The major surface glycoprotein of Pneumocystis carinii induces release and gene expression of interleukin-8 and tumor necrosis factor alpha in monocytes.

Recent studies suggest that interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-alpha) may play a central role in host defense and pathogenesis during Pneumocystis carinii pneumonia. In order to investigate whether the major surface antigen (MSG) of human P. carinii is capable of eliciting the release of IL-8 and TNF-alpha, human monocytes were cultured in the presence of purified MSG. MSG-stimulated cells released significant amounts of IL-8 within 4 h, and at 20 h, cells stimulated with MSG released 45.5 +/- 9.3 ng of IL-8/ml versus 3.7 +/- 1.1 ng/ml for control cultures (P = 0.01). In a similar fashion, MSG elicited release of TNF-alpha. Initial increases were also seen at 4 h, and at 20 h, TNF-alpha levels reached 6.4 +/- 1.1 ng/ml, compared to 0.08 +/- 0.01 ng/ml for control cultures (P < 0.01). A concentration-dependent increase in IL-8 and TNF-alpha secretion was observed at 20 h with 0.2 to 5 microg of MSG/ml (P < 0.01). Secretion of IL-8 and TNF-alpha from MSG-stimulated monocytes at 20 h was inhibited by 60 and 86%, respectively, after coincubation with soluble yeast mannan (P = 0.01). With an RNase protection assay, increases in steady-state mRNA levels for IL-8 and TNF-alpha were detectable at 4 h. These data show that recognition of MSG by monocytes involves a mannose-mediated mechanism and results in the release of the proinflammatory cytokines IL-8 and TNF-alpha.     

Transforming growth factor-beta synthesis by human peritoneal mesothelial cells. Induction by interleukin-1.

Peritoneal mesothelial cells are uniquely located to regulate cellular events in the peritoneal cavity and are a potentially important source for various cytokines. The present study was designed to elucidate the capacity of human peritoneal mesothelial cells (HPMCs) to synthesize and secrete the transforming growth factor (TGF)-beta isoforms 1, 2, and 3 and to characterize their regulation by inflammatory cytokines. HPMCs constitutively released appreciable amounts of TGF-beta 1 and low amounts of TGF-beta 2 as detected by specific immunoassays. TGF-beta 1 levels secreted within 48 hours (45 +/- 8.9 pg/10(5) cells) were 60-fold higher than TGF-beta 2 levels (0.9 +/- 0.1 pg/10(5) cells), respectively. Treatment of HPMCs with interleukin (IL)-1 beta (10 ng/ml) resulted in a significant increase of both TGF-beta 1 (mean, 5-fold; P < 0.001) and TGF-beta 2 (mean, 6-fold; P < 0.01) generation. After 48 hours of IL-1 beta treatment the levels were 185 +/- 17.1 pg/10(5) cells for TGF-beta 1 and 5.3 +/- 1.5 pg/10(5) cells for TGF-beta 2, respectively. Neither tumor necrosis factor (TNF)-alpha nor interferon (IFN)-gamma (both 10 ng/ml) affected TGF-beta 1 or TGF-beta 2 synthesis by HPMCs. TGF-beta 3 could not be detected in any of the supernatant media. Stimulation of HPMCs with IL-1 beta increased steady-state levels of TGF-beta 1- and TGF-beta 2-specific mRNA. Western blot analysis of supernatants revealed the presence of an immunoreactive band at 25 kd. Indirect competition assays confirmed receptor-binding activity of HPMC-derived TGF-beta. Appreciable amounts of TGF-beta were present in a bioactive form. Our results demonstrate that HPMCs synthesize the TGF-beta isoforms 1 and 2 and that the levels of mRNA and protein release can be up-regulated by the proinflammatory cytokine IL-1 beta.     

Secretion of cytokines by natural killer cells primed with interleukin-2 and stimulated with different lipoproteins.

Natural killer (NK) cells were shown to secrete differentially interleukins (IL), IL-1 alpha, IL-1 beta, IL-2, IL-8, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), and leukaemia inhibitory factor (LIF) upon stimulation with optimal concentrations of chylomicrons (CM), very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL) or acetyl-modified low-density lipoprotein (AcLDL). CM, VLDL, LDL and AcLDL induced LIF secretion which was absent in nonstimulated cells. CM, VLDL, and LDL did not affect IL-1 alpha secretion. CM stimulated IL-8 > TNF-alpha > IL-1 alpha > IL-2 = IFN-gamma, and decreased seventeen-fold GM-CSF secretion. VLDL stimulated IL-8 secretion > IL-1 alpha = IL-2 > IFN-gamma > TNF-alpha and decreased fivefold GM-CSF secretion. LDL stimulated IL-8 secretion > IL-1 alpha > IL-2 = IFN-gamma, it did not modify TNF-alpha and inhibited five hundred-fold GM-CSF secretion. HDL stimulated IL-2 secretion = IFN-gamma > IL-8, it decreased GM-CSF secretion > IL-1 alpha > IL-1 beta > TNF-alpha without affecting LIF. AcLDL stimulated IL-8 secretion > TNF-alpha > IL-1 alpha > IL-2 = IFN-gamma = IL-1 beta, and decreased GM-CSF secretion eightfold. When NK cells were primed with 10, 100 or 500 IU/ml of IL-2 before the addition of lipoproteins, a decrease in the secretion of cytokines was observed as compared with cells primed with IL-2 only. Differences in cytokine secretion were observed among the diverse type of lipoproteins used for cell stimulus. Thus, lipoproteins may condition NK cytokine secretion and cell activation.     

Basic fibroblast growth factor synthesis by human peritoneal mesothelial cells: induction by interleukin-1

Peritoneal mesothelial cells are uniquely located to regulate cellular events in the peritoneal cavity and are an important source for various cytokines and growth factors. This study was conducted to analyze the capacity of human peritoneal mesothelial cells (HPMCs) to synthesize and release basic fibroblast growth factor (bFGF) and to characterize its regulation by inflammatory cytokines. HPMCs constitutively synthesized and released considerable amounts of bFGF as detected by a specific immunoassay. Almost 80% of bFGF (1547 +/- 173 pg/10(5) cells) was localized intracellularly. Approximately 20% of the bFGF (357 +/- 27 pg/10(5) cells) was associated with extracellular matrix components on the HPMC surface. Small amounts of bFGF (<1%) were detectable in tissue culture supernatants (8.4 +/- 1.4 pg/10(5) cells). Treatment of HPMCs with interleukin-1beta (IL-1beta; 1 ng/ml) resulted in a significant increase in bFGF production. The intracellular bFGF content showed a rapid but only transient increase, which was significant above background levels after 24 hours (41% increase; P < 0.05). This increase in intracellular bFGF concentration was associated with an induction of the release of bFGF. Within 96 hours, the release of bFGF to the cell surface and into the supernatant increased by 58% (564 +/- 52.4 pg/10(5) cells; P < 0.01) and by 214% (26.4 +/- 3.2 pg/10(5) cells; P < 0.001), respectively. Neither tumor necrosis factor-alpha nor interferon-gamma affected bFGF synthesis by HPMCs. Stimulation of HPMCs with IL-1beta increased steady-state levels of bFGF-specific mRNA. Immunohistochemical analyses of peritoneal tissue revealed constitutive expression of bFGF by HPMCs. This in situ expression proved to be most pronounced in areas of serosal inflammation in activated HPMCs. Our study demonstrates that HPMCs synthesize and release significant amounts of bFGF and that the expression of this growth factor is significantly up-regulated by the proinflammatory cytokine IL-1beta. The data support the view that HPMCs are key regulators of abdominal disease processes such as peritonitis, peritoneal fibrosis, or peritoneal tumor metastasis.     

Expression of RANTES in human airway epithelial cells: effect of corticosteroids and interleukin-4, -10 and -13.

RANTES is a C-C chemokine with strong chemoattractant and activating properties for eosinophils, basophils and T lymphocytes. We investigated the expression of RANTES in human airway epithelial cells and its modulation. Epithelial cells obtained from tracheas of donor lungs were stimulated with interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) or with a mixture of the three cytokines ('cytomix'). Levels of mRNA and protein were assayed by Northern blot and radioimmunoassay, respectively. Each individual cytokine produced a small increase in RANTES protein: IL-1 beta 24 +/- 1 pM, TNF-alpha 13 +/- 7 pM and IFN-gamma 29 +/- 7 pM, but cytomix increased protein to 236 +/- 22 pM (P < 0.002) and mRNA expression by > 20-fold (P < 0.002). Both RANTES protein and mRNA expression were inhibited by dexamethasone (10(-6) M) (38 +/- 5%, P < 0.05 and 55 +/- 8%, P < 0.007, respectively), and by IL-4 (42 +/- 7%, P < 0.03 and 19 +/- 1%, not significant, respectively). No inhibitory effect was observed with IL-10 or IL-13. We also demonstrated in vivo expression of RANTES protein by epithelial cells in human airways using immunohistochemistry. Our data show that human airway epithelial cells can be stimulated to express and release RANTES, an effect that is inhibited by corticosteroids and IL-4, but not by IL-10 and IL-13.     

Cytokines in symptomatic asthma airways.

To determine whether cytokines are generated in vivo in subjects with asthma, we have measured cytokine levels (tumor necrosis factor [TNF], granulocyte-macrophage-colony-stimulating factor [GM-CSF], interleukin [IL]-1 alpha, IL-1 beta, IL-2, IL-4, and IL-6) in the airways of subjects with symptomatic (N = 24) and asymptomatic (N = 9) asthma with immunoassays (GM-CSF, IL-1 alpha, IL-1 beta, IL-2, and IL-4) or bioassays (TNF and IL-6) and the polymerase chain reaction (IL-1 beta and TNF). Significant levels of TNF (578 +/- 917 pg/ml versus 24 +/- 29 pg/ml) (p = 0.01), GM-CSF (24 +/- 41 pg/ml versus less than 8 pg/ml) (p = 0.02), and IL-6 (225 +/- 327 pg/ml versus 7 +/- 12 pg/ml) (p = 0.01), but not IL-1 alpha or IL-4, were detected in the bronchoalveolar lavage fluid (BALF) of patients with symptomatic compared with BALF of patients with asymptomatic asthma. Levels of IL-1 beta (266 +/- 270 pg/ml versus less than 20 pg/ml) (p = 0.001) and IL-2 (1.4 +/- 2.8 ng/ml versus less than 0.3 ng/ml) (p = 0.05) in BALF in patients with symptomatic compared with that in BALF levels in patients with asymptomatic asthma suggested activation of alveolar macrophages and T cells. Thus, in episodes of asthma, several cytokines, including TNF, GM-CSF, IL-1 beta, IL-2, and IL-6 are detectable in BALF.     

Cytokines in patients with lung cancer

Lung cancer is one of the most common malignant diseases and is amongst the leading causes of death. Cell-mediated immune response and cytokines could play an important role in antitumour immunity. The aim of the study was to evaluate the cytokines', tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and IL-6, releasing capacity in patients with lung carcinoma and benign lung disease. A group of 41 patients were tested for the production of TNF-alpha, IL-1beta and IL-6 in bronchoalveolar lavage (BAL) and blood. The levels of cytokines in the lung cancer patients were: (1) in BAL - IL-6, 173 +/- 85 pg/ml; TNF-alpha, 170 +/- 116 pg/ml; and IL-1beta, 473 +/- 440 pg/ml; (2) in the blood - IL-6, 197 +/- 53 pg/ml; TNF-alpha, 311 +/- 202 pg/ml; and IL-1beta, 915 +/- 239 pg/ml. Alveolar macrophages of the patients with a lung cancer secreted significantly more cytokines, IL-6 (P = 0.0004) and IL-1beta (P = 0.0047), than alveolar macrophages of the patients with a nonmalignant lung cancer. However, significantly lower levels of cytokine production by the BAL cells were found in patients with small cell lung cancer. This production decreased further in phase IV of nonsmall cell lung cancer.     

Activation of human macrophages by allogeneic islets preparations: inhibition by AOP-RANTES and heparinoids

During transplantation, pancreatic islets release chemokines which promote macrophage attraction, hampering engraftment of islets. The aim of this study was to modulate chemotaxis and the immune response of human macrophages induced by islets. Human monocyte-derived macrophages of healthy subjects were exposed to supernatants of human islets. Chemotaxis, tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) release were evaluated. To modulate migration, human macrophages were incubated in the presence of aminooxypentane-regulated on activation, normal, T-cell expressed, and secreted (AOP-RANTES), a potent antagonist of CCR5. Chemotactic activity of islets supernatant was modulated by the addition of heparin or heparinoids [pentosan and calix[8S]arene (C8S)]. AOP-RANTES significantly reduced, in a dose-dependent manner, macrophage chemotaxis and cytokine release induced by islets supernatant. The chemotactic index was reduced from 3.05 +/- 0.27 to 0.71 +/- 12, TNF-alpha from 1205 +/- 52 to 202 +/- 12 pg/ml, and IL-1beta from 234 +/- 12 to 10 +/- 6 pg/ml. The trapping of chemokines by heparinoids reduced the chemotactic activity of islets supernatant from 3.05 +/- 0.27 to 1.2 +/- 0.1 with heparin or pentosan and to 1.72 +/- 0.22 with C8S, and also decreased the TNF-alpha release by human macrophages from 1205 +/- 35 to 1000 +/- 26 (C8S), 250 +/- 21 (heparin) and 320 +/- 19 (pentosan) pg/ml, and IL-1beta from 234 +/- 13 to 151 +/- 5 (C8S), 50 +/- 3 (heparin) and 57 +/- 4 (pentosan) pg/ml. In conclusion, AOP-RANTES and heparinoids inhibit human macrophage activation and migration induced by islets supernatant.     

Beneficial effects of interleukin-6 in neonatal mouse models of group B streptococcal disease.

Previous studies have shown that tumor necrosis factor alpha (TNF-alpha) plays a pathophysiologic role in sepsis induced in rat pups by group B streptococci (GBS). In this model, TNF-alpha is also partially responsible for the induction of interleukin-6 (IL-6). The present study was undertaken to investigate the role of IL-6 in neonatal BALB/c mice infected with type III GBS. The effect of anti-IL-6 monoclonal antibodies and recombinant IL-6 on lethality and TNF-alpha production was investigated. In mouse pups infected with GBS strain COH1, plasma IL-6 reached levels of 3,067 +/- 955 and 1,923 +/- 891 U/ml when measured at 22 and 48 h, respectively (P < 0.05 compared with uninfected controls). Pretreatment with 25 micrograms of anti-IL-6 antibodies totally prevented the increase in circulating IL-6 bioactivity at both 22 and 48 h after infection (P < 0.05). Treatment with anti-IL-6 also induced a moderate decrease in survival time of mice infected with lethal doses of strains COH1 and COH31, as evidenced by increased lethality (P < 0.05) at 24 to 48 h but not at 96 h. Mouse recombinant IL-6 (12,500 U) given 6 h before challenge with strains COH1 and COH31 consistently increased survival time, as evidenced by decreased (P < 0.05) lethality at 48 to 72 h but not at 96 h. The effects of IL-6 pretreatment were dose dependent, since no protection was observed with doses lower than 12,500 U. In addition, no effects on lethality were noted when IL-6 was given at the time of challenge or at later times. TNF-alpha elevations (P < 0.05 compared with uninfected controls) were measured at 12, 22, and 48 h after challenge with strain COH1 (68 +/- 28, 233 +/- 98, and 98 +/- 34 U, respectively). Pretreatment with IL-6 significantly (P < 0.05) decreased plasma TNF-alpha levels at 12 and 22 h, with 55 and 69% inhibitions, respectively. Anti-IL-6 had an opposite effect, as evidenced by a 145% increase (P < 0.05) in TNF-alpha levels at 48 h after challenge. Collectively, our data are compatible with the hypothesis that IL-6 is involved in negative feedback regulation of plasma TNF-alpha levels in experimental GBS sepsis. In this model, IL-6 pretreatment can increase survival time. Future studies will be needed to investigate the mechanisms underlying this effect.     

IL-8 as an important chemoattractant for neutrophils in ulcerative colitis and Crohn's disease.

IL-8 is generating increasing interest as a powerful neutrophil chemoattractant and activator. To elucidate the mechanisms of neutrophil infiltration in inflammatory bowel disease, we examined 33 patients with ulcerative colitis (UC), 18 with Crohn's disease (CD), eight with some other type of colitis, and 18 normal control subjects for measurement of IL-8 in homogenates of colonic biopsy specimens. The affected colonic mucosa was found to contain significantly more IL-8 in patients with active inflammatory bowel disease than in patients with inactive disease (UC, P < 0.001; CD, P < 0.001), in patients with other types of colitis (UC, P < 0.05; CD, P < 0.01), or in normal control subjects (UC, P < 0.001; CD, P < 0.001). Colonic IL-8 levels correlated significantly with the macroscopic grade of local inflammation, especially in patients with UC (P < 0.001). Colonic IL-8 levels also correlated well with the neutrophil numbers in mucosal tissue (UC, r = 0.950, P < 0.001; CD, r = 0.940, P < 0.001), and with colonic IL-1 beta (r = 0.911, P < 0.001) and tumour necrosis factor-alpha (TNF-alpha) levels (r = 0.604, P < 0.001) in patients with these two conditions. These data suggest a potential role for IL-8 and its regulatory cytokines IL-1 and TNF-alpha in mediating neutrophil infiltration of the gut wall in inflammatory bowel disease.     

Generation of interleukin-8 from human monocytes in response to Trichomonas vaginalis stimulation.

Neutrophils are the predominant inflammatory cells found in the vaginal discharges of patients with Trichomonas vaginalis infection. We have investigated the possible role of interleukin-8 (IL-8) in the inflammatory response elicited by T. vaginalis infection. This study has shown that T. vaginalis induces blood monocytes to produce large amounts of bioactive IL-8, mainly by membrane components of T. vaginalis (MTV). Monocyte-derived IL-8 induced by MTV was dose and time dependent. The peak level of IL-8 was 102 +/- 11 ng/ml of conditioned media (mean +/- standard error; n = 5) obtained from MTV-stimulated monocytes (MTVCM) at 36 h of cultivation. With a multichamber chemotactic assay, we found an optimal neutrophil chemotaxis (177 +/- 14 migrated cells) induced by MTVCM collected at 16 h of cultivation when the level of IL-8 was 42 +/- 8 ng/ml. A neutralizing monoclonal antibody directed against IL-8, but not the irrelevant antibodies, significantly blocked the neutrophil chemotactic activity (decreased from 153 +/- 6 to 23 +/- 3 migrated cells; n = 3 [P < 0.001]) induced by MTVCM. Moreover, the maximum increase of the IL-8 mRNA level from MTV-treated monocytes was observed after a 5-h cultivation and decreased thereafter. Monocytes cocultured with MTV in the presence of a neutralizing monoclonal antibody directed against tumor necrosis factor alpha, but not against IL-1 beta, decreased IL-8 production by 25% (P < 0.05), indicating that the release of IL-8 in MTV-stimulated monocytes is partially dependent on tumor necrosis factor alpha. The capacity of MTV-induced monocytes to synthesize IL-8 suggests that these cells can contribute to the induction of the acute inflammatory response seen in T. vaginalis infection.     

Effects of fibronectin and group B streptococci on tumour necrosis factor-alpha production by human culture-derived macrophages.

Group B streptococci (GBS) are an important cause of sepsis and shock in the new-born. We have previously reported that GBS induce the production of tumour necrosis factor-alpha (TNF-alpha) by human monocytes and culture-derived macrophages. We have also shown that fibronectin (FN) promotes interaction between GBS and human phagocytes. In the present study, we investigated the effect of FN and GBS on the production of TNF-alpha by adult and neonatal culture-derived macrophages. We report that soluble FN alone was a strong stimulus for the production of TNF-alpha by culture-derived macrophages (FN 50 micrograms/ml = 623.33 +/- 47 pg/ml TNF, versus media alone 3 +/- 1.5 pg/ml; P < 0.0001). While GBS also induce the production of TNF-alpha by macrophages, the addition of FN to GBS had more than an additive effect on TNF-alpha levels. FN-mediated TNF-alpha production by macrophages was inhibited by both soluble arginine-glycine-aspartic acid (RGD) peptide (71%; P < 0.0001) and anti-beta 3-integrin monoclonal antibody 7G2 (54%; P < 0.0001). Neonatal culture-derived macrophages produced significantly more TNF-alpha in response to GBS (356.4 pg/ml +/- 27.7) than adult cells did (222.0 pg/ml +/- 21.0; P = 0.037), and dramatically more in response to FN alone (neonatal 1931.0 pg/ml +/- 23.0 versus adult 463.5 43.5 pg/ml; P < 0.0001). FN may contribute to the high levels of TNF-alpha production implicated in the pathophysiology of GBS sepsis and shock.     

Interleukin-1 (IL-1) receptor antagonist prevents Staphylococcus epidermidis-induced hypotension and reduces circulating levels of tumor necrosis factor and IL-1 beta in rabbits.

Similar to shock in gram-negative sepsis, shock from gram-positive organisms is mediated, in part, by tumor necrosis factor (TNF) and interleukin-1 (IL-1). In the present study, rabbits were infused with IL-1 receptor antagonist (IL-1ra) prior to and during Staphylococcus epidermidis-induced hypotension. After injection of bacteria, a maximal fall in mean arterial pressure to -42% below baseline occurred at 200 min in vehicle-treated animals compared with a nonsignificant decrease of only 7% in the IL-1ra-treated group (P < 0.01, vehicle versus IL-1ra). A similar attenuation was observed in the fall in systemic vascular resistance (P < 0.05). After the injection of S. epidermidis, TNF levels rose to a peak elevation of 475 +/- 160 U/ml in vehicle-treated rabbits, but in rabbits receiving IL-1ra, maximal TNF levels rose only to 85 +/- 23 U/ml (P < 0.01). Plasma IL-1 beta reached maximal concentrations at 180 min of 364 +/- 71 pg/ml in vehicle-treated animals but only 145 +/- 12 pg/ml in rabbits given IL-1ra (P < 0.05). The reductions in TNF and IL-1 were not due to interference by IL-1ra in the respective assays. In vitro, IL-1ra inhibited S. epidermidis-induced TNF from mononuclear cells by 31% +/- 11%, from spleen cells by 17% +/- 4% (P < 0.05), and from whole blood by 42% +/- 17%. Despite the near reversal of the fall in mean arterial pressure and systemic vascular resistance in IL-1ra-treated rabbits, leukopenia and thrombocytopenia were unaffected. These results demonstrate that IL-1ra blocks shock-like hemodynamic parameters and reduces circulating IL-1 and TNF levels in a model of gram-positive sepsis.     

Circulating antiinflammatory cytokine IL-10 in patients with inflammatory bowel disease (IBD).

IBD is characterized by increased serum concentrations of different cytokines. IL-10 inhibits the production of proinflammatory cytokines such as IL-1, tumour necrosis factor-alpha (TNF-a), interferon-gamma (IFN-gamma) and IL-6 through inhibitory action on Th1 cells and macrophages, and it is thought to be a suppressor type cytokine. In the present study we determined serum concentrations of IL-10 in patients with ulcerative colitis (UC) and Crohn's disease (CD). We measured human IL-10 by our own newly established ELISA system using PharMingen antibodies. Serum antibodies were assessed in 44 patients with UC, 40 patients with CD, and in 30 healthy controls. Human IL-10 serum levels were significantly increased in patients with active UC (144 +/- 34 pg/ml (mean +/- s.e.m.), P < 0.001) and in active CD (132 +/- 32 pg/ml, P < 0.001) compared with healthy controls (44 +/- 9.5 pg/ml). Only patients with active CD and active UC presented with significantly increased IL-10 serum levels, while patients with inactive disease did not show any significant increase. There was no statistically significant difference between IL-10 serum levels in patients with CD or UC. Compared with clinical disease activity indices there was a significant correlation between IL-10 serum concentration and CDAI in patients with CD (r = 0.45, P < 0.01) and CAI in UC patients (r = 0.39, P < 0.05). Comparing IL-10 serum levels with serum concentrations of other proinflammatory cytokines there was a significant correlation to serum levels of sIL-2R (r = 0.417, P < 0.05) and IL-6 (r = 0.387, P < 0.05) in patients with CD. Serum cytokine levels in patients with UC did not show any significant correlation to IL-10 serum concentration. IL-10 is elevated in serum of patients with active CD and UC, suggesting that IL-10 acts as a naturally occurring damper in the acute inflammatory process of IBD.     

Characterization of CD4+ T helper cells in patients with Kawasaki disease (KD): preferential production of tumour necrosis factor-alpha (TNF-alpha) by V beta 2- or V beta 8- CD4+ T helper cells.

KD is an acute febrile illness in children characterized by coronary arteritis accompanied by aneurysm and thrombotic occlusion. The etiology of KD is unknown. It has been recently reported that KD is associated with the selective expansion of V beta 2+ and V beta 8.1+ T cells in peripheral blood lymphocytes (PBL), by studying the T cell receptor (TCR) repertoire of in vitro activated T cells. KD may therefore be caused by a superantigen [1-3]. To understand better the immunopathology of KD, we investigated TCR V beta 2 and V beta 8.1 expression on both the T cells of freshly isolated PBL and T cell clones (TCC) from patients with KD. Cytokine production by TCC was also studied. Blood samples were obtained from patients with acute (n = 20) and convalescent (n = 20) KD, age-matched children with non-infectious diseases (n = 18), and healthy adults (n = 20). Among these four groups, there were no significant differences in the percentages of either V beta 2+ or V beta 8.1+ T cells of freshly isolated PBL. The same was true for the CD4+ or CD8+ T cell subsets. One hundred and five TCC (98 CD3+ CD4+ CD8- and seven CD3+ CD4- CD8+) established from the affected skin, lymph node or PBL of six patients with KD were also negative for either V beta 2 or V beta 8.1 TCR. Sixty-eight of 105 TCC (65%) produced detectable levels (> 5 pg/ml) of TNF-alpha (6-1016 pg/ml), in the absence of any stimuli. In contrast, only 11 (10%) of 105 TCC or 7 (7%) of 97 TCC produced detectable levels of IL-2 or IL-6, respectively, in the absence of any stimuli. Stimulation with phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) induced most TCC to produce higher amounts of TNF-alpha, IL-2 and IL-6. These results suggest that CD4+ T helper cells expressing TCR-beta other than V beta 2 or V beta 8 receptor, primarily through TNF-alpha production, are involved in the immunopathology of KD.     

Elevated plasma amylase levels in advanced chronic heart failure secondary to ischemic or idiopathic dilated cardiomyopathy: correlation with circulating interleukin-6 activity.

It has been reported that proinflammatory cytokine activation is associated with both mesenteric venous congestion and peripheral tissue underperfusion in advanced chronic heart failure. The aim of our study was to investigate if plasma amylase (as an easily approached marker of a low-grade peripheral organ injury caused by elevated systemic venous pressure and reduced cardiac output) is elevated in severe heart failure and if this elevation is correlated with cytokine and neurohormonal activation in the plasma of heart failure patients. Plasma levels of amylase, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), norepinephrine, and renin activity were measured in 43 severe heart failure patients (ischemic, 28; dilated, 15; left ventricular ejection fraction [LVEF] 27 +/- 3%; New York Heart Association [NYHA] classes III-IV), in 37 mild heart failure patients (ischemic, 26; dilated, 11; LVEF, 33 +/- 5%; NYHA classes I-II), and in 20 age-matched and gender-matched healthy controls. NYHA III-IV heart failure patients exhibited significantly higher plasma levels of amylase (342 +/- 19 vs. 174 +/- 13 U/L, p < 0.01), TNF-alpha (6.2 +/- 0.5 vs. 4.2 +/- 0.3 pg/ml, p < 0.01), IL-6 (5.9 +/- 0.3 vs. 4.4 +/- 0.3 pg/ml, p < 0.05), GM-CSF (21.2 +/- 2.7 vs. 4.1 +/- 0.9 pg/ml, p < 0.001), and neurohormones (both p < 0.001) compared with NYHA I-II heart failure patients and healthy controls (amylase, 165 +/- 11 U/L, p < 0.01; TNF-alpha, 2.7 +/- 0.3 pg/ml, p < 0.001; IL-6, 3.2 +/- 0.2 pg/ml, p < 0.01; GM-CSF, 3.1 +/- 0.7 pg/ml, p < 0.001). Only in NYHA III-IV heart failure patients, plasma amylase levels were significantly correlated with plasma IL-6 activity (r = 0.86, p < 0.001), plasma norepinephrine levels (r = 0.82, p < 0.001) and right atrial pressure (r = 0.52, p < 0.05). Additionally, circulating IL-6 was also significantly correlated with plasma norepinephrine (r = 0.86, p < 0.001) and right atrial pressure (r = 0.57, p < 0.01). In conclusion, plasma amylase levels were elevated in severe heart failure patients and correlated well with circulating IL-6 activation, possibly as a result of both mesenteric venous congestion and impaired peripheral tissue perfusion observed in advanced chronic heart failure. However, the lack of association between plasma IL-6 and amylase levels in mild heart failure patients indicates an independent correlation of each variable with the functional status of the disease.     

Polarized secretion of interleukin-8 by human mesothelial cells: a role in neutrophil migration.

We investigated the role of human mesothelium in an in vitro model of peritonitis with emphasis on the secretion of the neutrophil chemoattractant interleukin-8 (IL-8) and the migration of polymorphonuclear leucocytes (PMN) across monolayers of peritoneal mesothelial cells. PMN showed minimal migration across non-activated mesothelial monolayers (< 2%). However, migration was induced after mesothelial cell activation by IL-1 beta (24%) and this induced migration was significantly blocked by antibodies against IL-8 (63% inhibition; P < or = 0.01). IL-1 beta-activated mesothelial monolayers were shown to secrete IL-8 in a polarized way, which was preferentially oriented towards the apical side of the monolayer. Our results indicate that the influx of PMN into the peritoneal cavity is, at least in part, controlled by the mesothelial cell layer of the peritoneal membrane.     

Differential effects of interleukin-12, interleukin-15, and interleukin-2 on human immunodeficiency virus type 1 replication in vitro.

Cytokines may have clinical utility as therapeutic agents for human immunodeficiency virus type 1 (HIV-1) infection and as an adjuvant for vaccines. The effect of interleukin-12 (IL-12) and IL-15 on in vitro HIV-1 replication was investigated. IL-12 and IL-15 at doses up to 10 ng/ml had little effect on basal HIV-1 p24 antigen production by chronically HIV-infected T (ACH-2) and monocytic (U1) cell lines. For ACH-2 cells stimulated with phorbol 12-myristate 13-acetate (PMA; 50 ng/ml), IL-12 and IL-15 significantly increased p24 antigen production by 20 and 30%, respectively (n = 6). In contrast, IL-12 and IL-15 (10 ng/ml) treatment of PMA-stimulated U1 cells decreased p24 antigen production by 16 and 15%, respectively (n = 6). We next studied the effect of IL-12 and IL-15 on HIV-infected peripheral blood mononuclear cells (PBMCs). In 10 HIV-seropositive patients' PBMCs cocultured with mitogen-activated HIV-seronegative donor cells, two patterns of p24 antigen production were observed in response to IL-2: low (p24 antigen production < 10(3) pg/ml; n = 8) and high (p24 antigen production > 10(3) pg/ml; n = 2) response. For the low-response pattern, IL-12 and IL-15 increased viral replication by 97-fold and 100-fold, respectively (P = 0.05 and 0.004, respectively). For the high-response pattern, both IL-12 and IL-15 suppressed HIV replication. The effect of IL-2, IL-12, and IL-15 on acute in vitro infection by HIV-1JRCSF was also examined. IL-12 did not increase p24 antigen production above basal levels while IL-2 and IL-15 significantly enhanced p24 antigen production (by approximately 2-fold). In conclusion, IL-12 and IL-15 may have differential effects on latent and acute HIV infection, and their ability to enhance HIV production may depend on cell activation. Thus, the use of these cytokines may be dictated by the clinical state of the patient.     

Early induction of IL-1 receptor antagonist (IL-1Ra) in infants and children undergoing surgery.

The cytokine response to injury or trauma is of interest in terms of both its mediation of the acute phase response and its possible relation to the immunological depression observed after major surgery. In this study, the production of cytokines IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6 and the naturally occurring inhibitor of IL-1, IL-1Ra, have been investigated in infants and children undergoing Swenson's pull-through operation for Hirschsprung's disease. Samples of peripheral blood were taken before, during and after surgery for the measurement of cytokines. IL-1Ra levels increased significantly (P < 0.01) at 2 h after commencement of surgery, with maximal levels for individual patients being attained between 3 h and 5 h (range 7.6-67.9 ng/ml). The mean level of IL-1Ra was maximal (26.2 ng/ml) at 5 h and returned to baseline levels between 24 h and 72 h. There were no changes observed in the circulating levels of IL-1 beta in nine out of 11 patients following commencement of surgery. TNF-alpha levels did not increase in any of the patients studied. IL-6 levels increased significantly (P < 0.02) 3 h after commencement of surgery, reaching maximum concentrations at 24 h (range 20-670 pg/ml), with levels falling between 48 h and 72 h. This study demonstrates, in vivo, the independent induction of IL-1Ra without a concomitant increase of IL-1 beta levels after major surgery. It also shows that IL-1Ra is the earliest cytokine produced in response to surgical stress.