Specific inhibition of the polymorphonuclear leukocyte chemotactic response to hydroxy-fatty acid metabolites of arachidonic acid by methyl ester derivatives

The human polymorphonuclear (PMN) leukocyte chemotactic activity of the hydroxy-fatty acid metabolites of arachidonic acid, 12-l-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and 12-l-hydroxy-5,8,10,14-eicosatetraenoic acid (HETE), is eliminated by methylation. Both methyl esters are specific competitive inhibitors of the PMN leukotactic responses to the parent stimuli, and exert no effect on the responses to formyl-methionyl peptides or chemotactic fragments of the fifth component of complement. 50% inhibition of the in vitro chemotactic responses of PMN leukocytes to HETE and HHT was achieved by an equimolar concentration of the corresponding methyl esters, whereas reciprocal cross-inhibition was observed at molar ratios of HETE methyl ester to HHT and HHT methyl ester to HETE which reflected the three- to fivefold greater chemotactic potency of HETE relative to HHT. Methyl esters of structurally related, but nonchemotactic, fatty acids did not competitively inhibit the chemotaxis elicited by HETE or HHT. The intraperitoneal injection of HETE in guinea pigs evoked an eosinophil response at 30 min and a neutrophil response at 5 h, which were prevented by a one-to twofold molar ratio of HETE methyl ester. The competitive inhibition of the in vitro chemotactic activity and the in vivo leukotactic effect of the unsaturated hydroxy-fatty acids by homologous methyl ester derivatives suggests that the cellular component of natural inflammatory reactions may be susceptible to specific regulation by receptor-directed modulation of the activity of the predominant chemotactic principles.

Identification of the Platelet Activating Activity in Rheumatoid Synovial Fluid as an Intermediate Molecular Weight Complex of IgG

The predominant platelet-activating activity assessed by the release of 14C-serotonin from washed human platelets was purified from the synovial fluid of patients with rheumatoid arthritis. Cation exchange chromatography on carboxymethyl cellulose, gel filtration on Sepharose 6B and preparative isoelectric focusing yielded a single factor with an apparent m.w. of 450,000 and an isoelectric point of 8.36 ± 0.25 (mean ± S.D.). Homogeneity of the purified synovial fluid platelet-activating activity, termed SF-PAA, was confirmed by the complete correspondence between platelet-activating activity and protein during gel filtration and electrophoresis in a glycerol gradient and by the elicitation of a monospecific antiserum. Platelet activation by SF-PAA, although coupled to serotonin secretion, was not associated with the release of the cytoplasmic marker lactic acid dehydrogenase or with platelet aggregation. Ouchterlony analysis of SF-PAA revealed a line of complete identity with human IgG with antiserum to either SF-PAA or γ heavy chains. Kappa and λ light chains were also identified in SF-PAA, whereas µ and α heavy chains, fibrinogen, and the complement components, Clq, C3, properdin, and B, were not present. Thus, SF-PAA appeared to be a complex of IgG of average m.w. 450,000. The inhibition of its action by monomeric IgG confirmed that the complex activated platelets through an IgG receptor.

Ascorbate therapy in impaired neutrophil and monocyte chemotaxis. With atopy, hyperimmunoglobulinemia E, and recurrent infection

A Candida albicans corneal ulcer developed in a 24-year-old man with a history of eczema, asthma, and multiple bacterial infections since childhood. The infection responded well to oral flucytosine (12 g/day for 15 days) and topical amphotericin B. Positive laboratory findings included eosinophilla, hyperimmunoglobulinemia E, and impaired neutrophil and monocyte spontaneous migration and chemotactic responses. Ascorbic acid corrected the monocyte defect in vitro and in vivo, but had no effect on neutrophil function.

Amplification of the activity of human leukocyte inhibitory factor (LIF) by the generation of a low molecular weight inhibitor of PMN leukocyte chemotaxis

Leukocyte inhibitory factor (LIF), which was derived from human peripheral blood lymphocytes by stimulation with concanavalin A ad partially purified by Sephadex G-100 gel filtration, inhibited the in vitro spontaneous migration and chemotaxis of human PMN leukocytes as assessed in a Boyden chamber micropore filter assay. The inhibitory activity was attributed to LIF, a principle defined in terms of its inhibition of PMN leukocyte migration from glass capillary tubes since it was preferentially directed to PMN leukocytes as compared to mononuclear leukocytes, exhibited a size comparable to LIF by gel filtration, and was inactivated by diisopropyl fluorophosphate in parallel with LIF. Incubation of PMN leukocytes with LIF released additional inhibitory activity, distinct from LIF, which resembled the neutrophil-immobilizing factor (NIF) by virtue of its approximate m.w. of 4000 by filtration on Sephadex G-25, inactivation by trypsin digestion, and preferential noncytotoxic inhibition of spontaneous migration and chemotaxis of PMN leukocytes as compared to mononuclear leukocytes. Thus LIF inhibits PMN leukocyte migration both by a direct action on the cells and by an amplification pathway that is mediated by low m.w. chemotactic inhibitors similar to NIF.

Amplification of the Activity of Human Leukocyte Inhibitory Factor (LIF) by the Generation of a Low Molecular Weight Inhibitor of PMN Leukocyte Chemotaxis

Leukocyte inhibitory factor (LIF), which was derived from human peripheral blood lymphocytes by stimulation with concanavalin A and partially purified by Sephadex G-100 gel filtration, inhibited the in vitro spontaneous migration and chemotaxis of human PMN leukocytes as assessed in a Boyden chamber micropore filter assay. The inhibitory activity was attributed to LIF, a principle defined in terms of its inhibition of PMN leukocyte migration from glass capillary tubes, since it was preferentially directed to PMN leukocytes as compared to mononuclear leukocytes, exhibited a size comparable to LIF by gel filtration, and was inactivated by diisopropyl fluorophosphate in parallel with LIF. Incubation of PMN leukocytes with LIF released additional inhibitory activity, distinct from LIF, which resembled the neutrophil-immobilizing factor (NIF) by virtue of its approximate m.w. of 4000 by filtration on Sephadex G-25, inactivation by trypsin digestion, and preferential noncytotoxic inhibition of spontaneous migration and chemotaxis of PMN leukocytes as compared to mononuclear leukocytes. Thus LIF inhibits PMN leukocyte migration both by a direct action on the cells and by an amplification pathway that is mediated by low m.w. chemotactic inhibitors similar to NIF.

Endomyocardial disease and eosinophilia. Report of a case

While an association between blood eosinophilia and endomyocardial disease has been recognized, the role of the eosinophil in the pathogenesis of the cardiac lesions remains uncertain. In a 69-year-old-man with large cell carcinoma of the lung, marked eosinophilia was stimulated by and progressed with the course of the neoplasm which was producing an eosinophil chemotactic factor. Peripheral blood eosinophils were vacuolated and degranulated while those in the bone marrow were morphologically normal. Clinical evidence of cardiac dysfunction developed one month prior to death. At autopsy, 12 months after the onset of symptoms, endomyocardial disease was present. There were numerous eosinophils in the damaged myocardium and surrounding the pulmonary neoplasm. In patients with endomyocardial disease and eosinophilia, the eosinophil may be directly cardiotoxic or a primary mediator of cardiac damage; therapeutic attempts to reduce the number of eosinophils might be benefit.

Production of a low molecular weight eosinophil polymorphonuclear leukocyte chemotactic factor by anaplastic squamous cell carcinomas of human lung

A peptide of approximately 300-400 daltons exhibiting in vitro chemotactic activity for human polymorphonuclear (PMN) leukocytes, with a preference for the eosinophil series, was isolated from extracts of anaplastic lung carcinomas of the large squamous cell type obtained from three patients with marked peripheral blood hypereosinophilia and eosinophilic infiltration of the tumors and surrounding normal pulmonary tissues. This chemotactic factor was termed ECF-LSC (eosinophil chemotactic factor of lung squamous cell carcinoma). ECF-LSC appeared in the urine of two of the patients in increasing quantities late in the course of their disease and was also elaborated by long-term cultures of dispersed tumor cells from the same two patients. Three anaplastic large cell bronchogenic carcinomas which were not associated with tumor tissue or peripheral blood eosinophilia, a bronchogenic adenocarcinoma from a patient with only peripheral eosinophilia, and a renal cell carcinoma metastatic to the lungs and associated with transient pleural tissue and fluid eosinophilia were all devoid of ECF-LSC. ECF-LSC from tumor tissue extracts, urine, and tumor cell culture medium was comparable to the mast cell-associated tetrapeptides of the eosinophil chemotactic factor of anaphylaxis (ECF-A) in size, but eluted from Dowex-1 at pH 5.0-3.5 in contrast to the more acidic ECF-A tetrapeptides which eluted at pH 3.2-2.2 ECF-LSC, like the tetrapeptides of ECF-A, had a secondary chemotactic activity for neutrophil PMN leukocytes, but not mononuclear leukocytes, and deactivated both eosinophil and neutrophil PMN leukocytes so that they would not respond to a subsequent in vitro chemotactic stimulus. Eosinophils from the two patients with urinary excretion of ECF-LSC and the highest concentrations in tumor extracts were hyporesponsive in vitro to homologous and heterologous chemotactic stimuli, suggesting that ECF-LSC had deactivated the eosinophils in vivo.

Morphologic and functional evidence for release of mast-cell products in bullous pemphigoid

We studied nine patients with bullous pemphigoid, a generalized cutaneous eruption- for evidence of mast-cell involvement during development of lesions. As in other reports, six of nine patients demonstrated a serum antibody directed against the epidermal basement-membrane zone. Direct immunofluorescence studies of lesions revealed depostion of immunoglobulin and complement proteins at the basement-membrane zone in six of nine and nine of nine patients, respectively. Participation of mast cells was suggested by a sequence of pathologic alterations in which there was progressive mast-cell degranulation and late eosinophil infiltration. In addition, a factor chemotactic for human eosinophils with the size and charge characteristics of the eosinophil chemotactic factor of anaphylaxis was identified in blullous fluid. The data indicate that, in addition to activation of the complement system, involvement of mast cells is an early and continuing event in the development of the cutanenous lesions of bullous pemphigoid.

Chemotactic and Chemokinetic Stimulation of Human Eosinophil and Neutrophil Polymorphonuclear Leukocytes by 12-L-Hydroxy-5,8,10-Heptadecatrienoic Acid (HHT)

Diverse lipid products of arachidonic acid were examined for in vitro human polymorphonuclear (PMN) leukocyte chemotactic activity and the ability to enhance PMN leukocyte migration in the absence of a concentration gradient of the stimulus, an effect termed chemokinesis. Highly purified 12-L-hydroxy-5,8,10-eicosatetraenoic acid (HETE), a lipoxygenase product, and 12-L-hydroxy-5,8,10-heptadecatrienoic acid (HHT), a cyclo-oxygenase product, were chemotactic for PMN leukocytes in concentrations ranging from 0.7 to 25 µg/ml and 2 to 50 µg/ml, respectively, with a preference for the eosinophil series. Preincubation with peak chemotactic concentrations of either hydroxy-lipid product irreversibly suppressed the response of PMN leukocytes to the homologous and other chemotactic stimuli. At minimally chemotactic concentrations, both HETE and HHT were positively chemokinetic and enhanced the chemotactic response of PMN leukocytes to the homologous lipid and to a stimulus derived from human C5 by tryptic digestion. PGE2 and PGF2α lacked chemotactic activity, but exhibited negative and positive chemokinetic activity, respectively, whereas thromboxane B2 had no effect on PMN leukocyte migration. Thus, HHT is the first leukocyte chemotactic factor that is a product of the cyclooxygenase pathway and whose generation would thus be inhibited by nonsteroidal anti-inflammatory agents. Unlike the potently deactivating chemotactic factors, such as the tetrapeptides of the eosinophil chemotactic factor of anaphylaxis (ECF-A), HHT and HETE are chemokinetic at low concentrations and may enhance PMN leukocyte influx in response to other chemotactic stimuli.

Intermediate Molecular Weight Eosinophil Chemotactic Factors in Rat Peritoneal Mast Cells: Immunologic Release, Granule Association, and Demonstration of Structural Heterogeneity

Previously uncharacterized eosinophil chemotactic activity of apparent m.w. 1500 to 2500 by Sephadex G-25 gel filtration was present preformed in rat peritoneal mast cells, was associated with the mast cell granules, and was released by challenge of the mast cells with rabbit anti-rat F(ab′)2 antiserum. Further purification of this activity by Dowex-1 chromatography revealed two peaks of eosinophil chemotactic activity eluting at pH 5.4 to 4.4 and pH 3.1 to 2.1, respectively. On Sephadex G-50 gel filtration both activities filtered just behind the α chain of insulin (m.w. 2540). The more acidic material gave a major peak of eosinophil chemotactic activity on high pressure liquid chromatography whereas the less acidic material separated into two equal peaks of eosinophil chemotactic activity of different hydrophobicity. Both the less acidic and the more acidic intermediate m.w. activities required a concentration gradient for expression of eosinophil chemotactic activity and were capable of rendering eosinophils unresponsive to homologous or heterologous chemotactic stimuli. Checkerboard assays of the more acidic factor over a range of concentrations did not reveal chemokinetic activity in the chemotactic dose-range and neither the more acidic nor the less acidic factors enhanced the spontaneous migration of eosinophils when placed on the cell side alone of the chemotactic chamber. The mast cell serves as a source of several eosinophil chemotactic factors differing in size and charge, which could possibly stabilize the chemotactic gradient and sustain an influx of eosinophils to the site of mast cell activation.

Immunologic Release in the Rat Peritoneal Cavity of Lipid Chemotactic and Chemokinetic Factors for Polymorphonuclear Leukocytes

Antigen challenge of the rat peritoneal cavity after passive preparation with IgGa-rich hyperimmune antiserum releases lipids that enhance the migration of human polymorphonuclear (PMN) leukocytes in a modified Boyden micropore filter assay. Deproteinated peritoneal fluid was applied to an Amberlite XAD-8 column equilibrated in distilled water and sequential elution yielded 30% of the migration-enhancing activity in water and 70% of the activity in 80% ethanol. The lipids in the 80% ethanol eluate were chromatographed on silicic acid that was developed sequentially with hexane, dichloromethane, acetone, 1-propanol, and ethanol:ammonia:water (6:3:1, v:v:v). The lipids with migration-enhancing activity eluted in hexane and acetone in two discrete peaks. These were separated from the other lipid mediators slow-reacting substance of anaphylaxis (SRS-A) and platelet-activating factor (PAF), which eluted in ethanol:ammonia:water. The activity in the acetone fraction had the functional characteristics of a chemotactic factor in that it required a concentration gradient to stimulate PMN leukocyte migration and induced chemotactic deactivation, whereas the hexane fraction contained a chemokinetic factor that enhanced PMN leukocyte migration irrespective of a concentration gradient. Both lipid factors were preferentially active on neutrophil and eosinophil PMN leukocytes as compared to mononuclear leukocytes. Reversed immunologic challenge of the rat peritoneal cavity with rabbit anti-rat F(ab′)2 antiserum released both the chemotactic and chemokinetic factors, whereas challenge with rabbit anti-rat myeloma IgE antiserum released predominantly the chemotactic factor. Pretreatment of the rat peritoneal cavity with 5,8,11,14-eicosatetraynoic acid (TYA) before direct immunologic challenge inhibited the release of both lipid factors and indomethacin pretreatment suppressed the immunologic release of the chemotactic factor, but not the chemokinetic factor. Thus, immunologic challenge of the rat peritoneal cavity by pathways dependent on antibodies other than IgE generates both PMN leukocyte chemotactic and chemokinetic activities from arachidonate or related fatty acids, whereas IgE-dependent stimulation releases predominantly the lipid chemotactic factor.

Elevation of the cyclic GMP concentration in human platelets by sodium ascorbate and 5-hydroxytryptamine

Sodium L-ascorbate (ascorbate) and sodium D-ascorbate produced a dose-related rise of guanosine 3':5'-cyclic monophosphate (cGMP) in platelets with a maximum increment averaging 25-fold at 5 mM ascorbate. The ascorbate-induced increment in cGMP reached a peak after 1 min and was maintained for 1 h in the presence of ascorbate. 5-hydroxytryptamine (5-HT) also produced a dose-related rise of cGMP in platelets with a peak effect of approximately 25-fold at 16 micrometer 5-HT. The elevation of cGMP in platelets by both ascorbate and 5-HT did not require extracellular calcium and was blocked by inhibitors of cyclo-oxygenase such as aspirin or indomethacin. A maximum ascorbate-induced rise in platelet cGMP at the time of addition of epinephrine, collage or thrombin did not augment the release of [14C]5-hydroxytryptamine ([14C]5-HT) measured over 30 min. Although ascorbate appeared to increase platelet cGMP by modulation of endoperoxide formation, its failure to aggregate platelets or to influence the release reaction indicates that the ascorbate-stimulated rise in cGMP does not have a simple relationship to thromboxane formation.

Mast cell-mediated reactions of host defense and tissue injury: the regulatory role of eosinophil polymorphonuclear leukocytes

Immunological stimulation of mast cells, by way of either IgE- or IgG-directed reactions, initiates the rapid release of an array of chemical mediators. The predominant local tissue effects of these mediators collectively constitute a defensive response of the host. The early humoral phase of defense is exemplified by the alterations in microvascular permeability induced by histamine which provide a local concentration of immunoglobulins and complement components. The later cellular phase of defense is composed of the PMN leukocytes that accumulate in response to mast cell-derived chemotactic principles and which phagocytose and degrade opsonized foreign material, thus eliminating the inciting stimulus. Of the several endogenous regulatory mechanisms which act to contain the immediate hypersensitivity reaction, the eosinophil has a special role since it is specifically attracted to sites of mast cell activation and has selective concentrations of several enzymes which degrade the mast cell-derived chemical mediators. Failure of the local regulatory processes can permit the mast cell responses of host defense to become pathological reactions leading to tissue injury by virtue of persistence of high levels of humoral mediators and/or increasing infiltration with PMN leukocytes.

A neutrophil-dependent pathway for the generation of a neutral peptide mediator. II. Subcellular localization of the neutrophil protease

The human neutrophil neutral peptide-generating protease was associated with the plasma membrane marker 5'-nucleotidase on sucrose density gradient centrifugation of sonicates of granule-free fractions following homogenization and velocity sedimentation. The two activities were also associated on sucrose density gradient fractionation of plasma membranes obtained by hypotonic lysis in EDTA containing buffers, a technique which minimizes aggregation. Treatment of fractions containing these enzymatic activities with 1-0 M NaCl separated the neutral peptide-generating proteasein to the eluate while leaving the 5'-nucleotidase in the pellet. Gel filtration of the solubilized neutral peptide-generating protease through Sephadex G-100 in 1-0 M NaCl demonstrated that the protease had an approximate mol. wt of 20,000 while filtration in physiological salt concentrations yielded activity only in the excluded volume. In both cases, there was complete recovery of neutral peptide-generating activity suggesting that the filtration characteristics of the protease were determined by the salt concentration. The solubilized purified protease, the whole cell sonicates, and the intact cells interacted with heat-inactivated plasma to yield the same product, a neutral peptide with a 1000 molecular weight and an isoelectric point of 7-2-7-6. The neutral peptide-generating protease in each instance was inhibited in dose-response fashion by alpha-1-antitrypsin, LBTI, and DFP. Only 30-60% of the protease sites were functional on intact cells as revealed by substrate cleavage or were available to inhibitors. The neutrophil protease which generates neutral peptide is an extrinsic plasma membrane protein with an approximate mol. wt of 20,000 which functions as an ectoenzyme.

Stimulation of human eosinophil and neutrophil polymorphonuclear leukocyte chemotaxis and random migration by 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid

A human platelet lipoxygenase-generated product of arachidonic acid, identified by thin-layer chromatographic and mass spectrometric properties as 12-L-hydroxy-5,8,10,14-eicosatertraenoic acid (HETE), was selectively chemotactic in vitro for human polymorphonuclear leukocytes (PMN), as compared to mononuclear leukocytes, with a preference for eosinophils. Preincubation of PMN with partially-purified HETE at peak chemotactic concentrations of 8-24 mug/ml reduced their random and chemotactic migration and stimulated the activity of their hexose monophosphate shunt; minimally chemotactic concentrations of 0.03-1 mug/ml enhanced PMN random migration without influencing other functions. HETE may thus be capable of preferentially attracting eosinophils to foci of tissue reaction associated with platelet activation.

Defective responsiveness to ascorbic acid of neutrophil random and chemotactic migration in Felty's syndrome and systemic lupus erythematosus

Polymorphonuclear (PMN) leucocytes from 4 patients with untreated systemic lupus erythematosus (SLE) showed defective random migration (P less than 0-05) and depressed chemotactic responses to C5a and kallikrein (P less than 0-01) compared to PMN leucocytes from normal subjects, or patients with rheumatoid arthritis (4) or Felty's syndrome (4) when examined at a standardized cell concentration with a micropore filter radioassay but not with a conventional Boyden technique. Normal in vitro enhancement of PMN leucocyte random and chemotactic migration by sodium ascorbate was absent in SLE and Felty's syndrome, but sodium ascorbate gave normal stimulation of hexose monophosphate shunt activity in the PMN leucocytes precluding a defect in ascorbate transport.

Structural determinants of the eosinophil: chemotactic activity of the acidic tetrapeptides of eosinophil chemotactic factor of anaphylaxis

The acidic tetrapeptides of ECF-A, Ala/Val-Gly-Ser-Glu, exhibit peak in vitro chemotactic activity for human eosinophils at concentrations of 3 X 10(-8) M to 10(-6) M, and rapidly deactivate eosinophils to homologous and other stimuli at concentrations as low as 10(-10) M. The analogue Leu-Gly-Ser-Glu reaches peak activity at 10(-8)M-10(-7)M, while Phe-Gly-Ser-Glu requires 10(-4)M to elicit a peak response. Although inversion of the order of glycine and serine does not alter the eosinophil chemotactic activity of the tetrapeptides, deletion of glycine increases by 10-fold the concentration required for peak chemotactic activity, indicating the critical nature of the spacing between NH2- and COOH-terminal residues. The substituent COOH-terminal tripeptide, which is only marginally chemotactic, irreversibly suppresses eosinophil chemotactic responsiveness at a concentration 10,000-fold higher than concentrations necessary for deactivation by the intact tetrapeptide. The high concentration of tripeptide required for this cell directed effect, which is assumed to be analogous to deactivation, is attributed to the absence of the NH2-terminal residue which would facilitate effective interaction with the eosinophil. A substituent NH2-terminal tripeptide and amides of the NH2-terminal amino acids, which are devoid of chemotactic and deactivating activities, reversibly inhibit the tetrapeptide stimulus in a dose-response fashion. The additional finding that the NH2-terminal tripeptide protects the eosinophil from deactivation by the intact tetrapeptide confirms that the competitive interaction is stimulus specific.

Modulation of human eosinophil polymorphonuclear leukocyte migration and function

Eosinophil migration toward a concentration gradient of a chemotactic factor is regulated at four levels. Diverse immunologic pathways generate stimuli with eosinophil chemotactic activity, including the complement products C5a and a fragment of C3a and the peptide products of mast cells and basophils activated by IgE-mediated reactions, such as eosinophil chemotactic factor of anaphylaxis (ECF-A) and other oligopeptides. The intrinsic preferential leukocyte activity of the chemotactic stimuli represents the second level of modulation, with ECF-A and other mast cell-derived peptides exhibiting the most selective action on eosinophils. The third level of control of eosinophil chemotaxis is composed of inactivators and inhibitors of chemotactic stimuli and is exemplified by degradation of C5a by anaphylatoxin inactivator or chemotactic factor inactivator and of ECF-A by carboxypeptidase-A or aminopeptidases. The activity of ECF-A is uniquely suppressed by equimolar quantities of its NH2- terminal tripeptide substituent, presumably by eosinophil membrane receptor competition. Factors comprising the fourth level of regulation, which alter eosinophil responsiveness to chemotactic stimuli, include the chemotactic factors themselves, through deactivation; nonchemotactic inhibitors such as the COOH-terminal tripeptide substituent of ECF-A, the neutrophil-immobilizing factor (NIF), the phagocytosis-enhancing factor Thr-Lys-Pro-Arg, and histamine at concentrations greater than 400 ng/ml; and nonchemotactic enhancing principles represented by ascorbate and by histamine at concentrations of 30 ng/ml or less. Local concentrations of eosinophils called to and immobilized at the site of a hypersenitivity reaction may express their regulatory functions by degrading the chemical mediators elaborated including histamine, slow-reacting substance of anaphylaxis (SRS-A), and platelet-activating factor (PAF) by way of their content of histaminase, arylsulfatase B, and phospholipase D, respectively. Immunologic pathways may thus provide the capability for early and specific host defense reactions with a later influx of eosinophils preventing irreversible local tissue alterations or distant organ effects.

A phagocytosis-enhancing factor in human plasma

A phagocytosis-enhancing factor (PEF) with the capacity to stimulate the ingestion of sensitized sheep erythrocytes by human polymorphonuclear and mononuclear leucocytes has been isolated from human plasma by chromatography on DEAE-cellulose and filtration on Sephadex G-150 and Sephadex G-100. PEF is a protein of approximately 70,000 molecular weight which is susceptible to inactivation by heating at 60 degrees or by tryptic digestion. PEF promotes phagocytosis of erythrocytes sensitized with intact 7S antibody or bearing the C3b complement fragment, but not of unsensitized erythrocytes or erythrocytes sensitized with 19S antibody. The specificity of PEF interaction with target erythrocytes and the persistence of its stimulatory effect after the target cells are washed suggest that it promotes phagocytosis by an action on the erythrocytes.

Isolation of human eosinophil phospholipase D

Phospholipase D preferentially contained in human eosinophil polymorphonuclear leukocytes as compared to other leukocytes was isolated by sequential asion and cation exchange chromatography and gel filtration. The purified eosinophil enzyme specifically liberated choline from I-alpha-phosphatidyl choline with a pH optimum of 4.5-6.0 and exhibited a pI of 5.8-6.2 on polyacrylamide-gel isoelectric focusing, which are properties shared by phospholipase D from plant sources; however, its apparent mol wt of 60,000 is approximately one-half that of the plant enzymes. Eosinophil and cabbage phospholipase D inactivated a partially purified rat platelet-activating factor (PAF) in a time- and dose-dependent reaction. The cleavage of this PAF activity was attributed to the inherent phospholipase D activity of the eosinophil enzyme since the two activities chromatographed together at each purification step, and there was apparent reciprocal inhibition of choline-generating activity by PAF and of PAF-inactivating activity by phosphatidyl choline. Thus, possible regulatory functions of the eosinophil in immediate hypersensitivity reactions include inactivation of a PAF by phospholipase D as well as degradation of slow-reacting substance of anaphylaxis by arylsulfatase B.

A chemotactic receptor for val(ala)-gly-ser-glu on human

Preferential eosinophil chemotactic activity is an in vitro and in vivo property of eosinophil chemotactic factor of anaphylaxis (ECF-A), a mixture of two peptides, Val-Gly-Ser-Glu and Ala-Gly-Ser-Glu, isolated from extracts and anaphylactic diffusates of human lung tissue. Purified native and synthetic ECF-A share with the synthetic N-formyl methionyl peptides such features as in vitro activity in nanomolar amounts, high dose inhibition of effect and a requirement for hydrophobic amino acid residues. The capacity of the substituents of ECF-A, Val-Gly-Ser, Ala-Gly-Ser, and Gly-Ser-Glu to modulate eosinophil chemotaxis has permitted a preliminary functional characterization of an eosinophil surface receptor. The activity, specificity, and structural characteristics of the active tetrapeptides suggest that distinct interactions of the peptide with a stereospecific receptor on the eosinophil surface is required for chemotactic movement.

Immunologic components of hypersensitivity reactions to cromolyn sodium

Manifestations of cellular and humoral hypersensitivity to cromolyn sodium were sought in six asthmatic patients suspected of having acute (three cases) or subacute (three cases) adverse reactions to cromolyn inhalation. Lymphocytes from all patients produced migration inhibition factor (MIF), and those from four patients incorporated increased amounts of 3H-thymidine in response to cromolyn in vitro. Lymphocytes from four of nine cromolyn-tolerant asthmatics demonstrated increased 3H-thymidine incorporation but none showed MIF production, whereas lymphocytes from normal subjects failed to react to cromolyn in either assay. Two of three patients with subacute reactions had increased serum binding of 3H-cromoglycate which was attributable to the IgG fraction. Thus although patients tolerating cromolyn therapy may demonstrate lymphocyte transformation in vitro, only those with clinically apparent adverse reactions produce lymphocyte MIF or possess serum-binding activity for the drug.

Purification and synthesis of eosinophilotactic tetrapeptides of human lung tissue: identification as eosinophil chemotactic factor of anaphylaxis

Preferential eosinophil chemotactic activity exhibiting a molecular weight comparable to that released from sensitized human lung fragments challenged with specific antigen and designated eosinophil chemotactic factor of anaphylaxis has been isolated from extracts of human lung fragments by sequential purification on Sephadex G-25, Dowex-1, Sephadex G-10, and paper chromatography. Two eosinophilotactic tetrapeptides of amino acid sequence Val-Gly-Ser-Glu and Ala-Gly-Ser-Glu were recovered from the extracts in 4-12% overall yield of the low molecular weight peak from Sephadex G-25. Purified eosinophil chemotactic factor of anaphylaxis and the synthetic tetrapeptides were maximally active in amounts from 0.1 to 1.0 nmol per chemotactic chamber, and the activity was dependent on both the NH2-terminal and the COOH-terminal residues. Both natural and synthetic peptides were preferentially chemotactic for eosinophils and rendered them unresponsive to a subsequent stimulus.

"Streaking leukocyte factor," arthritis, and pyoderma gangrenosum

A 14-year-old boy with a 12-year history of episodes of sterile pyarthrosis and cutaneous inflammation and ulceration was found to possess a serum factor which enhanced the random migration of leukocytes in vitro. The serum factor was isolated by Sephadex G-200 gel filtration and found to have a molecular weight of approximately 160,000. This partially purified principle enhanced the random migration of purified normal human neutrophils or mononuclear leukocytes by up to 200% without influencing chemotaxis. Trauma or other stimuli may lead to an accumulation of this serum factor in some tissues of the patient with resultant excessive leukocyte influx and heightened local activity of the leukocytes in the inflammatory exudate.

Studies of immediate hypersensitivity in a patient with Acanthocheilonema perstans filarial infection

A 25-year-old white female returned from West Africa with a two-year history of epidosic swelling, pruritus, and pain in a wrist, associated with peripheral eosinophilia. Serologic and immediate skin tests with Dirofilaria immitis antigen were positive, and blood smears transiently showed microfilariae of Acanthocheilonema perstans after the patient had been treated with diethylcarbamazine. Before treatment, both the serum concentration of IgE and the eosinophil content of arylsulfatase, an enzyme that selectively inactivates slow-reacting substance of anaphylaxis, were elevated; the patient's peripheral leukocytes released histamine and eosinophil chemotactic factor of anaphylaxis when challenged with D. immitis antigen. After one course of diethylcarbamazine, the clinical manifestations and abnormal in vitro immunologic results resolved. Host response to A. perstans infection appears to involve both IgE-mediated hypersensitivity and alterations in an eosinophil enzyme.

Chemotactic activity derived from interaction of factors D and B of the properdin pathway with cobra venom factor or C3B

Interaction of D (the activated form of D) and B, factors of the properdin pathway, with C3b (the major cleavage fragment of C3) generates a convertase, C3B, which cleaves C3 and initiates the terminal complement sequence C5-C9. A functionally analogous more stable C3 convertase, CoVFB, ir formed by substituting cobra venom factor (CoVF) for C3b. Mixtures of highly purified CoVF, B, and D were chemotactic for human neutrophil polymorphonuclear leukocytes as assessed in Boyden chambers either by microscopic enumeration of migrating cells or by counting of 51Cr-labeled cells. Control mixtures containing CoVF, B, and D, reacted in the absence of Mg++, were hemolytically inactive and devoid of chemotactic activity. Over a range of doses, the chemotactic activity of mixtures yielding CoVFB correlated with their hemolytic activity. Pretreatment of neutrophils with mixtures containing CoVFB rendered them unresponsive to subsequent chemotactic stimulation by kallikrein of C5a, indicating cross-deactivation to other chemotactic factors. Similar neutrophil deactivation occurred after exposure to a mixture of C3b, B, and D in which C3B was formed; with short incubation times and high cell concentration C3B also exhibited some chemotactic activity. The chemotactic activity of C3B and CoVFB is an example of a biologic function arising from interactions among factors of the properdin pathway per se, as distinguished from the capacity of this pathway to activate C3 and the terminal complement sequence.

Inactivation of slow reacting substance of anaphylaxis by human eosinophil arylsulfatase

Arylsulfatase preferentially present in the human eosinophil as compared to other leukocytes was isolated by sequential gel filtration and cation exchange chromatography. The apparent molecular weight of 60,000, the preferential cleavage of 4-nitrocatechol sulfate (PNCS) over p-acetyl-benzenesulfonic acid (PABS), inhibition by phosphate ions and pH optimum of 5.7 are characteristics of a type II B arylsulfatase. Eosinophil arylsulfatase inactivated purified human slow reacting substance of anaphylaxis (SRS-A) in a time-dependent reaction with the rate dependent upon the enzyme/substrate ratio. That SRS-A inactivation was the result of intrinsic arylsulfatase activity was indicated by association of PNCS cleavage and SRS-A inactivating activity during chromatography, the similar pH optimum for cleavage of both substrates and the capacity of SRS-A to inhibit PNCS cleavage by arylsulfatase. The finding that eosinophil arylsulfatase inactivates SRS-A suggests that eosinophil ingress into the site of an immediate hypersensitivity reaction in response to ECF-A could represent a regulatory function.

Inactivation of Slow Reacting Substance of Anaphylaxis by Human Eosinophil Arylsulfatase

Arylsulfatase preferentially present in the human eosinophil as compared to other leukocytes was isolated by sequential gel filtration and cation exchange chromatography. The apparent molecular weight of 60,000, the preferential cleavage of 4-nitrocatechol sulfate (PNCS) over p-acetyl-benzenesulfonic acid (PABS), inhibition by phosphate ions and pH optimum of 5.7 are characteristics of a type II B arylsulfatase. Eosinophil arylsulfatase inactivated purified human slow reacting substance of anaphylaxis (SRS-A) in a time-dependent reaction with the rate dependent upon the enzyme/substrate ratio. That SRS-A inactivation was the result of intrinsic arylsulfatase activity was indicated by association of PNCS cleavage and SRS-A inactivating activity during chromatography, the similar pH optimum for cleavage of both substrates and the capacity of SRS-A to inhibit PNCS cleavage by arylsulfatase. The finding that eosinophil arylsulfatase inactivates SRS-A suggests that eosinophil ingress into the site of an immediate hypersensitivity reaction in response to ECF-A could represent a regulatory function.

The Release of Four Mediators of Immediate Hypersensitivity from Human Leukemic Basophils

The availability of a patient with basophilic leukemia manifesting 75 to 90% mature basophils permitted the use of a cell concentration sufficient to generate and release mediators upon interaction with a calcium ionophore in quantities adequate for their physicochemical characterization. The mediators were defined in terms of their physicochemical characteristics: slow reacting substance of anaphylaxis (SRS-A) by purification through silicic acid chromatography and inactivation by arylsulfatase; eosinophil chemotactic factor of anaphylaxis (ECF-A) by its gel filtration through Sephadex G-25 and inactivation by subtilisin and not trypsin; and platelet-activating factor (PAF) by its inherent binding to albumin. Both ECF-A and histamine were present in their preformed state, and for histamine it was possible to establish that the concentration per cell was comparable to that of normal human basophils. Dibutyryl cyclic AMP suppressed release of histamine and SRS-A, indicating that their availability was under a control similar to that observed with normal cells subjected to immunologic activation. The demonstration that a suspension of leukemic human basophils contained the preformed mediators, histamine and ECF-A, and generated SRS-A and PAF for release along with histamine and ECF-A, after activation with a calcium ionophore, establishes that a single cell type can serve as a source of the four recognized mediators of immediate-type hypersensitivity.

Eosinophil polymorphonuclear leukocyte function in immediate hypersensitivity

An eosinophil chemotactic factor of anaphylaxis (ECF-A), released along with other chemical mediators of immediate hypersensitivity from sensitized mast cells that have been challenged with specific antigen, is capable of selectively attracting eosinophils. The rate and magnitude of tissue eosinophil influx may be enhanced by ascorbate and inhibited by the neutrophil immobilizing factor (NIF). Eosinophils may then exercise a local regulatory function. Phagocytosis or the action of ECF-A at high concentrations causes eosinophils to release arylsulfatase, which inactivates slow reacting substance of anaphylaxis (SRS-A). Additional possible functions of eosinophils may follow from their content of factors that inhibit histamine release or its mediator function, and the high levels of intracellular plasminogen and phospholipase B. Thus, the unique enzymes and factors released from eosinophils may form the basis of their role in immediate and subacute hypersensitivity reactions.

Modulation of the random migration of human platelets

Random migration of human platelets has been recognized as a parameter of platelet function which can be assessed in a reproducible manner by modification of the Boyden micropore filter technique for evaluating this function in other cells (Boyden, S. 1962. J. Exp. Med. 115: 453-466). Because platelets are extremely susceptible to aggregation, the conditions for collecting and isolating platelets and the migration buffer (Ca(++) and Mg(++)-free phosphate buffered saline, pH 6.8, with glucose and gelatin) were selected to minimize such a possibility. The random movement of platelets into the micropore filter was maximal at 30-37 degrees C and was contingent upon the metabolic integrity of the cell; thus, it can be attributed to active spontaneous migration. While the initiating and enhancing effects of epinephrine on the platelet aggregation-release reaction are mediated by an alpha-adrenergic receptor, the inhibition of random migration involved a beta-receptor. Equimolar propranolol but not phentolamine prevented epinephrine inhibition of random migration, and isoproterenol had activity comparable to epinephrine while phenylephrine was inactive. The capacity of the cholinomimetic agent, carbachol, to increase platelet migration is reminiscent of the recent findings in several cell systems in which beta-adrenergic and cholinergic stimuli have opposite effects. The prostaglandins E1 and E2 augmented spontaneous migration in contrast to their well established inhibitory action on platelet aggregation at the concentrations employed. The suppression by indomethacin of prostaglandin enhancement and of spontaneous migration implies a requirement for the prostaglandin biosynthetic pathway during the migration process. Thus, the spontaneous migration of human platelets, an additional parameter of platelet function for in vitro investigations, disclosed not only a beta-adrenergic receptor for epinephrine, but also a capacity for cholinergic augmentation and an apparent requirement for prostaglandin biosynthesis.

A neutrophil-dependent pathway for the generation of a neutral peptide mediator: partial characterization of components and control by alpha-1-antitrypsin

A biologically active neutral peptide mediator is cleaved from a plasma protein substrate by an alpha-1-antitrypsin-inhibitable serine protease apparently residing on the membrane of the human neutrophil. The peptide mediator has an approximate mol wt of 1,000, and is distinguished from the kinin peptides by a neutral isoelectric point, susceptibility to inactivation by trypsin as well as chymotrypsin and activity on the isolated, atropinized, and antihistamine-treated guinea pig ileum with relatively little action on the estrous rat uterus. The neutrophil protease is fully inhibitable by DFP, trypsin inhibitors from lima or soy bean, and alpha-1-antitrypsin and is associated with the high mol wt fragments of the neutrophil and not the nuclear, lysosomal, or cytoplasmic subcellular fraction. The substrate has an approximate mol wt of 90,000 and is chromatographically separable from kininogen. The exquisite sensitivity of the neutrophil protease to alpha-1-antitrypsin was established both by inhibition with highly purified alpha-1-antitrypsin and by the inability of the protease to generate detectable neutral peptide in a homozygous (ZZ) alpha-1-antitrypsin-deficient patient without heat inactivation of the residual inhibitor. On the other hand, plasma from a (null) alpha-1-antitrypsin-deficient patient supported neutral peptide generation and revealed an additional factor which inactivated neutral peptide.

Modulation of the immunological release of the eosinophil chemotactic factor of anaphylaxis from human lung

The antigen-induced release of preformed eosinophil chemotactic factor of anaphylaxis (ECF-A) from passively sensitized human lung tissue, requires divalent cations, an intact glycolytic pathway and a diisopropyl fluorophosphate (DFP) inhibitable esterase, and appears to be modulated by prototype adrenergic and cholinergic receptors. Increases in intracellular cyclic AMP inhibit the release of ECF-A as shown not only by the effect of exogenous dibutyryl cyclic AMP but also by the kinetic relationship between increases in tissue cyclic AMP and inhibition of the release of ECF-A, histamine and slow reacting substance of anaphylaxis from lung tissue interacted with cholera toxin. Cholinergic enhancement of the antigen-induced release of ECF-A was not associated with measurable alterations in the intracellular content of cyclic AMP and is attributed to elevation of intracellular cyclic GMP, as the introduction of 8-bromo cyclic GMP enhances ECF-A release.

Enhancement of random migration and chemotactic response of human leukocytes by ascorbic acid

Incubation of human leukocytes with ascorbic acid at neutral pH and at concentrations 10-50 times that of normal blood levels augmented both the in vitro random migration and chemotaxis of the cells by 100-300% without influencing their phagocytic capacity. Enhancement of mobility by ascorbate was evident for isolated neutrophils, eosinophils, and mono-nuclear leukocytes and was independent of the specific chemotactic stimulus. Stimulation by ascorbate of the hexose monophosphate shunt of adherent neutrophils and augmentation by ascorbate of neutrophil mobility had comparable dose-response relationships, could be reversed by washing the cells, and were both suppressed by preincubation of the neutrophils with 6-aminonicotinamide, but not with the neutrophil-immobilizing factor. Glutathione, the proposed intermediate for ascorbate action, similarly stimulated hexose monophosphate shunt activity and enhanced migration. The enhancement in vitro of leukocyte mobility by ascorbate at concentrations found in some normal tissues, therefore, appears to be dependent upon stimulation of the leukocyte hexose monophosphate shunt.

Stimulation of human neutrophil leukocyte aerobic glucose metabolism by purified chemotactic factors

The interaction of human neutrophils adherent to plastic petri dishes with the purified chemotactic factors C5a and kallikrein increased their rate of aerobic glycolysis 25-120% and the activity of their hexose monophosphate shunt (HMPS) 100-600%, reaching a plateau after 2 hr at 37 degrees C. The stimulation of either pathway required a chemotactically active stimulus since neither C5 nor prekallikrein or inactivated kallikrein could enhance metabolic activity. Marked suppression of the neutrophil chemotactic response by preincubation with a chemotactic factor to achieve deactivation, 5 x 10(-7) M diisopropyl fluorophosphate, or the neutrophil immobilizing factor (NIF) did not prevent the stimulation of HMPS activity or glycolysis by chemotactic factors. The metabolic inhibitors iodoacetate and 6-aminonicotinamide at concentrations which blocked enhancement of glycolysis or HMPS activity, respectively, partially suppressed the chemotactic response of neutrophils to the chemotactic factors. The capacity of a chemotactic factor to stimulate glucose metabolism of human neutrophils is associated with a maximal chemotactic response, but this stimulation is not alone sufficient for chemotaxis.

Preformed Eosinophil Chemotactic Factor of Anaphylaxis (ECF-A)

The eosinophil chemotactic factor of anaphylaxis (ECF-A), previously recognized as being released from sensitized human or guinea pig lung tissue by antigen challenge, has been demonstrated to exist preformed in these tissues and in isolated rat mast cells. The presence of performed ECF-A in the mast cell of the rat was established by the full recovery of ECF-A with mast cells purified from a mixed peritoneal cell population and cellular subfractionation which revealed the preformed ECF-A to be largely associated with the mast cell granules. The sum of the ECF-A released by antigen and that remaining in the sensitized challenged human or guinea pig lung tissue or isolated rat mast cells equalled that extractable from the equivalent unchallenged lung tissue or rat mast cells, indicating that the ECF-A available exists entirely in a preformed state.