Immortalization of human lymphocytes by transfection with DNA from mouse L929 cytoplasts.

Transfection of human peripheral blood lymphocytes with DNA from mouse L929 cytoplasts induced proliferation of lymphocytes and the formation of B and T cell-derived cell lines with apparently unlimited growth potential. The cell lines could be grown in serum-containing media as well as in chemically defined serum-free media, have a nearly normal human karyotype, did not form colonies in soft-agar medium, and were not tumorigenic after injection into nude mice. For immortalization of human lymphocytes, DNA from L929 cytoplasts was 100-fold more efficient than L929 nuclear DNA. The ability of cytoplast DNA to immortalize lymphocytes could be consecutively transferred by using total cellular DNA from primary or secondary transfectants. Circular or linear mitochondrial DNA of L929 cells did not lead to immortalization of human lymphocytes. Since DNA with immortalizing activity could be isolated from cytoplasts, the Hirt supernatant, and a mitochondria-depleted cytoplasmic fraction of L929 cells, we conclude that the immortalizing DNA is located extramitochondrially in the cytoplasm of L929 cells.     

A novel bispecific protein (ULBP2-BB4) targeting the NKG2D receptor on natural killer (NK) cells and CD138 activates NK cells and has potent antitumor activity against human multiple myeloma in vitro and in vivo

The inability of the immune system to recognize and kill malignant plasma cells in patients with multiple myeloma (MM) has been attributed in part to the ineffective activation of natural killer (NK) cells. In order to activate and target NK cells to the malignant cells in MM we designed a novel recombinant bispecific protein (ULBP2-BB4). While ULBP2 binds the activating NK receptor NKG2D, the BB4 moiety binds to CD138, which is overexpressed on a variety of malignancies, including MM. ULBP2-BB4 strongly activated primary NK cells as demonstrated by a significant increase in interferon-gamma (IFN-gamma) secretion. In vitro, ULBP2-BB4 enhanced the NK-mediated lysis of 2 CD138+ human MM cell lines, U-266 and RPMI-8226, and of primary malignant plasma cells in the allogenic and autologous setting. Moreover, in a nude mouse model with subcutaneously growing RPMI-8226 cells, the cotherapy with ULBP-BB4 and human peripheral blood lymphocytes abrogated the tumor growth. These data suggest potential clinical use of this novel construct in patients with MM. The use of recombinant NK receptor ligands that target NK cells to tumor cells might offer new approaches for other malignancies provided a tumor antigen-specific antibody is available.     

Extracellular superoxide dismutase accelerates endothelial recovery and inhibits in-stent restenosis in stented atherosclerotic Watanabe heritable hyperlipidemic rabbit aorta.

OBJECTIVES: This study examined whether local gene therapy with extracellular superoxide dismutase (EC-SOD) could inhibit in-stent restenosis in atherosclerotic Watanabe heritable hyperlipidemic rabbits. BACKGROUND: Stenting causes an acute increase in superoxide anion production and oxidative stress; EC-SOD is a major component of antioxidative defense in blood vessels and has powerful cardioprotective effects in ischemic myocardium. METHODS: Endothelial denudation and stenting were done in 36 adult (15 to 18 months old) rabbits. Catheter-mediated intramural delivery of clinical good manufacturing practice-grade adenoviruses encoding rabbit EC-SOD were done simultaneously with stenting. Control animals received adenovirus-encoding nuclear-targeted beta-galactosidase (AdLacZ). Circulating markers for oxidative stress (nonesterified 8-iso-prostaglandin F2 alpha) were measured. Analysis of 6-day, 28-day, and 90-day vessel histology, radical production, oxidation-specific epitopes, and expression studies were performed. RESULTS: The EC-SOD treatment reduced oxidant production in stented vessels compared with control vessels. Early systemic recovery of total SOD activity was observed in the treated rabbits. The EC-SOD significantly accelerated endothelial recovery (67.4% +/- 10.8% vs. 24.2.1% +/- 4.6% at 6 days, p < 0.05; 89.3% +/- 3.7% vs. 45.1% +/- 9.6% at 28 days, p < 0.05), and the beneficial effect involved increased proliferation of regenerating endothelium. The EC-SOD group showed a 61.3% lower (p < 0.05) neointimal formation at 28 days, with a similar, albeit nonsignificant trend at 90 days (1.20 +/- 0.32 mm2 vs. 1.88 +/- 0.24 mm2, p = 0.06). CONCLUSIONS: The results suggest a central pathogenetic role of oxidation sensitive signaling processes in endothelial recovery and developing in-stent restenosis in atherosclerotic vessels. Local therapy against oxidative stress represents a promising therapeutic strategy in stent-induced vascular injury.     

CD28-ζ CAR T Cells Resist TGF-β Repression through IL-2 Signaling,Which Can Be Mimicked by an Engineered IL-7 Autocrine Loop

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A functional genetic screen identifies retinoic acid signaling as a target of histone deacetylase inhibitors

Understanding the pathways that are targeted by cancer drugs is instrumental for their rational use in a clinical setting. Inhibitors of histone deacetylases (HDACI) selectively inhibit proliferation of malignant cells and are used for the treatment of cancer, but their cancer selectivity is understood poorly. We conducted a functional genetic screen to address the mechanism(s) of action of HDACI. We report here that ectopic expression of two genes that act on retinoic acid (RA) signaling can cause resistance to growth arrest and apoptosis induced by HDACI of different chemical classes: the retinoic acid receptor alpha (RARalpha) and preferentially expressed antigen of melanoma (PRAME), a repressor of RA signaling. Treatment of cells with HDACI induced RA signaling, which was inhibited by RARalpha or PRAME expression. Conversely, RAR-deficient cells and PRAME-knockdown cells show enhanced sensitivity to HDACI in vitro and in mouse xenograft models. Finally, a combination of RA and HDACI acted synergistically to activate RA signaling and inhibit tumor growth. These experiments identify the RA pathway as a rate-limiting target of HDACI and suggest strategies to enhance the therapeutic efficacy of HDACI.     

Using text analysis to identify functionally coherent gene groups

The analysis of large-scale genomic information (such as sequence data or expression patterns) frequently involves grouping genes on the basis of common experimental features. Often, as with gene expression clustering, there are too many groups to easily identify the functionally relevant ones. One valuable source of information about gene function is the published literature. We present a method, neighbor divergence, for assessing whether the genes within a group share a common biological function based on their associated scientific literature. The method uses statistical natural language processing techniques to interpret biological text. It requires only a corpus of documents relevant to the genes being studied (e.g., all genes in an organism) and an index connecting the documents to appropriate genes. Given a group of genes, neighbor divergence assigns a numerical score indicating how "functionally coherent" the gene group is from the perspective of the published literature. We evaluate our method by testing its ability to distinguish 19 known functional gene groups from 1900 randomly assembled groups. Neighbor divergence achieves 79% sensitivity at 100% specificity, comparing favorably to other tested methods. We also apply neighbor divergence to previously published gene expression clusters to assess its ability to recognize gene groups that had been manually identified as representative of a common function.     

Stimulation of P2 purinergic receptors induces the release of eosinophil cationic protein and interleukin-8 from human eosinophils

1. Extracellular nucleotides are the focus of increasing attention for their role as extracellular mediators since they are released into the extracellular environment in a regulated manner and/or as a consequence of cell damage. 2. Here, we show that human eosinophils stimulated with different nucleotides release eosinophil cationic protein (ECP) and the chemokine interleukin 8 (IL-8), and that release of these two proteins has a different nucleotide requirement. 3. Release of ECP was triggered in a dose-dependent manner by ATP, UTP and UDP, but not by 2'-&3'-o-(4-benzoyl-benzoyl)adenosine 5'-triphosphate (BzATP), ADP and alpha,beta-methylene adenosine 5' triphosphate (alpha,beta-meATP). Release of IL-8 was triggered by UDP, ATP, alpha,beta-meATP and BzATP, but not by UTP or ADP. Pretreatment with pertussis toxin abrogated nucleotide-stimulated ECP but not IL-8 release. 4. Release of IL-8 stimulated by BzATP was fully blocked by the P2X(7) blocker KN-62, while release triggered by ATP was only partially inhibited. IL-8 secretion due to UDP was fully insensitive to KN-62 inhibition. 5. Priming of eosinophils with GM-CSF increased IL-8 secretion irrespectively of the nucleotide used as a stimulant. 6. It is concluded that extracellular nucleotides trigger secretion of ECP by stimulating a receptor of the P2Y subfamily (possibly P2Y(2)), while, on the contrary, nucleotide-stimulated secretion of IL-8 can be due to activation of both P2Y (P2Y(6)) and P2X (P2X(1) and P2X(7)) receptors.