Arye Weinreb

Decrease of intracellular fluorescein fluorescence polarization (IFFP) in human peripheral blood lymphocytes undergoing stimulation with phytohaemagglutinin (PHA), concanavalin A (ConA), pokeweed mitogen (PWM) and anti-CD3 antibody

Summry— In the present study we describe the induction of changes in intracellular fluorescein fluorescence polarization (IFFP) in lymphocytes undergoing activation with a variety of stimulants. These stimulants included the lectins phytohaemagglutinin (PHA), concanavalin (ConA), pokeweed mitogen (PWM) and anti‐CD3 antibody. Changes in IFFP were detected in individual cells using the Cellscan apparatus. Our results show that by employing mitogenic concentrations of PHA, as revealed in a [3H]‐thymidine incorporation assay, a decrease in the IFFP in human peripheral blood lymphocytes (PBL) occurred within 40 min. ConA and anti‐CD3 affected similarly IFFP, whereas PWM, a B lymphocyte lectin, had no effect on IFFP at the concentrations employed. Kinetic analysis revealed that changes in IFFP occurred within 20–40 min after exposure to the stimulants and lasted for 24 h. Our results show that stimulants which activate CD3+ lymphocytes caused immediate changes in IFFP, in an enriched population of human PBL. The possible mechanisms involved in IFFP modulation following exposure to selected stimulants are discussed.

Lymphocyte fluorescence polarization measurements with the cellscan system: Application to the SCM cancer test

The SCM (Structuredness of Cytoplasmic Matrix) cancer test, a procedure based on detection of differences in lymphocyte activation between individuals with and without cancer, has remained controversial with inconsistent results reported by different authors. As originally described, the test includes two technically demanding steps, the first a lymphocyte separation procedure and the second a series of fluorescence polarization measurements. The Cellscan, a high-precision static cytometer system has been configured to perform the SCM test. The apparatus facilitates the polarization measurements and can analyze cells separated using simpler procedures than were originally described. Using methods and diagnostic criteria adapted for the Cellscan system, the SCM test correctly classified > 90% of patients with cancer and > 90% of individuals without cancer.

Adaptation of the cellscan technique for the SCM test in breast cancer

The value of the SCM (Structuredness of Cytoplasmic Matrix) cancer test, a procedure based on the detection of differences in lymphocyte activation in the presence and absence of cancer, has remained controversial, with inconsistent results having been reported among investigators. The Cellscan, a high-precision static cytometer system, has been designed to perform the SCM test; the apparatus facilitates the polarisation measurements and can examine cells which have been separated by simpler procedures than were originally described. In this study, using methods and diagnostic criteria adapted for the Cellscan system in a hospital environment, the SCM test correctly classified over 90% (76/80) of patients with breast cancer and differentiated over 90% (72/73) of individuals without cancer.

Tumour specificity of the SCM test for cancer diagnosis

Phytohaemagglutinin (PHA), a well-known mitogen, and encephalitogenic factor (EF) are recognized by lymphocytes of patients with different malignant diseases as non-specific antigens. Utilizing these two antigens, the SCM (structuredness of the cytoplasmatic matrix) test offers a means of discrimination between malignant and non-malignant diseases. The SCM test can also be used as a specificity test since lymphocytes from donors with a given malignant disease react exclusively with the tumour-associated antigen (TAA) of that disease. Results from 73 donors (15 healthy patients, 38 patients with different types of malignant disorders and 20 patients with autoimmune diseases) indicate the predictive value of the test. First, the non-specific test was applied in order to establish whether the patients suffered from an active malignant disease. The lymphocytes of those patients which were found to suffer from an active malignant disorder were then exposed to different types of tumour tissues. Twenty-five out of the 38 patients with malignant disorders were found by the SCM test to have an active disease. The lymphocytes of 24 out of these 25 patients showed a positive reaction when exposed to tumour tissue of the same type of cancer of which they were found to suffer by other clinical tests, and displayed no reaction with any other tumour tissues for which they were tested. One patient, with an inconclusive value of the SCM test, showed no reaction with any type of tumour to which he was exposed. The remaining 13 patients, who were diagnosed by the test as non-cancerous, did not show any clinical evidence of malignancy at the time of the test, after their tumours had been excised. Eighteen out of 20 patients with autoimmune diseases showed negative results when tested by the general test and by the various specificity tests.

Cell activation influences cell staining kinetics

Stimulation of cells has so far been observed, among other methods, by the decrease of the intracellular fluorescein fluorescence polarization (IFFP). It is shown that the rate constant of leakage of the fluorescent marker out of the cells increases with stimulation much more significantly than the polarization decreases; thus it might provide a more sensitive method to observe cells stimulation. It is also shown that due to negligible leakage of the marker out of the cells shortly after initiation of the staining of the cell suspension, the fluorescein fluorescence polarization (FFP) of the cell suspension, is very close to IFFP.

Carboxyfluorescein as a fluorescent probe for cytoplasmic effects of lymphocyte stimulation

The application of carboxyfluorescein (CF), as an impermeable fluorescent probe for lymphocyte stimulation with phytohaemagglutinin (PHA), is investigated by following a decrease in the degree of fluorescence polarization. Since CF does not enter the mitochondria, the present results indicate that the measured effect of stimulation occurs in the cytoplasm. The results also reveal that the fluorescence yield of intracellular CF is smaller than that of extracellular CF. Moreover, the degree of fluorescence polarization of intracellular CF is inversely related to its concentration. Following cell disruption, fluorescence intensity increases and polarization decreases. These effects might indicate a weak or reversible association of intracellular CF with cytoplasmic proteins.

Fluorescence Polarization as a Functional Parameter in Monitoring Living Cells: Theory and Practice

The use of fluorescence polarization as a functional parameter in monitoring cellular activation calls for the reliable and accurate measurement of the fluorescence intensity and polarization (FI and FP) of microscopic objects. The relevant experimental parameters that enter such measurements are thoroughly discussed. The possibility of executing FP measurements properly by flow-through systems is compared with that of static cytometry. Remarks on the effects of high-power excitation on markers and cells conclude the paper.

Effect of Interleukin-1α, Interleukin-1β and Tumor Necrosis Factor-α on the Intracellular Fluorescein Fluorescence Polarization of Human Lung Fibroblasts

In the present study we aimed to detect early intracellular changes in the cytoplasmic matrix induced in human, pulmonary-derived fibroblasts following exposure to interleukin (IL)-1 alpha, IL-1 beta and tumor necrosis factor-alpha. Such changes were detected by measuring intracellular fluorescein fluorescence polarization (IFFP) using the Cellscan apparatus. IFFP measurement was selected in our study since it has been shown to reflect the microviscosity of the cytoplasmic matrix. Significant reductions (> or = 5%) in the IFFP were induced in fibroblasts by all the cytokines employed. The effect of cytokines on IFFP was achieved at concentrations of 5-10 ng/ml of the cytokines. The reduction in IFFP, following stimulation with the cytokines, was detected as early as 20 min after exposure to the cytokines, lasted at least 40-60 min after exposure to IL-1 alpha and IL-1 beta, and was inhibited by vinblastine, an inhibitor of the polymerization of microtubules. Our results show that IFFP measurements by the Cellscan may reveal rapid intracellular changes occurring in the cytoskeleton components of activated cells.

2',7'-bis-(Carboxyethyl)-5-(6')-Caroboxyfluorescein (BCECF) as a probe for intracellular fluorescence polarization measurements

The utility of 28,78-bis-(carboxyethyl)-5-(68)-carboxyfluorescein (BCECF) for the execution of the structuredness of the cytoplasmic matrix (SCM) measurement for lymphocyte activation is investigated. Cells were incubated with BCECF/AM [28,78-bis-(carboxyethyl)-5(68)-carboxyfluorescein acetoxymethylester], a nonfluorescent lipophilic acetoxymethylester that readily enters cells and is enzymatically hydrolyzed to fluorescent BCECF once inside. Leakage of BCECF out of cells is negligible in comparison to that observed with fluorescein, greatly reducing one source of background fluorescence. However, spontaneous hydrolysis of BCECF/AM in aqueous solution does contribute significant background fluorescence, which can be minimized by staining at relatively high concentrations of cells and subsequent dilution. As is the case with fluorescein, the polarization spectrum of intracellular BCECF shows a wavelength dependence not seen in the spectrum of the dye in homogeneous media of various viscosities. The more pronounced wavelength dependence of the polarization observed with BCECF compared with fluorescein suggests that BCECF might be preferable to fluorescein as a marker for the SCM test.

Cancer Diagnosis by Fluorescence Polarization

The work presented in the following originated in an attempt to modify the SCM test in such a way as to make it applicable as a routine method for the early detection and follow up of cancer. To do this we had first to validate the test itself which has been described by B.& L. Cercek in 1974 and later on, since until this day the test is a controversial issue. When this was done in 1980 we made it our aim to facilitate the test, to increase its accuracy and speed. This lead to the development of a novel method of cell scanning which permits the repeated measurement of a great number of cells, each one individually, after any desired number of manipulations on these cells. Although this method may have important applications in many fields of biology, we limit our discussion here to its original purpose, the diagnosis of cancer. Our presentation will thus be divided into two parts. In the first part we give a description of the SCM test as executed by us; in the second part we describe the Cytoscan, which is the method of cell scanning developed by us, and the tests performed with this equipment until present.