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C L Geczy

Publications and source records attributed to C L Geczy.

At least 73 records · Page 4Linked to original sources
PubMed1986

Lymphokine-induced monocyte procoagulant activity is depressed in patients with advanced malignancies.

Fibrin deposition in the microenvironment of tumor cells may be critical to tumor growth and metastasis formation. Procoagulant activities of tumor cells themselves, or of infiltrating macrophages, activated by the host's immune system to the tumor, may both contribute to coagulopathies associated with metastases. Lymphokine (LK) supernatant activated procoagulant activity on normal peripheral blood monocytes but failed to induce activity on mononuclear cells from 18/22 patients with locally advanced or disseminated non-lymphoid tumors. Monocytes from the remaining patients had very low basal levels of MPCA and were less sensitive than normal cells to LK. Monocytes from 4 patients (3 with tumors with a high growth fraction) had extremely elevated levels of basal procoagulant activity, possibly due to maximal activation in vivo. Neither LK nor bacterial lipopolysaccharide (LPS) stimulated procoagulant production of these cells. By contrast, cells from 8/13 patients produced procoagulant in response to LPS. This study indicated that monocyte function of patients with disseminated cancer is suppressed with respect to LK stimulation, but that cells with normal basal levels of MPCA respond to LPS. Preactivation of mononuclear procoagulant in vivo precluded subsequent stimulation by either LPS or LK.

Adenocarcinoma↗
PubMed1986

Conditioned medium from macrophage cell lines supports the single-cell growth of hybridomas.

The aim of this study was to establish whether conditioned medium (CM) from macrophage cell lines would support the growth of hybridomas under conditions commonly used in hybridization experiments and in cloning of antigen-specific hybridomas. The ability of CM from macrophage cell lines J774, WEHI 274, WEHI 265, and PU 5 to support single-cell growth during cloning was compared with CM from cultures of resident mouse peritoneal cells, EL 4 mouse thymoma cells, L929 mouse fibrosarcoma, and feeder layers of resident peritoneal cells. CM from J774, L929, and resident peritoneal cells supported single-cell growth at the same level as the macrophage feeder layer. J774 and L929 CM were most effective at a final concentration of 25% with fresh medium supplemented with 20% fetal calf serum (FCS). The ability of J774 CM to support hybridoma growth was increased by prior stimulation with LPS but not PMA. CM from LPS-stimulated J774 cells used in fusion experiments resulted in increased numbers of hybridomas compared with those obtained with macrophage feeder layers.

Animals↗
PubMed1984

Induction of macrophage procoagulant by products of activated lymphocytes.

The induction of macrophage procoagulant activity by specific antigens is a close in vitro correlate of delayed-type hypersensitivity (DTH) reactions and provides a quantitative and sensitive measure of cell-mediated immune responses. The reaction is mediated by lymphokines from activated T lymphocytes and is potentiated by bacterial lipopolysaccharide. Lymphokines directly activated procoagulant activity on some murine and human macrophage tumor cell line cells although others required the collaboration of T lymphocytes, in the presence of lymphokine, to express activity. Macrophages in different stages of differentiation may vary, therefore, in their response to lymphokines. Pharmacological agents which regulate DTH reactions also mediated either the ability of lymphocytes to produce macrophage procoagulant inducing factor or the response of macrophages to the factors. Histamine and an anticoagulant found on stimulated T lymphocytes may be important regulatory mediators of macrophage procoagulant activity in vivo.

Animals↗
PubMed1984

Susceptibility and resistance to experimental autoimmune encephalomyelitis and neuritis in the guinea pig correlate with the induction of procoagulant and anticoagulant activities.

Activation of macrophage procoagulant activity (MPCA) is involved in the manifestation of EAE and EAN in susceptible guinea pigs and provides a mechanism for the deposition of fibrin, which is a feature of histologic lesions of EAE. Peritoneal exudate cells (PEC) from susceptible (strain 13) guinea pigs immunized with either central or peripheral nervous tissue antigens produce procoagulant activity when incubated with the immunogen in vitro. The production of the procoagulant is quantitative and antigen-specific and is maximal at the time of clinical signs of the disease. After recovery, the production of procoagulant activity decreased. The MPCA test was able to discriminate the biochemical differences existing between chicken and mammalian peripheral nerve proteins, thus providing a quantitative and sensitive indicator of cell-mediated immunity in EAE and EAN. The autoimmune response to brain and nerve antigens in nonsusceptible (strain 2) guinea pigs was coincident with the antigen-specific production of a cell-bound anticoagulant activity by stimulated mononuclear cells. The production of anticoagulant activity followed the same sequence of time changes after immunization as that of the MPCA in susceptible guinea pigs, and high immunizing doses of nerve antigens induced high levels of anticoagulant activity. The same cells produced high levels of procoagulant when incubated with tuberculin or lipopolysaccharide. The recalcification time of normal plasma was prolonged by the anticoagulant, and the decreased clotting time of plasma induced by the procoagulant activity obtained by incubating sensitized strain 13 PEC with myelin basic protein was suppressed by the anticoagulant produced by culturing sensitized strain 2 PEC with myelin basic protein. Preliminary evidence indicates that the anticoagulant has properties similar to antithrombin III. The anticoagulant could play a role in the control of effector cell function, and therefore in recovery from clinical features of EAE and EAN in susceptible guinea pigs.

Animals↗
PubMed1983

Macrophage procoagulant activity as a measure of cell-mediated immunity in the mouse.

Thioglycollate-induced peritoneal exudate cells (TG-PEC) developed increased procoagulant activity after incubation with lymphokine and lipopolysaccharide (LPS). Dilutions of up to 1/1000 for insoluble Con A and 1/200 for periodate-induced lymphokine supernatants were active in enhancing macrophage procoagulant activity (MPCA), which was detected after a 2-hr incubation period and steadily increased over 20 hr. MPCA could also be induced by antigen; peritoneal cells from sensitized B6AF1 mice with strong footpad reactions to ovalbumin (OVA) responded to as little as 0.1 microgram/ml OVA in the MPCA test in an antigen-specific manner. By contrast, PEC from sensitized CBA/J mice that gave poor in vivo responses to OVA only reacted with high concentrations of the antigen in vitro. Production of the lymphokine responsible for induction of MPCA required an Ly-1+2- T cell, a nylon wool-adherent cell, and an la-17-bearing adherent cell. The MPCA induced by lymphokine or LPS did not appear to be a serine esterase and was not inhibited by phospholipase C. Coagulation of human factor-deficient plasma with activated TG-PEC indicated a requirement for Factor X.

Animals↗
PubMed1983

Cyclosporin A inhibits lymphokine production but not the responses of macrophages to lymphokines.

Cyclosporin A (Cs A) exerted a dose-related inhibitory effect on antigen (ovalbumin, OVA) and phytohaemagglutinin (PHA)-induced transformation of guinea-pig lymph node cells (LNC). Whereas 0.05 micrograms/ml was sufficient to depress these responses markedly, it required 100-fold this concentration of Cs A to inhibit the production of lymphocyte activating factor (LAF) by lipopolysaccharide (LPS) stimulated peritoneal macrophages. Addition of Cs A together with insoluble concanavalin A (iCon A) to LNC cultures resulted in suppressed lymphokine production, as assessed by measurement of migration inhibition factor (MIF), the generation of macrophage procoagulant activity (MPCA) and the release of lymphocyte-derived-macrophage chemotactic factor (LDCF). Cs A also inhibited MIF and procoagulant production by sensitized peritoneal exudate cells in response to antigen, at the same concentrations which blocked lymphocyte transformation. In contrast, Cs A had no direct effect on the migration of peritoneal cells from capillary tubes, or on the responses of macrophages to preformed MIF, the lymphokine inducing MPCA or LDCF. Overnight incubation of macrophages with Cs A did, however, result in mild inhibition of their basal level of procoagulant activity.

Animals↗
PubMed1983

The ability of lymphokine and lipopolysaccharide to induce procoagulant activity in mouse macrophage cell lines.

A comparison was made of the abilities of mouse macrophage cell lines and cultured bone marrow-derived macrophages to respond to lymphokine and lipopolysaccharide (LPS) in the macrophage procoagulant assay (MPCA). Mouse macrophage cell lines PU5 and WEHI 265 responded to low concentrations of lymphokine and LPS by increased procoagulant activity; the activity of PU5 cells was comparable to that of TG-PEC. Approximately one-half of the MPCA induced by lymphokine after 20 hr culture was detectable after 2 hr with either cell line. J774 was unresponsive to LPS but responded weakly to lymphokine, and P388D1 and WEHI 274 were unresponsive to both stimuli as determined by the MPCA test. Addition of purified T cells (five T cells to one macrophage) to the unresponsive cell lines induced procoagulant activity in the presence of either stimulus, which suggests that cell contact is necessary in some cases. Only J774 cells responded to lymphocyte-derived chemotactic factor (LDCF) or endotoxin-activated mouse serum (EAMS) in chemotaxis assays. Immature bone marrow cells responded to chemotactic stimuli, and procoagulant activity was induced with lymphokine after 4 days in culture. Cells cultured for 7 days had about twice as much MPCA, but further culturing did not result in cells with enhanced activity. The procoagulant responsiveness of different macrophage cell lines to lymphokine or LPS may reflect differences in the maturation and differentiation states of these cells.

Animals↗
PubMed1983

Modification of delayed-type hypersensitivity reactions to ovalbumin in cyclosporin A-treated guinea-pigs.

Cyclosporin A (Cs A) administered daily (25 mg/kg per os) to outbred guinea-pigs for 2 weeks following immunization with ovalbumin (OVA; CsA 0-13) caused profound suppression of 14-day delayed-type hypersensitivity (DTH) skin reactions. Very marked impairment of DTH was also found when Cs A was given for the first time 24 hr before skin testing and at 6 and 24 hr thereafter. In contrast, Cs A given on days 0-4 following OVA immunization (Cs A 0-4) caused dose-related potentiation of 14-day skin responses. These changes in the magnitude and character of DTH in vivo were accompanied by striking alterations in lymphocyte transformation responses and in the extent of macrophage migration inhibition and lymphokine production. Whereas Cs A (0-13) caused almost total suppression of the mitogenic responses of lymph node cells to PHA and antigen, OVA-induced migration inhibition and production of the lymphokine inducing macrophage procoagulant activity (MPCA), Cs A (0-4) augmented these responses to OVA, but did not affect lymphocyte transformation or lymphokine production in response to mitogen. Strain 13 guinea-pigs treated with Cs A (0-4) showed depressed Arthus, but augmented DTH responses to OVA. This significant increase in cell-mediated immunity could be passively transferred using spleen and peritoneal exudate cells, suggesting that under these circumstances Cs A (0-4) may interfere with the generation of a population of suppressor cells which regulate DTH reactions in the guinea-pig.

Adjuvants, Immunologic↗
PubMed1983

Lymphokine-like products of cultured tumour cells.

Supernatants from cultures of rat and guinea-pig tumour cells, guinea-pig fibroblasts and kidney cells, but not rat fibroblasts, inhibited the migration of peritoneal exudate macrophages in vitro. The inhibitory activity in tumour-cell supernatants differed from that of lymphokine in being heat stable (60 degrees, 3 hr) and dialysable, not inhibited by fucose and, in the case of guinea-pig line 1 tumour, not absorbed by an anti-lymphokine immunoabsorbent. Rat lymphokine and supernatants from four cultured rat tumours and, to a lesser extent, fibroblasts induced procoagulant activity in rat peritoneal exudate macrophages. The tumour procoagulant-inducing activity was heat stable and non-dialysable. Direct procoagulant activity was also found in rat lymphokine, fibroblast and tumour culture supernatants. This activity was partly or completely heat-labile but was non-dialysable.

Animals↗
PubMed1982

Leukocyte procoagulant activity in man: an in vitro correlate of delayed-type hypersensitivity.

Human mononuclear leukocytes generate cell-bound procoagulant activity (LPCA) after incubation with an antigen (mumps or tuberculin) to which the donor was previously sensitized. An inhibitor of coagulation appears to be liberated into the extracellular culture fluid during incubation of leukocytes with the sensitizing antigen. Removal of this activity before measuring LPCA resulted in a reliable test that correlated directly with delayed skin reactivity. The assay was particularly sensitive in that cells from weakly sensitized donors who reacted only to high doses of tuberculin (100 TU) in the delayed skin tests produced detectable LPCA in vitro. By contrast cells from weakly sensitized donors did not react to PPD in the lymphocyte blast transformation test or the direct macrophage migration inhibition factor test. The LPCA assay correlated closely with the blast transformation and MIF tests in which cells were used from more strongly sensitized donors who reacted in skin tests with lower doses of tuberculin (1 or 10 TU). The assays were antigen-specific in that cells from donors sensitive to mumps antigen but not to tuberculin reacted only to mumps antigen in vitro. The assay was extremely reproducible; cells from individual donors reacted to the same extent over a period of 8 mo). We propose that the assay system reported here represents an improved method for the measurement of cell-mediated immunity in vitro because it requires fewer donor cells, is technically simpler, and is more sensitive than previously described methods.

Animals↗
PubMed1981

A mechanism of migration inhibition in delayed-type hypersensitivity reactions. II. Lymphokines promote procoagulant activity of macrophages in vitro.

Although lymphokine supernatants had no procoagulant activity per se, guinea pig peritoneal exudate cells (PEC), incubated with lymphokine supernatants or with a lymphokine fraction of 35,000 to 50,000 daltons decreased the recalcification time of platelet-poor plasma. PEC from animals immunized with BCG or with ovalbumin and incubated with the corresponding antigen had increased procoagulant activity. Similar effects were observed with PEC incubated with endotoxin. The induction of procoagulant activity by the cells was accompanied by a concomitant decrease in their ability to respond to chemotactic agents and to migrate from capillary tubes. Separation of exudate cells by sedimentation velocity indicated that large macrophages had the highest degree of procoagulant activity after incubation with lymphokines. The clotting time of Factor IX-deficient plasma was decreased by lymphokine-treated macrophages, indicating that the extrinsic clotting sequence may be activated as a result of increased tissue factor on the treated cells. Heparin abolished the ability of lymphokines to inhibit macrophage migration.

Animals↗