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The effect of fibronectin (FN) on IL-1 alpha, IL-1 beta, TNF-alpha, and IL-6 production was investigated with cultured monocytes isolated from human peripheral blood. Monokine concentrations were determined by ELISA. FN markedly stimulated the secretion of IL-1 alpha, IL-1 beta, TNF-alpha, and IL-6 from cultured monocytes. Northern blot analysis revealed the up-regulated expression of mRNA specific for each monokine on exposure of monocytes to FN. GM-CSF, IFN-gamma, and LPS synergistically enhanced FN-induced IL-1 alpha production. We further investigated the signal transduction pathways involved in FN-stimulated monokine secretion. FN-stimulated TNF-alpha secretion was markedly inhibited by either herbimycin A or genistein, inhibitors of protein tyrosine kinase (PTK), but was not affected by staurosporin, a inhibitor of protein kinase C (PKC). The results suggest that PTK is required for FN-stimulated TNF-alpha secretion. In contrast, LPS-stimulated TNF-alpha secretion was markedly inhibited by not only herbimycin A or genistein, but also staurosporin. Therefore, both PTK and PKC may be involved in LPS-stimulated TNF-alpha secretion. We also demonstrated that, in monocytes, cytoplasmic proteins of about 70 and 240 kDa were phosphorylated after FN stimulation. Our results indicate that FN may contribute to the inflammatory response of monocyte by inducing monokine production.

It is well known that monokines, IL-1 (Interleukin-1) and TNF (Tumor Necrosis Factor), are produced by macrophages after stimulated with various agents. These cytokines are involved in various aspects of the inflammatory process and immunological response in addition to their original activities to proliferate T lymphocytes and causing tumor necrosis, respectively. Recently, there have been reported that IL-1 and TNF also play an important role in mycobacterial infections such as granuloma formation. In the present study, IL-1 and TNF productions were observed by mouse peritoneal exudate and resident macrophages after incubation with heat-killed M. lepraemurium and M. avium in vitro. The production was enhanced by phagocytosis of these mycobacteria in a dose dependent manner, and the time course of the production was maximum within 24 hr after phagocytosis of these mycobacteria. It was also shown of morphological changes and enhanced glucose consumption in media by these macrophages. Above results suggest that phagocytosis of mycobacteria by macrophages leads to monokine production, which would not only causes well known immunological reactions but also makes characteristic phenomena to be observed in mycobacterial infections.

Dialysis patients are weak in immune host defense, which is associated with their high morbidity of infection. Polymorphonuclear leukocytes (PMNLs) and mononuclear cells play a key role in innate host defense. PMNLs and monocytes have bactericidal activity through the process of phagocytosis. Monocytes and lymphocytes contribute to the development of innate immunity by their cytokine actions. We studied the intracellular cytokine syntheses in response to ex-vivo stimuli, which may reflect the potential reactivity of immune cells in cytokine syntheses when pathogens invade humans. Furthermore, phagocytic activity was assessed in granulocytes and monocytes. Twenty HD, 15 CAPD, and 10 age-matched controls were enrolled in this study. One milliliter of whole blood from each subject was incubated with lipopolysaccharides (LPS) or mitogens for 4 hours at 37 degrees C. Monoclonal antibodies to CD14+ and CD4+ were used for identifying monocytes and helper T cells, respectively. Intracellular cytokines were stained using FASTIMMUNE staining kits. Interleukin-1beta and TNF-alpha syntheses were examined in monocytes, which are the most important early-response cytokines in innate immunity. IFN-gamma and IL-4 syntheses were examined in helper T cells to observe their polarization into Th1 and Th2 cells. IFN-gamma is a key factor in establishing innate immunity. The percentage of cells that stained positive for each cytokine was analyzed using a flow cytometer. The following results were obtained: 1) In CAPD patients, IL-1beta and TNF-alpha response to LPS in monocytes were significantly reduced, as compared to other subjects. Polarization of helper T cells was reduced, resulting in a significant decrease in Th1 cells. 2) In HD patients, monokine responses were not altered, but polarization of helper T cells was skewed toward a Th1 type. Phagocytic activities were not impaired in both dialysis groups. In conclusion, mononuclear cells from CAPD patients have the potential to exhibit failure of a cytokine response to ex-vivo stimuli in terms of innate immunity.

The characteristics and function of human lymphocytes in tuberculous morbid site were studied. Exudative-sensitized lymphocytes in tuberculous pleural fluid reacted to the specific antigen more effectively and produced higher titers of cytokines including interferon gamma (IFN-gamma) than circulating lymphocytes. CD4+/CD8- T-cell subset is responsible for the antigen-specific IFN-gamma production in pleural T lymphocytes of patients with tuberculous pleurisy. Thus, activated T lymphocytes concern the production of cytokines at the morbid site and they effectively exert local cellular immunity through the action of such cytokines. Immunofluorescence study showed increased production of inducible nitric oxide synthase (iNOS) and peroxynitrite in BCG-inoculated human alveolar macrophages (AM). Reverse transcriptase-polymerase chain reaction methods also revealed the higher expression of iNOS-coding mRNA. Colony assay demonstrated that human AM effectively killed BCG in their cytoplasm. However, treatment of AM with NG-monomethyl-L-arginine monoacetate resulted in markedly reduced killing activity. These results clearly show that BCG-induced NO and its reactive product with the oxygen radical, peroxynitrite, could play an important role in BCG killing in human AM. We measured the pleural concentrations of IFN-gamma, interferon-gamma-inducing cytokines; interleukin (IL)-12 and IL-18 and interferon-gamma-inducible chemokines; IFN-gamma-inducible protein of 10 kDa (IP-10), monokine induced by IFN-gamma (Mig), and IFN-inducible T cell alpha chemoattractant (I-TAC). These cytokines and chemokines in tuberculous pleural effusions were much higher than those in malignant pleural effusions. These findings indicate that IFN-gamma plays an important role in the cell mediated immunity in tuberculosis.

The effects of both fibronectin (FN) and monokines (IL-1 alpha, IL-6, TNF) on monocyte activation were studied. FN in the culture medium (200 micrograms/ml) induced strong monokine production that was mediated by the domain epitope including RGD sequence on FN and the VLA-5 integrins on monocytes. Each monokine or the combination of suboptimal dose of any monokines strongly induced FN production. These results indicate that monocytes activation in vitro may depend on not only monokines but on adhesion molecules such as FN-VLA-5. Peripheral blood monocytes from patients with systemic lupus erythematosus (SLE) demonstrated low responses to both fibronectin and monokines, while the plasma levels of FN in SLE patients elevated markedly compared with normal individuals (640 vs 285 micrograms/ml). Many studies have been reported that cytokines elevated in serum from SLE patients. These results indicated that maximally activated monocytes with both monokines and soluble FN in vivo in SLE patients could not be activated in vitro. Together with these results, FN play important roles in the cellular and humoral mechanisms of inflammation.

Interleukin 1 is a monokine produced by macrophage and has an ability to activate thymocytes. In addition to the immunological regulatory effect, interleukin 1 has attracted a great deal of investigators as a new peptide hormone that was secreted by many cells and has a various physiological activities. In central nervous systems, interleukin 1 promotes the glial cells proliferations on the injured brain and the fetal brain. The cell sources of interleukin 1 in central nervous systems are considered to the microglial cells. On gliomas, Lachmann and Dinarello reported growth promoting effect of IL-1 on U-373 MG human glioblastoma cell. The authors investigated the roles and effects of IL-1 on the growth of gliomas using recombinant human IL-1 beta and anti-HuIL-1 beta monoclonal antibody. On Immunohistochemistry, paraffin sections of 10 cases of gliomas were stained with immunoperoxidase method using anti-human IL-1 beta and anti-GFAP mouse monoclonal antibody. All astrocytomas examined and 2 of 4 glioblastomas were stained by anti-IL-1 beta. The origin of IL-1 that was stained by immunoperoxidase staining is unknown. The authors think it that IL-1 existed in glioma cells were secreted by microglial cells or that the glioma cells themselves secreted IL-1. In either case, IL-1 must be related to the growth of glioma in situ. On immunocytochemistry, U-373 MG human glioblastoma cells purchased from ATCC were incubated on cover-slip with 0 and 10 U/ml of rHuIL-1 beta for 3 or 7 days. The cells were stained with immunoperoxidase method using anti-GFAP monoclonal antibody.(ABSTRACT TRUNCATED AT 250 WORDS)