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BACKGROUND AIMS - To develop a treatment option for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+)ALL) resistant to tyrosine kinase inhibitors (TKIs), we evaluated the anti-leukemic activity of T cells non-virally engineered to express a CD19-specific chimeric antigen receptor (CAR).
METHODS - A CD19.CAR gene was delivered into mononuclear cells from 10 mL of blood of healthy donors through the use of piggyBac-transposons and the 4-D Nucleofector System. Nucleofected cells were stimulated with CD3/CD28 antibodies, magnetically selected for the CD19.CAR, and cultured in interleukin-15-containing serum-free medium with autologous feeder cells for 21 days. To evaluate their cytotoxic potency, we co-cultured CAR T cells with seven Ph(+)ALL cell lines including three TKI-resistant (T315I-mutated) lines at an effector-to-target ratio of 1:5 or lower without cytokines.
RESULTS - We obtained ∼1.3 × 10(8) CAR T cells (CD4(+), 25.4%; CD8(+), 71.3%), co-expressing CD45RA and CCR7 up to ∼80%. After 7-day co-culture, CAR T cells eradicated all tumor cells at the 1:5 and 1:10 ratios and substantially reduced tumor cell numbers at the 1:50 ratio. Kinetic analysis revealed up to 37-fold proliferation of CAR T cells during a 20-day culture period in the presence of tumor cells. On exposure to tumor cells, CAR T cells transiently and reproducibly upregulated the expression of transgene as well as tumor necrosis factor-related apoptosis-inducing ligand and interleukin-2.
CONCLUSIONS - We generated a clinically relevant number of CAR T cells from 10 mL of blood through the use of piggyBac-transposons, a 4D-Nulcleofector, and serum/xeno/tumor cell/virus-free culture system. CAR T cells exhibited marked cytotoxicity against Ph(+)ALL regardless of T315I mutation. PiggyBac-mediated CD19-specific T-cell therapy may provide an effective, inexpensive and safe option for drug-resistant Ph(+)ALL.
Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.
The chemotaxis of phosphoinositide kinase-3 (PI3K)-inhibited differentiated HL-60 cells stably expressing CXCR2 was studied in a microfluidic switching gradient device that can generate stable and well-defined forward and reverse gradients. Wortmannin, a widely used PI3K inhibitor, was added during cell preparation and the experiment process. The studies quantify the chemotaxis gradient and the effects of a change in the direction of a CXCL-8 gradient on cell migration. PI3K-inhibited HL-60 cells migrated more efficiently toward the gradient before gradient switching than after, as measured by the effective chemotactic index. The inhibited HL-60 cells also showed that inadequate polarization, slower response time, and reduced cell populations can follow the gradient change. We observed that the role of PI3K in directing cellular response to gradient reversal was important in cell polarization and directional sensing associated with gradient switching.
Integration of receptor tyrosine kinase, integrin, and cadherin activities is crucial for normal cell growth, motility, and adhesion. Here, we describe roles for p120-catenin (p120) and p190RhoGAP that coordinate crosstalk between these systems and regulate cadherin function. Surprisingly, PDGFR-induced actin remodeling in NIH3T3 cells is blocked in the absence of p120, and the cells are partially transformed via constitutive activation of Rho. We have traced the mechanism to unexpected codependent roles for p120 and p190RhoGAP in regulating Rac-dependent antagonism of Rho. Receptor-induced Rac activity causes translocation of p190RhoGAP to adherens junctions (AJs), where it couples to the cadherin complex via interaction with p120. AJ formation is dependent on this p120-p190RhoGAP interaction and fails altogether if either of these proteins are compromised. We propose that Rac activation links diverse signaling systems to AJ assembly by controlling transient p190RhoGAP interactions with p120 and localized inhibition of Rho.
Prostaglandin E2 (PGE2), a major cyclooxygenase (COX) metabolite, plays important roles in tumor biology. We studied the role of EP2, a receptor for PGE2, in tumor angiogenesis using EP2 knockout mice. We found that deletion of the EP2 receptor impaired tumor angiogenesis and this finding was confirmed by an in vivo corneal angiogenesis model and an ex vivo aortic ring assay. To further characterize the cellular mechanisms of the EP2 receptor in angiogenesis, we isolated primary pulmonary endothelial cells (ECs) from wild-type (wt) and EP2-/- mice and observed that EP2-/- ECs exhibited defects in vascular branch formation when compared to wt ECs. In addition, EP2-/- ECs showed impaired cell motility on collagen-coated surface and they responded poorly to PGE2-induced cell migration compared to control cells. However, no difference in cell proliferation was observed between the EP2-/- and wt Ecs. In addition, EP2-/- ECs were more susceptible to apoptosis than wt cells under growth factor depletion conditions. Collectively, our data demonstrate that EP2 signaling in endothelium directly regulates tumor angiogenesis by contributing to cell survival and endothelial cell motility. Moreover, our finding suggests that EP2 is a major receptor in PGE2-mediated cell motility in ECs.
We have examined the interaction of transforming growth factor (TGF)beta receptors with phosphatidylinositol 3-(PI3) kinase in epithelial cells. In COS7 cells, treatment with TGFbeta increased PI3 kinase activity as measured by the ability of p85-associated immune complexes to phosphorylate inositides in vitro. Both type I and type II TGFbeta receptors (TbetaR) associated with p85, but the association of TbetaRII appeared to be constitutive. The interaction of TbetaRI with p85 was induced by treatment with TGFbeta. The receptor association with PI3 kinase was not direct as (35)S-labeled rabbit reticulocyte p85 did not couple with fusion proteins containing type I and type II receptors. A kinase-dead, dominant-negative mutant of TbetaRII blocked ligand-induced p85-TbetaRI association and PI3 kinase activity. In TbetaRI-null R1B cells, TGFbeta did not stimulate PI3 kinase activity. This stimulation was restored upon reconstitution of TbetaRI by transfection. In R1B and NMuMG epithelial cells, overexpression of a dominant active mutant form of TbetaRI markedly enhanced ligand-independent PI3 kinase activity, which was blocked by the addition of the TbetaRI kinase inhibitor LY580276, suggesting a causal link between TbetaRI function and PI3 kinase. Overexpressed Smad7 also prevented ligand-induced PI3 kinase activity. Taken together, these data suggest that 1) TGFbeta receptors can indirectly associate with p85, 2) both receptors are required for ligand-induced PI3 kinase activation, and 3) the activated TbetaRI serine-threonine kinase can potently induce PI3 kinase activity.
Trophoblast invasion of the uterine extracellular matrix, a critical process of human implantation and essential for fetal development, is a striking example of controlled invasiveness. To identify molecules that regulate trophoblast invasion, mRNA signatures of trophoblast cells isolated from first trimester (high invasiveness) and term placentae (no/low invasiveness) were compared using U95A GeneChip microarrays yielding 220 invasion/migration-related genes. In this 'invasion cluster', KiSS-1 and its G-protein-coupled receptor KiSS-1R were expressed at higher levels in first trimester trophoblasts than at term of gestation. Receptor and ligand mRNA and protein were localized to the trophoblast compartment. In contrast to KiSS-1, which is only expressed in the villous trophoblast, KiSS-1R was also found in the extravillous trophoblast, suggesting endocrine/paracrine activation mechanisms. The primary translation product of KiSS-1 is a 145 amino acid polypeptide (Kp-145), but shorter kisspeptins (Kp) with 10, 13, 14 or 54 amino acid residues may be produced. We identified Kp-10, a dekapeptide derived from the primary translation product, in conditioned medium of first trimester human trophoblast. Kp-10, but not other kisspeptins, increased intracellular Ca(2+) levels in isolated first trimester trophoblasts. Kp-10 inhibited trophoblast migration in an explant as well as transwell assay without affecting proliferation. Suppressed motility was paralleled with suppressed gelatinolytic activity of isolated trophoblasts. These results identified Kp-10 as a novel paracrine/endocrine regulator in fine-tuning trophoblast invasion generated by the trophoblast itself.
The ability to rescue viable prostate precursor tissue from retinoblastoma-deficient (Rb-/-) fetal mice has allowed for the isolation and characterization of the first Rb-/- prostate epithelial cell line. This cell line, designated Rb-/-PrE, was utilized for experiments examining the consequences of Rb loss on an epithelial population. These findings demonstrated that Rb deletion has no discernible effect on prostatic histodifferentiation in Rb-/-PrE cultures. When Rb-/-PrE cells were recombined with embryonic rat urogenital mesenchyme and implanted into athymic male, nude mouse hosts, the recombinants developed into fully differentiated and morphologically normal prostate tissue. The Rb-/-PrE phenotype was characterized by serum independence in culture and immortality in vivo, when compared with wild type controls. Cell cycle analysis revealed elevated S phase DNA content accompanied by increased expression of cyclin E1 and proliferating cell nuclear antigen. Rb-/-PrE cultures also exhibited a diminished ability to growth arrest under high density culture conditions. We believe that the development of Rb-/- prostate tissue and cell lines has provided a unique experimental platform with which to investigate the consequences of Rb deletion in epithelial cells under various physiological conditions. Additionally, the development of this technology will allow similar studies in other tissues and cell populations rescued from Rb-/- fetuses.
We report a simplified culture system for human fetal lung type II cells that maintains surfactant expression. Type II cells isolated from explant cultures of hormone-treated lungs (18-22 wk gestation) by collagenase + trypsin digestion were cultured on plastic for 4 days in serum-free medium containing dexamethasone (Dex, 10 nM) + 8-bromo-cAMP (0.1 mM + isobutylmethylxanthine (0.1 mM) or were untreated (control). Surfactant protein (SP) mRNAs decreased markedly in control cells between days 1 and 4 of culture, but mRNA levels were high in treated cells on day) 4 (SP-A, SP-B, SP-C, SP-D; 600%, 100%, 85%, 130% of day 0 content, respectively). Dex or cAMP alone increased SP-B, SP-C, and SP-D mRNAs and together had additive effects. The greatest increase in SP-A mRNA occurred with cAMP alone. Treated cells processed pro-SP-B and pro-SP-C proteins to mature forms and had a higher rate of phosphatidylcholine (PC) synthesis (2-fold) and higher saturation of PC (approximately 34% versus 27%) than controls. Only treated cells maintained secretagogue-responsive phospholipid synthesis. By electron microscopy, the treated cells retained lamellar bodies and extensive microvilli. We conclude that Dex and cAMP additively stimulate expression of surfactant components in isolated fetal type II cells, providing a simplified culture system for investigation of surfactant-related, and perhaps other, type II cell functions.
The pro-apoptotic molecule BAD binds BCL-[X(L)] or BCL2 and inactivates their survival function. In addition to their anti-apoptotic function, BCL2 and BCL-[X(L)] also delay cell cycle entry from quiescence. We found that the BH3-only molecule BAD also exerted a cell cycle effect. BAD expression resulted in failure to cell cycle block in growth arrest conditions. In low serum and in confluence, fibroblasts constitutively or inducibly expressing BAD persisted in S phase, continued to incorporate BrdU, and exhibited sustained cyclin E/cdk2 activity. Mutation analysis indicated that the cell cycle effect of BAD was not dependent on its phosphorylation status or subcellular localization, but strictly co-segregated with BCL-[X(L)] binding. bclx(-/-) MEFs expressing BAD and bad(-/-) MEFs both arrested in G0/G1 in low serum similar to wild-type controls, suggesting that the ability to overcome the G0/G1 checkpoint resulted from the presence of BAD/BCL-x(L) heterodimers, rather than the absence of BCL-[X(L)] or BAD. These data provide evidence that in addition to regulating apoptosis, the BAD/BCL-[X(L)] heterodimer has a novel cell cycle function.
An inverse correlation between p27(Kip1) expression and proliferation has been recently established in tissues derived from human lymphomas. The nucleophosmin-anaplastic lymphoma kinase (NPM-ALK)/phospholipase C-gamma (PLCgamma) complex also appears to play an important role in cell proliferation and malignant transformation of anaplastic large cell lymphoma (ALCL). In this study, we report that SUDHL-1 and KARPAS 299 ALCL-derived cell lines present different sensitivity to the antiproliferative effect of recombinant adenovirus-mediated p27(Kip1) expression or to serum-starvation in culture media. The results indicate that exogenous p27(Kip1) may interact with the NPM-ALK/PLCgamma pathway in SUDHL-1 but not in KARPAS 299 cells. This interaction correlates with changes in cell cycle and cell morphology observed mainly in SUDHL-1 cells. The percentage of SUDHL-1 cells in S phase declines, whereas it is almost unchanged in KARPAS 299 cells as compared to the controls after 96 h of infection with the recombinant adenovirus. Furthermore KARPAS 299 cells are resistant to serum-starvation due to deficient p27(Kip1)-upregulation and G1 arrest, whereas SUDHL-1 cells respond with increased G1 phase and p27(Kip1)-upregulation after 48 h of serum-starvation. Both cell lines express appropriate variation of levels of cyclins E and A, and Rb-phosphorylation as expected by growing them in culture media with different FBS content. Although both cell lines express cyclin D2, SUDHL-1 cells only present high level of cyclin D3. Moreover SUDHL-1 cells express high level of PTEN and the PKB/Akt pathway is constitutively activated in both cell lines. Lastly SUDHL-1 cells show higher levels of phosphotyrosine-containing proteins that is correlated with a higher NPM-ALK-associated autophosphorylation activity compared to KARPAS 299 cells. Our study clearly identifies some of the biochemical differences that may explain the difference in sensitivity to antiproliferative stimuli shown by two cell lines derived from the same type of lymphoma.