RANTES and macrophage inflammatory protein 1 alpha induce the migration and activation of normal human eosinophil granulocytes

The cellular infiltrates of certain inflammatory processes found in parasitic infection or in allergic diseases consist predominantly of eosinophilic granulocytes, often in association with activated T cells. This suggests the existence of chemotactic agonists specific for eosinophils and lymphocyte subsets devoid of neutrophil-activating properties. We therefore examined four members of the intercrine/chemokine superfamily of cytokines (monocyte chemotactic peptide 1 [MCP-1], RANTES, macrophage inflammatory protein 1 alpha [MIP-1 alpha], and MIP-1 beta), which do not activate neutrophils, for their ability to affect different eosinophil effector functions. RANTES strongly attracted normal human eosinophils by a chemotactic rather than a chemokinetic mechanism with a similar efficacy as the most potent chemotactic myeloid cell agonist, C5a. MIP-1 alpha also induced eosinophil migration, however, with lower efficacy. RANTES and MIP-1 alpha induced eosinophil cationic protein release in cytochalasin B-treated eosinophils, but did not promote leukotriene C4 formation by eosinophils, even after preincubation with interleukin 3 (IL-3), in contrast to other chemotactic agonists such as C5a and formyl-methionyl-leucyl-phenylalanine (FMLP). RANTES, but not MIP-1 alpha, induced a biphasic chemiluminescence response, however, of lower magnitude than C5a. RANTES and MIP-1 alpha both promoted identical transient changes in intracellular free calcium concentration ([Ca2+]i), with kinetics similar to those induced by chemotactic peptides known to interact with G protein-coupled receptors. No cross-desensitization towards other peptide agonists (e.g., C5a, IL-8, FMLP) was observed, suggesting the presence of specific receptors. Despite its weaker eosinophil-activating properties, MIP-1 alpha was at least 10 times more potent on a molar basis than RANTES at inducing [Ca2+]i changes. Interestingly, RANTES deactivated the MIP-1 alpha-induced [Ca2+]i changes, while the RANTES response was preserved after MIP-1 alpha stimulation. MCP-1, a potent monocyte chemoattractant and basophil agonist, as well as MIP-1 beta, a peptide with pronounced homology to MIP-1 alpha, did not activate the eosinophil functions tested. Our results indicate that RANTES and MIP-1 alpha are crucial mediators of inflammatory processes in which eosinophils predominate.

Immune response to tumor antigens in a patient with colorectal cancer after immunization with anti-idiotype antibody

An active vaccination protocol was performed on one patient with colon carcinoma as a pilot to a prospective randomized double-blind clinical trial with the vaccine SDZ SCV 106. This vaccine is an anti-idiotype goat antibody to the monoclonal antibody 17-1A, which is directed against the tumor antigen 17-1A. To study the effect of the therapy on the immune reactivity, several tests were performed to detect anti-tumor antibodies in the serum as well as in eluates of metastatic tissue. Furthermore metastases removed from the lung were examined by immunohistochemistry. The results suggest that the humoral and cellular immune reactivity against the tumor are enhanced.

Binding of neutrophil attractant/activation protein-1 (interleukin 8) to resident dermal cells

Putative tissue receptors for leukocyte attractants, including neutrophil attractant/activation protein-1 (interleukin 8, NAP-1/IL-8), have been implicated in the regulation of neutrophil emigration into the tissues. An in-situ binding assay and an ex-vivo autoradiographic approach were used to investigate the binding of radiolabeled NAP-1/IL-8 to human and animal skin. These methods revealed the presence of saturable NAP-1/IL-8-binding sites on the endothelial cells of venules and veins but not arteries or capillaries of the dermis. In addition, the binding of NAP-1/IL-8 to dermal macrophages and perivascular mast cells was observed. We suggest that the NAP-1/IL-8-binding sites described here could be involved in the regulation of NAP-1/IL-8-induced neutrophil emigration.

Endothelial cell binding of NAP-1/IL-8: role in neutrophil emigration

In this article Antal Rot calls into question the generally accepted notion that gradients of soluble chemotactic factors are responsible for leukocyte emigration from the circulation into sites of inflammation. He presents an alternative model in which chemoattractants bound to the surface of endothelial cells promote neutrophil adhesion and emigration, while soluble blood-borne attractants inhibit adhesion and emigration.

Calcitonin gene-related peptide is chemotactic for human T lymphocytes

Certain neuropeptides, such as CGRP, are associated with C-type nerve fibers in the skin and are known to be proinflammatory mediators. Because of their probable role in various cutaneous diseases, we investigated the effect of alpha- and beta-CGRP on human leukocyte migration in a 48-well microchemotaxis chamber using a 5-microns-pore filter. Elutriated peripheral blood leukocytes (enriched 80-90% for CD3+ and 10-20% for CD20+ lymphocytes) were added to the upper wells, and CGRP to the lower ones in a dose range of 10(-19)-10(-5) M; both were diluted in RPMI medium containing 0.05% fetal calf serum. The chamber was incubated at 37 degrees C for 2.5 hours, and the filter was washed and stained. The mean number of cells migrating through the filter was calculated for quadruplicate wells in each treatment group. Chemotactic activity was expressed as a migration index (MI = number of cells responding to CGRP/media control). Both alpha- and beta-CGRP were optimally chemotactic for leukocytes at approximately 50 pM, with a mean migration index of 11.5 for filter-adherent cells (n = 13 experiments); migration due to chemokinesis was minimal, as measured by checkerboard analysis. Almost all leukocytes that responded to CGRP were T cells (TCs), and the CD4 to CD8 ratio was similar to that of the input population; B cells were not observed. CGRP-induced migration appears to be a specific receptor-mediated event, as pretreating the cells with CGRP resulted in significant down-regulation of their chemotactic response to CGRP, but not to interleukin-1 alpha. Our data suggest that the release of CGRP from free nerve endings near the dermal-epidermal junction could influence cutaneous TC trafficking. As neuropeptides exacerbate (possibly initiate) the inflammatory process, they are likely to be important pharmacological targets in dermatological disorders.

Inhibitory and promoting effects of carbon tetrachloride-induced liver cirrhosis on the diethylnitrosamine hepatocarcinogenesis in rats

The modifying effect of the experimentally induced liver cirrhosis on the diethylnitrosamine (DENA)-hepatocarcino-genesis was investigated in male Fischer 344 rats. Cirrhosis was produced by either repeated intragastric doses of CCl4 for 3 months or by simultaneous administration of CCl4 and phenobarbital (PB) in drinking water for 6 weeks. The hepatocarcinogenic regimen consisted of multiple ip. administrations of DENA (10 mg/kg b.w. per dose, up to a total dose of 200 mg/kg b.w.). All the animals were killed 8 months after starting the experiment. The chronic CCl4-post-treatment exerted a strong promoting effect, while the established cirrhosis completely prevented the formation of hepatocellular carcinomas.

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.

Chemotactic potency of recombinant human neutrophil attractant/activation protein-1 (interleukin-8) for polymorphonuclear leukocytes of different species

In order to establish the species cross-reactivity of the human neutrophil attractant/activation protein-1 (interleukin-8, NAP-1/IL-8) and find which experimental species are responsive to the human cytokine, blood polymorphonuclear leukocytes (PNMLs) were isolated from chicken, dog, goat, guinea-pig, monkey, mouse, pig, rabbit, and rat and their in vitro migration in response to this cytokine was investigated. PMNLs from all of the tested species migrated in response to recombinant human NAP-1/IL-8 (rhNAP-1/IL-8). The potency of rhNAP-1/IL-8 for the PMNLs of different species varied and was considerably lower than its potency for human cells. The morphological study combined with the leukocyte enumeration in the intradermal rhNAP-1/IL-8 injection sites established an in vivo proinflammatory potency of rhNAP-1/IL-8 for rabbit and rat that was comparable to the observed in vitro chemotactic potency of rhNAP-1/IL-8 for neutrophils of these species.

Demonstration of the organ preference of liver selected 'high metastatic' Lewis lung tumor cell line

The experimental metastasis patterns of 'low metastatic' Lewis lung tumor (LLT) and liver selected 'high metastatic' LLT-HH were studied following their arterial dissemination. In previous reports it was shown that both tumor lines develop metastases only in the first encountered organ. Here the liver preference of the liver selected cell line is demonstrated. The model of two LLT cell lines can provide experimental evidence for both the 'mechanical' and 'seed and soil' theories of metastasis formation, depending on the site of tumor cell injection.

Staphylococcus aureus tetrapeptide with high chemotactic potency and efficacy for human leukocytes

A chemotactic tetrapeptide from culture fluids of Staphylococcus aureus was purified to homogeneity by reverse-phase high-pressure liquid chromatography. The peptide comprises equimolar methionine, leucine, isoleucine, and phenylalanine. It inhibited binding of fluoresceinated fMet-Leu-Phe-Lys to human monocytes, which showed that it interacted with the formyl-methionyl peptide receptor and suggested that it was a formyl-methionyl peptide. Based on a comparison of dose-response curves for inhibition of fluoresceinated fMet-Leu-Phe-Lys binding, the relative affinity of the peptide for the receptor was comparable to that of fMet-Leu-Phe-Lys. At optimal concentrations, chemotactic efficacy (percentage of monocytes migrating to the attractant) was 53 +/- 4%, in contrast to 36 +/- 3% for the reference attractant fMet-Leu-Phe. Since approximately 60% of human monocytes have formyl-peptide receptors, the bacterial peptide is capable of attracting all receptor-bearing monocytes.

A series of six ligands for the human formyl peptide receptor: tetrapeptides with high chemotactic potency and efficacy

We recently isolated, from culture fluids of Staphylococcus aureus, a chemotactic peptide that comprised equimolar quantities of methionine, leucine, phenylalanine, and isoleucine. It interacted with the formylmethionyl peptide receptor of human leukocytes and had considerably higher potency and efficacy than the widely studied tripeptide agonist fMet-Leu-Phe. On the assumption that the attractant was a formylmethionyl tetrapeptide, we synthesized the six possible sequences and tested the products for chemotactic potency and efficacy, as well as their capacity to inhibit binding of fluorescein isothiocyanate-labeled fMet-Leu-Phe-Lys to human monocytes. The concentrations required for inhibition of fluorescein-labeled fMet-Leu-Phe-Lys binding by the six peptides covered three orders of magnitude. Chemotactic potency (concentration that caused 50% of the maximum chemotactic response) ranged from 3.1 X 10(-11) M to 6.4 X 10(-10) M; efficacy (percentage of monocytes migrating at optimal attractant concentration) ranged from 41% to 66%. When the six synthetic tetrapeptides were ranked for chemotactic efficacy, they paired according to the position of phenylalanine. The average percentage migration was 66% for the two peptides with phenylalanine in position 3, 51% for phenylalanine in position 4, and 41% for phenylalanine in position 2. Since the published value for the percentage of human monocytes with detectable formyl peptide receptors is 60%, it is apparent that the two tetrapeptides with phenylalanine in position 3 (fMet-Ile-Phe-Leu and fMet-Leu-Phe-Ile) are full chemotactic agonists, which are capable of inducing migration of all the receptor-bearing cells. This is in contrast to the tripeptide fMet-Leu-Phe, which induces migration of only 50% of monocytes with receptors (efficacy of 33%). Since the chemotactic efficacy of the six tetrapeptides covers a wide range, the series may be useful to investigate signals that lead to directed movement after occupancy of receptors by chemoattractants.

Chemoattractant efficacy: oxidation of stimulus by responding cells

Although all human neutrophils have receptors for formyl-methionyl-leucyl-phenylalanine, only 20-30% migrate in vitro at optimal attractant concentrations. Since this attractant can be oxidized by myeloperoxidase from stimulated neutrophils, we determined if its efficacy was increased by protection from oxidation. Efficacy was increased by reducing agents and by molecules with oxidizable sulfur, 10(-5) M methionine or 1.5 X 10(-6) M albumin. The antioxidant effect was on the attractant, not the cells: albumin in the cell compartment did not increase responses. Furthermore, antioxidants had no effect on efficacy of fNle-Leu-Phe-Nle-Tyr-Lys, an attractant that also stimulated superoxide release but had no oxidizable sulfur.

Staphylococcus aureus-derived chemoattractant activity for human monocytes

Products of bacteria are potent chemoattractants for mammalian leukocytes. Several reports suggest that these attractants are small peptides. We compared the properties of culture fluids of Staphylococcus aureus with fMet-Leu-Phe, considered a prototype of bacterial attractant. Chemotactic activity for human monocytes of Staph. aureus culture filtrates was determined in multiwell chemotaxis chambers. At optimal concentrations, the filtrate attracted almost twice as many monocytes as fMet-Leu-Phe (53 +/- 5% of input number compared with 30 +/- 3%, in a series of ten experiments). Gel-filtration characteristics and susceptibility to proteolytic digestion suggested that chemotactic activity was due to peptides with a molecular size range of 500-2,000 daltons. Reverse-phase high-pressure liquid chromatography (HPLC) of unfractionated filtrate revealed nine peaks of chemotactic activity, most of which was in five of the peaks. One peak accounted for 40% of total activity. Individual peaks, like the unfractionated material, were capable of attracting about twice as many monocytes as the optimal concentration of fMet-Leu-Phe. Quantitative bioassay of the HPLC peaks showed that only 5% of the total Staph. aureus chemotactic activity eluted in the position of fMet-Leu-Phe. This is in contrast to the report that fMet-Leu-Phe accounted for 70% of neutrophil lysosomal enzyme-releasing activity of Escherichia coli culture fluid. In summary, chemotactic activity for monocytes of Staph. aureus culture fluid is due to peptides other than fMet-Leu-Phe; these peptides recruit a higher percentage of monocytes than fMet-Leu-Phe.

Expression of MHC class II antigens on bile duct epithelium in experimental graft versus host disease

Recently we observed the expression of MHC class II antigens on bile duct epithelium in human liver transplantation rejection. In this report we present evidence for the expression of MHC class II antigens on bile duct epithelium in experimental GVHD. These findings support the idea, that the target tissue elements in liver transplantation rejection and GVHD are the bile ducts, on the other hand this is a new experimental model for the analysis of MHC class II antigen expression on epithelial tissue.