Surfactant enhancement of polyethyleneglycol-induced cell fusion

Derivation of Arbas Cashmere Goat Induced Pluripotent Stem Cells in LCDM with Trophectoderm Lineage Differentiation and Interspecies Chimeric Abilities

The Arbas cashmere goat is a unique biological resource that plays a vital role in livestock husbandry in China. LCDM is a medium with special small molecules (consisting of human LIF, CHIR99021, (S)-(+)-dimethindene maleate, and minocycline hydrochloride) for generation pluripotent stem cells (PSCs) with bidirectional developmental potential in mice, humans, pigs, and bovines. However, there is no report on whether LCDM can support for generation of PSCs with the same ability in Arbas cashmere goats. In this study, we applied LCDM to generate goat induced PSCs (giPSCs) from goat fetal fibroblasts (GFFs) by reprogramming. The derived giPSCs exhibited stem cell morphology, expressing pluripotent markers, and could differentiate into three germ layers. Moreover, the giPSCs differentiated into the trophectoderm lineage by spontaneous and directed differentiation in vitro. The giPSCs contributed to embryonic and extraembryonic tissue in preimplantation blastocysts and postimplantation chimeric embryos. RNA-sequencing analysis showed that the giPSCs were very close to goat embryos at the blastocyst stage and giPSCs have similar properties to typical extended PSCs (EPSCs). The establishment of giPSCs with LCDM provides a new way to generate PSCs from domestic animals and lays the foundation for basic and applied research in biology and agriculture.

Synergistic effect of non-ionic surfactants Tween 80 and PEG6000 on cytotoxicity of insecticides

The use of surfactants in the development of a suitable formulation for insecticides should improve the solubility behavior, the permeability and the efficiency against pests meanwhile decrease the toxic risks of insecticides on human health. Cytotoxicity of insecticides including abamectin, chlorfluazuron, hexaflumuron, chlorpyrifos, and tebufenozide was assessed on human HepG2 and lepidopteran Tn5B1-4 cells utilizing insecticide alone and in combination with nontoxic concentrations of nonionic surfactants Tween 80 and PEG6000. The results showed avermection revealed high cytotoxicity, chlorfluazuron and hexaflumuron possessed median cytotoxicity, and chlorpyrifos and tebufenozide had little cytotoxicity on HepG2 and Tn5B1-4 cells. The co-incubation with Tween 80 and PEG6000 powerfully counteracted the cytotoxicity of avermectin. Tween 80 enhanced, whereas PEG6000 compressed, the cytotoxicity of chlorfluazuron on Tn5B1-4 cells, and also improved a bit of the cytotoxicity of chlorpyrifos or tebufenozide on HepG2 cells. PEG6000 was more suitable to be used as surfactant in improving insecticide solubility and reducing the cytotoxicity. The present investigation demonstrates the necessity of utilizing surfactants to weaken the cytotoxicity of insecticides.

Semiallogeneic cell hybrids as therapeutic vaccines for cancer

The authors have engineered a cell line that can be used in human studies as a universal donor cell for the formation of semiallogeneic cell hybrids after fusion with patient-derived tumor cells. These hybrids can be irradiated and injected as a patient-tailored therapeutic vaccine in patients affected by virtually any type of cancer. A crucial step in this research effort has been the derivation of an allogeneic cell line (FO1-12) that expresses both a dominant selectable marker (neomycin resistance) and a recessive selectable marker (sensitivity to hypoxanthine, aminopterin, and thymidine), which allows easy selection of semiallogeneic cell hybrids derived from the fusion of FO1-12 cells with patient-derived tumor cells. Tumor-infiltrating lymphocytes derived from select patients with melanoma and exposed to semiallogeneic cell hybrids from the same patient were better able to specifically lyse autologous tumor cells. Furthermore, FO1-12 cells express carcinoembryonic antigen, which is ubiquitous in adenocarcinomas, and fusion of FO1-12 cells with various patient-derived adenocarcinoma cells showed that the hybrid cells also express carcinoembryonic antigen. Because of the results of these preclinical studies, the authors were given permission to use semiallogeneic cell hybrids for immunotherapy of patients with metastatic melanoma or metastatic adenocarcinoma who had not responded to standard treatment regimens. Treatment with semiallogeneic vaccines is associated with minimal or no toxicity and can induce a specific anti-tumor immune response.

Phospholipase A2-like catalytic antibody

The phospholipase A2-like catalytic antibody 13C2-1F6 was elicited against the hapten 1 as the transition state analog for the hydrolysis of the C2 ester in the phospholipid. The Michaelis-Menten kinetics for the hydrolysis of the phospholipid 2 by 13C2-1F6 afforded a kcat of 1.0 x 10(-2) min(-1) and aKm of 71 microM. This antibody hydrolyzes the C2 ester in (R)-2, regio- and enantioselectively.

Real-time measurements of chemically-induced membrane fusion in cell monolayers, using a resonance energy transfer method

Fusion of mouse melanoma cells grown in monolayers has been directly monitored by fluorescence resonance energy transfer between fluorescein and rhodamine probes attached to octadecanoic acid. Various poly(ethylene glycol)s (PEG), either alone or in combination with amphipathic molecules, have been used as fusogens. Fusion starts at a maximum rate as soon as PEG is removed from the medium and reaches a plateau after 20-30 min. Both the initial rate and extent of fusion have been recorded for each experiment. The extent of fusion shows in general a positive correlation with the initial rate, although PEGs with different molar masses appear to induce fusion at different rates, but to a similar extent. A good correlation has been found between the extent of fusion, as measured by fluorescence, and the 'fusion index' computed from cell and nucleus counting; a calibration curve is provided for the interconversion of both parameters. Optimum fusion values are obtained with 50% (w/v) PEG 1500. The effect of pre-treatments with surfactants (Triton X-100, sodium dodecylsulphate) on PEG-induced fusion has also been tested. Sodium dodecylsulphate, but not Triton, enhances considerably both the rate and extent of cell fusion. The in situ generation of the amphipathic molecule diacylglycerol, through the catalytic activity of a phospholipase C, also enhances significantly the fusion parameters. These results are in good agreement with previous studies based on syncytia counting.