Selection of adenovirus-specific and Epstein-Barr virus-specific T cells with major histocompatibility class I streptamers under Good Manufacturing Practice (GMP)-compliant conditions.

BACKGROUND AIMS: Despite antiviral drug therapies, human adenovirus (HAdV), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections still contribute substantially to transplant-related death of patients after hematopoietic stem cell transplantation. Earlier clinical studies demonstrated successful adoptive transfer of magnetically selected CMV-specific T cells via removable, and thus Good Manufacturing Practice-compliant, major histocompatibility class I streptamers. Thus, the primary focus of the present study was the selection of HAdV-streptamer+ T cells, although in three experiments, EBV-streptamer+ T cells were also selected. METHODS: Cells from leukaphereses of healthy donors were prepared in large (1-6 × 10(9)) and small (25 × 10(6)) cell batches. Whereas the larger batch was directly labeled with streptamers to select HAdV- and/or EBV-specific T cells (large-scale), the smaller batch was used to generate in vitro virus-specific T-cell lines before streptamer labeling for streptamer selection (small-scale). Isolation of HAdV- and/or EBV-specific T cells was performed with the use of the CliniMACS device. RESULTS: The purity of HAdV- and EBV-streptamer+ T cells among CD3+ cells, obtained from large-scale selection, was up to 6.7% and 44%, respectively. If HAdV- and EBV-streptamers were applied simultaneously, the purity of antigen-specific T cells reached up to 50.7%. A further increase in purity reaching up to 98% was achieved by small-scale selection of HAdV-specific T cells. All final products fulfilled the microbiological and chemical release criteria. Interferon-γ-response indicating functional activity was seen in 6 of 9 HAdV and 2 of 3 EBV large-scale selections and in 2 of 3 HAdV small-scale selections. CONCLUSIONS: HAdV-streptamers were shown to be clinically feasible for few patients after the large-scale approach but for larger patient numbers if combined with EBV-streptamers or after the small-scale approach.

First-in-man clinical results with good manufacturing practice (GMP)-compliant polypeptide-expanded adenovirus-specific T cells after haploidentical hematopoietic stem cell transplantation.

Adoptive immunotherapy against viral infections is a promising treatment option for patients after hematopoietic stem cell transplantation. However, the generation of virus-specific T cells is either cost-intensive or time-consuming. We developed the first GMP-compliant protocol to generate donor-derived adenovirus (HAdV), cytomegalovirus, and Epstein-Barr virus-specific T-cell lines (TCLs) within 12 days by the use of overlapping polypeptides derived from different viruses in combination with IL-15. Two patients after undergoing haploidentical hematopoietic stem cell transplantation with HAdV viremia displaying rising viral loads despite treatment with cidofovir received 1×10 donor-derived short-term expanded HAdV-specific TCLs per kg body weight. In both patients, HAdV-specific T cells could be detected by IFN-γ-ELISpot 30 and 22 days postinfusion, and resulted in complete clearance or >1.5 log reduction of viral load within 15 and 18 days, respectively. This protocol facilitates rapid and cost-effective generation of virus-specific TCLs, which appear to provide an effective treatment option.

Fatty acids induce apoptosis in human smooth muscle cells depending on chain length, saturation, and duration of exposure.

OBJECTIVE: Plasma free fatty acid (FFA) concentrations are increased in states of insulin resistance. Therefore, this study evaluated apoptosis and underlying mechanisms induced by selected nutritional FFAs, a defined FFA-mix, and human plasma containing high FFA concentrations in human smooth muscle cells (HSMCs). RESEARCH DESIGN AND METHODS: HSMCs were incubated (24-72 h) with selected FFAs (100-300 micromol/l), an FFA-mix (palmitic-/stearic-/oleic-/linoleic-/alpha-linolenic acid=2.6/1/3.6/9/1; 300-900 micromol/l), or with high FFA-plasma (600 micromol/l) versus respective control cultures. Apoptosis, caspase activation, and protein expression were determined by DNA-fragmentation assays, flow cytometry, and Western blots, respectively. RESULTS: Exposure (24h) of HSMCs to 300 micromol/l stearic-, oleic-, linoleic-, alpha-linolenic-, and arachidonic acid induced apoptosis, correlating (p<0.01) with the FFAs' chain length (r=0.602) and number of FFA double bonds (r=0.956). After 48 h, 100 micromol/l of all tested FFAs - including palmitic acid - were already sufficient to trigger HSMCs' cell death. FFA-exposure resulted in activation of caspases and apoptosis was completely abolished by co-incubation with caspase inhibitors and negatively correlated (p<0.01) with the base-excision repair protein XRCC1 (r=-0.765) and with c-myc's antagonist mad (r=-0.916), whereas positive correlations (p<0.01) were found for protein expression of the proto-oncogene c-myc (r=0.972) and the transcription factor E2F-1 (r=0.971). Exposure of HSMCs to the defined FFA-mix and to plasma samples from individuals with elevated plasma FFAs supported the results obtained by defined FFA stimulation. CONCLUSIONS: Since smooth muscle cells surround the macrophage/foam cell/lipid-laden artheromatous core of atherosclerotic lesions with a protective fibrous cap, their FFA-induced HSMC apoptosis could contribute to progression of atherosclerosis by thinning of the fibrous cap and subsequent plaque destabilization.

Different mechanisms of saturated versus polyunsaturated FFA-induced apoptosis in human endothelial cells.

Apoptosis and underlying mechanisms were evaluated in human umbilical vein endothelial cells (HUVECs), in target tissues of late diabetic vascular complications [human aortic endothelial cells (HAECs) and human retinal endothelial cells (HRECs)], and in endothelial progenitor cells (EPCs) exposed to FFAs, which are elevated in obesity and diabetes. Saturated stearic acid concentration dependently induced apoptosis that could be mediated via reduced membrane fluidity, because both apoptosis and membrane rigidity are counteracted by eicosapentaenoic acid. PUFAs triggered apoptosis at a concentration of 300 micromol/l in HUVECs, HAECs, and EPCs, but not HRECs, and, in contrast to stearic acid, involved caspase-8 activation. PUFA-induced apoptosis, but not stearic acid-induced apoptosis, strictly correlated (P < 0.01) with protein expression of E2F-1 (r = 0.878) and c-myc (r = 0.966). Lack of c-myc expression and activity owing to quiescence or transfection with dominant negative In373-Myc, respectively, renders HUVECs resistant to PUFA-induced apoptosis. Because c-myc is abundant in growing cells only, apoptosis triggered by PUFAs, but not by saturated stearic acid, obviously depends on the growth/proliferation status of the cells. Finally, this study shows that FFA-induced apoptosis depends on the vascular origin and growth/proliferation status of endothelial cells, and that saturated stearic acid-induced apoptosis and PUFA-induced apoptosis are mediated via different mechanisms.

R-(+)-alpha-lipoic acid inhibits endothelial cell apoptosis and proliferation: involvement of Akt and retinoblastoma protein/E2F-1.

Lipoic acid was recently demonstrated to improve endothelial dysfunction or retinopathy not only in rats but also in diabetic patients. We tested the hypothesis that R-(+)-alpha-lipoic acid (LA) directly affects human endothelial cell (EC) function (e.g., apoptosis, proliferation, and protein expression), independent of the cells' vascular origin. Macrovascular EC (macEC), isolated from umbilical (HUVEC) and adult saphenous veins and from aortae, as well as microvascular EC (micEC) from retinae, skin, and uterus, were exposed to LA (1 mumol/l-1 mmol/l) with/without different stimuli (high glucose, TNF-alpha, VEGF, wortmannin, LY-294002). Apoptosis, proliferation, cell cycle distribution, and protein expression were determined by DNA fragmentation assays, [(3)H]thymidine incorporation, FACS, and Western blot analyses, respectively. In macro- and microvascular EC, LA (1 mmol/l) reduced (P < 0.05) basal (macEC, -36 +/- 4%; micEC, -46 +/- 6%) and stimulus-induced (TNF-alpha: macEC, -75 +/- 11%; micEC, -68 +/- 13%) apoptosis. In HUVEC, inhibition of apoptosis by LA (500 mumol/l) was paralleled by reduction of NF-kappaB. LA's antiapoptotic activity was reduced by PI 3-kinase inhibitors (wortmannin, LY-294002), being in line with LA-induced Akt phosphorylation (Ser(437), +159 +/- 43%; Thr(308), +98 +/- 25%; P < 0.01). LA (500 mumol/l) inhibited (P < 0.001) proliferation of macEC (-29 +/- 3%) and micEC (-29 +/- 3%) by arresting the cells at the G(1)/S transition due to an increased ratio of cyclin E/p27(Kip) (4.2-fold), upregulation of p21(WAF-1/Cip1) (+104 +/- 21%), and reduction of cyclin A (-32 +/- 11%), of hyperphosphorylated retinoblastoma protein (macEC: -51 +/- 7%; micEC: -50 +/- 15%), and of E2F-1 (macEC: -48 +/- 3%; micEC: -31 +/- 10%). LA's ability to inhibit apoptosis and proliferation of ECs could beneficially affect endothelial dysfunction, which precedes manifestation of late diabetic vascular complications.

The Mammalian target of rapamycin pathway regulates nutrient-sensitive glucose uptake in man.

The nutrient-sensitive kinase mammalian target of rapamycin (mTOR) and its downstream target S6 kinase (S6K) are involved in amino acid-induced insulin resistance. Whether the mTOR/S6K pathway directly modulates glucose metabolism in humans is unknown. We studied 11 healthy men (29 years old, BMI 23 kg/m(2)) twice in random order after oral administration of 6 mg rapamycin, a specific mTOR inhibitor, or placebo. An amino acid mixture was infused to activate mTOR, and somatostatin-insulin-glucose clamps created conditions of low peripheral hyperinsulinemia (approximately 100 pmol/l, 0-180 min) and prandial-like peripheral hyperinsulinemia (approximately 450 pmol/l, 180-360 min). Glucose turnover was assessed using d-[6,6-(2)H(2)]glucose infusion (n = 8). Skeletal muscle biopsies were performed at baseline and during prandial-like peripheral hyperinsulinemia (n = 3). At low peripheral hyperinsulinemia, whole-body glucose uptake was not affected by rapamycin. During prandial-like peripheral hyperinsulinemia, rapamycin increased glucose uptake compared with placebo by 17% (R(d 300-360 min), 75 +/- 5 vs. 64 +/- 5 micromol x kg(-1) x min(-1), P = 0.0008). Rapamycin affected endogenous glucose production neither at baseline nor during low or prandial-like peripheral hyperinsulinemia. Combined hyperaminoacidemia and prandial-like hyperinsulinemia increased S6K phosphorylation and inhibitory insulin receptor substrate-1 (IRS-1) phosphorylation at Ser312 and Ser636 in the placebo group. Rapamycin partially inhibited this increase in mTOR-mediated S6K phosphorylation and IRS-1 Ser312 and Ser636 phosphorylation. In conclusion, rapamycin stimulates insulin-mediated glucose uptake in man under conditions known to activate the mTOR/S6K pathway.

Chemical modulation of VLA integrin affinity in human breast cancer cells.

The fact that disruption of integrin-extracellular matrix contacts leads to cell death, has converted cell adhesion into a potential target for the control of invasive cancer. In this work, we studied the functional consequences of the interference with the activity of the very late activation antigen (VLA) family of integrins in human breast cancer cell lines of distinct malignancy. The alpha2beta1-mediated adhesion reduced the entry of highly malignant, hormone-independent breast cancer cells into apoptosis. Adhesion of breast cancer cells through the VLA integrins alpha2beta1 and alpha5beta1 was significantly reduced by an apoptosis-inducing natural triterpenoid, dehydrothyrsiferol (DT), when studied on low amounts of extracellular matrix. This effect was dose-dependent, not related to cell toxicity and not shared with apoptosis-inducing standard chemotherapeutics, such as doxorubicin and taxol. The compound did not affect either the cell surface expression level of VLA integrins or cell distribution of vinculin and actin during cell spreading. In addition, neither phosphorylation of the focal adhesion kinase pp125FAK on Tyr397 nor the protein kinase B (Akt/PKB) on Ser473 was significantly altered by DT. The integrin activation level, assessed by binding of soluble collagen to the alpha2beta1 integrin, was reduced upon cell treatment with DT. Importantly, the TS2/16, an anti-beta1 activating monoclonal antibody was able to rescue DT-treated cells from apoptosis. Since the activation state of integrins is increasingly recognized as an essential factor in metastasis formation, findings presented herein reveal that the chemical regulation of integrin affinity may be a potential therapeutic strategy in cancer therapy.

Free fatty acids normalize a rosiglitazone-induced visfatin release.

The detrimental effect of elevated free fatty acids (FFAs) on insulin sensitivity can be improved by thiazolidinediones (TZDs) in patients with type 2 diabetes mellitus. It is unknown whether this salutary action of TZD is associated with altered release of the insulin-mimetic adipocytokine visfatin. In this study, we investigated whether visfatin concentrations are altered by FFA and TZD treatment. In a randomized, double-blind, placebo-controlled, parallel-group study 16 healthy volunteers received an infusion of triglycerides/heparin to increase plasma FFA after 3 wk of treatment with rosiglitazone (8 mg/day, n = 8) or placebo (n = 8), and circulating plasma visfatin was measured. As a corollary, human adipocytes were incubated with synthetic fatty acids and rosiglitazone to assess visfatin release in vitro. The results were that rosiglitazone treatment increased systemic plasma visfatin concentrations from 0.6 +/- 0.1 to 1.7 +/- 0.2 ng/ml (P < 0.01). Lipid infusion caused a marked elevation of plasma FFA but had no effect on circulating visfatin in controls. In contrast, elevated visfatin concentrations in subjects receiving rosiglitazone were normalized by lipid infusion. In isolated adipocytes, visfatin was released into supernatant medium by acute addition and long-term treatment of rosiglitazone. This secretion was blocked by synthetic fatty acids and by inhibition of phosphatidylinositol 3-kinase or Akt. In conclusion, release of the insulin-mimetic visfatin may represent a major mechanism of metabolic TZD action. The presence of FFA antagonizes this action, which may have implications for visfatin bioactivity.

Thiazolidinediones inhibit apoptosis and heat shock protein 60 expression in human vascular endothelial cells.

This study evaluated direct effects of peroxisome proliferatoractivated receptor gamma(PPARgamma) agonists, including thiazolidinediones (TZDs), on vascular cell apoptosis and related protein expression to test the hypothesis that these effects are dependent on i) the respective agent's structure and ii) endothelial cells' vascular origin. Exposure (48 h) of human umbilical vein endothelial cells (HUVECs, n=6) to up to 10 microM troglitazone (TRO), rosiglitazone, pioglitazone, and to up to 50 microM RWJ241947=MCC-555 (RWJ) inhibited (p<0.05) apoptosis by 8-25%, whereas 15-deoxy-Delta(12-14)-prostaglandin J(2) (PGJ(2)) triggered (50 microM: + 400%, p<0.05) endothelial cell death versus control (=100%). Moreover, RWJ (50 microM) completely abrogated TNF-alpha(2000 U/ml) and stearic acid (200 microM) induced apoptosis in HUVECs . Similar results were obtained in human adult (saphenous) vein- and aortic endothelial cells, the latter showing no anti-apoptotic response to TRO. In HUVECs, TZDs' anti-apoptotic effects inversely correlated (r=-0.95, p<0.01) with increased (p<0.05) expression of the apoptosis-inhibitor bcl-2, whereas PGJ(2)-induced apoptosis was associated with upregulation of c-myc (+447%) and E2F-1 (+339%). Additionally, TZDs (by 25-39%) and PGJ(2) (-70%) reduced (p<0.05) expression of heat shock protein 60 (hsp60) showing no correlation with apoptosis (r=0.14, n.s.). Modulation of apoptosis by PPARgammaagonists differs in endothelial cells dependent on their vascular origin and the agonists' structure. Thiazolidinediones' ability to reduce both, endothelial apoptosis and hsp60 expression could well add to beneficial vascular effects attributed to these oral antidiabetic drugs.

TYK2 is a key regulator of the surveillance of B lymphoid tumors.

Aberrant activation of the JAK-STAT pathway has been implicated in tumor formation; for example, constitutive activation of JAK2 kinase or the enforced expression of STAT5 induces leukemia in mice. We show here that the Janus kinase TYK2 serves an opposite function. Mice deficient in TYK2 developed Abelson-induced B lymphoid leukemia/lymphoma as well as TEL-JAK2-induced T lymphoid leukemia with a higher incidence and shortened latency compared with WT controls. The cell-autonomous properties of Abelson murine leukemia virus-transformed (A-MuLV-transformed) TYK2(-/-) cells were unaltered, but the high susceptibility of TYK2(-/-) mice resulted from an impaired tumor surveillance, and accordingly, TYK2(-/-) A-MuLV-induced lymphomas were easily rejected after transplantation into WT hosts. The increased rate of leukemia/lymphoma formation was linked to a decreased in vitro cytotoxic capacity of TYK2(-/-) NK and NKT cells toward tumor-derived cells. RAG2/TYK2 double-knockout mice succumbed to A-MuLV-induced leukemia/lymphoma faster than RAG2(-/-)TYK2(+/-) mice. This defines NK cells as key players in tumor surveillance in Abelson-induced malignancies. Our observations provide compelling evidence that TYK2 is an important regulator of lymphoid tumor surveillance.

Free fatty acids trigger apoptosis and inhibit cell cycle progression in human vascular endothelial cells.

Plasma free fatty acid (FFA) concentrations are increased in states of insulin resistance and impair endothelial function. Because the underlying mechanisms are largely unknown, we examined selected, purified FFAs' (100-300 micromol/l, 24-48 h) action on apoptosis, cell cycle distribution, and associated gene/protein expression in human umbilical vein endothelial cells (HUVECs). Stearic acid, but not oleic acid, time and concentration dependently increased endothelial apoptosis by fivefold (n=6, P<0.01), whereas polyunsaturated FFAs (PUFAs; linoleic, gamma-linolenic, and arachidonic acid) exerted proapoptotic activity only at 300 micromol/l (P<0.05). Proapoptotic FFA action increased with FFAs' number of double bonds and with protein expression of the apoptosis promotor bak. The G0/G1 cell cycle arrest (n=6, P<0.05) induced by stearic acid (+14%) and PUFAs (+30%) is reflected by up-regulation of p21(WAF-1/Cip1). In addition, all FFAs concentration dependently reduced (P<0.05) gene/protein expression of clusterin (-54%), NF-kappaB's inhibitor, IkappaBalpha (-50%), endothelin-1 (-44%), and endothelial NO synthase (-44%). Plasma samples obtained from individuals with elevated plasma FFAs (372+/-22 micromol/l) increased endothelial apoptosis by 4.2-fold (P<0.001, n=10) compared with intra-individually matched low plasma FFA (56+/-21 micromol/l) conditions, underlining the results obtained by defined FFA stimulation. In conclusion, FFA structure differently affects endothelial cell proliferation and apoptosis, both representing key factors in the development of micro- and macrovascular dysfunction.

JunB inhibits proliferation and transformation in B-lymphoid cells.

The activator protein 1 (AP-1) member JunB has recently been implicated in leukemogenesis. Here we surveyed human lymphoma samples for expression of JunB and other AP-1 members (c-Jun, c-Fos, Fra1, JunD). JunB was strongly expressed in T-cell lymphomas, but non-Hodgkin B-cell lymphomas do not or only weakly express JunB. We therefore asked whether JunB acted as a negative regulator of B-cell development, proliferation, and transformation. We used transgenic mice that expressed JunB under the control of the ubiquitin C promoter; these displayed increased JunB levels in both B- and T-lymphoid cells. JunB transgenic cells of B-lymphoid, but not of T-lymphoid, origin responded poorly to mitogenic stimuli. Furthermore, JunB transgenic cells were found to be less susceptible to the transforming potential of the Abelson oncogene in vitro. In addition, overexpression of JunB partially protected transgenic mice against the oncogenic challenge in vivo. However, transformed B cells eventually escaped from the inhibitory effect of JunB: the proliferative response was similar in explanted tumor-derived cells from transgenic animals and those from wild-type controls. Our results identify JunB as a novel regulator of B-cell proliferation and transformation.

Diabetic LDL triggers apoptosis in vascular endothelial cells.

This study compares the effects of LDL glycated either in vitro (LDL(iv)) or in vivo in diabetic patients (LDL(D)) on apoptosis, proliferation, and associated protein expression in cultured human umbilical vein endothelial cells. At 100 mg/l, both LDL species considerably increase apoptosis (LDL(iv) 63%, LDL(D) 40%; P < 0.05) compared with intraindividual nonglycated LDL subfractions. Considering its lower degree of glycation (LDL(D) 5-10%, LDL(iv) 42%), LDL(D)'s relative proapoptotic activity is 2.7-fold greater than that of LDL(iv). Glycated LDL-induced apoptosis is associated with increased expression of apoptosis promotors (LDL(iv): bak 88%, CPP-32 49%; LDL(D): bak 18%, CPP-32 11%; P < 0.05) and is attenuated by caspase inhibitors. Glycated LDL's antiproliferative activity (LDL(iv) -34%, LDL(D) -9%; P < 0.01) relates to reduction (P < 0.05) of cyclin D3 (LDL(iv) -27%, LDL(D) -24%) and of hypo- (LDL(iv) -22%, LDL(D) -19%) and hyperphosphorylated (LDL(iv) -53%, LDL(D) -22%) retinoblastoma protein and is paralleled by reduced expression of endothelial nitric oxide synthase (LDL(iv) -30%, LDL(D) -23%). In response to lipoprotein lipase, LDL(D) more markedly triggers endothelial apoptosis (27.1-fold) compared with LDL(iv), suggesting that LDL(D) owns a higher potential for endothelial cell damage than LDL(iv). The observed behavior of LDL(D) versus LDL(iv) could be of clinical importance and well relate to differences in structure and cellular uptake of LDL(D) compared with LDL(iv).