Detection of Anti-Phospholipid and Anti-DNA Antibodies and their Idiotypes in Newborns of Mothers with Anti-Phospholipid Syndrome and Sle

The titers, isotypes and idiotypes of antiphospholipid and anti-dsDNA antibodies were determined in seven pairs of mothers with antiphospholipid syndrome (APLS) and their offspring, in 11 pairs of SLE mothers and their matched infants and in seven respective pairs of healthy subjects. In addition, maternal as well as fetal sera were evaluated for the presence of anti-SSA (Ro), anti-SSB (La) and anti-70 kd RNP autoantibodies.

In the sera from APLS patients, as well as in the sera from their offspring, the mean antibody titer of IgG aCL was found to be significantly higher then the corresponding value in the control group (P < 0.01). Highly significant increased titers of IgG anti-DNA antibodies were found in the sera of SLE mothers and their matched offspring (P < 0.0008).

The prevalance of anti-SSA, anti-SSA, and anti-7OKd RNP antibodies was lower then that of antiphospholipid and anti-dsDNA antibodies. Only one of the respective offspring had increased levels of these antibodies.

The quantity of maternal antibodies transferd to the fetus was depended on their concentration in the maternal circulation, as well as on their type and specificity. Follow-up of newborn sera showed a progressive decrease in the antiphospholipid antibody titers during 3 months. After 6 months it was undetected.

Our results point to a transplacental transfer of aCL and anti-DNA antibodies, a phenomenon which is not necessarily associated with respective clinical manifestations, in contrast to the classical humoral mediated autoimmune diseases (e.g. myasthenia gravis).

An Information-theoretical Model for Breast Cancer Detection

Objectives: Formal diagnostic modeling is an important line of modern biological and medical research. The construction of a formal diagnostic model consists of two stages: first, the estimation of correlation between model parameters and the disease under consideration; and second, the construction of a diagnostic decision rule using these correlation estimates. A serious drawback of current diagnostic models is the absence of a unified mathematical methodological approach to implementing these two stages. The absence of aunified approach makesthe theoretical/biomedical substantiation of diagnostic rules difficult and reduces the efficacyofactual diagnostic model application. Methods: The present study constructs a formal model for breast cancer detection. The diagnostic model is based on information theory. Normalized mutual information is chosen as the measure of relevance between parameters and the patterns studied. The “nearest neighbor” rule is utilized for diagnosis, while the distance between elements is the weighted Hamming distance. The model concomitantly employs cellular fluorescence polarization as the quantitative input parameter and cell receptor expression as qualitative parameters.

Results: Twenty-four healthy individuals and 34 patients (not including the subjects analyzed for the model construction) were tested by the model. Twenty-three healthy subjects and 34 patients were correctly diagnosed.

Conclusions: The proposed diagnostic model is an open one,i.e.it can accommodate new additional parameters, which may increase its effectiveness.

Hydrogel microstructure live-cell array for multiplexed analyses of cancer stem cells, tumor heterogeneity and differential drug response at single-element resolution

Specific phenotypic subpopulations of cancer stem cells (CSCs) are responsible for tumor development, production of heterogeneous differentiated tumor mass, metastasis, and resistance to therapies. The development of therapeutic approaches based on targeting rare CSCs has been limited partially due to the lack of appropriate experimental models and measurement approaches. The current study presents new tools and methodologies based on a hydrogel microstructure array (HMA) for identification and multiplex analyses of CSCs. Low-melt agarose integrated with type I collagen, a major component of the extracellular matrix (ECM), was used to form a solid hydrogel array with natural non-adhesive characteristics and high optical quality. The array contained thousands of individual pyramidal shaped, nanoliter-volume micro-chambers (MCs), allowing concomitant generation and measurement of large populations of free-floating CSC spheroids from single cells, each in an individual micro-chamber (MC). The optical live cell platform, based on an imaging plate patterned with HMA, was validated using CSC-enriched prostate and colon cancer cell lines. The HMA methodology and quantitative image analysis at single-element resolution clearly demonstrates several levels of tumor cell heterogeneity, including morphological and phenotypic variability, differences in proliferation capacity and in drug response. Moreover, the system facilitates real-time examination of single stem cell (SC) fate, as well as drug-induced alteration in expression of stemness markers. The technology may be applicable in personalized cancer treatment, including multiplex ex vivo analysis of heterogeneous patient-derived tumor specimens, precise detection and characterization of potentially dangerous cell phenotypes, and for representative evaluation of drug sensitivity of CSCs and other types of tumor cells.

Donut-shaped chambers for analysis of biochemical processes at the cellular and subcellular levels

In order to study cell-cell variation with respect to enzymatic activity, individual live cell analysis should be complemented by measurement of single cell content in a biomimetic environment on a cellular scale arrangement. This is a challenging endeavor due to the small volume of a single cell, the low number of target molecules and cell motility. Micro-arrayed donut-shaped chambers (DSCs) of femtoliter (fL), picoliter (pL), and nanoliter (nL) volumes have been developed and produced for the analysis of biochemical reaction at the molecular, cellular and multicellular levels, respectively. DSCs are micro-arrayed, miniature vessels, in which each chamber acts as an individual isolated reaction compartment. Individual live cells can settle in the pL and nL DSCs, share the same space and be monitored under the microscope in a noninvasive, time-resolved manner. Following cell lysis and chamber sealing, invasive kinetic measurement based on cell content is achieved for the same individual cells. The fL chambers are used for the analysis of the same enzyme reaction at the molecular level. The various DSCs were used in this proof-of-principle work to analyze the reaction of intracellular esterase in both primary and cell line immune cell populations. These unique DSC arrays are easy to manufacture and offer an inexpensive and simple operating system for biochemical reaction measurement of numerous single cells used in various practical applications.

The Influence of Different Cultivating Conditions on Polymorphonuclear Leukocyte Apoptotic Process In Vitro, II: Ultrastructural Characteristics of PMN Populations Incubated with Proteinase 3 Anti-neutrophil Autoantibodies

The present study shows the effects of proteinase 3 anti-neutrophil cytoplasmic autoantibodies (PR3 ANCA) on polymorphonuclear leukocytes (PMN) apoptotic processes in vitro. The results are part of a generalized morphological analysis of 3 identical experiments on the influence of different cultivating conditions on the apoptotic processes. As controls, the authors use the results on spontaneous PMN apoptosis (Guejes L, Zurgil N, Deutsch M, Gilburd B, Shoenfeld Y. Ultrastruct Pathol. 2003;27: 23-32) and PMN populations incubated with normal human IgG. Interaction of PR3 ANCA with the target antigen proteinase 3 (PR3) is one of the crucial pathogenic factors in Wegener granulomatosis (systemic autoimmune vasculitis). Following 40min and 12h incubation, PMN populations were evaluated by light microscopy, transmission electron microscopy, and immunogold electron microscopy. Twelve-hour cultures, either control or incubated with PR3 ANCA, contained different cell forms ranging from normal cells to cells at the final stages of apoptosis. Neutrophils at the state of complete manifestation of apoptotic phenotype were analyzed and compared. Three morphologically distinct apoptotic cell lines were characteristic for all PMN populations studied, regardless of cultivating conditions. As in spontaneous apoptosis, these cell lines are code-named "first," "second," and "third." The present study has shown, firstly, that in the presence of PR3 ANCA, all 3 apoptotic lines were modified or altered. Secondly, the modifications or alterations of apoptotic cell lines effected by PR3 ANCA are specific for each cell line: the "first" line is characterized by intensification and modification of activation; the "second" by vacuolized cell forms; and the "third" by pronounced lytic alterations of the nuclei, while the cytoplasm is fully identical to that of control cell lines.

Methotrexate selectively modulates TH1/TH2 balance in active rheumatoid arthritis patients

OBJECTIVE

The mechanism by which low dose methotrexate (MTX, the gold standard treatment for rheumatoid arthritis) exerts its anti-inflammatory effect in rheumatoid arthritis (RA) patients is still debated. Lately, the MTX immunosuppressive effect has been related to apoptosis, especially in active RA patients, with ROS involvement.

METHODS

In the present research we investigated MTX oxidative effect and its ability to modulate immune balance in active versus non-active RA patients.

RESULTS

Our results show that MTX induces IL-10 secretion (a TH2 cytokine) and significantly reduces TH1 profile in Peripheral Mononuclear Cells (PMNC) derived from active RA patients (n=28). Additionally, we found that MTX modulates the immune status towards TH2 dominance by decreasing the IL-12R and the CXCR3 receptors typical for the TH1 population. Moreover, MTX was found to inhibit the production of nitric oxide (NO) in these patients, a phenomenon that might contribute to MTX action toward cytokine homeostasis. A significant correlation was found between MTX IL-10 induction and NO inhibition in active RA patients.

CONCLUSION

Our data suggest that, in active RA patients, apoptosis induction by MTX may be primarily due to IL-10 production via modulation of oxidative stress, which may restore the critically important immune balance. These findings may contribute to determining which group of RA patients may better respond to MTX therapy.

An information-theoretical model for breast cancer detection

OBJECTIVES

Formal diagnostic modeling is an important line of modern biological and medical research. The construction of a formal diagnostic model consists of two stages: first, the estimation of correlation between model parameters and the disease under consideration; and second, the construction of a diagnostic decision rule using these correlation estimates. A serious drawback of current diagnostic models is the absence of a unified mathematical methodological approach to implementing these two stages. The absence of a unified approach makes the theoretical/biomedical substantiation of diagnostic rules difficult and reduces the efficacy of actual diagnostic model application.

METHODS

The present study constructs a formal model for breast cancer detection. The diagnostic model is based on information theory. Normalized mutual information is chosen as the measure of relevance between parameters and the patterns studied. The "nearest neighbor" rule is utilized for diagnosis, while the distance between elements is the weighted Hamming distance. The model concomitantly employs cellular fluorescence polarization as the quantitative input parameter and cell receptor expression as qualitative parameters.

RESULTS

Twenty-four healthy individuals and 34 patients (not including the subjects analyzed for the model construction) were tested by the model. Twenty-three healthy subjects and 34 patients were correctly diagnosed.

CONCLUSIONS

The proposed diagnostic model is an open one, i.e. it can accommodate new additional parameters, which may increase its effectiveness.

Low dose methotrexate induces apoptosis with reactive oxygen species involvement in T lymphocytic cell lines to a greater extent than in monocytic lines

BACKGROUND

The mechanism by which low dose methotrexate (MTX) exerts its anti-inflammatory and immunosuppressive effect in rheumatoid arthritis (RA) patients is still debated. Recently it has been related to the induction of apoptosis.

OBJECTIVE

We investigated the degree of apoptotic induction by MTX in lymphocytic (Jurkat T, EL4 T, and Raji B) and monocytic cell lines (U937 and THP1) and its relation to reactive oxygen species (ROS) generation, as a possible mechanism underlying the apoptotic events.

METHODS

All cell types were incubated with a range of MTX concentrations (0.001, 0.01, 0.1, 1, and 10 muM) for up to 24 h. Cytotoxicity was assessed by Trypan Blue exclusion and MTT test; cell size and granularity by forward and side scatters (FSC, SSC). Apoptosis was measured by Annexin V test and FDA polarization; and mitochondrial ROS generation by DHR123 probe and by NAC inhibition.

RESULTS

MTX significantly reduced cell viability and proliferation in all cell lines, being most effective in the Jurkat T lymphocytic line. The MTX cytotoxicity (at the optimal concentrations corresponding to low dose MTX therapy) was attributed to apoptosis, as suggested by morphological changes (shrinkage, increased granularity) and confirmed by Annexin V binding and FDA hyperpolarization. The apoptotic induction and the ROS generation (statistically correlated to apoptosis) were most pronounced in the Jurkat and EL4 T cell lines, and were partially inhibited by the antioxidant N-acetyl L-cysteine (NAC).

CONCLUSION

According to the present observations, MTX may most likely induce apoptosis through oxidative stress. The high susceptibility of T cell lines to MTX induced apoptosis may account for the beneficial effect of MTX treatment in rheumatoid arthritis, which is characterized by hyperproliferation of T cells.

Overexpression of 15-lipoxygenase in the vascular endothelium is associated with increased thymic apoptosis in LDL receptor-deficient mice

BACKGROUND

15-Lipoxygenase (15-LO) is a nonheme iron-containing enzyme that catalyzes the peroxidation of fatty acids. Herein, we studied the effect of 15-LO overexpression in the vascular endothelium on thymocyte apoptosis by evaluating thymuses from low-density lipoprotein receptor-deficient (LDL-RD) mice and LDL-RD/15-LO mice. Thymuses were evaluated by immunohistochemistry and by TUNEL whereas in vitro studies were carried out by employing freshly isolated thymocytes from the respective mice and evaluation of apoptosis by propidium iodide and annexin V cytometry.

METHODS AND RESULTS

The apoptotic index in LDL-RD/15-LO mice was significantly higher than in the LDL-RD mice. In the thymic medulla the difference was smaller, although still significant. Freshly isolated thymus cells from LDL-RD/15-LO mice exhibited a higher rate of spontaneous cell death than controls. Incubation of thymus cells in the presence of the cell-permeable caspase-3 inhibitor DEVD-CMK resulted in a decrease in the frequency of apoptotic cells in LDL-RD/15-LO thymocytes, whereas no effect was evident in control thymocytes. The antioxidant N-acetylcysteine causes the increase in apoptosis in both groups.

CONCLUSION

LDL-RD/15-LO mice exhibit increased thymocyte apoptosis both in vivo and in vitro. These findings may suggest a role for 15-LO in the natural selection of thymocytes.

Antineutrophil cytoplasmic autoantibodies penetrate into human polymorphonuclear leukocytes and modify their apoptosis

OBJECTIVE

The interaction of extracellular anti-neutrophil cytoplasmic autoantibodies (ANCA) with neutrophilic granules may play an important role in the pathogenesis of ANCA-related disorders. It has been confirmed that apoptosis is an essential trigger associated with translocation of the cytoplasmic granules to the cell surface, and with the expression of ANCA antigens. Since cell penetration by autoantibodies and apoptosis may be associated processes, we tested the hypothesis that penetration of ANCA-autoantibodies into polymorphonuclear leukocytes (PMNs) has an effect on apoptosis and thereby can influence surface antigen expression.

METHODS

PMNs were isolated from the blood of healthy volunteers and incubated in the presence of anti-proteinase3 (PR3) enriched IgG or normal human IgG. For each period of incubation (40 minutes or 12 hours) we evaluated: 1) PMN morphology by light microscopy (LM) and transmission electron microscopy (TEM) for general estimation of the apoptotic process, and 2) ANCA binding to the target antigen by immunogold electron microscopy (IgEM).

RESULTS

Both normal and anti-PR3 IgG penetrate PMNs. The labeled PR3-ANCA were localized on PR3 granules, regardless of the granules' location within the cell, and in the sites where the PMN destruction processes were most expressed. The destructive processes showed extensive apoptotic characteristics, in contrast to PMNs penetrated by normal IgG.

CONCLUSION

PR3 ANCA penetrate PMNs and, via the interaction between PR3-ANCA and PR3-containing granule components, initiate a modification of the apoptotic process.

The influence of different cultivating conditions on polymorphonuclear leukocyte apoptotic processes in vitro, I: the morphological characteristics of PMN spontaneous apoptosis

Polymorphonuclear leukocyte (PMN) populations incubated in vitro with normal human serum are save-regulated systems of spontaneous apoptosis. Light microscopy (LM), transmission (TEM), and scanning (SEM) electron microscopes were used for the evalution of PMN apoptopic alteration. Twelve-hour PMN populations were represented by optimal number of normal and different apoptotic forms. Their ultrastructural analysis showed that on this background, 3 apoptotic cell lines (code named "first," "second," and "third") were predominated. The following characteristics were featured: "first"--vacuolization of same organelles, release of their content outside, increase of general cytoplasmic density, nuclear filling with condensed chromatin, and formation of PMNs mainly into small, round, dense forms; "second"--involvement of micronuclei or nuclei in apoptosis, their displacement to the cytoplasmic membrane and separation from the cells, and cytoplasm had numerous intact granules almost until the completion of apoptosis; "third"--synchronous apoptotic process of the nuclei and cytoplasm, moderate electronic density of cytoplasm, and granular translocation to the cell surface. Secondary necrosis was completed mainly in the apoptotic process of the "second" and "third" lines. SEM surfaces confirmed the results of TEM. This research showed that neutrophil spontaneous apoptosis is a complicated process. The 3 apoptotic cell lines reflect different pathways characteristic for the studied systems under certain conditions of cultivation.

Analysis of early apoptotic events in individual cells by fluorescence intensity and polarization measurements

Apoptosis is a dynamic process of variable duration. The ability to continuously detect the death process occurring in single or subgroups of cells is therefore very important in identifying apoptotic cells within a complex population. The Individual Cell Scanner (ICS), a multiparametric, multilaser-based scanning static cytometer, was used in the present report for the continuous monitoring of the apoptosis process. Fluorescence intensity (FI), polarization (FP), kinetic measurements, and cluster analysis of subpopulations were carried out utilizing various fluorescent probes. Hydrogen peroxide-induced apoptosis was monitored online in intact live lymphocytes by continuous sequential measurements of intracellular hyperpolarization. Plasma membrane asymmetry, mitochondrial membrane potential, and lysosomal rupture were monitored in individual cells. Cytoplasmic condensations, due to cell shrinkage and early lysosomal rupture, were found to be very early events of apoptosis. The new analytical capabilities suggested here may provide simple and convenient methods for detecting apoptosis from its earlier stages.

Analysis of laser scattering pattern as an early measure of apoptosis

Light scattering pattern analysis (LSPA) was applied in the current study for accurate and sensitive detection of subtle changes in cell size, which occur in mouse thymocytes undergoing apoptosis. The decrease in cell diameter as measured by LSPA was found to be an early signal of apoptosis preceding the externalization of phosphatidylserine on the outer membrane. When apoptosis was induced by dexamethasone, the change in cell size was dose and time dependent, and could be blocked by pretreatment of the thymocytes with N-acetylcysteine (NAC). This implies that the scattering pattern, when combined with fluorescent markers such as annexine-V, may be a powerful tool for early detection of apoptosis. Another advantage gained by the use of this method is the ability to repeatedly trace the same cells and to monitor the kinetics of their size changes.

Fluorescein fluorescence hyperpolarization as an early kinetic measure of the apoptotic process

The ability to identify apoptotic cells within a complex population is crucial in the research and diagnosis of normal physiology and disease states. The Cellscan mark S (CS-S) cytometer was used in this study to detect intracellular fluorescence intensity and polarization (FI and FP) in several well-established models of apoptosis: Following spontaneous apoptosis, as well as glucocorticoid or anti Fas-induced apoptosis, CS-S individual cell-based analysis revealed the appearance of a cell cluster characterized by low FI and high FP. Temporal analysis of annexine V binding and FP measurements following DXM treatment showed that hyperpolarization preceded phosphatidylserine appearance on the outer plasma membrane. The early increase in FP was found to be dose dependent and inversely related to cell diameter. Cell dehydration and alteration of plasma membrane transport properties, both occurring during early stages of apoptosis, may be involved in the phenomena of intracellular fluorescein hyper-polarization in apoptosis.

Analysis of enzyme kinetics in individual living cells utilizing fluorescence intensity and polarization measurements

BACKGROUND

The Cellscan mark-S (CS-S) scanning cytometer was used for tracing enzymatic reactions in the same individual cells under various physiological conditions over periods of minutes. On-line reagent addition and changes in the experimental conditions (buffers, ions, substrates and inhibitors) were performed.

METHODS

Kinetic events were monitored by fluorescence intensity (FI) and fluorescence polarization (FP) measurements of fluorescein diacetate (FDA) and chloromethyl fluorescein diacetate (CMFDA) intracellular hydrolysis. FP measurements have been used to assess the intracellular marker's mobility restrictions.

RESULTS

Kinetic measurement along 1000 s of FDA labeled individual Jurkat T cells, indicated variation of 65% for FI(t) and approximately 10% for FP(t). While FI increased linearly with time, FP(t) decreased nonlinearly and asymptotically, reaching a constant value. The FP(t) of CMFDA-labeled cells was different from that of FDA-labeled cells. Average cellular Km of 3.9 microM was calculated from individual cell FDA hydrolysis curves.

CONCLUSIONS

(1) Analysis of the reaction kinetics of intracellular enzymes can be refined by using FP measurements of the products of fluorogenic substrates in addition to the FI measurements. (2) Subpopulations or individual cells could be classified according to their reaction rates. (3) A specific dependence of FP(t) on type of enzyme substrate is suggested.

Determination of cellular thiol levels in individual viable lymphocytes by means of fluorescence intensity and polarization

Cellular thiol levels regulate lymphocyte proliferation and death and play a significant role in the immune response. Therefore, the ability to analyze the total protein and non-protein thiol compounds and their distribution among individual living lymphocytes is of great importance. A quantitative measurement of intracellular sulphydryl groups in living lymphocytes using the Cellscan mark F (CS-F) cytometer, in conjunction with the probe CMFDA, is described. This technique permits the detection, identification, and study of sub-populations and single cells in a sample of heterogeneous lymphocytes. The Cellscan apparatus is a laser based scanning cytometer incorporating a unique cell carrier which allows repeated, high-precision measurements of fluorescence intensity (FI) and fluorescence polarization (FP) to be made on intact individual living cells under controlled physiological conditions. The discernible effect of fluorophore molecules bound to thiols having a higher FP than free molecules was used to estimate their relative fractions in living lymphocytes. The results were more conspicuous when the ratio between FP measured at two wavelengths (FPR) of the fluorogenic molecules was used for analysis. In addition, the intracellular dynamic changes in the FI, FP and FPR of the fluorescent probe were also monitored. The cellular sulphydryl content of each lymphocyte within a population was recorded by the CS-F, and sub-populations or individual cells were classified according to their thiol levels and their metabolic rates. Changes in thiol concentration were observed following mitogenic activation of peripheral lymphocytes.

The trace and subgrouping of lymphocyte activation by dynamic fluorescence intensity and polarization measurements

Cell activation involves conformational changes of cytosolic enzymes, and/or their regulatory proteins, as well as intracellular matrix re-organization. In this work, these changes were monitored by dynamic measurements of fluorescence polarization in single cells incubated with or without phytohaemagglutinin (PHA), using the Cellscan mark S (CS-S) cytometer. This instrument and the procedure used proved to be a powerful tool for distinguishing subpopulations of cells. Grouping of cells by their staining rates (the time rate of change of the fluorescence intensity) yielded three major subgroups. For each subgroup, the fluorescence depolarization (FDP) induced by the incubation with PHA was measured. The kinetics of the subgroups indicate that the major FDP is contributed by the cells with the lowest staining rate. This FDP is approximately 1.5 times greater than that of a bulk population. It is believed that the analysis of kinetic probing might yield an important and more sensitive method for functional marking of subgroups of cells by their response characteristics.

Reactivity of peripheral blood lymphocytes to oxidized low-density lipoprotein: a novel system to estimate atherosclerosis employing the Cellscan

BACKGROUND

The assumption that atherosclerosis involves an autoimmune response to oxidized LDL (oxLDL) is based on the presence of immunocompetent cells and immunoglobulin deposition in the atherosclerotic lesions by successful immunomodulation of the atherosclerotic process and by inhibition of experimental atherosclerosis by antioxidants. The Cellscan system is a multiparameter laser-based static cytometer that enables repeated monitoring of the fluorescence intensity (FI) and polarization (FP) of individual living cells. Analysis of intracellular fluorescein fluorescence polarization (IFFP) has previously been used to define activated lymphocyte population.

HYPOTHESIS

In this study, the Cellscan apparatus has been used to monitor cellular response to oxLDL in patients with atherosclerosis and in controls.

METHODS

The FI and FP of fluorescein diacetate (FDA)-labeled peripheral lymphocytes were measured following exposure to oxLDL in vitro. Using cluster analysis we were able to identify subpopulations of cells that were characterized by their FI and FP. Forty-two subjects were studied: 22 patients with severe coronary heart disease and 22 control individuals, either healthy or with other diseases.

RESULTS

Fluorescence intensity of fluorescein-labeled peripheral blood lymphocytes (PBL) was markedly decreased upon exposure to high doses (> 25 micrograms/ml) of oxLDL concurrently with an increase in FP. A specific and dose-dependent reduction in FP of the high-intensity cell subpopulations, accompanied by higher FI, was evident in patients with ischemic heart disease upon exposure to low doses of oxLDL (up to 25 micrograms/ml). Maximal depolarization was shown upon triggering with 2 micrograms/ml oxLDL. The polarization ratio (the mean polarization value of the specific cell population with and without activation) obtained for patients' lymphocytes was significantly lower (p < 0.01) than that of the control group (0.936 +/- 0.05 and 1.028 +/- 0.055, respectively).

CONCLUSION

These data suggest that PBL from patients with active ischemic heart disease show an increased reactivity to oxLDL. A 73% positivity rate was found for ischemic heart disease patients compared with 5% in the control subjects. One of the future prospects of this study might be the advent of a simple and rapid noninvasive test that could assess the extent of atherosclerosis, and possibly even the response to therapy, by monitoring the reactivity of PBL to oxLDL.

Indication that intracellular fluorescence polarization of T lymphocytes is cell cycle dependent

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 (Gzero/G1) predominated, and the mean IFFP was 0.186 +/- 0.015. At the lowest density, with diminished proportion of cells in the G1/G2 stages the mean IFFP decreased to 0.126 +/- 0.01. Treatment of the Jurkat T cell line with phase arrested agents 1 microM hydroxyurea, or 1 microM nocodazole, arrests the cells in the S and G2/M phases, respectively. These treated cells exhibit significantly lower IFFP values, mean polarization value 0.140, as compared to 0.171 +/- 0.009 in control cells. Preincubation of Jurkat cells in buffer in accumulation of the cells in the Gzero/G1 phases as well as a parallel increase in IFFP. A characteristic decrease in IFFP was demonstrated upon triggering these cells with Phytohaemagglutinin (PHA). High correlation (Pearson correlation = 0.942) was found between percentage of cells in the Gzero/G1 phases and the mean IFFP of the measured cell population. These results may indicate that the intracellular microviscosity of Jurkat T cells as measured by IFFP, is changing over the cell cycle.

Anti-topoisomerase-I and clinical findings in systemic sclerosis (scleroderma)

The relationship between anti-topoisomerase-I antibodies and clinical findings was studied in 191 patients with definite systemic sclerosis. This was done by performing ELISA to detect antibodies to recombinant topoisomerase-I. Antibodies to topoisomerase-I were found in 72 patients (37%) with systemic sclerosis, which is a higher percentage than reported in most previous reports on a large unselected population. In 43 patients the presence of antibodies to recombinant topoisomerase-I was confirmed using both the immunodiffusion method and ELISA, with similar results. When classified into diffuse versus limited disease, a significant difference in antibody prevalence was demonstrated (P < 0.005), thus indicating that anti-topoisomerase-I antibody detection with ELISA may assist in early identification of systemic sclerosis subtypes.

Antimitochondrial (pyruvate dehydrogenase) antibodies in leprosy

Sera from 69 patients with leprosy but without liver involvement were assayed for the presence of mitochondrial pyruvate dehydrogenase (PDH)-specific autoantibodies by enzyme-linked immunoabsorbent assay (ELISA), immunoblotting using PDH as an antigen and by enzymatic inhibition test. Twenty-seven of the leprosy serum samples (39.1%) were found to react with PDH by ELISA. However, unlike sera from primary biliary cirrhosis (PBC) patients, none of these were able to inhibit the PDH enzymatic activity. By immunoblotting, it was found that only 2 of the 27 positive sera recognized the 74-kD protein of the PDH complex, which is recognized by sera of most PBC patients. The antimitochondrial antibodies in lepra most probably recognize different epitopes than those in PBC. These findings may indicate that anti-PDH autoantibodies in patients with leprosy may arise by polyclonal B cell stimulation and may represent natural anti-PDH autoantibodies.

The effect of intravenous gamma-globulin on the induction of experimental antiphospholipid syndrome

Antiphospholipid syndrome (APLS) is characterized by anti-cardiolipin antibodies (ACA) and/or lupus anticoagulant, recurrent thromboembolic phenomena, thrombocytopenia, and recurrent fetal loss. Recently, we reported on the induction of experimental APLS by passive transfer of ACA to naive mice. In the current study we examined the effect of intravenous gamma-globulins (IVGG) on the obstetric complication of experimental APLS. After showing the binding of IVGG to mouse and human ACA (e.g., the existence of natural anti-idiotypic autoantibodies to ACA) we infused 36 micrograms of IVGG to the tail vein of mice in which experimental APLS was induced by passive transfer of monoclonal mouse ACA (CAR). Mice treated with IVGG had significantly less fetal resorptions when mated, in comparison to untreated mice (5-13 +/- 6% vs 25 +/- 17%). The best results were achieved when IVGG was given 2 days after induction of the disease (on Day 6 of pregnancy). It seems that IVGG may be employed as a good adjunct to any therapy of APLS.

Increased anti-Sm antibodies in schizophrenic patients and their families

1. Autoantibodies in the Sm complex have become a useful serologic aid in the diagnosis of systemic lupus erythematosus (SLE) and have rarely been observed in other diseases. 2. A subset of SLE patients have a variety of psychiatric abnormalities, including schizophrenia. 3. The authors have recently observed that schizophrenic patients have a high incidence of autoantibodies suggesting that autoimmune phenomena may play a role in the pathogenesis of this disease. 4. In the present study the authors investigated multicase families with schizophrenia for the presence of anti-Sm antibodies and showed that these autoantibodies are elevated both in patients and in their healthy relatives. 5. An autoimmune process may be involved in the pathology of schizophrenia.

Detection of anti-phospholipid and anti-DNA antibodies and their idiotypes in newborns of mothers with anti-phospholipid syndrome and SLE

The titers, isotypes and idiotypes of antiphospholipid and anti-dsDNA antibodies were determined in seven pairs of mothers with antiphospholipid syndrome (APLS) and their offspring, in 11 pairs of SLE mothers and their matched infants and in seven respective pairs of healthy subjects. In addition, maternal as well as fetal sera were evaluated for the presence of anti-SSA (Ro), anti-SSB (La) and anti-70 kd RNP autoantibodies. In the sera from APLS patients, as well as in the sera from their offspring, the mean antibody titer of IgG aCL was found to be significantly higher then the corresponding value in the control group (P < 0.01). Highly significant increased titers of IgG anti-DNA antibodies were found in the sera of SLE mothers and their matched offspring (P < 0.0008). The prevalence of anti-SSA, anti-SSA, and anti-70Kd RNP antibodies was lower then that of antiphospholipid and anti-dsDNA antibodies. Only one of the respective offspring had increased levels of these antibodies. The quantity of maternal antibodies transferred to the fetus was depended on their concentration in the maternal circulation, as well as on their type and specificity. Follow-up of newborn sera showed a progressive decrease in the antiphospholipid antibody titers during 3 months. After 6 months it was undetected. Our results point to a transplacental transfer of aCL and anti-DNA antibodies, a phenomenon which is not necessarily associated with respective clinical manifestations, in contrast to the classical humoral mediated autoimmune diseases (e.g. myasthenia gravis).

Antimitochondrial (pyruvate dehydrogenase) autoantibodies in autoimmune rheumatic diseases

Anti-pyruvate dehydrogenase (PDH) antibodies were determined in 1451 sera of patients with primary biliary cirrhosis (PBC) and several autoimmune rheumatic conditions by ELISA and immunoblotting. They were detected in sera of 93% of the patients with PBC (179 of 192 patients) in 60 of 277 (22%) patients with Sjogren's syndrome (SjS), 34 of 437 (8%) patients with scleroderma, 33 of 191 patients with SLE (17%), and 5 of 55 (10%) patients with rheumatoid arthritis (RA) but in none of the patients with polymyositis or the antiphospholipid syndrome. The ELISA studies were confirmed by immunoblots showing binding of autoimmune rheumatic sera to the same epitope (74 kd) of mitochondria that the PBC sera reacted with. The identical binding characteristics were also confirmed by protein competition assays with purified PDH. In 4 of 53 patients with SjS who were positive for anti-PDH, high titers as in PBC were detected. The anti-PDH antibodies in Sjogren's patients were associated with deranged liver function tests and extraglandular features but did not correlate with any other non-organ-specific antibody. Follow-up studies confirmed the association of the emergence of anti-PDH antibodies with defects in liver function tests. The antibodies were more prevalent in SLE and RA when they were associated with Sjogren's syndrome (30 and 18.8%, respectively). Among patients with different forms of scleroderma, anti-PDH antibodies were noted in subjects with systemic sclerosis, morphea, and Raynaud's phenomenon.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between in vitro fertilization and naturally occurring antibodies: evidence for increased production of antiphospholipid autoantibodies

OBJECTIVE

Assessment of possible effects of ovarian stimulation during in vitro fertilization (IVF) treatment cycles on circulating levels of antiphospholipid and antinuclear autoantibodies.

DESIGN

The study was performed prospectively. Sera were obtained at three time points along IVF treatment cycle. Levels of autoantibodies directed against nuclear components, mitochondrial antigens, and phospholipids were determined using enzyme-linked immunosorbent assay.

PATIENTS

Thirty-five patients, who underwent at least one previous IVF attempt, and 36 age- and sex-matched controls were analyzed. All participants were randomly selected.

RESULTS

The mean levels of antiphospholipid (but not antinuclear) autoantibodies in sera from IVF-treated patients were found to be significantly higher than the corresponding values of the control group (for immunoglobulin [Ig]M isotype: anticardiolipin, antiphosphatidyl L-serine; for IgG isotype: anticardiolipin, antiphosphatidyl L-serine, and antiphosphatidylcholine; P less than 0.0001, assessed by Mann-Whitney test). The autoantibody levels remained more or less constant at different time points along the treatment cycle. No correlation with age and number of previous IVF cycles was demonstrated.

CONCLUSIONS

Serum levels of antiphospholipid (but not antinuclear) autoantibodies increase after IVF treatment. Based on these preliminary data, it is not yet possible to estimate if the observed changes in autoantibody levels might have any future clinical influence on infertile patients undergoing IVF treatment.

Anti-pyruvate dehydrogenase autoantibodies in primary biliary cirrhosis

Antimitochondrial antibodies (AMA) may be detected in 95% of patients with primary biliary cirrhosis (PBC). The target autoantigens for the AMA were recently identified as four closely related metabolic enzymes located in the mitochondria. We have purified the pyruvate dehydrogenase (PDH) enzyme from bovine heart, showing that all PBC sera reacted with a 74-kd band. PDH was utilized to establish an ELISA assay for detecting the relevant antibodies. One hundred twelve of 120 sera from patients with PBC (95%) reacted with the PDH but none of the 201 control sera, including normal subjects and a panel of sera from other patients with liver diseases, showed similar reactivity. In 77% of the PBC sera the anti-PDH antibody isotype was identified as a combination of IgG and IgM, while in 18% only IgM was detected. In 5% of the sera the isotype was confined to IgG. PBC sera specifically inhibited the PDH enzyme activity. The enzyme inhibition correlated with the anti-PDH antibody titers. Thus, PDH seems to be one of the major target epitopes for AMA observed in sera of patients with PBC.

Concurrent inactivation of calcium dependent phosphorylation and neurotransmitter release in cultured rat brain neurons

Depolarization of cultured rat brain neurons preloaded with 3H-dopamine provokes a transient (t 1/2 = 9.6 sec), Ca(2+)-dependent release of the labeled neurotransmitter from cells. In parallel, the amount of 32Pi incorporated into a protein of apparent molecular weight of 43,000 increased whereas the phosphorylation of a protein with an apparent molecular weight of 55,000 daltons decreased. The time course of the change in phosphorylation pattern was examined. The depolarization-induced phosphorylation of the 45,000 protein and dephosphorylation of the 55,000 dalton protein consisted of an initial, rapidly terminating phase (t 1/2 = 5 sec), and of a slow, Ca(2+)-independent phosphorylation of both proteins which persisted during maintained depolarization. The depolarization-evoked changes in the neuronal protein phosphorylation were dependent on the extracellular Ca2+ concentration (half saturation at 0.4-0.5 mM Ca2+). These data indicate that the entry of Ca2+ into the depolarized cells induces rapid phosphorylation-dephosphorylation activities. These processes terminate within 10 sec, concurrently with the depression of neurotransmitter release.

Detection of antimitochondrial antibodies: characterization by enzyme immunoassay and immunoblotting

Mitochondrial antigens were purified from rat liver and characterized by immunoblotting. Sera from 19 well defined patients with primary biliary cirrhosis (PBC) reacted with two mitochondrial polypeptides of 68 Kd and 45 Kd. Antibodies to these antigens were not detected in any of the sera of patients with cirrhosis of the liver, chronic active hepatitis or other autoimmune diseases. The two polypeptides were derived from the soluble fraction of the mitochondrial matrix. An enzyme-linked immunosorbent assay (ELISA) employing these rat liver mitochondrial antigens is described. Positive results were obtained with all except one PBC sera (95%), five out of 47 patients with cirrhosis (11%), one out of 20 patients with chronic active hepatitis (5%), and two out of 19 patients with various autoimmune disorders (11%). The titers detected in PBC were markedly higher than those recorded in patients with other liver and autoimmune diseases. Strong correlation was found between immunoblotting and the ELISA in determining antimitochondrial antibodies. The ELISA presented is easily performed and seems to be a useful diagnostic tool for antimitochondrial antibodies in patients with PBC.

Concerted enhancement of calcium influx, neurotransmitter release and protein phosphorylation by a phorbol ester in cultured brain neurons

We have recently shown that the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate enhances the depolarization induced, calcium dependent release of [3H]dopamine from cultured brain neurons in the rat. In the present study the effects of 12-O-tetradecanoyl-phorbol-13-acetate on the kinetic parameters of depolarization induced calcium influx and on Ca2+ dependent neurotransmitter release and protein phosphorylation were investigated. Depolarization induced neurotransmitter release from the neurons occurs in two phases: an initial, fast release and a subsequent slow release. At low extracellular Ca2+, 12-O-tetradecanoyl-phorbol-13-acetate enhanced the quantity of fast release and in addition, increased the rate constant of the slow release. These effects mimicked the effects of increasing the extracellular Ca2+. Various phorbol derivatives known to activate the Ca2+ activated phospholipid dependent protein kinase (protein kinase C) were also able to enhance the stimulated release of [3H]dopamine from the neurons. 12-O-tetradecanoyl-phorbol-13-acetate induced the incorporation of 32Pi into a protein with an apparent molecular weight of 45,000 daltons regardless of depolarization or of the presence of Ca2+. In addition, 12-O-tetradecanoyl-phorbol-13-acetate induced in unstimulated neurons, Ca2+ dependent increase in the amount of 32Pi incorporated into a 43,000 dalton protein and decrease in the amount incorporated into a 55,000 dalton protein. These changes mimicked the Ca2+ dependent changes in protein phosphorylation which occur upon stimulation of the neurons. Kinetic studies of depolarization induced Ca2+ uptake by the neurons indicated that 12-O-tetradecanoyl-phorbol-13-acetate enhanced the maximal influx of Ca2+ through the voltage sensitive Ca2+ channels by 40%. The results indicate that 12-O-tetradecanoyl-phorbol-13-acetate acts primarily on the regulation of stimulated Ca2+ entry into the cells. Consequently neurotransmitter release at submaximal extracellular [Ca2+] is enhanced.

Calcium permeability changes and neurotransmitter release in cultured brain neurons. II. Temporal analysis of neurotransmitter release

The coupling between depolarization-induced calcium entry and neurotransmitter release was studied in rat brain neurons in culture. The endogenous dopamine content of the cells was determined by high performance liquid chromatography utilizing electrochemical detection. The amount of dopamine in unstimulated cells was found to be about 16 ng/mg of protein. Depolarization of the neurons by elevated K+ caused a Ca2+-dependent release of dopamine from the cells. Following 1 min of depolarization, the cellular dopamine content and the amount of [3H]dopamine in cells preloaded with the radioactive transmitter were reduced by 35%. The release of [3H]dopamine by the neurons was measured at 1.5-6-s intervals by a novel rapid dipping technique. Depolarization in the presence of Ca2+ (1.8 mM) enhanced the rate of neurotransmitter release by 90-fold (0.072 +/- 0.003 s-1) over the basal release in the presence of Ca2+. The evoked release consisted of a major rapidly terminating phase (t1/2 = 9.6 s) which comprised about 40% of the neurotransmitter content of the cells and a subsequent slower efflux (t1/2 = 575 s) which was observed during following prolonged depolarization. Predepolarization of the cells in the absence of extracellular Ca2+ did not affect the kinetics of the evoked release. The fast evoked release could be re-elicited in the cells after 20 min "rest" in reference low K+ buffer. The effects of varying the extracellular Ca2+ concentrations on the kinetic parameters of the evoked release were measured. The amount of neurotransmitter released during the fast kinetic phase was very sensitive to the external Ca2+ (from 0% in the absence of Ca2+ to 40% of the neurotransmitter content at Ca2+ 0.3 mM). The rate constant of the fast release did not depend on the extracellular Ca2+, whereas the rate constant of the slow release increased from 0.0004 +/- 0.0001 s-1 at 0.4 mM Ca2+ to 0.0012 +/- 0.0002 s-1 at 0.8 mM Ca2+. The fast evoked release was inhibited by verapamil in a concentration-dependent manner. By contrast, verapamil enhanced the basal and the slow release independent of the presence of Ca2+. Both fast and slow phases of the evoked release were blocked by Co2+. Addition of Co2+ within the first 6 s after the onset of depolarization inhibited the fast release but failed to do so when added later on.(ABSTRACT TRUNCATED AT 400 WORDS)

Calcium permeability changes and neurotransmitter release in cultured rat brain neurons. I. Effects of stimulation on calcium fluxes

The permeability of neuronal membranes to Ca2+ is of great importance for neurotransmitter release. The temporal characteristics of Ca2+ fluxes in intact brain neurons have not been completely defined. In the present study 45Ca2+ was used to examine the kinetics of Ca2+ influx and efflux from unstimulated and depolarized rat brain neurons in culture. Under steady-state conditions three cellular exchangeable Ca2+ pools were identified in unstimulated cells: 1) a rapidly exchanging pool (t1/2 = 7 s) which represented about 10% of the total cellular Ca2+ and was unaffected by the presence of Co2+, verapamil, or tetrodotoxin; 2) a slowly exchanging pool (t1/2 = 360 s) which represented 42% of the total cellular Ca2+ and was inhibited by Co2+, but not by verapamil or tetrodotoxin; 3) a very slowly exchanging pool (t1/2 = 96 min) which represented 48% of the total cell Ca2+ was observed only in the prolonged efflux experiments. The rate of exchange of 45Ca2+ in the unstimulated cells was dependent on the extracellular Ca2+ concentration (half-saturation at 70 microM). Depolarization of the neurons with elevated K+ causes a rapid and sustained 45Ca2+ uptake. The cellular Ca2+ content increased from 56 nmol/mg protein in unstimulated cells to 81 nmol/mg protein during 5 min of depolarization. The kinetics of the net 45Ca2+ uptake by the stimulated neurons was consistent with movement of the ion with a first order rate constant of 0.0096 s-1 (t1/2 = 72 s) into a single additional compartment. The other cellular Ca2+ pools were apparently unaffected by stimulation. The stimulated 45Ca2+ uptake was inhibited by Co2+ and by the Ca2+ channel blocker verapamil but not by the Na+ channel blocker tetrodotoxin. Ca2+ uptake into this compartment was dependent on the extracellular Ca2+ concentration (half-saturation at 0.80 mM Ca2+). Predepolarization of the cells with high K+ for 10-60 s prior to the addition of the radioactive calcium did not alter the rate of 45Ca2+ incorporation into the stimulated cells. It is concluded that the rapidly exchanging, the slowly exchanging, and the depolarization-induced Ca2+ pools observed in intact brain neurons are physically as well as kinetically distinct from each other. In addition, the depolarization-induced component observed in stimulated cells represents movement of the Ca2+ ions through a single class of voltage-sensitive Ca2+ channels. These Ca2+ channels are inhibited by Co2+ ions and by verapamil and are not inactivated during depolarization of the brain neurons.

Phorbol ester and calcium act synergistically to enhance neurotransmitter release by brain neurons in culture

Preincubation of intact fetal brain neurons in culture with the phorbol ester TPA (12-O-tetradecanoyl phorbol-13-acetate) in the presence of calcium, resulted in the enhancement of the depolarization-induced, Ca2+-dependent neurotransmitter release by the cells. This effect was due to a marked decrease in the concentration of extracellular Ca2+ required to provoke the release. The concentration of Ca2+ needed to produce half-maximal release shifted from approx 0.1 mM in the absence of TPA to 0.018 mM in its presence. This activity of TPA was concentration-dependent (half-maximal effect at 4 nM TPA) and was also dependent on the presence of calcium during the preincubation period. The TPA-induced enhancement of the stimulated release was also observed when Ca2+ entry into the depolarized cells was partially inhibited by Co2+. The results suggest that TPA acts synergistically with Ca2+ to activate neuronal component(s) involved in Ca2+-dependent neurosecretion.

Calcium uptake and calcium-dependent phosphorylation during development of rat brain neurons in culture

The emergence of the capacities for calcium uptake and calcium-regulated protein phosphorylation during the development of embryonic brain neurons in tissue culture was examined. In the maturing cells, the enhancement in 45Ca2+-uptake upon stimulation with high K+ increased by 3-4 fold during the second week in vitro, in parallel to an increase in the capacity for high K+-induced Ca2+-dependent release of prelabeled [3H]dopamine. The pattern of incorporation of [32Pi]phosphate into the major phosphoproteins in maturing cells under nonstimulating conditions also changed during cell development: the incorporation of 32Pi into two proteins of apparent molecular weights--55,000 and 43,000 dalton--increased, but decreased in a 45,000 dalton protein. Stimulation of mature cells (after 10-11 days in vitro) resulted in a Ca2+-dependent increase in the amount of 32Pi incorporated into the 43,000 dalton protein and a decrease in the amount incorporated into the 55,000 dalton protein. This calcium-regulated phosphorylation pattern was not observed until 6 days in vitro. Introduction of Ca2+ into the immature cells by means of the Ca2+ ionophore A23187 did not alter the phosphorylation pattern and did not cause neurotransmitter release. The amount of [35S]methionine incorporated into a 43,000 dalton protein which comigrated with the 43,000 dalton phosphoprotein also increased upon cell maturation. The results suggest that this phosphoprotein (which does not comigrate with nonphosphorylated actin on two-dimensional polyacrylamide gels) develops in the cells in parallel to the emerging processes of the stimulation-induced calcium entry and calcium-dependent neurosecretion.

Calcium-dependent protein phosphorylation and dephosphorylation in intact brain neurons in culture

Preincubation of intact fetal rat brain neurons in culture with 32Pi results in the incorporation of 32Pi into about 20 specific proteins. Upon stimulation by electrical field stimulation or by K+-induced depolarization, highly significant calcium-dependent increase in phosphorylation of a protein of app. Mr 43 000 and decrease in phosphorylation of an app. Mr 55 000 protein occur. These changes can be attributed to the entry of Ca2+ into the cellular cytoplasm since they can occur upon selective permeabilization of the cell membrane to Ca2+ by the Ca2+-ionophore A23187 and are not observed upon stimulation of the cells in the presence of the Ca2+ channel blocker D-600. These data suggest that these phosphoproteins may be involved in the regulation of processes underlying neurotransmitter release.

Studies on synaptic vesicles in mammalian brain characterization of highly purified synaptic vesicles from bovine cerebral cortex

Synaptic vesicles have been isolated from bovine cerebral cortex by sequential differential and density gradient centrifugations followed by chromatography on a Sepharose 6B column. We have studied the morphology, enzymatic markers, neurotransmitter and ATP contents and protein composition of the vesicles. The specific contents of acetylcholine, gamma-aminobutyric acid, aspartate, glutamate and catecholamines were 4--8-fold higher in the vesicle fraction compared to the crude synaptosomal pellet. Electron micrographs of the vesicle preparation showed enrichment of vesicular material with an average diameter of 50 nm. The purity of the preparation was assessed by the very low activities of enzymatic markers of cellular membranes and cytosol components. Some Ca--Mg-activated ATPase activity was detected in the vesicle preparations, but its content relative to the neurotransmitters fell on chromatography, suggesting that this activity may be partially contributed by non-synaptic vesicle components, such as small microsomes. The isolated synaptic vesicles were solubilized with 1% sodium dodecyl sulfate and subjected to polyacrylamide gel electrophoresis. The major Coomassie blue stained bands observed with apparent molecular weights of 160,000 and 55,000 were enriched in parallel to the increase in purity of the preparation.