Interleukin-4 inhibits the expression of tumour necrosis factors alpha and beta, interleukins-1 beta and -6 and interferon-gamma

Immunomodulation and liver protection of Yinchenhao decoction against concanavalin A-induced chronic liver injury in mice

OBJECTIVE

This study investigated the immunoregulatory and protective roles of Yinchenhao decoction, a compound of Chinese herbal medicine, in a mouse model of concanavalin A (ConA)-induced chronic liver injury.

METHODS

Female BalB/c mice were randomly divided into 4 groups: normal control, ConA model, ConA model treated with Yinchenhao decoction (400 mg/kg, orally), and ConA model treated with dexamethasone (0.5 mg/kg, orally). All treatments were given once a day for 28 d. Except of the normal control, mice received tail vein injection of ConA (10 mg/kg) on days 7, 14, 21, and 28, at 1 h after treatment with Yinchenhao decoction or dexamethasone or saline to induce chronic liver injury.

RESULTS

Repeated ConA injection induced chronic liver injury, which was evidenced by inflammatory cell infiltration and necrosis, increased serum alanine aminotranferease activities, decreased albumin levels, and an imbalanced expression of immunoregulatory genes in the liver tissues including significantly enhanced interferon-γ, interleukin-4, monocyte chemotactic protein-1, and cluster of differentiation 163 mRNA levels, and reduced tumor necrosis factor-α and interleukin-6 mRNA levels. Treatment with Yinchenhao decoction significantly reversed the ConA-induced changes in immunoregulatory gene expression in the liver tissues, reduced serum alanine aminotranferease activity, enhanced serum albumin level, and attenuated the extent of liver inflammation and necrosis. Furthermore, Yinchenhao decoction did not result in hepatocyte degeneration and spleen weight loss that were observed in mice received long-term treatment with dexamethasone.

CONCLUSION

Yinchenhao decoction treatment protected liver against the ConA-induced chronic liver damage and improved liver function, which were associated with the modulation of gene expression related to immune/inflammatory response.

Interferon-γ, interleukins-6 and -4, and factor XIII-A as indirect markers of the classical and alternative macrophage activation pathways in chronic periodontitis

BACKGROUND

Macrophages account for 5% to 30% of the inflammatory infiltrate in periodontitis and are activated by the classic and alternative pathways. These pathways are identified by indirect markers, among which interferon (IFN)-γ and interleukin-6 (IL)-6 of the classic pathway and IL-4 of the alternative pathway have been studied widely. Recently, factor XIII-A (FXIII-A) was reported to be a good marker of alternative pathway activation. The aim of this study is to determine the macrophage activation pathways involved in chronic periodontitis (CP) by the detection of the indirect markers IFN-γ, IL-6, FXIII-A, and IL-4.

METHODS

Biopsies were taken from patients with CP (n = 10) and healthy individuals (n = 10) for analysis of IFN-γ, IL-6, IL-4, and FXIII-A by Western blot (WB), immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA). The same biopsies of healthy and diseased gingival tissue were used, and the expressions of these markers were compared between healthy individuals and those with CP.

RESULTS

The presence of macrophages was detected by CD68+ immunohistochemistry and their IFN-γ, IL-6, IL-4, and FXIII-A markers by WB, IHC, and ELISA in all samples of healthy and diseased tissue. IL-6, IL-4, and FXIII-A were significantly higher in patients with CP, whereas FXIII-A was higher in healthy individuals.

CONCLUSION

The presence of IFN-γ, IL-6, IL-4, and FXIII-A in healthy individuals and in patients with CP suggests that macrophages may be activated by both classic and alternative pathways in health and in periodontal disease.

Recurrent headache as the main symptom of acquired cerebral toxoplasmosis in nonhuman immunodeficiency virus-infected subjects with no lymphadenopathy: the parasite may be responsible for the neurogenic inflammation postulated as a cause of different types of headaches

Headache and/or migraine, a common problem in pediatrics and internal medicine, affect about 5% to 10% children and adolescents, and nearly 30% of middle-aged women. Headache is also one of the most common clinical manifestations of acquired Toxoplasma gondii infection of the central nervous system (CNS) in immunosuppressed subjects. We present 11 apparently nonhuman immunodeficiency virus-infected children aged 7 to 17 years (8 girls, 3 boys) and 1 adult woman with recurrent severe headaches in whom latent chronic CNS T. gondii infection not manifested by enlarged peripheral lymph nodes typical for toxoplasmosis, was found. In 7 patients, the mean serum IgG Toxoplasma antibodies concentration was 189 +/- 85 (SD) IU/mL (range 89 to 300 IU/mL), and in 5 other subjects, the indirect fluorescent antibody test titer ranged from 1:40 to 1:5120 IU/mL (n= <1:10 IU/mL). Some of the patients suffered also from atopic dermatitis (AD) and were exposed to cat and/or other pet allergens, associated with an increased IL-4 and decreased IFN-gamma production. These cytokine irregularities caused limited control of cerebral toxoplasmosis probably because IL-4 down-regulated both the production of IFN-gamma and its activity, and stimulated production of a low NO-producing population of monocytes, which allowed cysts rupture, increased parasite multiplication and finally reactivation of T. gondii infection. The immune studies performed in 4 subjects showed a decreased percentage of T lymphocytes, increased total number of lymphocytes B and serum IgM concentration, and impaired phagocytosis. In addition, few of them had also urinary tract diseases known to produce IL-6 that can mediate immunosuppressive functions, involving induction of the anti-inflammatory cytokine IL-10. These disturbances probably resulted from the host protective immune reactions associated with the chronic latent CNS T. gondii infection/inflammation. This is consistent with significantly lower enzyme indoleamine 2,3-dioxygenase (IDO) activity reported in atopic than in nonatopic individuals, and an important role that IDO and tryptophan degradation pathways plays in both, the host resistance to T. gondii infection and its reactivation. Analysis of literature information on the subjects with different types of headaches caused by foods, medications, and other substances, may suggest that their clinical symptoms and changes in laboratory data result at least in part from interference of these factors with dietary tryptophan biotransformation pathways. Several of these agents caused headache attacks through enhancing NO production via the conversion of arginine to citrulline and NO by the inducible nitric oxide synthase enzyme, which results in the high-output pathway of NO synthesis. This increased production of NO is, however, quickly down-regulated by NO itself because this biomolecule can directly inactivate NOS, may inhibit Ia expression on IFN-gamma-activated macrophages, which would limit antigen-presenting capability, and block T-cell proliferation, thus decreasing the antitoxoplasmatic activity. Moreover, NO inhibits IDO activity, thereby suppressing kynurenine formation, and at least one member of the kynurenine pathway, 3-hydroxyanthranilic acid, has been shown to inhibit NOS enzyme activity, the expression of NOS mRNA, and activation of the inflammatory transcription factor, nuclear factor-kB. In addition, the anti-inflammatory cytokines IL-4 and IL-10, TGF-beta, and a cytokine known as macrophage deactivating factor, have been shown to directly modulate NO production, sometimes expressing synergistic activity. On the other hand, IL-4 and TGF-beta can suppress IDO activity in some cells, for example human monocytes and fibroblasts, which is consistent with metabolic pathways controlled by IDO being a significant contributor to the proinflammatory system. Also, it seems that idiopathic intracranial hypertension, pseudotumor cerebri, and aseptic meningitis, induced by various factors, may result from their interference with IDO and inducible nitric oxide synthase activities, endogenous NO level, and cytokine irregularities which finally affect former T. gondii status 2mo in the brain. All these biochemical disturbances caused by the CNS T. gondii infection/inflammation may also be responsible for the relationship found between neurologic symptoms, such as headache, vertigo, and syncope observed in apparently immunocompetent children and adolescents, and physical and psychiatric symptoms in adulthood. We therefore believe that tests for T. gondii should be performed obligatorily in apparently immunocompetent patients with different types of headaches, even if they have no enlarged peripheral lymph nodes. This may help to avoid overlooking this treatable cause of the CNS disease, markedly reduce costs of hospitalization, diagnosis and treatment, and eventually prevent developing serious neurologic and psychiatric disorders.

Effect of methanol intoxication on spcific immune functions of albino rats

Our previous studies revealed that methanol intoxication significantly altered the non-specific immune functions in albino rats. The present investigation focuses on the effect of methanol on certain specific immune functions of cell mediated immunity such as footpad thickness, leukocyte migration inhibition test (LMI) and antibody levels. In addition, serum interleukins (IL-2, IL-4, TNF-alpha and IFN-gamma), and splenic lymphocyte subsets were measured after an immune challenge. The specific immune function tests were carried out in three different groups of albino rats, which include control, 15 and 30 days methanol intoxication. Our study reports that animal body weight, organ weight ratio, lymphoid cell counts, footpad thickness, antibody titer, IL-2, TNF-alpha, IFN-gamma, Pan T cell, CD4, macrophages, MHC class II molecule expression, and B cell counts were significantly decreased compared to control animals nevertheless, LMI, IL-4, and DNA single strand breakage were increased significantly. Plasma corticosterone level was significantly increased in the 15 days group whereas the 30 days methanol intoxication group showed considerable decrease in corticosterone level compared with control animals. Therefore, our investigation concluded that repeated exposure of methanol profoundly suppressed the cell mediated and humoral immune functions in albino rats.

Purification of placenta-eluted gamma globulins and their strong effect against graft-versus-host reactions in vitro and in vivo

In the 1980s, attempts were made to use placenta-eluted gamma globulins (PEGG) in patients with graft-versus-host disease (GVHD) after bone marrow transplantation (BMT). Because production of PEGG had been discontinued for many years, we aimed to reestablish a method of production and further explore the mechanisms of the effect of these globulins on GVHD. PEGG were prepared by elution at acid pH from extensively washed human placenta followed by precipitation with saturated ammonium sulfate and absorption on a protein A Sepharose column. In vitro study showed PEGG significantly inhibited both the proliferative response of T-cells to phytohemagglutinin (PHA) and the mixed lymphocyte reaction (MLR). Results of flow cytometric analysis indicated that PEGG down-regulated the expression of CD25 and CD69 on T-cells stimulated by PHA. Cytokine quantification in MLR supernatant showed that PEGG decreased secretion of interferon 3 (IFN-3) but increased production of interleukin 4. In a murine GVHD model, we investigated the preventive effect of PEGG on lethal GVHD in irradiated recipients of allogeneic bone marrow cells and spleen cell transplants by in vivo administration. Compared with controls, recipients treated with PEGG had a markedly increased survival rate with less histopathological evidence of GVHD. These results suggest that PEGG may be a potent therapeutic agent for GVHD.

Urinary tract diseases revealed after DTP vaccination in infants and young children: cytokine irregularities and down-regulation of cytochrome P-450 enzymes induced by the vaccine may uncover latent diseases in genetically predisposed subjects

Prophylactic vaccinations may sometimes shorten the incubation period of some illnesses and/or convert a latent infection/inflammation into a clinically apparent disease. Cytokines play a major role in mediating the inflammatory process in various clinical entities and represent a potential source of tissue damage if their production is not sufficiently well controlled. It seems that irregularities in production of proinflammatory cytokines may be responsible for the abnormalities associated with full-blown clinical symptoms of various urinary tract diseases observed after DTP vaccination in 13 infants and young children hospitalized over the past 24 years. On admission, upper respiratory tract diseases, atopic dermatitis, and/or latent urinary tract infection/inflammation were found in these children. It is suggested that the whole-cell pertussis present in DTP vaccine, acting as an excessive stimulus in these patients, produced symptoms reminiscent of biologic responses to circulating proinflammatory monokines such as IL-1beta, TNF-alpha, and IL-6 because earlier it was reported that in vitro the whole-cell vaccine induced significantly more such cytokine production than did the acellular pertussis or diphtheria-tetanus-only vaccine. Analysis of the cellular immune disturbances previously reported in urinary tract infection/inflammation (increased serum and/or urinary IL-1alpha, IL-1 receptor antagonist, IL-6 and IL-8), steroid-sensitive nephrotic syndrome (increased IL-2, IFN-gamma, TNF-alpha, and decreased or increased IL-4, depending on the cells studied), and atopic dermatitis (decreased IFN-gamma and increased IL-4 production), may suggest that similar subclinical chronic cytokine-mediated abnormalities produced in the course of latent diseases revealed in our patients, combined with those caused by DTP vaccination stimulus, were responsible for the pathomechanism of these clinical entities. This speculation is in agreement with the reports on the long-lasting induction of cytokine release and down-regulation of hepatic cytochrome P-450 isoenzyme activities after administration of DTP vaccine to mice and may be supported by the fact that TH1 phenotype is associated with the up-regulation of intercellular adhesion molecule-1 and RANTES, whereas TH2 phenotype is associated with the up-regulation of the vascular cell adhesion molecule and P-selectin, which are key players in the migration into inflamed tissues and localization of lymphocytes and other allergic effector and inflammatory cells. Because several inflammatory cytokines down-regulate gene expression of major cytochrome P-450 and/or other enzymes with the specific effects on mRNA levels, protein expression, and enzyme activity, thus affecting the metabolism of several endogenous lipophilic substances such as steroids, lipid-soluble vitamins, prostaglandins, leukotrienes, thromboxanes, and exogenous substances, their irregularities in the body may eventually lead to the flare of latent diseases in some predisposed subjects. Also, interleukin genetic polymorphisms, especially the constellation of TNF-alpha and IL-6 genetic variants, might predispose some infants with infection to a more than usually intense inflammatory response in the kidneys after vaccination. It seems that the aforementioned pathomechanism may also be responsible for some cases of sudden infant death syndrome, which is often preceded by infection/inflammation.

Coxsackievirus B3 infection and type 1 diabetes development in NOD mice: insulitis determines susceptibility of pancreatic islets to virus infection

Group B coxsackieviruses (CVB) are believed to trigger some cases of human type 1 diabetes (T1D), although the mechanism by which this may occur has not been shown. We demonstrated previously that inoculation of young nonobese diabetic (NOD) mice with any of several different CVB strains reduced T1D incidence. We also observed no evidence of CVB replication within islets of young NOD mice, suggesting no role for CVB in T1D induction in the NOD mouse model. The failure to observe CVB replication within islets of young NOD mice has been proposed to be due to interferon expression by insulin-producing beta cells or lack of expression of the CVB receptor CAR. We found that CAR protein is detectable within islets of young and older NOD mice and that a CVB3 strain, which expresses murine IL-4, can replicate in islets. Mice inoculated with the IL-4 expressing CVB3 chimeric strain were better protected from T1D onset than were mock-infected control mice despite intraislet viral replication. Having demonstrated that CVB can replicate in healthy islets of young NOD mice when the intraislet environment is suitably altered, we asked whether islets in old prediabetic mice were resistant to CVB infection. Unlike young mice in which insulitis is not yet apparent, older NOD mice demonstrate severe insulitis in all islets. Inoculating older prediabetic mice with different pathogenic CVB strains caused accelerated T1D onset relative to control mice, a phenomenon that was preceded by detection of virus within islets. Together, the results suggest a model for resolving conflicting data regarding the role of CVB in human T1D etiology.

Effects of adenoviral-mediated gene transfer of interleukin-10, interleukin-4, and transforming growth factor-beta on the survival of axotomized retinal ganglion cells

Nitric oxide, synthesized by reactive microglia and astrocytes has been implicated in promoting neuronal degeneration observed in many diseases and insults of the central nervous system. We have recently shown that inducible nitric oxide synthase is expressed by retinal glial cells following optic nerve transection and that inhibition of nitric oxide synthesis enhances the survival of injured retinal ganglion cells. Anti-inflammatory cytokines including interleukin-10 (IL-10), interleukin-4 (IL-4), and transforming growth factor-beta (TGF-beta) have been shown to prevent inducible nitric oxide synthase expression, and inhibit nitric oxide synthesis by microglia and astrocytes in culture. In the present study, we examined the effects of adenoviral mediated gene transfer of anti-inflammatory cytokines on the survival of axotomized retinal ganglion cells. Intraocular administration of adenoviral vectors encoding interleukin-10 (Ad.IL-10) and interleukin-4 (Ad.IL-4) enhanced the survival of axotomized retinal ganglion cells at 14 days after axotomy. Adenoviral vectors encoding TGF-beta (Ad.TGF-beta) had no effect on retinal ganglion cell survival. Separate animals were pretreated by injection of Ad.IL-10 or Ad.IL-4 into the superior colliculus (s.c.), the major target of ganglion cells, 7 days prior to axotomy. S.c. administration of Ad.IL-10 or Ad.IL-4 significantly increased ganglion cell survival compared with intraocular injection. IL-10 and IL-4 gene transfer also reduced the density of infiltrating ED1 positive monocytes in the nerve fiber layer at 14 days postaxotomy. Ad.TGF-beta increased the density of ED1 positive monocytes infiltrating the nerve fiber layer after axotomy. Vectors encoding IL-10 or IL-4 also decreased nitrotyrosine immunoreactivity in the inner retina at 7 days postaxotomy, suggesting that these cytokines protect retinal ganglion cells from peroxynitrite formation that results from nitric oxide synthesis by activated glial cells. The present study has implications for the treatment of CNS injury and diseases that involve reactive microglia and astrocytes. Our results suggest that interleukin-10 and interleukin-4 may help prevent neurodegeneration caused by the activation of glial cells after CNS injury.

Treatment with an acetylcholinesterase inhibitor in Alzheimer patients modulates the expression and production of the pro-inflammatory and anti-inflammatory cytokines

Elevated levels of cytokines have been detected in brains of Alzheimer's disease (AD) patients, and altered peripheral levels of IL-1beta, TNFalpha and IL-6 have been reported in these patients. We studied the ability of PBMC from patients with AD, matched with a control group, to release pro- and anti-inflammatory cytokines, and the effect of AChEI treatment on cytokine release. Our data indicates that AChEI treatment down-regulates IL-1, IL-6 and TNF, and up-regulates the expression and production of IL-4 in PBMC in AD patients, and that AChEI leads to the remodelling of the cytokine network, probably acting on the lymphocytic cholinergic system.

Effects of deviating the Th2-response in murine mercury-induced autoimmunity towards a Th1-response

T-helper cells type 1 (Th1) and type 2 (Th2) play an important role in the pathogenesis of autoimmune diseases. In many Th1-dependent autoimmune models, treatment with recombinant interleukin-12 (rIL-12) accelerates the autoimmune response. Mercury-induced autoimmunity (HgIA) in mice is an H-2 regulated condition with antinucleolar antibodies targeting fibrillarin (ANoA), systemic immune-complex (IC) deposits and transient polyclonal B-cell activation (PBA). HgIA has many characteristics of a Th2 type of reaction, including a strong increase of IgE, but disease induction is critically dependent on the Th1 cytokine IFN-gamma. The aim of this study was to investigate if a strong deviation of the immune response in HgIA towards Th1 would aggravate HgIA. Injections of both rIL-12 and anti-IL-4 monoclonal antibody (alpha-IL-4) reduced the HgCl2-(Hg-)induced concentration of the Th2-dependent serum IgE and IgG1, but increased the Th1-dependent serum IgG2a. The IgG-ANoA developed earlier and attained a higher titre after combined treatment, and the ANoA titre of the IgG1 isotype decreased while the ANoA titre of the Th1-associated IgG2a, IgG2b and IgG3-ANoA isotypes increased. Treatment with rIL-12 alone increased the Hg-induced IgG2a and IgG3 ANoA titres, the PBA, and the IC deposits in renal and splenic vessel walls, while treatment with alpha-IL-4 + Hg inhibited renal but not splenic vessel wall IC deposits. We conclude that manipulating the cytokine status, by altering the Th1/Th2 balance, will influence autoimmune disease manifestations. This might be an important way of modulating human autoimmune diseases.

Possible pathomechanism of autoimmune hepatitis

The hepatotropic viruses, measles, and herpesviruses as well as different drugs were repeatedly shown to act presumably as a trigger in patients with autoimmune hepatitis (AI-H). On the other hand, it is known that viral infections stimulate interferon production, which inactivates the cytochrome P-450 enzymes involved in the metabolism of several endogenous substances and exogenous environmental agents. Moreover, it was reported that several cytokines, including interferons, as well as transforming growth factor beta1 and human hepatocyte growth factor, which are abundantly produced and released in the body during infections, also downregulated expression of major cytochrome P-450 and/or other biotransformation enzymes. It seems that all these factors, in addition to individual immune response and the nature and amount of the neoantigen(s) produced, impair the equilibrium of bioactivation and detoxication pathways, thus leading to the development of AI-H in a genetically predisposed person continually exposed to harmful environmental factor(s). Possible increased/decreased density of lysine residues at position D-related human leukocyte antigen locus (DR)beta71 of the antigen-binding groove may affect the eventual steroid-sparing effect of this critical amino acid at the cellular level. In addition, some food additives, such as monosodium glutamate (MSG) and/or aspartame regularly consumed in excessive amounts, may eventually disturb the delicate balance between a positively charged amino acid residue at position DRbeta71 (lysine or arginine) and a negatively charged amino acid residue at position P4 on the antigenic peptide (glutamic acid or aspartic acid). This may favor formation of a salt bridge between these amino acid residues within the hypervariable region 3 on the alpha-helix of the DRbeta polypeptide and facilitate autoantigen presentation and CD4 T-helper cell activation. MSG and aspartate may also depress serum concentrations of growth hormone, which downregulate the activity of several cytochrome P-450 hepatic and other drug-metabolizing enzymes, thus increasing sensitivity to some environmental agents and possibly influencing efficacy of treatment regimens and final outcome of patients with type 1 AI-H.

Autoimmune hepatitis associated with the odour of fish food proteins: a causal relationship or just a mere association?

We present the case of a 15-year-old boy [HLA phenotype: A 1, 25 (10); B 18, 8; C 7; DR 17 (3), 6] with classic (type 1) autoimmune hepatitis presumably caused by a long-term exposure to the strong odour of food fed to a large number of tropical fish which that the boy kept in tanks in his bedroom. The boy presented with a history of recent symptoms of common cold, and a high cytomegalovirus-IgG titer, both known to activate proinflammatory cytokines. The patient's laboratory results and physical findings improved without specific treatment during his first stay in the hospital for several weeks, as well as when the thanks were removed from his bedroom while disease activity increased after his return home. This suggests that the association with fish food odour (putative volatile protein antigens) was not simply coincidental. Our patien's history is in agreement with the recently postulated pathomechanism of autoimmune hepatitis, according to which viral infections may trigger the disease in a genetically predisposed individuals persistently exposed to a constant antigenic stimulus, which results in ongoing allergic inflammation and finally develops into an immune process. The spontaneous remissions observed in our patient were characteristic of the natural course of autoimmune hepatitis and may reflect periods when he was not exposed to the eventually harmful effects of the odour of fish food proteins.

Granulocyte colony-stimulating factor directly affects human monocytes and modulates cytokine secretion

OBJECTIVE

Recent reports have indicated that monocytes express receptors for the granulocyte colony-stimulating factor (G-CSF). The direct effects of G-CSF on cytokine secretion in monocytes were examined.

MATERIALS AND METHODS

A monocytic cell line NOMO-1 that secretes multiple cytokines upon stimulation with lipopolysaccharide (LPS) was used. Normal human monocytes were purified by negative selection using magnetic beads. Cells pretreated with or without G-CSF were stimulated with LPS, and the subsequent concentrations of cytokines and chemokines in supernatants were determined by sandwich enzyme-linked immunosorbent assay.

RESULTS

NOMO-1 cells were found to express receptors for G-CSF. Although G-CSF stimulation did not induce cytokine secretion, pretreatment with G-CSF significantly attenuated LPS-stimulated secretion of the proinflammatory cytokines tumor necrosis factor-alpha and interleukin (IL)-12 in NOMO-1 cells. Simultaneously, however, G-CSF pretreatment apparently enhanced LPS-induced secretion of IL-10 and monocyte chemoattractant protein-1, whereas secretions of IL-1beta, IL-6, and IL-8 were unaffected. When normal human monocytes from healthy volunteers were similarly examined, marked individual variations in LPS-induced secretion of cytokines were observed. Although some exceptions exist, a similar tendency as to the effects of G-CSF treatment on cytokine secretions as that in NOMO-1 cells was observed in human monocytes.

CONCLUSIONS

Our data suggest that G-CSF directly affects monocytes and modulates their cytokine secretion. NOMO-1 cells can provide an alternate model for in vitro culture of monocytes to investigate the effects of G-CSF on cytokine secretion by these cells.

Important role of prodromal viral infections responsible for inhibition of xenobiotic metabolizing enzymes in the pathomechanism of idiopathic Reye's syndrome, Stevens-Johnson syndrome, autoimmune hepatitis, and hepatotoxicity of the therapeutic doses of acetaminophen used in genetically predisposed persons

Upper respiratory tract febrile illnesses caused by various viruses, mycoplasma, chlamydia infections, and/or inflammatory diseases are usually observed a few days to a few (several) weeks before the onset of Reye's syndrome, Stevens-Johnson syndrome, autoimmune hepatitis (hepatotropic virus infections), or hepatotoxicity associated with therapeutic administration of acetaminophen in persons with varying degrees of deficits of important enzymatic activity. Activation of systemic host defense mechanisms by inflammatory component(s) results in depression of various induced and constitutive isoforms of cytochrome P-450 mixed-function oxidase system superfamily enzymes in the liver and most other tissues of the body. Because several cytochrome P-450 enzymes activities important for biotransformation of many endogenous and egzogenous substances show considerable variability between individuals, in some genetically predisposed persons, even the administration of therapeutic doses of a drug may result in serious clinical mishaps, if an important concomitant risk factor (eg, acute viral infection) is involved. Several inflammatory cytokines, such as interleukins, transforming growth factor beta1, human hepatocyte growth factor, and lymphotoxin, downregulate gene expression of major cytochrome P-450 enzymes with the specific effects on mRNA levels, protein expression, and enzyme activity observed with a given cytokine varying for each P-450 studied, thus eventually leading to metabolite-mediated adverse drug reactions and immunometallic diseases which sometimes result in tissue injury beyond the site(s) where metabolic bioactivation takes place. On the other hand, it must be emphasized that inhibition of metabolism of several drugs, as well as influence on the concentration and/or ratio of various cytokines in inflamed tissues, may exert beneficial effects in patients with different diseases, thus opening new therapeutic possibilities. Clinically relevant interactions may be exemplified by the effects of some fluoroquinolone antibiotics, such as pefloxacin and ciprofloxacin, which probably have a steroid-sparing effect in some patients with frequently relapsing nephrotic syndrome, and an increased bioavailability of several drugs following concomitant intake with freshly pressed grapefruit juice, eventually caused by inhibition of their metabolism, mediated mainly by CYP3A and specifically inhibited by naturally occurring flavonoids.

Murine metal-induced systemic autoimmunity: baseline and stimulated cytokine mRNA expression in genetically susceptible and resistant strains

Cytokines play an important and complex role in the pathogenesis of systemic autoimmune diseases. In susceptible H-2s mice, inorganic mercury (Hg) induces lymphoproliferation, antinucleolar antibodies against the 34-kDa-protein fibrillarin, and systemic immune-complex (IC) deposits. Here, we report extensive analysis of cytokine mRNA levels in susceptible A.SW (H-2s) and resistant A.TL (H-2tl) mice under unstimulated conditions and during oral treatment with Hg and/or silver nitrate (Ag). Cytokine mRNA expression in lymphoid tissues was assessed using the ribonuclease protection assay and phosphorimaging. Baseline expression of IL-2 and IFN-gamma mRNA was higher in A.SW than in A.TL mice. In A.SW mice, Hg treatment caused early up-regulation of IL-2 and IFN-gamma levels, followed by substantial expression of IL-4 mRNA, which was significant compared to control A.SW and Hg-treated A.TL mice. Hg-exposed A.TL mice exhibited unchanged IFN-gamma, reduced IL-2 and greatly increased IL-10 mRNA expression. Ag-treated A.SW mice, which develop antifibrillarin antibodies (AFA) but exhibit minimal immune activation and no IC deposits, showed an early increase in IL-2 and IFN-gamma mRNA, but only a small and delayed rise in IL-4 mRNA. In conclusion, H-2-linked resistance to Hg-induced AFA is characterized by low constitutive expression of IL-2 and IFN-gamma mRNA, which is not increased by Hg, and a marked increase in IL-10 expression. Conversely, the key features of H-2-linked susceptibility to Hg- and Ag-induced AFA are up-regulation of IL-2, IFN-gamma and IL-4 mRNA expression, and down-regulation of IL-10 expression.

Cytokine- and microbially induced sleep responses of interleukin-10 deficient mice

Interleukin (IL)-1 and tumor necrosis factor (TNF) promote slow-wave sleep (SWS), whereas IL-10 inhibits the synthesis of IL-1 and TNF and promotes waking. We evaluated the impact of endogenous IL-10 on sleep-wake behavior by studying mice that lack a functional IL-10 gene. Under baseline conditions, C57BL/6-IL-10 knockout (KO) mice spent more time in SWS during the dark phase of the light-dark cycle than did genetically intact C57BL/6 mice. The two strains of mice showed generally comparable responses to treatment with IL-1, IL-10, or influenza virus, but differed in their responses to lipopolysaccharide (LPS). In IL-10 KO mice, LPS induced an initial transient increase and a subsequent prolonged decrease in SWS, as well as profound hypothermia. These responses were not observed in LPS-treated C57BL/6 mice. These data demonstrate that in the absence of endogenous IL-10, spontaneous SWS is increased and the impact of LPS on vigilance states is altered. Collectively, these observations support a role for IL-10 in sleep regulation and provide further evidence for the involvement of cytokines in the regulation of sleep.

Programmed inflammatory processes induced by mucosal immunisation

Inflammation is essential to repair tissue damaged by physical, microbial or allergic mechanisms. Inappropriately zealous responses lead to destructive pathology or chronic disease cycles, whereas ideal outcomes are associated with complete and rapid restoration of tissue structure and function. The establishment of a rodent model investigating the different immune responses to non-typeable Haemophilus influenzae infection in both the lung and the ear indicate an ability to clear bacteria and reduce inflammation following mucosal immunisation. Lung histochemistry, upregulaion of macrophages and polymorphonuclear neutrophils, recruitment of gammadelta(+) and CD8(+) T cells, cytokine levels and depletion studies all support the hypothesis that mucosal immunisation facilitates control of the immune response resulting in enhanced bacterial clearance and programming of inflammation which limits damage and promotes the rapid restoration of structural normality.

Regulatory effects of interleukin-4 and interleukin-10 on human neutrophil function ex vivo and on neutrophil influx in a rat model of arthritis

OBJECTIVE

To assess the capacity of interleukin-4 (IL-4) and IL-10 to block polymorphonuclear neutrophil (PMN) activation in an ex vivo human model system, and to confirm their effect on neutrophil function in an animal model of arthritis.

METHODS

The ex vivo phagocytic capacity of cytokine-activated human PMNs was assessed by use of assays for measuring the ingestion of heat-killed yeast and by subsequent hexose-monophosphate shunt activation using nitroblue tetrazolium reduction. The in vivo activity of IL-4 and IL-10 was measured using a rat adjuvant arthritis model in which the mycobacterial antigen concentration was titrated to modify disease intensity.

RESULTS

IL-4 and IL-10 suppressed the ex vivo activation state of interferon-gamma- and tumor necrosis factor alpha-activated human neutrophils. In the rat adjuvant arthritis model, treatment with systemic murine IL-10 (mIL-10) effectively suppressed all disease parameters in rats that received the lower concentrations of mycobacteria, whereas systemic mIL-4 was effective against even the most severe disease. Both cytokines were effective in lowering the absolute PMN cell number recovered and the PMN activation state in the joint synovia. We also observed lower levels of the messenger RNA transcript for CINC protein (cytokine-induced neutrophil chemoattractant; a rat homolog for human IL-8) in the synovia.

CONCLUSION

IL-10 is an effective antiarthritic agent and has a major effect on the presence and function of PMNs in the joint synovia when disease intensity is not severe. IL-4 has an inhibitory profile that is similar to that of IL-10, but is effective in modifying even the most severe disease. Both cytokines reduced the phagocytic activation of human PMNs in response to proinflammatory cytokines. These data demonstrate that IL-4 and IL-10 can exert powerful regulatory effects on neutrophil function that translate into a therapeutic response in a disease model of arthritis. Treatment with these cytokines alone or in combination may therefore be very useful in the management of patients with rheumatoid arthritis.

Inhibition of the constitutive and induced IFN-beta production by IL-4 and IL-10 in murine peritoneal macrophages

We had previously reported that freshly harvested peritoneal macrophages (PM) are in a type I IFN-mediated antiviral state, which is lost during in vitro culture of PM, concomitantly with a progressive decline in the expression of IFN-beta. We report herein that in vitro culture of PM in the presence of IL-4 or IL-10 results in an enhanced decay of the IFN-beta-mediated antiviral state to vesicular stomatitis virus (VSV). Moreover, IL-4 and IL-10 inhibited the production of type I IFN induced by LPS or NDV infection, as assessed by IFN production and induction of IFN-mediated antiviral state. The accumulation and physiological turnover of IFN-beta mRNA was not affected by IL-4 or IL-10. Finally, neither IL-10 nor IL-4 exerted any inhibitory effect on the antiviral activity induced by exogenous type-I IFN. These results suggest that Th2 cytokines, such as IL-4 and IL-10, act as negative regulators of the type I IFN-mediated antiviral response in PM and may represent stop signals for the constitutive or induced type I IFN expression in PM.

IL-10, but not IL-4, suppresses infection-stimulated bone resorption in vivo

Periapical bone resorption occurs following infection of the dental pulp and is mediated mainly by IL-1alpha in the murine model. The production and activity of IL-1alpha is modulated by a network of regulatory cytokines, including those produced by Th1 (pro-inflammatory) and Th2 (anti-inflammatory) subset T cells. This study was designed to assess the functional role of the Th2-type cytokines IL-4 and IL-10 in infection-stimulated bone resorption in vivo. The dental pulps of the first molars were exposed and infected with a mixture of four common endodontic pathogens, and bone destruction was determined by micro-computed tomography at sacrifice on day 21. The results demonstrate that IL-10(-/-) mice had significantly greater infection-stimulated bone resorption in vivo compared with wild-type mice (p < 0.001), whereas IL-4(-/-) exhibited no increased resorption. IL-10(-/-) had markedly elevated IL-1alpha production within periapical inflammatory tissues (>10-fold) compared with wild type (p < 0.01), whereas IL-4(-/-) exhibited decreased IL-1alpha production (p < 0.05). IL-10 also suppressed IL-1alpha production by macrophages in a dose-dependent fashion in vitro, whereas IL-4 had weak and variable effects. We conclude that IL-10, but not IL-4, is an important endogenous suppressor of infection-stimulated bone resorption in vivo, likely acting via inhibition of IL-1alpha expression.

Induction of interleukin-4 (IL-4) by legionella pneumophila infection in BALB/c mice and regulation of tumor necrosis factor alpha, IL-6, and IL-1beta

Infection of BALB/c mice with a sublethal concentration of Legionella pneumophila causes an acute disease that is resolved by innate immune responses. The infection also initiates the development of adaptive Th1 responses that protect the mice from challenge infections. To study the early responses, cytokines induced during the first 24 h after infection were examined. In the serum, interleukin-12 (IL-12) was detectable by 3 h and peaked at 10 h, while gamma interferon was discernible by 5 h and peaked at 8 h. Similar patterns were observed in ex vivo cultures of splenocytes. A transient IL-4 response was also detected by 3 h postinfection in ex vivo cultures. BALB/c IL-4-deficient mice were more susceptible to L. pneumophila infection than were wild-type mice. The infection induced higher serum levels of acute-phase cytokines (tumor necrosis factor alpha [TNF-alpha], IL-1beta, and IL-6), and reducing TNF-alpha levels with antibodies protected the mice from death. Moreover, the addition of IL-4 to L. pneumophila-infected macrophage cultures suppressed the production of these cytokines. Thus, the lack of IL-4 in the deficient mice resulted in unchecked TNF-alpha production, which appeared to cause the mortality. Monocyte chemoattractant protein-1 (MCP-1), a chemokine that is induced by IL-4 during Listeria monocytogenes infection, was detected at between 2 and 30 h after infection. However, MCP-1 did not appear to be induced by IL-4 or to be required for the TNF-alpha regulation by IL-4. The data suggest that the early increase in IL-4 serves to regulate the mobilization of acute phase cytokines and thus controls the potential harmful effects of these cytokines.

Interleukin-13 and transforming growth factor-beta1 inhibit spontaneous sleep in rabbits

Proinflammatory cytokines, including interleukin-1beta and tumor necrosis factor-alpha are involved in physiological sleep regulation. Interleukin (IL)-13 and transforming growth factor (TGF)-beta1 are anti-inflammatory cytokines that inhibit proinflammatory cytokines by several mechanisms. Therefore, we hypothesized that IL-13 and TGF-beta1 could attenuate sleep in rabbits. Three doses of IL-13 (8, 40, and 200 ng) and TGF-beta1 (40, 100, and 200 ng) were injected intracerebroventricularly 3 h after the beginning of the light period. In addition, one dose of IL-13 (200 ng) and one dose of TGF-beta1 (200 ng) were injected at dark onset. The two higher doses of IL-13 and the highest dose of TGF-beta1 significantly inhibited spontanenous non-rapid eye movement sleep (NREMS) when they were given in the light period. IL-13 also inhibited NREMS after dark onset administration; however, the inhibitory effect was less potent than that observed after light period administration. The 40-ng dose of IL-13 inhibited REMS duration during the dark period. TGF-beta1 administered at dark onset had no effect on sleep. These data provide additional evidence for the hypothesis that a brain cytokine network is involved in regulation of physiological sleep.

Pharmacologic doses of granulocyte colony-stimulating factor affect cytokine production by lymphocytes in vitro and in vivo

Peripheral blood stem cell (PBSC) transplantation is successful in improving engraftment without increasing acute graft-versus-host disease (GVHD), despite much larger numbers of T cells in unmanipulated PBSCs than in bone marrow grafts. In mouse models and retrospective human studies, granulocyte colony-stimulating factor (G-CSF) therapy has been associated with less acute GVHD. We studied the effect of G-CSF on interferon (IFN)-γ and IL-4 expression in CD4+lymphocytes. CD4+ cells co-cultivated with G-CSF and stimulated with PHA or CD3 monoclonal antibodies showed significant decreases in IFN-γ and increases in IL-4 expression (n = 13;P &lt; .01). G-CSF appeared to have a direct effect on CD4+ cells independent of monocytes present in the culture because purified CD4+ cells exposed to G-CSF, washed, and cocultivated with untreated monocytes demonstrated similar changes in IFN-γ and IL-4 expression, whereas untreated CD4+ cells cocultured with G-CSF–stimulated monocytes behaved as controls. We then studied peripheral blood mononuclear cells (PBMCs) from G-CSF–mobilized PBSC donors. When their PBMCs were cultured with PHA or CD3 monoclonal antibody, the percent of IFN-γ–expressing cells decreased by a mean of 55% and 42%, respectively, whereas the percent of IL-4–containing cells increased by a mean of 39% and 58%, respectively, following G-CSF stimulation. Increased apoptosis of IFN-γ–producing CD4+ cells was not responsible for the shift in TH1/TH2 subsets. G-CSF-R mRNA was present in both CD4+ and CD8+ cells. These results suggest that G-CSF decreases IFN-γ and increases IL-4 production in vitro and in vivo and likely modulates a balance between TH1 and TH2 cells, an effect that may be important in PBSC transplantation.

Pharmacologic doses of granulocyte colony-stimulating factor affect cytokine production by lymphocytes in vitro and in vivo

Peripheral blood stem cell (PBSC) transplantation is successful in improving engraftment without increasing acute graft-versus-host disease (GVHD), despite much larger numbers of T cells in unmanipulated PBSCs than in bone marrow grafts. In mouse models and retrospective human studies, granulocyte colony-stimulating factor (G-CSF) therapy has been associated with less acute GVHD. We studied the effect of G-CSF on interferon (IFN)-γ and IL-4 expression in CD4+lymphocytes. CD4+ cells co-cultivated with G-CSF and stimulated with PHA or CD3 monoclonal antibodies showed significant decreases in IFN-γ and increases in IL-4 expression (n = 13;P < .01). G-CSF appeared to have a direct effect on CD4+ cells independent of monocytes present in the culture because purified CD4+ cells exposed to G-CSF, washed, and cocultivated with untreated monocytes demonstrated similar changes in IFN-γ and IL-4 expression, whereas untreated CD4+ cells cocultured with G-CSF–stimulated monocytes behaved as controls. We then studied peripheral blood mononuclear cells (PBMCs) from G-CSF–mobilized PBSC donors. When their PBMCs were cultured with PHA or CD3 monoclonal antibody, the percent of IFN-γ–expressing cells decreased by a mean of 55% and 42%, respectively, whereas the percent of IL-4–containing cells increased by a mean of 39% and 58%, respectively, following G-CSF stimulation. Increased apoptosis of IFN-γ–producing CD4+ cells was not responsible for the shift in TH1/TH2 subsets. G-CSF-R mRNA was present in both CD4+ and CD8+ cells. These results suggest that G-CSF decreases IFN-γ and increases IL-4 production in vitro and in vivo and likely modulates a balance between TH1 and TH2 cells, an effect that may be important in PBSC transplantation.

Orthodontic movement induces high numbers of cells expressing IFN-gamma at mRNA and protein levels

Cytokines are important signaling proteins that are liberated during immune challenges and exhibit many modulatory activities. However, their role in periodontal modeling during orthodontic tooth movement is not fully understood. The aim of this study was to analyze effects of mechanical force during orthodontic tooth movement, in the pressure zone, on the induction of interferon-gamma (IFN-gamma) as a proinflammatory cytokine of Th1 type and interleukin-4 (IL-4)/IL-10 as anti-inflammatory cytokines of Th2 type. In 12 Wistar rats 40-45 days old, the maxillary first molar was moved mesially by means of a closed coil spring for 3, 7, and 10 days. The contralateral side served as a control. IFN-gamma, IL-4, and IL-10 mRNA were determined by in situ, hybridization, and protein levels of IFN-gamma was measured by immunohistochemistry. Induction of IFN-gamma at both mRNA and protein levels was significantly higher on the experimental side than on the contralateral control side on day 3. The signal gradually became stronger on day 7 and remained high on day 10. Cytokines of the Th2 type (IL-4 and IL-10) were not detected at all examined time points in both pressure and contralateral control sides. Considering the potential immunoregulatory roles played by IFN-gamma, our data suggest that IFN-gamma may be involved in periodontium remodeling during orthodontic tooth movement.

Fluticasone propionate-induced regulation of the balance within macrophage subpopulations

In asthma, treatment with inhaled corticosteroids reduces chronic peribronchial inflammation and restores the balance within macrophage subpopulations. This study investigates whether corticosteroids can regulate monocyte differentiation in vitro and thereby influence the balance of functionally distinct macrophages. Graded doses of fluticasone propionate (FP) were added to cultures of normal peripheral blood monocytes in the presence or absence of IL-4. Cells were harvested after 7 days' culture. Double immunofluorescence studies were performed on cytospins of differentiated macrophages using the MoAbs RFD1 and RFD7 to distinguish inductive and suppressive macrophages by their respective phenotypes. Macrophage function was determined by quantifying allostimulation in a mixed leucocyte reaction and by measuring tumour necrosis factor-alpha (TNF-alpha) production. FP reduced the number of mature cells with a D1+ antigen-presenting phenotype and up-regulated the development of cells with the D1/D7+ and D7+ phenotypes. Functionally, this was associated with reduced stimulation of T cell proliferation in a mixed leucocyte reaction (MLR). Fluticasone also reversed the increase in both D1+ expression and TNF-alpha production induced by IL-4. The effect of FP persisted for 24 h after removal of FP from the culture medium. These results suggest that FP treatment of asthmatics may have a direct beneficial effect by normalizing the macrophage subset imbalance that contributes to the chronic peribronchial inflammation present in this condition.

Tumor necrosis factor-beta is associated with thymic apoptosis during acute rejection

BACKGROUND

Intrathymic events undergoing allograft rejection remain undefined. The present study investigated the role of tumor necrosis factor-beta on acute thymic involution in rat hepatic allograft recipients during rejection.

METHODS

Apoptosis and cellular phenotypic changes in the thymus were studied after hepatic transplantation.

RESULTS

Thymocytes in both the medulla and cortex were sparse during acute rejection. Phenotypically, CD4+CD8+ T cells decreased significantly, whereas there were relative increases in CD4-CD8-, CD4+CD8-, and CD4-CD8+ T cells in untreated allograft recipients. Additionally, thymic apoptosis was found by in situ DNA end labeling and electron microscopy. Apoptotic cells were predominantly distributed in the cortex. Biologic lymphotoxin (tumor necrosis factor-beta)/tumor necrosis factor-alpha cytotoxic activity in the serum was significantly increased in untreated hepatic allograft recipients. Tumor necrosis factor-beta mRNA was detected in untreated allograft livers, and intraperitoneal administration of recombinant human tumor necrosis factor-beta induced extensive apoptosis of thymocytes in vivo. In contrast, no significant thymic involution was observed in donor-specific blood transfusion-treated allograft and isograft recipients. Intraperitoneal administration of rabbit anti-human tumor necrosis factor-beta polyclonal antibody or recombinant human interleukin-10 inhibited thymic apoptosis in untreated hepatic allograft recipients.

CONCLUSIONS

Allograft rejection, but not donor-specific transfusion-induced immunologic unresponsiveness, is associated with thymic involution, a process that may be mediated by tumor necrosis factor-beta.

Interleukin-4 inhibits spontaneous sleep in rabbits

Proinflammatory cytokines, including interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha, are involved in sleep regulation. IL-4 is an antiinflammatory cytokine that inhibits proinflammatory cytokine production. The hypothesis that IL-4 should attenuate sleep was studied by determining the effects of IL-4 on rabbit spontaneous sleep. Thirty-six rabbits were used. Four doses of IL-4 (0.25, 2.5, 25, and 250 ng) were injected intracerebroventricularly during the rest (light) period. One dose of IL-4 (25 ng) was injected during the active (dark) cycle. Appropriate time-matched control injections of saline were done in the same rabbits on different days. The three highest doses of IL-4 significantly inhibited spontaneous non-rapid eye movement sleep if IL-4 was given during the light cycle. The highest dose of IL-4 (250 ng) also significantly decreased rapid eye movement sleep. On the other hand, IL-4 administered at dark onset had no effect on sleep. The sleep inhibitory properties of IL-4 provide additional evidence for the hypothesis that a brain cytokine network is involved in the regulation of physiological sleep.

Inflammatory mediators of the terminal dentition in adult and early onset periodontitis

Based upon the prosthodontic literature, subjects who are at the transition stage between natural dentition and edentulism are called "terminal dentition" (TD) cases. The aim of the present cross-sectional investigation was to characterize the local and systemic inflammatory responses in 2 groups of patients with terminal dentition periodontitis. Eight severe adult periodontitis terminal dentition (AP-TD) subjects and 8 early onset periodontitis terminal dentition (EOP-TD) subjects were entered into the study. Our purpose was to measure an extended battery of cytokines in the gingival crevicular fluid (GCF) and in lipopolysaccharide (LPS)-stimulated monocytic culture supernatants as well as gingival mononuclear cell messenger RNA (mRNA) transcripts determined from biopsy samples. Within the GCF there were 3 tiers (levels) of mediators based upon approximate 10-fold differences in concentration. The highest tier included prostaglandin E2 (PGE2), interleukin-1 beta (IL-1 beta) and interleukin-2 (IL-2), the intermediate tier included tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN-gamma) and at the lowest concentration level were interleukin-4 (IL-4) and interleukin-6 (IL-6). Thus, the GCF analysis clearly indicated that in both AP-TD and EOP-TD groups the monocytic, i.e. IL-1 beta and PGE2 and Th1, i.e. IL-2 and IFN-gamma, inflammatory mediator levels quantitatively dominated over the Th2 mediators, i.e. IL-4 and IL-6. LPS-stimulated monocytic release of IL-1 beta, PGE2 and TNF alpha was significantly elevated in both AP-TD and EOP-TD groups compared to those of a control group of 21 subjects with moderate to advanced adult periodontitis. The cytokine mRNA expression of isolated gingival mononuclear cells showed that in both the AP-TD and the EOP-TD groups Th1 and Th2 cytokines were expressed, with low levels of IL-4 and IL-12. In conclusion, our data suggest that this cross-sectional TD periodontitis model may reflect progressive periodontal disease associated with tooth loss. Furthermore, although Th1 cytokine levels in the GCF dominate over the Th2 response, monocytic activation provides the main source of proinflammatory mediators. In addition, LPS-stimulated peripheral blood monocytes demonstrate an upregulated inflammatory mediator secretion in the terminal dentition.

Differential expression of cytokine transcripts in human epithelial ovarian carcinoma by solid tumour specimens, peritoneal exudate cells containing tumour, tumour-infiltrating lymphocyte (TIL)-derived T cell lines and established tumour cell lines

T cell lines derived in low concentrations of recombinant IL-2 (rIL-2) from TIL of patients with epithelial ovarian carcinoma (EOC) often exhibit specific cytotoxicity against autologous tumour cells. However, the ability of T cells at the tumour site to respond to ovarian carcinoma cells may be affected by the production of cytokines by the various cell types present. Using reverse transcriptase-polymerase chain reaction (RT-PCR) we investigated cytokine transcripts in: (i) established EOC tumour cell lines; (ii) solid tumour specimens or peritoneal exudate cells (PEC) from ascites or peritoneal washings of patients with EOC; and (iii) CD4+ TCRalphabeta+ and CD8+ TCRalphabeta+ TIL-derived T cell lines developed in rIL-2. We have found that (i) established EOC tumour cell lines expressed transcripts for transforming growth factor-beta 2 (TGF-beta2) (7/7), but not IL-10 (0/7) or interferon-gamma (IFN-gamma) (0/7) and rarely IL-2 (1/7); (ii) PEC expressed transcripts for IL-2 (12/13), IL-10 (9/13), and TGF-beta2 (12/13), and less often, IFN-gamma (3/13), whereas solid tumour specimens from eight patients with EOC expressed transcripts for IL-2 (4/8), TGF-beta2 (4/8), and IL-10 (5/8), but not for IFN-gamma (0/8); (iii) CD4+ TCRalphabeta+ T cell lines expressed transcripts for IFN-gamma (4/4), IL-2 (4/4) and IL-10 (3/4), whereas CD8+ TCRalphabeta+ T cell lines expressed transcripts for IFN-gamma (5/5), IL-2 (1/5) and IL-10 (2/5). None of these T cell lines expressed TGF-beta2 transcripts. The frequency of IL-2 and TGF-beta2 transcripts in solid tumours was significantly lower than in the PEC (P = 0.0475). CD4+ or CD8+ T cell lines expressing IFN-gamma, IL-2 and IL-10 transcripts were derived in culture with rIL-2 from the TIL of specimens that did not necessarily express these cytokines in the absence of rIL-2. The frequency of cytokine transcripts in T cell lines compared with these same transcripts in the PEC was significantly higher for IFN-gamma (P = 0.0005) and lower for TGF-beta2 (P = 0.0001). An association was observed between the expression of cytokine transcripts in vivo or by TIL-derived cell lines and functions exhibited by either production of cytokines or in vitro cytotoxicity.

A primer on cytokines: sources, receptors, effects, and inducers

Protection against pathogens is a prerequisite for survival of most organisms. To cope with this continuous challenge, complex defense mechanisms have evolved. The construction, adaptation, and maintenance of these mechanisms are under control of an extensive network of regulatory proteins called cytokines. A great number of cytokines have been described over the last 2 decades. This review consists of an overview of cytokines that are involved in immune responses and describes some historical and general aspects as well as prospective clinical applications. Major biological effects together with information on cytokine receptors, producers, inducers, and biochemical and molecular characteristics are listed in tables. In addition, some basic information is given on cytokine receptor signal transduction. Finally, the recent discoveries of cytokine receptors functioning as coreceptors in the pathogenesis of human immunodeficiency virus are summarized.

Interindividual variations in cytokine levels following cardiopulmonary bypass

Cardiopulmonary bypass (CPB) is associated with an inflammatory response, mainly caused by the trauma of surgery, contact of blood with the artificial surface of the circuit, and reperfusion injury, resulting in increased capillary permeability, respiratory distress, low cardiac output, and multiorgan failure. The inflammatory reaction includes an activation of the humoral and cellular immune system with enhanced release of cytokines. The present study focused on the effect of CPB on the time course of pro- and anti-inflammatory cytokines. In 20 patients undergoing coronary artery bypass grafting, the plasma concentration of interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-2, IL-4, IL-6, IL-8, and IL-10 was investigated pre-, intra-, and postoperatively by enzyme-linked immunosorbent assay technique. With the exception of IFN-gamma, all the other cytokines could be detected in the patients plasma. However, neither TNF-alpha nor IL-1 beta and IL-2 revealed significant changes in concentration during the investigated time period. In contrast, IL-6 and IL-8 levels peaked early postoperatively, reaching median concentrations of 430 pg/ml (221 pg per ml/558 pg per ml; lower/upper quartiles, respectively) and approximately 12 pg/ml (0/17 pg/ml; lower/upper quartiles, respectively). IL-4 and IL-10, respectively, revealed maximal concentrations of approximately 2 pg/ml (0/39 pg/ml; lower/upper quartiles, respectively) and 208 pg/ml (76 pg per ml/380 pg per ml; lower/upper quartiles, respectively) immediately after protamine administration, preceding the maximal concentration of IL-6. The degree of the observed modulation of cytokine patterns during and after CPB seemed to be patient-dependent, since large interindividual variations in cytokine levels were observed, not only preoperatively, but especially during and following CPB. However, IL-6 and IL-10 showed the least interindividual variations, suggesting that these cytokines may give reliable information regarding modulation of the immune response following CPB and its consequences for the patient's outcome.

Interleukin-4 blocks the release of collagen fragments from bovine nasal cartilage treated with cytokines

Interleukin-1 (IL-1) in combination with other cytokines can induce a reproducible release of collagen fragments from bovine nasal cartilage in culture. Over 70% of the total collagen is released by day 14 and this release is accompanied by the appearance of collagenolytic activity in the medium that cleaves collagen specifically at the one quarter/three quarter position. Interleukin-4 is able to prevent the release of collagen fragments from the tissue and this is accompanied by a reduced secretion and activation of collagenase (MMP-1) with an increase in tissue inhibitor of metalloproteinases-1 (TIMP-1). IL-4, especially in the presence of IL-1, increased TIMP secretion by bovine nasal cartilage in culture. These results suggest that IL-4 is able to specifically block cartilage collagen resorption by down-regulating the production of collagenase (MMP-1) and up-regulating TIMP-1 by chondrocytes within the cartilage.

Down-regulation of human tumor necrosis factor-beta gene expression by cells with suppressive activity

Human TNF-beta (lymphotoxin) gene expression is down-regulated by immunosuppression. Induction of TNF-beta mRNA in lymphoid cells is greatly enhanced by gamma-irradiation, cyclophosphamide and cimetidine, agents that each inhibit activation of suppressive cells. The level of TNF-beta mRNA expressed in response to stimulation, whether by mitogen or antigen, is reduced strongly by concomitant activation of suppressive cell subsets. Removal of CD8 or CD11b cells leads to a pronounced superinduction of TNF-beta mRNA in the depleted cell population. Induction of TNF-beta mRNA precedes appearance of suppressive cell activity, allowing for temporary expression. The TNF-beta gene is as sensitive as IFN-gamma and IL-2 genes to suppression. Hence, three genes characteristically expressed in Th1 cells, encoding IL-2, IFN-gamma, and TNF-beta, are similarly regulated by cell-mediated suppression. Actual levels of TNF-beta during an immune response are determined by the balance between activities of expressing and suppressing cell subsets, both transiently manifested.