Indication that Intracellular Fluorescence Polarization of T Lymphocytes is Cell Cycle Dependent.

Abstract

ABSTRACT. The degree of depolarization of fluorescence light emitted from an organic dye, used as a molecular probe, is a powerful tool in probing the microenvironment. Polarization measurements of intracellular exogenous fluorescein have been shown to reflect the physiological state of the cells. The relationship between intracellular fluorescein fluorescence polarization (IFFP) and cell cycle, was investigated in the leukemia T-lymphocyte Jurkat cell line. Jurkat T cells were cultured in increasing cell densities, their cell cycle progression cytometrically monitored and the IFFP measured. At the highest cell density, the subpopulation of cells at the resting phases the (G0/Gi) predominated, and the mean IFFP was 0.186 ±0.015. At the lowest density, with diminished proportion of cells in the Gi/G2 stages the mean IFFP decreased to 0. sis, Ca+2 mobilization and the induction of early protooncogenes. These events are followed by the increased expression of the genes for interleukine IL-2 and its receptor, leading to cell proliferation. Stimulation of T lymphocytes with PHAhas also

A Novel System to Diagnose Cutaneous Adverse Drug Reactions Employing the Cellscan—Comparison with Histamine Releasing Test and Inf‐γ Releasing Test

“…The CellScan is unique in its capability of repetitive measurements of individual cells in a cell population. It has been used to detect activation of lymphocytes both in physiological (Eisenthal et al 1996, Zurgil et al 1996 and pathological situations including: cancer (Ron et al 1995, Merimsky et al 1996, Rahmani et al 1996, Schiffenbauer et al 2002, Cohen et al 2003, autoimmune disorders (Zurgil et al 1997, and atherosclerosis ).…”

Application of a Static Fluorescence‐based Cytometer (the CellScan) in Basic Cytometric Studies, Clinical Pharmacology, Oncology and Clinical Immunology

“…Both hydroxyurea mediated S phase arrest and noconazole mediated G 2 /M arrest induced a reduction in FP. Thus, FP is cell-cycle dependent with significantly lower values for cycling than for non-cycling populations (Zurgil et al 1996).…”

“…Among these probes is fluorescein diactetate (FDA), a non-fluorescent molecule that undergoes fluorochromasia in viable cells. This includes penetration of FDA, its enzymatical hydrolysis, which converts it to fluorescein, and the accumulation of the latter (Zurgil et al 1996).…”

Application of a Static Fluorescence-Based Cytometer: The Cellscan in Clinical Immunology

“…After it penetrates the cell, FDA is converted by enzymatical hydrolysis to fluorescein, which accumulates in the cell. 4 Upon excitation with a polarized light, FP reflects the level of freedom of the intracellular dye. 2 The more the molecule rotational movement is restricted, the higher the fluorescence polarization value, and vice versa.…”