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Biomedical subjects

A Walz

Publications and source records attributed to A Walz.

At least 19 recordsLinked to original sources
PubMed1992

Leukoregulin, a T cell-derived cytokine, induces IL-8 gene expression and secretion in human skin fibroblasts. Demonstration and secretion in human skin fibroblasts. Demonstration of enhanced NF-kappa B binding and NF-kappa B-driven promoter activity.

It was shown previously that leukoregulin (LR), a T cell-derived cytokine with unique antitumor properties, modulates fibroblast functions in vitro, including prostaglandin production, matrix synthesis, and protease gene expression. Here, we have focused on the ability of LR to modulate IL-8 gene expression in human dermal fibroblasts. Using a specific ELISA, we demonstrated a dose-dependent enhancement of IL-8 production by LR, accompanied by a parallel elevation of the corresponding mRNA levels, as measured by Northern hybridizations. Maximum accumulation of IL-8 mRNA was observed after 6 h of incubation with LR, and the elevation persisted over 24 h. Inhibition of protein synthesis by cycloheximide resulted in superinduction of IL-8 mRNAs by LR. Dexamethasone, all-trans-retinoic acid, and TGF-beta 1 failed to counteract the effect of LR on IL-8 gene expression. Transient cell transfections with an IL-8 promoter/CAT reporter gene construct showed a dose-dependent enhancement of the promoter activity by LR, suggesting transcriptional regulation. Gel shift assays with oligonucleotides containing the consensus NF-kappa B binding sequences of the IL-8 and Ig kappa light chain genes showed enhanced binding activity in nuclear extracts from cells incubated with LR. Transient transfection experiments using a NF-kappa B/SV2 promoter-CAT reporter gene construct showed enhanced CAT activity by LR. Taken together, these data suggest that LR may up-regulate IL-8 gene expression by activation of the binding of NF-kappa B to the corresponding cis-acting element in the IL-8 promoter. Our results demonstrate that LR, together with IL-1 and TNF-alpha, could participate in the recruitment of neutrophils to the sites of inflammation by induction of IL-8 production in fibroblasts.

Antineoplastic Agents↗
PubMed1992

Activation of human basophils through the IL-8 receptor.

IL-8 and its structural analogs derived from blood platelets have been proposed as stimuli of IgE-independent basophil activation. In order to clarify the mechanism of action of these peptides, we examined the effects of pure IL-8, connective tissue-activating peptide III (CTAP-III), neutrophil-activating peptide 2 (NAP-2), and platelet factor 4 (PF-4) on blood basophils with and without pretreatment by IL-3, which modulates mediator release. After pretreatment with IL-3, significant histamine release was observed with 10(-8) M and 10(-7) M IL-8 and 10(-7) M NAP-2, but not with the other peptides. At higher concentrations (10(-6) M), however, all IL-8 analogs, as well as the unrelated cationic peptides poly-D-lysine, histone VS, and lysozyme, induced histamine release to variable degrees. Binding and competition studies with [125I]IL-8 revealed specific IL-8R on basophils from a patient with chronic myelogenous leukemia and normal individuals. From 3500 to 9600 receptors with a mean Kd value of 0.15 nM were found on average per chronic myelogenous leukemia and normal basophil, respectively. NAP-2 weakly competed for IL-8 binding. IL-8 and, to a lesser extent, NAP-2 led to a transient rise of cytosolic free calcium concentration ([Ca2+]i), which was independent of a preexposure to IL-3. IL-8 prevented the [Ca2+]i rise induced by NAP-2, but did not influence [Ca2+]i responses to other agonists, e.g. C5a, C3a, or platelet-activating factor. IL-8 induced [Ca2+]i changes and histamine release in IL-3-primed basophils were pertussis toxin sensitive. CTAP-III or PF-4 did not compete for IL-8 binding, did not induce [Ca2+]i changes, and did not influence the [Ca2+]i response to IL-8 and NAP-2. This study shows that IL-8 and NAP-2 activate human basophils by a receptor-mediated mechanism similar to that operating in neutrophils. At high concentrations histamine release can also be induced by cationic peptides by a mechanism that does not involve the IL-8R, and probably depends on cationic interactions.

Amino Acid Sequence↗
PubMed1992

Interleukin-8 is produced in neoplastic and infectious diseases of the human central nervous system.

The presence of interleukin-8 (IL-8), a leukocyte chemotactic factor, was examined in primary and metastatic central nervous system tumors and in nonneoplastic acute meningoencephalitides. In vitro: (a) 11 of 12 glioblastoma cell lines constitutively expressed IL-8 mRNA; (b) 5 of 6 of these cell lines secreted IL-8 protein as detected by enzyme-linked immunosorbent assay and a glucosaminidase release bioassay; and (c) IL-1 beta or tumor necrosis factor was able to augment both IL-8 mRNA steady state levels and protein secretion of all cell lines tested except IN-319. IL-8 was also found in vivo. (a) IL-8 poly A+ mRNA was detected in 2 of 2 low grade astrocytomas, 1 of 2 anaplastic astrocytomas, and 6 of 6 glioblastomas. (b) IL-8 protein was present in the cyst fluid of 1 of 4 low grade astrocytomas, 1 anaplastic astrocytoma, 2 of 2 glioblastomas, 1 oligodendroglioma grade III, and one central nervous system cervical carcinoma metastasis. (c) The cerebrospinal fluid of 3 of 4 metastatic lymphomas, 2 of 16 glioblastomas, 1 of 2 low grade astrocytomas, but none of 3 anaplastic astrocytomas and none of 9 meningiomas contained IL-8. The presence of IL-8 was not restricted to central nervous system tumors as 2 of 2 bacterial meningitis and 5 of 5 acute viral meningitis patients contained considerable IL-8 levels in the cerebrospinal fluid. (d) Immunohistochemical analysis showed IL-8 immunoreactivity in perivascular tumor cells in 11 of 15 glioblastoma sections. These data suggest that IL-8 secretion could be a key factor involved in the determination of the lymphoid infiltrates observed in brain tumors and the development of cerebrospinal fluid pleocytosis in meningoencephalitides.

Astrocytoma↗
PubMed1992

The detection of a novel neutrophil-activating peptide (ENA-78) using a sensitive ELISA.

Neutrophil elicitation into tissue is an essential element of the host defense in response to various stimuli, including, tissue injury, infection, or cancer. This event has gained renewed interest with the discovery of a family of small polypeptides (less than 10 kD). The salient features of these cytokines are the presence of four cysteine amino acids (first two separated by one amino acid; C-X-C) and their ability to induce neutrophil chemotaxis and activation. Recently, our laboratories have discovered a new member of this C-X-C chemotactic cytokine supergene family, neutrophil-activating peptide, ENA-78. ENA-78 shares significant amino acid sequence homology with neutrophil activating peptide-2 (NAP-2; 53%), growth regulated oncogene/melanoma growth stimulatory activity (GRO alpha; 52%), and IL-8 (22%). In addition, ENA-78 appears to activate neutrophils through the IL-8 receptor. Since both in vitro and in vivo biological fluids may contain an array of chemotactic cytokines that may be relevant to the activation and chemotaxis of neutrophils, we have developed a highly specific and sensitive sandwich ELISA for the detection of ENA-78.

Chemokine CXCL5↗
PubMed1992

Functional analysis of monocyte activity through synthesis patterns of proinflammatory cytokines and neopterin in patients in surgical intensive care.

This study was designed to further differentiate monocyte behavior in critically ill patients with operative or accidental trauma. The patient population studied consisted of 39 patients (17 patients undergoing elective surgery [ES], seven patients with major multiple injuries [MI], and 15 patients in an acute septic state [S]). Immunologic parameters assessed included monocyte phenotyping with the monoclonal antibody LeuM3, measurement of the cytokines interleukin (IL)-1, IL-6, and IL-8 in lipopolysaccharide-stimulated in vitro cultures of mononuclear leukocytes (PBMCs), and determination of neopterin in gamma-interferon-stimulated in vitro cultures and corresponding serum samples. Serum neopterin levels were very high in S patients (89.0 nmol/L; p less than 0.05) compared with control values (4.6 nmol/L), with a rise to 16.4 nmol/L in ES patients on day 7 and 13.4 nmol/L in MI patients on day 7. The concentrations of gamma-interferon-induced neopterin in the supernatants of the PBMC cultures were elevated in all patient groups. Severe impairment of IL-1 synthesis was seen in MI and S patients. IL-8 synthesis (818 +/- 150 units/ml, control value) was also suppressed (p less than 0.05) in MI patients; the values were 135 +/- 65 units/ml on day 1,231 +/- 110 units/ml on day 3,347 +/- 131 units/ml on day 7, and 355 +/- 107 units/ml in S patients. The kinetic patterns of synthesis were comparable for IL-1 and IL-8 in all patient groups. Lipopolysaccharide-induced IL-6 synthesis (9.4 +/- 1.5 x 10(3) units/ml, control value) was significantly elevated in the PBMC cultures of all patient groups, with the exception of the early phase after accidental trauma. Maximum amounts of IL-6 synthesis after surgery were 19.6 +/- 7 x 10(3) units/ml in S patients and 19.0 +/- 2.2 x 10(3) units/ml in ES patients. These results demonstrate (1) the impairment of the functional capacity of circulating monocytes and (2) that the degree of functional impairment is proportional to the severity of the injury.

Adolescent↗
PubMed1991

Differential effects of neutrophil-activating peptide 1/IL-8 and its homologues on leukocyte adhesion and phagocytosis.

Several structural homologues of the chemotactic peptide neutrophil-activating peptide 1/IL-8 (NAP-1/IL-8) were tested for their ability to influence the expression and function of adhesion-promoting receptors on human polymorphonuclear leukocytes (PMN). NAP-2, melanoma growth stimulatory activity, and two forms of NAP-1/IL-8 (ser-NAP-1/IL-8 and ala-NAP-1/IL-8, consisting of 72 and 77 amino acids, respectively), each caused an increase in the expression of CD11b/CD18 (CR3) and CR1, which was accompanied by a decrease in the expression of leukocyte adhesion molecule-1 (LAM-1, LECAM-1). The binding activity of CD11b/CD18 was also enhanced 3- to 10-fold by these peptides, but enhanced function was transient: binding of erythrocytes coated with C3bi reached a maximum by 30 min and declined thereafter. Ser-NAP-1/IL-8, ala-NAP-1/IL-8, NAP-2, and melanoma growth stimulatory activity also caused a two- to threefold enhancement of the phagocytosis of IgG-coated erythrocytes (EIgG) by PMN without causing a large increase in the expression of Fc gamma receptors. Enhanced phagocytosis of EIgG appeared to be mediated through CD11b/CD18, because F(ab')2 fragments of an antibody directed against CD18 inhibited NAP-1/IL-8-stimulated ingestion of EIgG. The four active peptides caused a rapid, transient increase in the amount of F-actin within PMN, indicating that they are capable of influencing the structure of the microfilamentous cytoskeleton, which participates in phagocytosis. Two other NAP-1/IL-8-related peptides, platelet factor 4 and connective tissue-activating peptide III, were without effect on expression of CD11b/CD18, CR1, and LAM-1, binding activity of CD11b/CD18, or Fc-mediated phagocytosis, and increased actin polymerization only slightly. Our observations indicate that several members of the NAP-1/IL-8 family of peptides were capable of promoting integrin-mediated adhesion and Fc-mediated phagocytosis, processes important in the recruitment of PMN to sites of inflammation and antimicrobial responses of PMN.

Actins↗
PubMed1991

Structure and neutrophil-activating properties of a novel inflammatory peptide (ENA-78) with homology to interleukin 8.

A new neutrophil-activating peptide, termed ENA-78, was identified in the conditioned media of stimulated human type II epithelial cell line A549. In response to stimulation with either interleukin 1 beta (IL-1 beta) or tumor necrosis factor alpha (TNF-alpha), ENA-78 was produced and secreted concomitantly with IL-8, GRO alpha, and GRO gamma. ENA-78 consists of 78 amino acids [sequence; see text] and has a molecular weight of 8,357. It has four cysteines positioned identically to those of IL-8 and analogues, and thus belongs to the CXC family of peptides. ENA-78 is related to neutrophil-activating peptide 2 (NAP-2) and GRO alpha (sequence identity, 53% and 52%, respectively) and IL-8 (22% identity). Like NAP-2 and GRO alpha, ENA-78 stimulates neutrophils, inducing chemotaxis, a rise in intracellular free calcium and exocytosis. Cross-desensitization experiments indicate that ENA-78 acts through the same type of receptors as IL-8, NAP-2, and GRO alpha.

Amino Acid Sequence↗
PubMed1991

Recombinant human MCP-1/JE induces chemotaxis, calcium flux, and the respiratory burst in human monocytes.

The JE gene was first described as a platelet-derived growth factor (PDGF)-inducible gene in mouse 3T3 cells. The human homologue of JE encodes a protein whose predicted amino acid sequence is identical to that of the monocyte chemoattractant MCP-1 (also called MCAF and SMC-CF), which belongs to a recently identified family of small secretory proteins with cytokine properties. We purified recombinant human MCP-1/JE (hMCP-1/JE) produced in COS cells and demonstrated that it is chemotactic for human monocytes with a specific activity similar to natural MCP-1. In addition, pure recombinant hMCP-1/JE stimulates monocytes, inducing an increase in cytosolic free calcium and the respiratory burst, but is completely inactive on human neutrophils. These results help to define functionally a well-known growth factor-inducible gene and a member of a new family of cytokines.

Animals↗
PubMed1991

Formation of neutrophil-activating peptide 2 from platelet-derived connective-tissue-activating peptide III by different tissue proteinases.

Neutrophil-activating peptide 2 (NAP-2) is generated by cleavage of two inactive precursors, connective-tissue-activating peptide III (CTAP-III) and platelet basic protein (PBP), which are stored in the alpha-granules of blood platelets. Using highly purified CTAP-III as the substrate we studied the generation of NAP-2 by several neutral tissue proteinases. CTAP-III was rapidly cleaved by chymotrypsin, cathepsin G and trypsin, yielding products with neutrophil-stimulating activity. This activity remained unchanged for 24 h in the presence of chymotrypsin, decreased only slowly in the presence of cathepsin G, but was rapidly destroyed by trypsin. CTAP-III was also degraded by human neutrophil elastase and porcine pancreatic elastase, but no active fragments were obtained. By contrast, no degradation of CTAP-III was observed with thrombin, plasmin or 'granzymes' from cytolytic T-lymphocyte granules. Two active fragments of CTAP-III, generated by chymotrypsin or cathepsin G, were purified and partially sequenced, and were found to have the same N-terminal sequence as NAP-2. These results indicate that both proteinases cleave preferentially the bond between amino acids 15 (Tyr) and 16 (Ala) of CTAP-III. We conclude that chymotrypsin-like proteolytic activity in the vicinity of activated platelets may generate NAP-2 intravascularly. Due to its presence in the primary granules of neutrophils and monocytes cathepsin G is likely to be involved in this process.

Amino Acid Sequence↗
PubMed1991

Chemical synthesis, purification, and characterization of two inflammatory proteins, neutrophil activating peptide 1 (interleukin-8) and neutrophil activating peptide.

Two recently identified pro-inflammatory proteins, namely, neutrophil activating peptide 1 (NAP-1) [also termed interleukin-8 (IL-8)] and NAP-2, were chemically synthesized, purified, and characterized. The fully protected NAP-1/IL-8 (72 residues) and NAP-2 (70 residues) peptide chains were assembled by automated solid-phase methods with average stepwise yields of 99.5 and 99.3%, resulting in overall chain assembly yields of 70 and 62%, respectively. Deprotection resulted in crude products, which were allowed to fold by air oxidation, and were purified by two cycles of reverse-phase high-pressure liquid chromatography, yielding 27 mg of NAP-1/IL-8 and 22 mg of NAP-2. Purity was established by reverse-phase high-pressure liquid chromatography and isoelectric focusing, and the primary structures of the purified products were verified by using mass spectrometry and Edman sequencing methods. Synthetic and recombinant NAP-1/IL-8 were equally active on human neutrophil granulocytes as determined by measuring the induction of cytosolic free calcium, elastase release, and chemotaxis. Synthetic NAP-2 was equivalent to purified natural NAP-2 in the elastase release and calcium mobilization assays, but it was consistently less potent (3-5-fold) as a stimulus of chemotaxis, perhaps indicative of additional chemotactic components in the natural preparation. The results indicate that by chemical synthesis these cytokines can be obtained in purity and quantities suitable for further structural analysis, as well as functional studies both in vivo and in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

Chemotactic activity and receptor binding of neutrophil attractant/activation protein-1 (NAP-1) and structurally related host defense cytokines: interaction of NAP-2 with the NAP-1 receptor.

Neutrophil attractant/activation protein-1 (NAP-1) has sequence similarity to platelet factor-4 (PF-4) and to NAP-2 (a truncated from of connective tissue activating protein-III [CTAP-III(des 1-15)]. We compared chemotactic activity for neutrophils of these related proteins. We also included for comparison CTAP-III, CTAP-III(des 1-13), the C-terminal dodecapeptide of PF-4 [PF-4(59-70)], and C5a. Chemotactic potency (EC50) was highest for NAP-1 and C5a. Although chemotactic efficacy (peak percentage of neutrophils migrating) was comparable for C5a, NAP-1, and NAP-2, the NAP-2 response occurred only at concentrations 100-fold higher than the NAP-1 EC50 of 10(8) M. Data for the CTAP-III proteins confirmed that CTAP-III is not an attractant and that chemotactic activity appears as a result of cleavage of residues at the N-terminus to make CTAP-III(des 1-13) or NAP-2 [CTAP-III(des 1-15)]. Chemotactic activity of PF-4 was low and variable, with no significant response by neutrophils from six of nine subjects. In contrast, PF-4(59-70) regularly induced high chemotactic responses, although the EC50 of 1.6 x 10(5)M was 1,000-fold greater than that of NAP-1. The binding of fluoresceinated NAP-1 to neutrophils was inhibited by unlabeled NAP-1 or NAP-2 but not by PF-4 or PF-4 (59-70). This suggests that NAP-2 interacts with the neutrophil NAP-1 receptor. Despite the low chemotactic potency of NAP-2, it is a potential attractant at sites of injury because of the relatively large amounts of the parent CTAP-III released from platelets, as indicated by a serum concentration of approximately 10(-6) M.

Chemotaxis, Leukocyte↗
PubMed1991

[Ca2+]i changes and respiratory burst in human neutrophils and monocytes induced by NAP-1/interleukin-8, NAP-2, and gro/MGSA.

The stimulatory effects of neutrophil-activating peptide 1 (NAP-1), also termed interleukin 8 (IL-8), neutrophil-activating peptide 2 (NAP-2), and melanoma growth-stimulatory activity (gro/MGSA) on human neutrophils and monocytes were compared on the basis of two responses that can be assessed in real time, the changes in cytosolic free calcium and the respiratory burst. All three peptides induced a rapid and transient rise of cytosolic-free calcium and the respiratory burst in neutrophils. Both responses were also obtained in monocytes on stimulation with NAP-1/IL-8 and gro/MGSA, but not with NAP-2, which appeared to be more selective for neutrophils. Pretreatment with concanavalin A (ConA) enhanced several fold the rate and duration of the respiratory burst of neutrophils stimulated with all three peptides and of monocytes stimulated with NAP-1/IL-8 and gro/MGSA, but not with NAP-2. Sequential stimulation showed mutual cross desensitization by NAP-2 and gro/MGSA in neutrophils. In addition, desensitization of neutrophils toward NAP-2 and gro/MGSA, and of monocytes toward gro/MGSA, was obtained by prestimulation with NAP-1/IL-8. Prestimulation with either NAP-2 or gro/MGSA, however, did not desensitize the cells for NAP-1/IL-8. These results suggest that under conditions where multiple stimulatory agents are produced, neutrophil-activating peptides may contribute to the formation of substantial amounts of oxygen-derived radicals. In addition, the study shows that NAP-1/IL-8 and gro/MGSA, but not NAP-2, have some stimulatory effects on monocytes as well.

Calcium↗
PubMed1991

Neutrophil-activating peptide-1/interleukin-8 detection in human urine during acute bladder inflammation caused by transurethral resection of superficial cancer and bacillus Calmette-Guérin administration.

Neutrophil-activating peptide-1/interleukin-8 (NAP-1/IL-8), secreted by monocytes, macrophages and a number of other cells, acts as a chemoattractant for neutrophil leukocytes and stimulates them to produce a series of responses such as shape change, adherence, exocytosis and respiratory burst, events that are of importance in inflammation. To study the release of NAP-1/IL-8, two human models of inflammation were chosen: transurethral resection of superficial bladder cancer and the subsequent instillation of bacillus Calmette-Guérin (BCG), performed in order to reduce the recurrence rate of papillary bladder tumors. As the secretions of the bladder wall are retained in the urine, patients' urine was collected during 4-hour periods. These urine samples were chromatographed on phosphocellulose. In the elution fractions NAP-1/IL-8 was quantified by a bioassay that measured the elastase release by human neutrophils. The neutrophil-stimulating activity was further purified by reverse phase high performance liquid chromatography. Although no NAP-1/IL-8 activity could be detected in normal individuals, formation of this inflammatory cytokine was observed in patients after transurethral resection and after BCG treatment. The significance and possible use of this secretion are discussed.

Administration, Intravesical↗
PubMed1990

Neutrophil-activating protein 1/interleukin 8 stimulates the binding activity of the leukocyte adhesion receptor CD11b/CD18 on human neutrophils.

The cytokine NAP-1/IL-8 is produced by a variety of different cells in response to inflammatory stimuli and elicits several biological responses from PMN. Experiments presented here demonstrate that PMN exposed to NAP-1/IL-8 expressed increased amounts of CD11b/CD18, as well as CD11c/CD18 and CR1, on their cell surface, while expression of Fc gamma RIII and HLA-A,B,C remained essentially unchanged. Increased CD11b/CD18 and CD11c/CD18 appears to correspond with the release of specific granules by NAP-1/IL-8. NAP-1/IL-8 was also a potent stimulator of several of the binding activities of CD11b/CD18. Ligation of EC3bi by CD11b/CD18 was rapidly enhanced by NAP-1/IL-8, but phagocytosis of the ligated particles was not induced by the agonist. In addition, enhanced binding of EC3bi was observed in the absence of an increase in receptor expression as shown with PMN cytoplasts. NAP-1/IL-8 promoted additional adhesive interactions between CD11b/CD18 and the biosynthetic precursor of LPS, lipid IVa, fibrinogen, and endothelial cells, suggesting that NAP-1/IL-8 may promote leukocyte adhesion in vivo that could lead to recruitment of PMN to sites of tissue inflammation.

Antibodies, Monoclonal↗