Effect of electric field pulses on the viability and on the membrane‐bound immunoglobulins of LPS‐activated murine B‐lymphocytes: Correlation with the cell cycle
Tóm tắt
The effects, of microsecond electropulses (1–kV/cm) on the viability of murine B lymphocytes and on their binding of antibodies by surface immunoglobulin (Ig) were studied in relation to the cell cycle. Before electropulsing, cultures given 48 h mitogenic stimulation showed at least two cell subpopulations, which were distinguishable by their levels of surface‐Ig expression as assessed with FITC‐labelled antibodies against mouse Ig. The immunofluorescence intensity of cells in S and G2/M phases was higher than that of G0/G1 cells.
After exposure of the mitogen‐stimulated lymphocytes to three exponentially decaying (time constantτ=5–40 μs) electric field pulses, dye exclusion assay showed that pulsing at 1 or 2 kV/cm (at 4°C or 20°C) did not cause permeabilization. Field strengths of 3, 4, or 5 kV/cm resulted in 20%, 45%, or 70% of dye‐permeable cells, respectively, if the pulsed cells were transferred to phosphate‐buffered saline on ice for 30 min. Incubation in full medium at 37°C for 30 min (“resealing”) significantly decreased the percentage of permeabilized cells. Electropulsed G0/G1 cells were not only more resistant to direct electric exposure (tolerated higher field strengths) than S+G2/M cells but also responded better to resealing.
The surface Ig of lymphocytes pulsed at higher fields and low temperature (4 or 5 kV/cm, τ =5 μs, three pulses, 4°C) was less easily immunostained than in controls or in cells pulsed at 2 kV/cm or less. At 5 kV/cm those cells that were not permeabilized showed a greater reduction in immunostaining, especially if resealed. © 1994 Wiley‐Liss, Inc.
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Tài liệu tham khảo
Amigorena S, 1990, Ion channel blockers inhibit B cell activation at a precise stage of the Gl phase of the cell cycle, J Immunol, 144, 2038, 10.4049/jimmunol.144.6.2038
Chauvin F, 1987, Voltage sensing of mitochondrial ATPase in pulsed electric field induced ATP synthesis, Biophys J, 51, 243a
Darzynkiewicz Z, 1990, Flow Cytometry and Sorting, 469
Hill BT, 1978, Cancer chemotherapy: The relevance of certain concepts of cell cycle kinetics, Biochim Biophys Acta, 516, 389
Kowalski M, 1990, Electrofused mammalian cells analyzed by free‐flow electrophoresis, BioTechniques, 9, 332
Pethig R, 1979, Dielectric and Electronic Properties of Bological Materials
Prouty WF, Effects of protease inhibitors on protein breakdown in Escherichia coli, J Biol Chem, 247, 3341, 10.1016/S0021-9258(19)45251-4
Valet G, 1984, Automated flow‐cytometric identification of colo–rectal tumour cells by simultaneous DNA, CEA‐antibody and cell volume measurements, J Clin Chem Clin Biochem, 22, 935
Valet G, 1987, Clinical Cytometry and Histometry, 58
Zimmermann U, 1983, Targeted Drugs, 153
Zimmermann U, 1989, Electromanipulation in Hybridoma Technology, 1