Cytokines (IL-1, TNF, G-CSF, GM-CSF, M-CSF, IL-3 and IFNγ), chemokines (IL-8, MCAF and others) and chemotactic factors (FMLP, C5a and PAF) stimulate respiratory burst activity in human neutrophils and/or monocytes via cell surface receptors specific for each agonist. Chemotactic factors and chemokines induce an increase in cytoplasmic free Ca²⁺ concentration, whereas cytokines other than chemokines do not. Cytokines do not induce activation of protein kinase C, and some of the responses triggered by chemotactic factors are also resistant to the inhibitors of protein kinase C.
Thus, the signaling pathways independent of Ca²⁺ and protein kinase C could be important in the activation of human phagocytes stimulated by the receptor-mediated agonists. One candidate for such pathway is tyrosine kinase and, in fact, we and other investigators found that cytokines and chemotactic factors induce tyrosine phosphorylation of 42-kDa microtubule-associated protein (MAP) kinase in a time course specific for each agonist in human neutrophils and/or monocytes.
So, MAP kinase pathway could be a central thema, though causal relationship between MAP kinase activation and functional activation is not clear. Among human phagocytes, mechanism of activation of macrophages await much further investigation.

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In order to assess a role of inflammatory cytokines for infiltration of leukocytes, we injected 4 cytokines into the pleural cavity of rats. Intrapleural injection of recombinant human interleukin-8 (rhIL-8) and cytokine-induced neutrophil chemoattractant (CINC) caused neutrophil infiltration in the pleural cavity dose dependently, and both, showed a peak at 3hr. Recombinant human tumor necrosis factor (rhTNF) and rhIL-1α also caused neutrophil infiltration in the cavity but lower extent than those by rhIL-8 and CINC. Neutrophil infiltration by rhTNF and rhIL-1α was suppressed significantly by the pretreatment with dexamethasone at a dose of 0.5 mg/kg.
These results suggest that IL-8 and CINC may act directly in the recruitment of neutrophils at local inflammatory sites, whereas TNF and IL-1 may express their activities for neutrophil infiltration through the induction of CINC in rats.

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Comparative efficacy of four glucocorticoids (GCs) was examined using lymphocyte-blasto-genesis assay procedure in 98 healthy subjects and 39 patients with chronic bronchial asthma. GCs examined were hydrocortisone, prednisolone, methylprednisolone, and dexamethasone.
Concentrations of the GCs to suppress mitogenresponded incorporation of [³H] thymidine into peripheral-blood lymphocytes in vitro were determined individually, and mean or median IC₅₀s were compared between healthy subjects and patients, or among the GCs. Individual IC₅₀s varied among the subjects, especially in hydrocortisone and prednisolone.
Effects of methylprednisolone and dexamethasone were significantly higher than those of hydrocortisone and prednisolone in both healthy subjects and patients (P<0.01) . When the median IC₅₀s were compared among the GCs, the relative potencies of hydrocortisone, prednisolone, methylprednisolone, and dexamethasone against healthy lymphocytes come to 1.0, 0.8, 8.9, and 16.0, respectively, and those against asthmatic lymphocytes, 1.0, 1.5, 15.2, and 38.0, respectively. Similar results were obtained when the mean IC₅₀s were compared.
These data showed that methylprednisolone may have relatively potent immunosuppressive effect than we expected from the relative potencies based on anti-inflammatory effect in both healthy subjects and patients.

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Lipopolysaccharide (LPS) primes human neutro-phils for enhanced O^-₂ production in response to stimulation by fMet-Leu-Phe. Serum factor is essential for priming at lower concentrations of LPS. This priming is dose and time dependent. Monoclonal antibody against CD14 (LPS-LPS binding protein complexes bind the antigen on the surface of neutrophils) inhibits all these actions of the LPS-serum complex. Neutralizing antibody against TNF-alpha does not inhibit priming of O^-₂ Production by LPS and serum treatment.
On the other hand, this antibody inhibits the priming by the direct addition of TNF-α.
In addition, the LPS-serum complex potentiates the fMet-Leu-Phe-induced stimulation of phospholipase D as evident by the release of phosphatidic acid. Furthermore, in the absence of a second stimulus, the LPS-serum complex but not TNF-α causes the increase in the amount of G₁₂ protein associated with the membrane.

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To identify the therapeutic efficacy of G-CSF and GM-CSF in severe sepsis, we examined their effects on the mortality and pathological changes in vital organs using the rat lethal sepsis model. Rats were given 15, μg of recombinant human G-CSF or 20 μg of recombinant murine GM-CSF three hours after the onset of peritonitis brought about by cecal ligation and puncture. The mortality rate after 72 hours was significantly decreased by administration of rhG-CSF (p<0.001) . In addition, the administration of rhG-CSF attenuated the increase in both GPT and BUN levels. It also reduced cell infiltration into the pulmonary septa in the lungs. On the contrary administration of GM-CSF did not improve the survival rate and earlier deaths were observed. Higher GPT level and marked pathological change-centrilobular degeneration and necrosis-showed a detrimental effects of GM-CSF on the liver.
These results indicated that administration of rhG-CSF, even after the onset of sepsis, was effective in decreasing the mortality of peritonitis-induced multiple organ failure. This finding was clearly useful in the clinical treatment of such sepsis-induced critical illness.

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We histochemically examined the affinity of hyaluronan (HA) with various molecular weight in deteriorated cartilage.
HA with four molecular weights (MW) were used ; HA with a MW of 1.9×10⁶Da, which was synthesized by Streptococcus equi, and ultrasonic-treated HA with MW of 1.5×10⁶Da, 0.64×10⁶Da and 0.17×10⁶Da. Human cartilaginous tissue sections were treated with Streptomyces hyaluronidase for use as a degenerated cartilage model. These sections were reacted with HA with various MW. HA affinity was judged by using biotinylated hyaluronan binding protein, FITC-labeled HA, and Alcian blue staining.
The results revealed that the higher the MW HA, the higher the affinity to degenerated cartilage.

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The plasma level of factor VIII procoagulant protein/von Willebrand factor complex (FVIII/vWF) was evaluated in 18 patients with Sjögren's syndrome (SjS 5, SjS+RA 4, SjS+SLE 3, SjS+MCTD 3, SjS+PN 1, SjS+TA 2) .
Factor VIII procoagulant activity (VIII : C), measured by the one-stage assay using commercially available human VIII : C-deficient plasma as the substrate, was relatively increased in the patients (121.5±40.7%), but not significant compared with normal subjects. On the other hand, von Willebrand factor antigen (vWF : Ag) assayed by the electroim-munodiffusion according to the method by Laurell was remarkably increased (287.5±1614%) . Ristocetin cofactor activity (RCof) measured by the aggregometer method using a RIPA-test kit^® was also increased (176.6±52.9%) . The vWF : Ag/RCof ratio was significantly high (1.61±0.60) . The vWF multimeric analysis by the electrophoresis on 1.5% agarose gels with discontinuous buffer system performed on these 18 patients, revealed that 12 cases had normal multimeric patterns, 3 had supranormal multimers, and 3 had lost high molecular weight multimers.
These findings suggest that plasma-vWF in patients with SjS is increased, while there is a variety of vWF multimeric structures, and also that there are some cases whose patterns of plasma-vWF multimers are normal inspite of their high vWF : Ag/RCof ratios.

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In order to identify the standpoint of TNFα in rheumatoid arthritis, we measured concentration of TNFα in serum and joint fluid, and further immunohistochemically examined TNFα-containing cells and their distributions in joint tissues of the patients with rheumatoid arthritis. TNFα concentration in serum and joint fluid was higher than controls, as mentioned by some preceding reports. No good correlation was seen between TNFα and other clinical and laboratory data except for positive correlation between serum TNFa concentration and serum IgG concentration.
There were a variety of cells that contained TNFα in the synovia and pannus of RA, in which osteoclast was the most striking of all cells. Expression of TNFα in the synovial tissues and concentration of TNFα in synovial fluid showed close relationship to the background feature, rather than the grade of lymphocytes aggregation in synovial tissues.
That is to say, the more severe the inflammatory infiltration is, the more highly the TNFα appeares in synovia and joint fluid. Our data, in vivo, suggested that TNFα play an imiportant role for persistance and progression of RA.

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We investigated the production of IL-1β, IL-6 and TNF-α by cultured synovial cells, and the effect of disease modifying antirheumatic drugs (DMARDs) on the production of those cytokines. Sulfasalazine (SASP), amethopterin (MTX), gold sodium thiomalate (GST), and bucillamine (BU) were used as DMARDs. Dexamethasone (DEX) and lipopolysaccharide (LPS) were used as negative and positive controls.
IL-1β and IL-6 were detected in the culture supernatant but TNF-α was not. LPS stimulated the production of IL-6 while DEX suppressed it. They did not modulate the production of IL-1β, GST suppressed the production of IL-1β at a concentration of 10^-3M. SASP and GST suppressed the production of IL-6 at the same concentration.
This result showed that SASP, MTX, GST and BU could not supress synovial cells to produce IL-6 and IL-1β at the level of clinical dosages.

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To determine the effect of the cytokine interleukin-8 (IL-8) on goblet cell secretion and a possible involvement of neutrophil elastase, we studied guinea pig trachea by a semi-quantitative method. Intravenously administered IL-8 decreased mucus score in a dose-dependent manner, indicating an increase in goblet cell secretion. Pretreatment of animals with ONO-5046, a specific inhibitor of neutrophil elastase, dose-dependently inhibited IL-8-induced goblet cell secretion.
These results suggest that IL-8 stimulates airway goblet cell secretion and that neutrophil elastase may play a role in this effect.

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