tumor necrosis factor α was substantially weaker (IC50>10 ng/ml) but provided synergy with IFNγ. None of the other
cytokines such as interleukin-2 (IL-2), IL-4, IL-6, IL-10, IL-12, or granulocyte/macrophage-colony-stimulating factor had
direct antitumor activity against B16F10 melanoma cells. However, when IL-2 and/or GM-CSF were combined with BCG either by
exogenous addition or through endogenous production by novel cytokine-secreting recombinant BCG (rBCG), a substantial increase
in INFγ production by splenocytes was observed. Antitumor activity of this conditioned medium directly correlated with IFNγ
concentration and was completely blocked by neutralizing antibody to IFNγ. These results suggest that BCG may exert part of
its antitumor action on melanoma through the induction of IFNγ, which can be greatly enhanced through the concomitant addition
of IL-2 and/or GM-CSF. Furthermore, by utilizing rBCG that secrete these cytokines, it may be possible to potentiate the antitumor
effect of BCG directly at the site of BCG inoculation.
Received: 29 January 1996 / Accepted: 9 April 1996 相似文献
9.
Kia Joo Puan John Seng Hooi Low Terence Wee Kiat Tan Joseph Tien Seng Wee Eng Huat Tan Kam Weng Fong Eu Tiong Chua Chenggang Jin José-Luis Giner Craig T. Morita Christopher Hood Keng Goh Kam M. Hui 《Cancer immunology, immunotherapy : CII》2009,58(7):1095-1107
Introduction Human Vγ2Vδ2 T cells play important role in immunity to infection and cancer by monitoring self and foreign isoprenoid metabolites
with their γδ T cell antigen receptors. Like CD4 and CD8 αβ T cells, adult peripheral Vγ2Vδ2 T cells represent a pool of heterogeneous
cells with distinct functional capabilities.
Purpose The aim of this study was to characterize the phenotypes and functions of various Vγ2Vδ2 T cell subsets in patients with nasopharyngeal
carcinoma (NPC). We sought to develop a better understanding of the role of these cells during the course of disease and to
facilitate the development of immunotherapeutic strategies against NPC.
Results Although similar total percentages of peripheral blood Vγ2Vδ2 T cells were found in both NPC patients and normal donors, Vγ2Vδ2
T cells from NPC patients showed decreased cytotoxicity against tumor cells whereas Vγ2Vδ2 T cells from normal donors showed
potent cytotoxicity. To investigate further, we compared the phenotypic characteristics of Vγ2Vδ2 T cells from 96 patients
with NPC and 54 healthy controls. The fraction of late effector memory Vγ2Vδ2 T cells (TEM RA) was significantly increased in NPC patients with corresponding decreases in the fraction of early memory Vγ2Vδ2 T cells
(TCM) compared with those in healthy controls. Moreover, TEM RA and TCM Vγ2Vδ2 cells from NPC patients produced significantly less IFN-γ and TNF-α, potentially contributing to their impaired cytotoxicity.
Radiotherapy or concurrent chemo-radiotherapy further increased the TEM RA Vγ2Vδ2 T cell population but did not correct the impaired production of IFN-γ and TNF-α observed for TEM RA Vγ2Vδ2 T cells.
Conclusion We have identified distinct alterations in the Vγ2Vδ2 T cell subsets of patients with NPC. Moreover, the overall cellular
effector function of γδ T cells is compromised in these patients. Our data suggest that the contribution of Vγ2Vδ2 T cells
to control NPC may depend on the activation state and differentiation of these cells.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
Bone marrow-derived mesenchymal stem cells (BMSCs) are of particular interest in the field of tissue engineering because of
their potential to differentiate into osteoblasts, chondrocytes, and neuronal cells. In order to promote the differentiation
of BMSCs into specific cell types, appropriate scaffold biomaterials and bioactive molecules that can support the differentiation
of BMSCs into specific cell types are needed. We hypothesized that β-mercaptoethanol (BME), which has been reported to induce
the differentiation of BMSCs into neural-like cells, promotes BMSCs to differentiate into neural-like cells when BME is added
to polymeric scaffolds containing the BMSCs. We fabricated biocompatible film shaped scaffolds composed of poly(lacti-co-glycolic)
acid (PLGA) and various concentrations of BME to confirm that BME-promoted differentiation of BMSCs is concentration-dependent.
Cell proliferation increased as the BME concentration in the films increased at the early stage, and the proliferation rate
remained similar on the PLGA films for 3 weeks following the BMSC seeding. The expression of neuronal markers in differentiated
BMSCs was assessed by RT-PCR. At 2- and 3-week time-points, mRNA expression of neurofilament and neuron specific enolase was
significantly increased in PLGA/BME films containing 400 μM BME compared to PLGA films. Thus, we have identified BMSC-seeded
PLGA/BME films with 200 μM and 400 μM BME as potentially useful candidates for neural tissue engineering applications by promoting
BMSC proliferation and differentiation towards neural-like cells. 相似文献
11.
Lenoir S Pagnoulle C Galleni M Compère P Jérôme R Detrembleur C 《Biomacromolecules》2006,7(8):2291-2296
Poly[2-(tert-butylamino)ethyl methacrylate] (PTBAEMA) belongs to a novel class of water-insoluble biocides. Dispersion of a poly(ethylene-co-butylene)-b-poly[2-(tert-butylamino)ethyl methacrylate] diblock copolymer (PEB-b-PTBAEMA) within low-density polyethylene (LDPE) imparts antimicrobial properties to the polyolefin as assessed by the viable cell counting method against Escherichia coli (E. coli). This diblock copolymer has been synthesized by atom transfer radical polymerization (ATRP) with a poly(ethylene-co-butylene) (PEB) oligomer end-capped by an activated bromide as a macroinitiator for the polymerization of 2-(tert-butylamino)ethyl methacrylate (TBAEMA). Morphological changes of E. coli bacteria in contact with modified LDPE have been observed by transmission and scanning electron microscopy and indicate that the diblock copolymer is bactericide rather than bacteriostatic. Finally, the action mode of the PEB-b-PTBAEMA copolymer more likely relies on the displacement of the Ca(2+) and/or Mg(2+) ions of the outer membrane of the bacteria, which is disorganized and finally disrupted. 相似文献
12.
We examined changes in nuclear peroxisome proliferator-activated receptor γ (PPARγ) in the striatum in methamphetamine (METH)-induced
dopaminergic neurotoxicity, and also examined effects of treatment with drugs possessing PPARγ agonistic properties. The marked
reduction of nuclear PPARγ-expressed cells was seen in the striatum 3 days after METH injections (4 mg/kg × 4, i.p. with 2-h
interval). The reduction of dopamine transporter (DAT)-positive signals and PPARγ expression, and accumulation of activated
microglial cells were significantly and dose-dependently attenuated by four injections of a nonsteroidal anti-inflammatory
drug and a PPARγ ligand, ibuprofen (10 or 20 mg/kg × 4, s.c.) given 30 min prior to each METH injection, but not by either
a low or high dose of aspirin. Either treatment of ibuprofen or aspirin, that showed no effects on METH-induced hyperthermia,
significantly blocked the METH-induced striatal cyclooxygenase (COX) expression. Furthermore, the treatment of an intrinsic
PPARγ ligand 15d-PG J2 also attenuated METH injections-induced reduction of striatal DAT. Therefore, the present study suggests
the involvement of reduction of PPARγ expression in METH-induced neurotoxicity. Taken together with the previous report showing
protective effects of other PPARγ ligand, these results imply that the protective effects of ibuprofen against METH-induced
neurotoxicity may be based, in part, on its anti-inflammatory PPARγ agonistic properties, but not on its COX-inhibiting property
or hypothermic effect.
Special issue article in honor of Dr. Akitane Mori. 相似文献
13.
T cell clones (CD4+CD8–TCRαβ+γδ–) derived from bone marrow transplant recipients were stimulated with phytohaemagglutinin (PHA) +interleukin-2 (IL-2) in the
presence of irradiated (50 Gy) peripheral blood mononuclear cells (PBMC) derived from acute leukaemia patients(leukaemic PBMC
containing more than 95% blast cells). Leukaemic PBMC could function as accessory cells during mitogenic T cell activation
resulting in both T cell proliferation and a broad T cell cytokine response [IL-3, IL-4, IL-10, granulocyte/macrophage-colony-stimulating
factor (GM-CSF) tumour necrosis factor α (TNFα) and interferon γ (IFNγ) secretion]. Blockade of IL-1 effects by adding IL-1
receptor antagonist together with PHA+IL-2+leukaemia blasts increased T cell proliferation, whereas IL-6-neutralizing antibodies
did not alter T cell proliferation. A qualitatively similar T cell cytokine response and a similar cytokine profile (highest
levels detected for GM-CSF and IFNγ) were detected when normal polyclonal T cell lines were stimulated with PHA in the presence
of non-irradiated leukaemic PBMC. When leukaemic PBMC derived from 18 acute myelogenous leukaemia patients were cultured with
PHA and cells from a polyclonal T cell line, increased concentrations of the T cell cytokines IFNγ and IL-4 were detected
for all patients. We conclude that T cell activation resulting in proliferation and a broad cytokine response can take place
in the presence of excess acute myelogenous leukaemia blasts.
Received: 30 November 1995 / Accepted: 9 January 1996 相似文献
14.
15.
Background
Hydroxycamptothecin (HCPT) has been shown to have activity against a broad spectrum of cancers. In order to enhance its tissue-specific delivery and anticancer activity, we prepared HCPT-loaded nanoparticles made from poly(ethylene glycol)-poly(γ-benzyl-L-glutamate) (PEG-PBLG), and then studied their release characteristics, pharmacokinetic characteristics, and anticancer effects. PEG-PBLG nanoparticles incorporating HCPT were prepared by a dialysis method. Scanning electron microscopy (SEM) was used to observe the shape and diameter of the nanoparticles. The HCPT release characteristics in vitro were evaluated by ultraviolet spectrophotometry. A high-performance liquid chromatography (HPLC) detection method for determining HCPT in rabbit plasma was established. The pharmacokinetic parameters of HCPT/PEG-PBLG nanoparticles were compared with those of HCPT. 相似文献16.
N. I. Agalakova A. V. Lapin G. P. Gusev 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1997,167(8):576-581
This study was undertaken to evaluate the effects of various metabolic blockers on the Na-K-pump activity and ATP content
of frog erythrocytes. To eliminate K-C1 cotransport, the frog erythrocytes were incubated in nitrate media at 20 °C. Incubation
of the red cells in a glucose-free medium for 2 h had no effect on cell ATP content and K+ influx measured as 86Rb uptake for 60 min. The Na+-K+-pump activity was also unchanged in the frog erythrocytes incubated in a glucose-free medium containing 10 mM 2-deoxy-D-glucose
or adenosine. Unexpectedly, the treatment of red cells with 1–2 mM glycolytic blocker iodoacetate produced a 2-fold increase
in the ouabain-sensitive K+ influx. The cell ATP content declined by 9.4% after 2 h of cell incubation with iodoacetate. Incubation of the red cells
for 90 min in the presence of 2 mM cyanide, 0.01 mM antimycin A or 5 mM azide resulted in a significant reduction in K+ influx by about 50%, 45% and 32%, respectively. The cell ATP content diminished over 60 min and 120 min of cell incubation
with 2 mM cyanide by 15.6% and 31.7% of control levels, respectively. In time-course experiments, a 50% reduction in the K+ influx was observed when the frog erythrocytes were incubated for only 30 min in the presence of 2 mM cyanide. In contrast,
0.01–0.10 mM rotenone, a site I inhibitor, and 0.01 mM carbonyl cyanide m-chlorophenylhydrazone, an uncoupler of oxidative
phosphorylation were without effect on K+ influx into frog erythrocytes. These results indicate that about one-half of the Na+ -K+-pump activity in frog erythrocytes is tightly functionally coupled to cytochromes via a separate “membrane-associated” ATP
pool.
Accepted: 12 July 1997 相似文献
17.
Tomohiro Yamaguchi Youichi Suzuki Ryuichi Katakura Takusaburo Ebina Junkichi Yokoyama Yoshiaki Fujimiya 《Cancer immunology, immunotherapy : CII》1998,47(2):97-103
γδT cells play a regulatory role in both primary and metastatic tumor growth in humans. The mechanisms responsible for the
activation and proliferation of circulating γδT cells should be fully understood prior to their adoptive transfer to cancer
patients. We have examined in vitro functional effects of interleukin-15 (IL-15) on highly purified γδT cells isolated from
glioblastoma patients. γδT cells constitutively express the heterotrimeric IL-2 receptor (IL-2R) αβγ, but the levels of IL-2Rβ
or γ expression were not increased by incubation with saturating amounts of IL-15. IL-15 was shown to induce a maximal γδT
cell proliferation, although at much higher concentrations (at least 2000 U/ml) than IL-2 (100 U/ml). Submaximal concentrations
of IL-15 plus low concentrations of IL-2 produced an additive proliferative response. In contrast to the IL-2-induced response,
this activity was completely or partially abrogated by anti-IL-2Rβ, or anti-IL-2Rγ antibodies, but not by anti-IL-2Rα antibodies.
Incubation of γδT cells in the presence of IL-15 resulted not only in the appearance of NK and LAK activity, but also in specific
autologous tumor cell killing activity, an additive effect being seen with IL-15 and IL-2. This IL-15-induced tumor-specific
activity could be significantly blocked by anti-IL-2Rγ and anti-IL-2R-β mAb, but not by anti-IL-2Rα mAb. Thus, in contrast
to IL-2, IL-15 activates tumor-specific γδT cells through the components of IL-2Rβ and IL-2Rγ, but not IL-2Rα. These enhanced
in vitro tumor-specific and proliferative responses of γδT cells seen with IL-15 suggest a rational adjuvant imunotherapeutic
use of γδT cells in cancer patients.
Received: 23 January 1998 / Accepted: 20 May 1998 相似文献
18.
Brady MS Lee F Petrie H Eckels DD Lee JS 《Cancer immunology, immunotherapy : CII》2000,48(11):621-626
Purpose: Most melanoma cell lines express HLA class II antigens constitutively or can be induced to do so with interferon γ (IFNγ).
We have previously demonstrated that peptide-specific CD4+ T cells proliferate in response to HLA-class-II-antigen-mediated peptide presentation by melanoma cells in vitro and produce
interleukin-10 (IL-10) and (IFNγ). We asked whether the responding T cells kill the tumor cells and, if so, whether direct
cell contact was required. Methods: Two HLA class II+ melanoma cell lines derived from metastases were co-cultured with a human CD4+ T cell clone specific for influenza hemagglutinin peptide (HA). T cells, melanoma, and HA were co-cultured for 48 h. Melanoma
cells with and without HA and/or T cells served as controls. After 36 h, the medium was removed for cytokine analysis by enzyme-linked
immunosorbent assay (ELISA). Twelve hours later non-adherent cells were washed away and the adherent melanoma cells were trypsinized
and counted. Dual-chamber culture plates were used to determine whether cell contact and/or exposure to cytokine were required
for tumor cell death. Results: Melanoma cell counts were over 80% lower in wells containing T cells than in wells with melanoma and peptide alone (P < 0.05). ELISA of supernatants revealed production of IFNγ and IL-10 by the responding T cells. Direct T cell contact with
tumor cells was not required for tumor cell death, as melanoma cells were killed when they shared medium but had no contact
with T cells responding to peptide presentation by HLA-class-II-antigen-positive melanoma cells in a separate chamber. Blocking
antibody to IFNγ but not IL-10 prevented melanoma cell death at levels of cytokine similar to that present in co-culture assays.
Conclusions: Peptide-specific CD4+ T cells kill melanoma cells in vitro when they recognize peptide presented by the tumor cell in the context of HLA class
II antigen. Direct cell contact is not required, suggesting that it is a cytokine-mediated event. Immunotherapy, using primed
CD4+ T cells and peptide, may be beneficial in patients whose tumors express HLA class II antigens or can be induced to do so
with IFNγ.
Received: 1 July 1999 / Accepted: 17 September 1999 相似文献
19.
The components of the media used to elicit the biosynthesis of poly-γ-glutamic acid (γ-PGA) byBacillus subtilis ZJU-7 were investigated, particularly the carbon and nitrogen sources. Of the 7 carbon sources investigated, sucrose induced
the highest rate of γ-PGA productivity; among the nitrogen sources, tryptone had the best effect for γ-PGA production. A 26−2 fractional factorial design was used to screen factors that influence γ-PGA production significantly, and a central composite
design was finally adopted to formulate the optimal medium. γ-PGA productivity improved approximately 2-fold when the optimal
medium was used compared with the original nonoptimized medium, and volumetric productivity reached a maximum of 58.2 g/L
after a 24-h cultivation period. 相似文献
20.
Yasushi Ohmi Hiroshi Shiku Takashi Nishimura 《Cancer immunology, immunotherapy : CII》1999,48(8):456-462
T helper type1 (Th1) or type2 (Th2) cells were induced from naive Th cells obtained from ovalbumin-specific T cell receptor
(TCR) transgenic mice. Th1 cells producing interferon γ (IFNγ) exhibited stronger antigen-specific cytotoxicity against ovalbumin-(323–339)-peptide-pulsed
A20 tumor cells than did Th2 cells. To develop a general method for applying antigen-nonspecific Th1 cells to tumor immunotherapy,
we examined the targeting of Th1 cells to tumor cells using a bispecific antibody (bsAb) consisting of anti-(mouse CD3) mAb
and anti-(human c-ErbB-2) mAb. When ovalbumin-specific Th1 or Th2 cells were cocultured with c-erbB-2-positive transfectants (CMS7HE), neither type of cell showed significant cytotoxicity or cytokine production in response
to tumor cells. However, addition of bsAb resulted in the triggering of both Th1 and Th2 cells. Th1 cells showed higher levels
of bsAb-dependent cytotoxicity against CMS7HE tumor cells than did Th2 cells. The targeting of Th1 cells to CMS7HE tumor cells
by bsAb also triggered the production of cytokines such as IFNγ, interleukin-2 and tumor necrosis factor α (TNFα). The released
TNFα was demonstrated to be a critical cytolytic factor in bsAb-mediated cytotoxicity by Th1 cells. Finally, Th1 cells were
demonstrated to show antitumor activity in vivo against human c-erbB-2-positive tumor cells implanted in nude mice. These results suggest that Th1 cells are useful effector cells for the application
to adoptive tumor immunotherapy in conjunction with bsAb.
Received: 22 April 1999 / Accepted: 2 July 1999 相似文献