Production of soluble ICAM-1 from human endothelial cells induced by IL-1 beta and TNF-alpha

The present study was designed to establish the effects of cytokines on soluble ICAM-1 (sICAM-1) production by human endothelial cells (EC) and ICAM-1 expression on these cells and the effects of purified sICAM-1 on lymphocyte-EC adhesion. Expression of ICAM-1 and production of sICAM-1 were measured by a specific ELISA method. ICAM-1 expression was enhanced by IL-1 beta, TNF-alpha, and most effectively by IFN-gamma. IL-4, IL-6, M-CSF, or GM-CSF showed no effects on ICAM-1 expression. IL-4 (100 units/ml) or IL-6(100 units/ml) abolished the enhancing effect of IL-1 beta, while TNF-alpha (1, 10, 100 units/ml) synergized with IL-1 beta to promote ICAM-1 expression in EC. In contrast with the transient increase of cell-associated ICAM-1 expression after activation by IL-1 beta, which peaked 40 h poststimulation and declined thereafter, sICAM-1 continued to accumulate in culture supernatants even after 48 h poststimulation in IL-1 beta-stimulated EC. IL-1 beta treatment resulted in an increase in adhesion. sICAM-1, purified from cell-free supernatants obtained after a 48-h culture of EC in IL-1 beta by affinity chromatography using monoclonal ICAM-1 antibody coupled to Sepharose beads, significantly inhibited lymphocyte EC adhesion. Preincubation of lymphocytes with conditioned medium of EC cultured with 100 units/ml IL-1 beta for 48 h, which contained a considerable amount of sICAM-1, resulted in a significant inhibition of lymphocyte adhesion to IL-1 beta-stimulated EC. These results suggest that there is a cumulative increase in sICAM-1 concentration in the vicinity of cytokine-stimulated EC and that this sICAM-1 modulates ICAM-1-mediated cell to cell interaction.

Possible mechanism of vascular damage in pre-eclampsia

To clarify the pathophysiological changes of pre-eclampsia, we investigated the injurious effect of sera from women with pre-eclampsia on cultured endothelial cells, vascular smooth muscle cells and fibroblasts. We obtained serum samples from 32 Japanese women, including 10 healthy nonpregnant women, 12 normal pregnant women and 10 women with pre-eclampsia. Cell injury was measured by the release of radiolabelled chromium from the cells into the culture medium. The mean values +/- SD of percentage chromium release from endothelial cells in normal nonpregnant, normal pregnant and pre-eclamptic subjects were 8.5 +/- 2.4, 8.8 +/- 2.1 and 19.7 +/- 3.6%, respectively. Sera from women with pre-eclampsia demonstrated significantly greater endothelial cell injury than did sera from normal pregnant and nonpregnant subjects. However, normal pregnant and pre-eclamptic subjects did not differ with respect to both vascular smooth muscle cell injury and fibroblast injury. These results indicate that a serum cytotoxic to endothelial cells is present in pre-eclampsia and that this activity has a cellular specificity for endothelial cells.

Effects of cytokines on alkaline phosphatase and osteocalcin production, calcification and calcium release by human osteoblastic cells

We examined the effect of TNF-alpha, IL-1 beta and IL-6 on alkaline phosphatase (ALP) and osteocalcin (OC) production, calcification and calcium (Ca) release in human osteoblastic cell cultures obtained from human periosteum. The cells were cultured with varying concentrations of cytokines for 3 days. TNF-alpha and IL-1 beta significantly inhibited ALP production, decreased cellular Ca content, and significantly enhanced 45Ca release in human osteoblastic cells. IL-6, on the other hand, significantly suppressed 45Ca release by osteoblastic cells. These cytokines did not influence the production of OC by osteoblastic cells. The results obtained suggest that TNF-alpha and IL-1 beta may inhibit bone formation and calcification and that the effects of IL-6 on osteoblastic cells may be different from those of TNF-alpha or IL-1 beta. These effects on osteoblastic cells may be one of the mechanisms by which bone loss occurs in patients with RA.

Functional oligomerization of purified human papillomavirus types 16 and 6b E7 proteins expressed in Escherichia coli

Purified non-fused soluble human papillomavirus type 16 and 6b E7 proteins expressed in Escherichia coli were found to form oligomers. For both proteins, several degrees of oligomerization were demonstrated by gel filtration, dynamic laser light scattering and scanning electron microscopy. Oligomerization was dependent on the concentration of E7 protein. Oligomerized E7 proteins were able to bind the retinoblastoma gene product pRB and stimulated DNA synthesis when introduced into cells.

Production of soluble ICAM-1 by mononuclear cells from patients with rheumatoid arthritis patients

The present study was designed to quantify the level of the soluble form of ICAM-1 (sICAM-1) produced by mononuclear cells (MNC) of rheumatoid arthritis (RA) patients, and to correlate these levels with the disease activity and with the amounts of cytokines or rheumatoid factors (RF) produced by MNC. Unstimulated synovial fluid (SF) MNC produced higher amounts of sICAM-1 than peripheral blood (PB) MNC in RA patients (P < 0.01). sICAM-1 production by PHA-stimulated MNC was higher in RA SF MNC than RA or normal PB MNC (P < 0.01). The amounts of SICAM-1 produced correlated with the amounts of soluble IL-2 receptor produced (P < 0.02) but not with IL-1B or the Lansbury activity index in RA PB MNC. sICAM-1 correlated with the amounts of soluble CD23 and IL-4 produced by normal PB MNC (P < 0.01). The amounts of sICAM-1 correlated with IgG-RF (P < 0.02) and IgM-RF (P < 0.01) produced by unstimulated MNC obtained from the bone marrow (BM) of RA patients. ICAM-1 expression of T-lymphocyte subsets, B lymphocytes, and monocytes obtained from RA PB and RA BM assayed by two-color flow cytometry ranged from 0.1 to 6%, which was not appreciably different from that of normal controls. The monocyte fraction of RA PB MNC produced significantly higher amounts of sICAM-1 than lymphocyte fraction. These results suggest that sICAM-1 produced by MNC may be a marker of cell activation in T and B lymphocytes, in contrast to the transient increase of ICAM-1 expression.

Transformation assays of the cell mitotic and proliferation activities of purified oncogene products

Using two direct introduction methods, DNA synthesis or cell proliferation activities of three purified proteins from E. coli, namely, human papillomavirus (HPV) E7 proteins of type 16, a mutant type 16 (24 C-G) (transformation defective) and type 6b, were measured in mouse fibroblast, C127 cells. By a microinjection method, the order of the cell mitotic indexes for the three E7 proteins as determined by 5-bromo-2'-deoxy-uridine (BrdU) staining was type 16, 6b and 16 (24 C-G). By the osmotic shock method, the 3H-TdR incorporation and coloration by (3-carboxymethoxy phenyl)-2-(4-sulfophenyl)-2H-tetolazorium (MTS) for the three proteins correlated with the pRb binding and focus forming activities previously reported (Munger et al. 1991). These results indicate that the simple osmotic shock method for direct protein introduction may be generally useful for transformation assays of oncoproteins.

Therapeutic effects of bovine enterovirus infections on autochthonous rat ovarian carcinomas induced by 7,12-dimethylbenz (a) anthracene (DMBA)

It has been previously reported that infection by a bovine enterovirus (MZ-468), which does not infect normal human cells, was remarkably effective for the therapy of adult T cell leukemia (ATL) in experimental rabbit models (Shingu et al. 1991). Therapeutic treatment studies were performed twice on 30 and 20 autochthonous rat ovarian carcinomas induced by DMBA. The average tumor size of the virus treatment group was significantly smaller than the control group when analyzed by a nonparametric Mann-Whitney method (p < 0.06 and 0.002 for the 1st and 2nd experiments, respectively). These results indicate that an enterovirus infection may be clinically useful for the therapy of human ovarian cancers with bad prognoses.

Association of RNA with human papillomavirus E7 protein of type 16 but not type 6b

Nonfused human papillomavirus (HPV) type 16 and 6b E7 proteins were expressed in E. coli and fractionated by ion exchange and gel filtration chromatography. The E7 protein of type 6b was purified, but that of type 16 was found to be associated with RNA molecules which could not be excluded by repeated chromatography. The type 16 E7 protein in CaSki cells was also associated with RNA molecules of the same size.

The effects of cytokines on metalloproteinase inhibitors (TIMP) and collagenase production by human chondrocytes and TIMP production by synovial cells and endothelial cells

It has been suggested that IL-1 produces cartilage matrix degradation by metalloproteinases such as collagenase, and that such degradation is regulated by metalloproteinase inhibitors (TIMP). Therefore, the balance between collagenase and TIMP is an important factor for tissue destruction in inflammatory joints. In the present study the effects of cytokines on collagenase and TIMP production in chondrocytes as well as the effects of cytokines on TIMP production in connective tissue cells were studied. IL-1 beta inhibited TIMP production in endothelial cells while enhancing TIMP production in synovial cells and chondrocytes. In addition, tumour necrosis factor-alpha (TNF-alpha) significantly inhibited and IL-6 significantly enhanced TIMP production in endothelial cells, synovial cells and chondrocytes. In the chondrocyte supernatant, collagenase activity/TIMP ratio was significantly elevated by the addition of either IL-1 beta or TNF-alpha to the cells, whereas the ratio was significantly decreased by IL-6. These results suggest that the cytokine effects on TIMP production are different among the different cell types, and that either IL-1 beta or TNF-alpha induce cartilage matrix degradation by disrupting the collagenase/TIMP balance, while, on the other hand, IL-6 protects the tissue through an opposite effect.

Two novel genes of herpes simplex virus type 1 involved in cell fusion

Herpes simplex virus type 1 (HSV-1) r mutants, which were defective in fusion function, were isolated from fusion inducing strains G7471 and G51, and classified into several groups by complementation (Yamamoto and Kabuta, 1977; Yamamoto et al. 1989). Marker rescue experiments of intact DNA from r mutants with EcoRI fragments of G7471 DNA revealed that the r mutations belonging to the groups A, B, E, F, G, and H were located in EcoRI-g, -c, -d, -h, -b, and -d fragments, respectively. The mutations belonging to the groups A, B, F, and G cover the loci affecting cell fusion which have been already reported by other investigators. The two novel mutations localized in EcoRI-d fragment were further finely mapped, and it was demonstrated that the mutations belonging to groups E and H were involved in the open reading frames UL10 and UL13, respectively.

Activation of complement in normal serum by hydrogen peroxide and hydrogen peroxide-related oxygen radicals produced by activated neutrophils

Neutrophils activated by soluble particulate stimuli generate superoxide anion and subsequently form hydrogen peroxide and other oxygen radicals. The effect of hydrogen peroxide on the complement system in normal serum was investigated. Treatment of normal serum with hydrogen peroxide resulted in a diminution of the haemolytic activity of the total and alternative complement pathways and the haemolytic titres of C3 and C5 but not of C2, in normal serum. These decreases in complement activity depended on the concentration of hydrogen peroxide added to the serum. Immunoelectrophoretic analysis of hydrogen peroxide-treated serum showed that C3 and C5 proteins were activated. Complement degradation products C3a and C5a were produced in normal serum treated with hydrogen peroxide, and 20 mM EDTA abolished C3a and C5a production in hydrogen peroxide-treated serum but 20 mM Mg-EGTA did not. Catalase completely abolished and dimethylsulphoxide and D-mannitol, hydroxyl radical scavengers, partially inhibited the hydrogen peroxide-mediated complement activation. Hypochlorite, incubated with normal serum, significantly inhibited serum haemolytic activity, and sodium thiosulphate, a reducing agent, abolished the effect of hypochlorite. Normal serum incubated with activated neutrophils showed neutrophil chemotactic activity and decreased serum haemolytic activity, and the addition of catalase or methionine (5 mM) completely abolished the effects of activated neutrophils. These results suggest that hydrogen peroxide activates complement via an alternative pathway of complement activation and that hydroxyl radicals and other hydrogen peroxide-related species such as hypochlorite are most likely involved in hydrogen peroxide-mediated complement activation. Complement activation by oxygen radicals produced by activated neutrophils may be one of the mechanisms by which complement is activated in human immune complex diseases.

The possible role of endothelial cells in hypertensive disorders during pregnancy

OBJECTIVE

To clarify the role of endothelial cells in pregnancy-related hypertensive disorders, we studied the cytotoxic effect of sera from normal pregnant women and from gravidas with various hypertensive complications of pregnancy.

METHODS

We obtained serum samples from 84 Japanese women: 17 with preeclampsia, ten with gestational hypertension, six with chronic hypertension, five with chronic hypertension with superimposed preeclampsia, 21 normal gravidas, and 25 healthy nonpregnant women. Endothelial cell injury was measured by the release of radiolabeled chromium from the cells into the culture medium.

RESULTS

The mean (+/- standard error of the mean) values of chromium 51 release in preeclampsia, gestational hypertension, chronic hypertension, chronic hypertension with superimposed preeclampsia, normal pregnancy, and healthy nonpregnant women were: 21.9 +/- 2.1, 10.0 +/- 2.0, 9.2 +/- 2.3, 12.9 +/- 0.8, 8.4 +/- 1.4, and 7.3 +/- 1.6%, respectively. Normal pregnant and nonpregnant subjects did not differ with respect to endothelial cell injury. Sera from women with preeclampsia demonstrated significantly greater endothelial cell injury than did sera from normal gravidas. Subjects with the three other categories of hypertensive disorders did not differ significantly from normal gravidas.

CONCLUSION

Preeclampsia is characterized by the presence of a serum factor cytotoxic to endothelial cells. Therefore, the mechanism responsible for the increase in blood pressure differs between women with preeclampsia and those with other hypertensive disorders in pregnancy.

Sjögren's syndrome and mixed connective tissue disease

We investigated the clinical significance of the close association of Sjögren's syndrome (SS) with mixed connective tissue disease (MCTD) by analyzing the clinical manifestations, sialographic findings and immunological parameters of MCTD and primary SS. The prevalence of sialectasia or SS in MCTD was significantly higher than in any other connective tissue diseases. The prevalence of Raynaud's phenomenon, swollen fingers, arthralgias, lymphadenopathy, sclerodactyly, muscle weakness, fever and erythema was significantly higher in MCTD than in primary SS. There were no significant differences between these manifestations in MCTD patients with sialectasia or SS, and those in MCTD patients without sialectasia or SS. Although the levels or prevalence of the erythrocyte sedimentation rate, CRP, antinuclear factor, anti-DNA antibody and anti-RNP antibody were significantly greater in MCTD than in primary SS, there were no significant differences in the levels or the prevalence of laboratory abnormalities between MCTD with sialectasia or SS, and MCTD without sialectasia or SS. Moreover, there was a strict dissociation between the occurrence of anti-RNP antibody and anti-SS-B antibody both in MCTD and primary SS. These results suggest that the association of secondary SS or sialectasia in MCTD, although more common than in other connective tissue diseases, is merely a consequence of MCTD and does not influence the clinical course of MCTD.

[Rapid detection of mycobacteria in sputa using media supplemented with culture filtrate of Gemella haemolysans]

The effect of the culture filtrate Gemella haemolysans in enhancing mycobacterial growth has been previously demonstrated. In the present studies, an attempt was made to confirm whether the addition of the filtrate into the medium would be an effective method to promote the rapid detection of mycobacteria in sputum specimens of patients. One-hundred and one sputum specimens pretreated with NaOH were inoculated with various media (Dubos, Dubos-agar, 1% Ogawa, Kudo PD, and Middlebrook 7H9) supplemented with the culture filtrate of Gemella haemolysans grown in blood-BHI or blood-HEM at the dilutions of 1/32 or 1/64. Addition of the filtrate reduced the amount of time required to detect mycobacterial growth (Mycobacterium tuberculosis, M. avium complex, and M. kansassi) by an average of 60-70%. The media containing the filtrate formed significantly larger numbers of colonies compared with the control media, and those colonies inoculated developed more rapidly in size. The findings clearly indicated that the culture filtrate promotes the effective growth of mycobacteria which cannot or only slowly grows in ordinary media. Also indicated was that the addition of the culture filtrate of Gemella haemolysans into media provides as a useful tool to allow the rapid diagnosis of mycobacterial diseases.

Construction of an expression vector for human papillomavirus type 16 E7-glutathione S transferase fusion protein

An expression vector for human papillomavirus type 16 (HPV 16) E7-glutathione S transferase fusion protein was constructed. The E7 gene was confirmed by southern blot analysis with a digoxygenin 11-dUTP labeled and simultaneously amplified E7 DNA probe by polymerase chain reaction (PCR). The fusion protein was expressed in E. coli, recovered as inclusion bodies, and was confirmed by western blot analysis using a monoclonal antibody against HPV 16-E7 protein. A polyclonal antibody against the HPV 16-E7 protein was raised in the serum of mice hyper-immuned with the fusion protein. This antibody will be available for screening of patients with cervical cancer.

Pattern recognition of continuity of discrete data points by scale changed plots

Graphs composed of a large number of data points plotted on an appropriate scale enables us to pattern recognize a specific continuous curve. This principle was used to follow signals from proton nuclear magnetic resonance as a function of pH in a large biomolecule, staphylococcal nuclease. The analysis was automated by auto peak-picking routines and by transferring the results to a graphic program, Graphic Operating System (Roome & Peterson, 1985). Expansion and contraction of the scale made it possible to differentiate specific tyrosine and histidine titration curves. This type of analysis is applicable for assignment of specific curves from a large number of data points which change as a function of perturbations.

Relationship between leukotriene B4 and immunological parameters in rheumatoid synovial fluids

Leukotriene B4 (LTB4) was measured in synovial fluid from 20 patients with rheumatoid arthritis and 15 patients with osteoarthritis. The level of LTB4 was significantly higher in synovial fluid from rheumatoid arthritis patients as compared with synovial fluid from osteoarthritis patients. LTB4 levels also significantly correlated with cell numbers, rheumatoid factor, and immune complexes in synovial fluid from rheumatoid arthritis patients. There was an inverse correlation between LTB4 levels and complement components. The high-pressure liquid chromatography peak of immunoreactivity extracted from the synovial fluid occurred at a retention volume identical to that of authentic LTB4. These results suggest that the increased level of this mediator in synovial fluid may contribute to perpetuation of inflammation and tissue destruction in rheumatoid arthritis.

Therapeutic effects of bovine enterovirus infection on rabbits with experimentally induced adult T cell leukaemia

A bovine enterovirus, MZ-468, showed cytopathic effects on cell line F-647a, which was established by coculture of human T cell lymphotropic virus type 1-transformed MT-2 cells and X-irradiated rabbit lymphocytes. Microcalorimetric assay showed that residual, viable, MZ-468-infected F-647a cells produced less heat than non-infected cells. The therapeutic effects of MZ-468 infection were examined in rabbits in which adult T cell-like leukaemia (ATL) had been induced by inoculation of F-647a cells (1 x 10(8) cells). Six newborn rabbits were separated into three groups: group A was inoculated with F-647a cells only; group B was treated with MZ-468 at the time of inoculation with cells; group C was treated with the same amount of virus 24 h after the inoculation with cells and then once every 4 days. Both of the animals in group A and one in group C died 10 and 11 days, and 22 days, respectively, after the inoculation with cells. Both rabbits in group B and one in group C survived for more than 4 months. The rabbits that died were examined pathologically; leukaemic infiltrations were found in the lungs of the group B rabbits, and in the lungs, spleens and livers of both group A rabbits. Two identical experiments produced almost the same findings. These results suggest that bovine enterovirus might be used clinically to prolong the life-span of ATL patients.

Multicentric reticulohistiocytosis associated with subclinical Sjögren's syndrome

A case of multicentric reticulohistiocytosis in a 60-year-old Japanese woman associated with subclinical Sjögren's syndrome is presented. The clinical features along with the light microscopic studies are commented. Partial improvement of the skin lesions and tendon sheath swelling was achieved after treatment with cyclophosphamide but the patient's general condition remained unchanged. Taking the rarity of multicentric reticulohistiocytosis into account, coexistence of these two conditions in the present and previously reported cases suggests that an autoimmune mechanism may play a part in the pathogenesis of multicentric reticulohistiocytosis.

Densitometric determination of human papillomavirus DNA quantities by chromato-scanning in the fluorescence mode

The quantitation of human papillomavirus DNA isolated from warts by chromato-scanning (fluorescence mode) photographs of ethidium bromide-stained agarose gels is described. Excitation at 200 nm (with a cutoff filter at 400 nm) generates fluorescence from the white portion of the printing paper. The fluorescent intensity correlated with the quantities of DNA in the band of interest. The amounts of DNA were determined using calibration curves of approximately the same size as lambda phage DNA fragments. This general method of quantification is applicable to photographs of other types of polynucleotides capable of being separated and stained in a gel medium.

Refolding and purification of human papillomavirus type 16 E7-lacZ fusion protein expressed in Escherichia coli

Human papillomavirus (HPV) type 16 E7-lacZ fusion protein was produced in Escherichia coli, extracted as inclusion bodies, refolded with reducing reagents, and subjected to gel filtration. The refolded protein was purified by ion-exchange column chromatography, resulting in a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 1H nuclear magnetic resonance spectral changes were observed in the high field methyl region in the presence of Zn2+ ion, suggesting that the refolded form of the fusion protein is possibly renaturated into the putative zinc finger motif (C. Edmond and K. H. Vousden, 1989, J. Virol. 63, 2650-2656) and supporting the data of J. A. Rawls, R. Pusztai, and M. Green (1990, J. Virol. 64, 6121-6129) on zinc binding to E7 protein using radioisotopically labeled zinc ion.

Effects of recombinant human IL-1 beta on production of prostaglandin E2, leukotriene B4, NAG, and superoxide by human synovial cells and chondrocytes

The effects of recombinant human IL-1 beta on the production of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), N-acetyl-beta-D-glucosaminidase (NAG), and superoxide by synovial cells and chondrocytes derived from osteoarthritis patients were determined. IL-1 beta markedly enhanced PGE2 production in chondrocytes and, to the lesser extent, in synovial cells. Synovial cells and chondrocytes spontaneously released LTB4 into culture medium and IL-1 beta significantly inhibited LTB4 production by these cells. IL-1 beta significantly suppressed the release of NAG and superoxide by synovial cells, whereas it significantly enhanced the production of NAG and superoxide by chondrocytes. Production of intracellular superoxide dismutase by synovial cells was significantly enhanced on incubation with IL-1 beta, but that of chondrocytes was not altered. IL-6, unlike IL-1 beta, significantly suppressed the production of NAG and superoxide by synovial cells and chondrocytes. These results suggest that IL-1 has differing effects on the release of mediators by synovial cells and chondrocytes and that these cells also vary in their responses to IL-1 beta and IL-6.