The mechanism of action of soluble lymphocytic mediators. II. Modification of macrophage migration and migration inhibitory factor action by drugs, enzymes and cationic environment

Leucocyte migration inhibitory activity of concanavalin-A-stimulated human lymphocytes. Modification by dipyridamole, lysine-acetylsalicylate and heparin

The in vitro effects of heparin, dipyridamole (DIPY) and lysine-acetylsalicylate (LASA) on human peripheral blood leucocyte migration and upon production/release and effect of leucocyte migration inhibitory activity (LMIA) from lymphocytes stimulated with concanavalin-A (con-A) have been studied. The final concentration of each drug was of the same order of magnitude as during clinical treatment. The leucocyte migration under agarose was significantly increased by DIPY at a concentration of 100 mug/ml. The release/production of LMIA was inhibited by DIPY at 1 mug/ml and by LASA at 0.3 mug/ml. Heparin had no influence on LMIA release, even at 10 IU/ml. The LMIA of supernatants from con-A-stimulated lymphocyte cultures was inhibited by DIPY at a concentration of 10 mug/ml, by LASA at 3 mug/ml and by heparin at 10 IU/ml. The findings suggest that DIPY and LASA could have a dual role as modifiers of inflammation: 1) the well known role as antiaggregants tending to limit and impede thrombosis, and 2) as antagonists to the lymphocyte-mediated (type IV) immune reaction through a depressive action on lymphokine production/release and activity.

Impairment of macrophage migration inhibitory factor synthesis and macrophage migration in protein-malnourished mice

Weanling CD2F1 mice were fed isocaloric diets that were protein sufficient (PS; containing 27% casein) or protein deficient (PD; containing 8% casein). Weight measurements demonstrated that the growth of PD mice was significantly impaired, thus indicating that the PD diet induced protein malnutrition. The cellular immune responsiveness of these mice was assessed from Day 21 to Day 49 of the diet using, as indicators, in vitro production of migration inhibitory factor (MIF) by splenic lymphocytes and MIF responsiveness of peritoneal macrophages. PD lymphocytes, when stimulated with the polyclonal activator concanavalin A, produced significantly less MIF than did PS lymphocytes. The amount of MIF produced by PD lymphocytes, however, increased throughout the study, possibly indicating delayed maturation of MIF synthetic capacity in PD mice. Normal CD2F1 mouse macrophages were used for these assays. MIF responsiveness of PD and PS macrophages was not significantly different when assayed using MIF produced by normal CD2F1 mouse lymphocytes. As compared to that of PS macrophages, the migratory ability of PD macrophages decreased progressively throughout the study. This impaired migratory ability did not interfere with MIF responsiveness of PD macrophages.

[Immunopharmacology of corticosteroids]

Immunopharmacological effects of corticosteroids are primarily dependent upon their capacity to modify inflammatory reactions at various levels. Their molecular effects are related to the vascular system and to lymphocytes, phagocytes and mast cells, all cell types being involved in inflammation. They modulate the physiology, molecular biology and membrane dynamics of these cells thereby influencing cellular and humoral immune functions. The complexity of these effects may at least partially explain the usefulness of corticosteroids in cases of immunoproliferative, autoimmune and allergic disorders.

Lymphokine-induced Macrophage aggregation: the possible role of cyclic nucleotides

The possible role of cyclic nucleotides in guinea pig macrophage aggregation, induced by human lymphokine (LK) has been investigated. Small increases were found in guanosine 3'5'-cyclic monophosphate (cGMP), but not adenosine 3'5'-cyclic monophosphate (cAMP), levels of lymphokine aggregated macrophages. Addition of exogenous dibutyryl (DB) cAMP, L-isoproterenol, or theophylline did not induce macrophage aggregation. By contrast, both exogenous DBcGMP and carbamyl-choline induced a macrophage aggregation; although DBcGMP was more effective. In addition, both L-isoproterenol and DBcAMP in the presence of theophylline decreased LK-induced macrophage aggregation, whereas D-isoproterenol and DBcGMP had no effect. The results obtained here are discussed in the context of the previously reported effects of cyclic nucleotides on migration inhibitory factor (MIF) activity and the possible role of these agents in the mechanism of action of MIF.

Inhibition of mitogen-induced lymphokine production by cyclosporin A

The new antilymphocytic agent Cyclosporin A was found to inhibit the production and/or secretion of migration inhibitory factor (MIF) in human lymphocytes stimulated by Concanavalin A. Preincubation for one hour with the compound, followed by 8 hr restoration period of the cells in absence of the drug, resulted in moderate decrease in MIF synthesis and/or release. Cell viability was not affected. The agent was shown not to interfere with MIF action on the macrophage. We conclude that the molecular mechanism of action of Cyclosporin A is based, at least partially, on a blockade of synthesis and/or secretion of lymphokines from immunocompetent cells.

Biological and clinical relevance of human macrophage migration inhibitory factor (MIF)

The first isolation and characterization of a lymphokine, the human MIF (MSF), and the availability of a specific MIF (MSF)-antibody provide an opportunity to establish a new parameter for detection of cellular immune mechanisms in various clinical situations. The precise estimation of quantitative amounts of MIF by sensitive immunochemical techniques could gain new insights into the pathogenesis of a number of clinical disorders. In addition, the exact detection of quantitative amounts of MIF in body fluids could have prognostic value.

Prostaglandins as regulators in cellular immunity

Guinea-pig peritoneal macrophages have been shown to generate substantial concentrations of E-type prostaglandins during culture in vitro. Partially purified lymphokine preparations stimulate PGE production by macrophages. Exogenous PGE1 and PGE2 are potent inhibitors of lymphocyte activation and secretion of lymphokines causing lymphocyte mitogenesis and macrophage migration inhibition. Also indomethacin augments the secretion of these lymphokines in vitro. It is therefore suggested that production of PGE by macrophages provides a physiological mechanism for the regulation of lymphocyte activation in reactions of delayed hypersensitivity.

Effects of prostaglandins on the spreading, adhesion and migration of mouse peritoneal macrophages

The effects of prostaglandins on the in vitro properties of mouse peritoneal macrophages namely spreading, adhesion and migration were investigated. PGE1 and PGE2 inhibit the spreading and adhesion of complete Freund's Adjuvant induced peritoneal macrophages significantly at concentrations of 1 ng per ml and above whereas they enhance the migration of these cells at concentrations of 100 ng per ml and above. PGA2 and PGB2 are less potent as they inhibit spreading and adhesion only at a concentration of 1 microgram per ml. At his concentration PGB2 enhances migration whereas PG2 has no effect. PGF 2alpha has no effect on the spreading, adhesion and migration of macrophages in the concentration range of 0.1 ng to 1,000 ng per ml.

A simple method for the production of migration inhibitory factor by concanavalin A - stimulated lymphocytes

A simple method for preparing culture supernatants containing macrophage migration inhibitory factor (MIF) by pulse exposure to guinea pig lymphocytes to concanavalin A (ConA), is described. The method is based on the property of originally nonadherent lymphocytes to attach to the flask surface in the presence of Con A. The Con A-induced lymphocyte 'monolayer' can be easily rinsed, allowing the removal of free Con A without repeated, cell damaging centrifugation. The Con A-pulsed lymphocytes are cultured for 24 h in medium and supernatants containing MIF but free of undesired Con A are regularly obtained.

Some physicochemical properties of human leucocyte migration inhibitory factor (LIF)

Leucocyte migration inhibitory factor (LIF) obtained from human lymphocytes stimulated with concanavalin A was consistently and irreversibly blocked by the serine-esterase inhibitor phenyl-methyl sulphonylfuoride (PMSF). This effect was not due to fluoride ions, hydrolysis products of PMSF or to impurities. PMSF pulse treatment of human buffy coat cells did not affect cell migration under agarose. LIF was also irreversibly destroyed by treatment with L-cysteine and 2-mercapto-ethanol, suggesting that the molecule contains disulphide linkage groups decisive for its configuration and biological activity. Di-sodium EDTA completely inhibited LIF activity but only if present during the entire migration period. Removal of EDTA before LIF assay restored LIF activity. Leucotye migration was neighter influenced by L-cysteine nor by EDTA. LIF activity was slightly diminished after treatment at 56 degrees C for 1 h and completely lost at 80 degrees C for 1/2 h. Furthermore, LIF appeared rather stable when treated at pH values between 4 and 11. These findings suggest, but do not prove, an esterase or a protease nature of human LIF.

Mechanisms responsible for defective human T-lymphocyte sheep erythrocyte rosette function associated with hepatitis B virus infections

The expression of selected lymphocyte surface-membrane markers was evaluated in 37 patients with acute viral hepatitis B, 10 of whom were studied serially through the resolving and convalescent phases of disease. Bone marrow-derived (B) lymphocytes were identified by reference to surface immunoglobulin, whereas normal thymus-derived (T) lymphocytes were assayed by their capacity to form spontaneous nonimmune rosettes with sheep erythrocytes (E rosettes, ER). During the acute and resolving phases of viral hepatitis B, the relative and absolute number of ER-positive lymphocytes was significantly reduced, whereas the number of surface immunoglobulin-positive lymphocytes and the absolute lymphocyte count remained normal. This resulted in the appearance of a third population of cells, deficient in respect to both surface immunoglobulin and ER markers. Such cells accounted for nearly 25% of peripheral blood lymphocytes, approximately 5 x 105ml blood. Depression of the number of ER-positive lymphocytes occurred at least once during the course of disease in every patient studied serially, and was observed in 55 of 67 individual assays of the 37 cases of acute viral hepatitis B. Lymphocytes from some patients reacquired ER function when cultured in fetal calf serum but not in the presence of autologous serum. Such autologous serum was capable of suppressing ER function of lymphocytes from normal donors. The extrinsic suppression of er function by a serum factor (designated as the Rosette Inhibitory Factor), was found to be time dependent, characterized by a 4-h latent period and requiring approximately 18 h for maximum attenuation of ER function. The Serum Rosette Inhibitory Factor was: (a) heat and freeze-thaw stable, (b) nondialyzable, (c) physically separable from hepatitis B surface antigen, (d) not a lymphocytotoxic antibody, and (e) had the buoyant density of a lipoprotein. This extrinsic mechanism was observed in 41.8% of patients with reduced numbers of ER-positive lymphocytes. The Rosette Inhibitory Factor was not detectable in the serum of the remaining 58.2% of the cases of acute and resolving viral hepatitis B despite the presence of reduced numbers of ER-positive lymphocytes. The lymphocytes from these cases did not reacquire ER function when cultured in the absence of autologous serum. The mechanisms responsible for the suppression of normal ER function in these cases appears to be intrinsic to the lymphocytes and not the result of a humoral factor. The T lymphocyte lineage of cells deficient in respect to ER function, whether of intrinsic or extrinsic type, was demonstrated by their capacity to form spontaneous rosettes with neuraminidase-treated sheep erythrocytes. Both intrinsic and extrinsic suppression of T lymphocyte ER function commonly occurred during the first 4 wk of acute viral hepatitis B.9 of the 10 patients followed serially continued to manifest defective ER function at 12 wk...