Five genetic markers in the interleukin 1 family in relation to inflammatory bowel disease

Background—An imbalance between theproinflammatory cytokine interleukin 1β (IL-1β) and theanti-inflammatory cytokine IL-1 receptor antagonist (IL-1ra) has beenpostulated as a pathogenic factor in inflammatory bowel disease (IBD).
Aims—To study allelic frequenciesof novel polymorphisms in the genes for IL-1β and IL-1ra in patientswith IBD and to assess the relation between ex vivo cytokine productionand allelic variants of the IL-1β and IL-1ra genes.
Subjects—Two hundred and seventyhealthy controls, 74 patients with ulcerative colitis (UC), 72 withCrohn's disease (CD), 40 with primary sclerosing cholangitis for theallelic frequencies, and 60 healthy individuals for the ex vivostimulation test.
Methods—Genotyping was performed bypolymerase chain reaction and subsequent cleavage with specificendonucleases (Mwo1, MspAI1, Alu1, Taq1, BsoF1) for five novelrestriction fragment length polymorphisms (RFLPs) in the genes forIL-1ra and IL-1β.
Results—No significant differences were found inthe allelic frequencies or allele carriage rates of the markers in theIL-1β and IL-1ra genes between CD, UC, and healthy controls. Noassociation between the genetic markers and cytokine production levelswas observed. Patients with UC carried the combination of both the infrequent allele of the Taq1 RFLP and the Mwo1 RFLP significantly morefrequently (35.2% in UC versus 71.1% in controls).
Conclusions—UC is associatedwith carriage of both infrequent alleles of the Taq1 and Mwo1 RFLPs.However, it could not be confirmed whether the association reflects apathogenic mechanism underlying UC.

     

Multisystemic production of interleukin 10 limits the severity of acute pancreatitis in mice

Background—Interleukin 10 (IL-10)decreases the severity of experimental acute pancreatitis. The role ofendogenous IL-10 in modulating the course of pancreatitis is currently unknown.
Aims—To examine the systemicrelease of IL-10 and its messenger RNA production in the pancreas,liver, and lungs and analyse the effects of IL-10 neutralisation incaerulein induced acute pancreatitis in mice.
Methods—Acute necrotisingpancreatitis was induced by intraperitoneal caerulein. Serum levels ofIL-10 and tumour necrosis factor (TNF), and tissue IL-10 and TNF-αgene expression were assessed. After injecting control antibody orafter blocking the activity of endogenous IL-10 by a specificmonoclonal antibody, the severity of acute pancreatitis was assessed interms of serum enzyme release, histological changes, and systemic andtissue TNF production.
Results—In control conditions,serum IL-10 levels increased and correlated with the course ofpancreatitis, with a maximal value eight hours after induction. BothIL-10 and TNF-α messengers showed a similar course, and wereidentified in the pancreas, liver, and lungs. Neutralisation ofendogenous IL-10 significantly increased the severity of pancreatitisand associated lung injury as well as serum TNF protein levels (+75%)and pancreatic, pulmonary, and hepatic TNF messenger expression (+33%,+29%, +43%, respectively).
Conclusions—In this non-lethalmodel, systemic release of IL-10 correlates with the course of acutepancreatitis. This anti-inflammatory response parallels the release ofTNF and both cytokines are produced multisystemically. Endogenous IL-10controls TNF-α production and plays a protective role in the localand systemic consequences of the disease.

Keywords:pancreatitis; interleukin 10; tumour necrosis factorα; adult respiratory distress syndrome

     

Imbalance of the interleukin 1 system in colonic mucosa—association with intestinal inflammation and interleukin 1 receptor agonist genotype 2

Background—Interleukin 1 (IL-1) α and β arepotent cytokines which play key roles in inflammation. They arecontrolled by IL-1 receptor antagonist (IL-1ra).
Aims—To investigate the influence of mucosalinflammation and IL-1ra genotype on the IL-1ra:IL-1 balance.
Patients and methods—IL-1α, IL-1β, and IL-1rawere measured by enzyme linked immunosorbent assay (ELISA) in biopsyspecimens taken from inflamed and non-inflamed colon of 60 patientswith Crohn's disease (CD), 34 with ulcerative colitis (UC), 15 inflammatory controls, and 103 non-inflamed controls. IL-1ra genotypewas determined by polymerase chain reaction and gel electrophoresis.
Results—IL-1α and IL-1β were significantlyincreased in inflamed mucosa in inflammatory bowel disease (IBD) (CD:53.5 (22.4) and 409.9 (118.7) pg/mg protein, respectively; UC: 18.9 (6.8) and 214.5 (78.2) pg/mg, respectively) and non-IBD patients (19.2(7.4) and 281.4 (121.0) pg/mg, respectively; p<0.0001) compared withnormal controls (2.8 (0.6) and 30.6 (5.6) pg/mg, respectively). In CDIL-1α and β were also significantly increased in non-inflamed mucosa (6.1 (1.3) pg/mg and 88.7 (17.4) pg/mg, respectively;p<0.0012). IL-1ra:(IL-1α+β) ratios were significantly decreased ininflamed mucosa of patients with CD (182 (45); p<0.0001), UC (425 (136); p=0.0018) and without IBD (221 (76); p<0.0001), and innon-inflamed mucosa in CD (369 (149); p<0.0001) compared with normalcontrols (1307 (245); p<0.0001). Patients with IL-1ra genotype 2 hadslightly but significantly reduced mucosal IL-1ra concentrations(p=0.003). The greatest difference was seen in colonic biopsy specimensfrom patients with inflamed Crohn's disease.
Conclusion—Mucosal inflammation can modulate thebalance of the IL-1:IL-1ra system in colonic mucosa.

Keywords:interleukin 1; interleukin 1 receptor antagonist; inflammatory bowel disease; Crohn's disease; mucosal inflammation; genotype

     

Glandular and extraglandular expression of costimulatory molecules in patients with Sjögren's syndrome

OBJECTIVES—To investigate the expression and regulation of CD80, CD86, and CD28 costimulatory molecules in sialoadenitis and interstitial nephritis in patients with Sjögren''s syndrome (SS).
METHODS—Expression of CD80, CD86, and CD28 molecules was studied by immunohistochemical staining of lip biopsy specimens obtained from patients who had sialoadenitis associated with SS, and renal biopsy specimens obtained from patients who had interstitial nephritis associated with SS. To elucidate the mechanism of de novo expression of CD80 and CD86 antigens, their induction by cytokines in human salivary duct cell line (HSG) and renal cortical epithelial cells (HRCE) by cell enzyme linked immunosorbent assay (ELISA) was quantitatively investigated.
RESULTS—In patients with severe sialoadenitis, CD80 and CD86 were strongly expressed on ductal epithelial cells. In contrast, these antigens were not found in the minor salivary glands of normal subjects or of patients with mild sialoadenitis. Some infiltrating cells expressed CD28. In patients who had interstitial nephritis associated with SS, some tubular epithelial cells expressed CD86 but not the CD80 antigen. Unstimulated HSG cells did not express CD80 or CD86. Interferon γ (IFNγ) consistently up regulated levels of CD80 and CD86. In contrast, tumour necrosis factor α (TNFα), interleukin 1β (IL1β), IL2, and IL4 had no effect on either CD80 or CD86 levels. Unstimulated HRCE did not express CD80 or CD86. IFNγ consistently up regulated CD86 expression. No CD80 expression was found on tubular cells. TNFα, IL1β, IL2, and IL4 had no discernible effects.
CONCLUSIONS—Salivary ductal cells in patients with SS can express CD80 and CD86 costimulatory molecules in response to IFNγ. Tubular epithelial cells in patients who have interstitial nephritis associated with SS express only CD86 molecules. In patients with SS, salivary ductal cells and tubular epithelial cells may activate infiltrating CD28 positive T lymphocytes by presenting antigens to T cells, potentially leading to tissue destruction.

     

Spontaneous secretion of interferon γ and interleukin 4 by human intraepithelial and lamina propria gut lymphocytes

Background—Cytokines secreted by intestinal Tlymphocytes probably play a critical role in regulation of the gutassociated immune responses.
Aims—To quantify interferon γ (IFN-γ) andinterleukin 4 (IL-4) secreting cells (SC) among human intraepithelial(IEL) and lamina propria (LPL) lymphocytes from the duodenum and rightcolon in non-pathological situations and in the absence of in vitro stimulation.
Patients—Duodenal and right colonic biopsyspecimens were obtained from patients with no inflammation of theintestinal mucosa.
Methods—Intraepithelial and lamina propria cellsuspensions were assayed for numbers of cells spontaneously secretingIFN-γ and IL-4 by a two site reverse enzyme linked immunospottechnique (ELISPOT).
Results—The relatively high proportion ofduodenal lymphocytes spontaneously secreting IFN-γ (IEL 3.6%; LPL1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very lownumbers of spontaneously IFN-γ SC and the absence of spontaneouslyIL-4 SC among peripheral blood mononuclear cells. In the basal state,both IFN-γ and IL-4 were mainly produced by CD4⁺ cells.Within the colon, only 0.2% of IEL and LPL secreted IFN-γ in thebasal state, and 0.1% secreted IL-4.
Conclusions—Compared with peripheral lymphocytessubstantial proportions of intestinal epithelial and lamina proprialymphocytes spontaneously secrete IFN-γ and/or IL-4. These cytokinesare probably involved in the normal homoeostasis of the humanintestinal mucosa. Disturbances in their secretion could play a role inthe pathogenesis of gastrointestinal diseases.

     

Decreased expression of the interleukin 2 receptor on CD8 recipient lymphocytes in intestinal grafts rendered tolerant by liver transplantation in rats

Background—In a previous study, it was shown thata spontaneously tolerated DA (RT1a) liver allograft in a PVG (RT1c)recipient was able to induce tolerance of a DA small bowel graftperformed 17 days later in spite of infiltration of the intestinalgrafts by mononuclear cells.
Aims—To compare the phenotype of graftinfiltrating cells in rejecting and tolerated small bowel grafts inorder to elucidate the mechanism(s) which block the graft infiltratingcells from mediating rejection.
Methods—Multiparameter immunofluorescence wasused to compare the phenotype and state of activation of donor andrecipient cells isolated from intestinal grafts rejected or toleratedafter liver transplantation.
Results—Three differences were found. Firstly,there was a more rapid replacement of lamina propria (LP) cells byrecipient lymphocytes in tolerated than in rejected grafts. Secondly,the proportion of LP recipient CD8αβ+ lymphocytes bearing the high affinity receptor for interleukin 2 was significantly less in toleratedgrafts (1.1%, range 0-2%) than in rejected grafts (21.3%, range9-26%). Finally, tolerated grafts contained significantly less NKlymphocytes (NKR-P1+) and macrophages than rejected intestinal allografts.
Conclusions—These observations make it possibleto delineate clear cut differences in the phenotype of cellsinfiltrating rejecting versus tolerated grafts. Furthermore, the datasuggest that liver transplantation induces tolerance of intestinalgrafts by hampering the activation of recipient TcRαβ+ CD8αβ+ Tcells and subsequently the recruitment of non-specific effector cells.

Keywords:liver transplantation; small bowel transplantation; tolerance; intestinal T lymphocytes; interleukin 2 receptor; rat

     

Tumour necrosis factor-α enhances intraepithelial lymphocyte proliferation and migration

Background—Tumour necrosis factor α (TNF-α)is a proinflammatory cytokine found in abundance in diseased intestine.
Aims—The T cell production of TNF-α and theimpact of this cytokine on intestinal T cell proliferation, migration,and cytotoxicity were studied.
Methods—Intestinal lymphocytes from normaljejunum were used. TNF-α production in culture supernates wasmeasured by enzyme linked immunosorbent assay (ELISA). Lymphocyteproliferation was measured using ³H thymidine uptake;migration, using transwell chambers; and cytotoxicity of HT-29 coloncancer cells, using the chromium-51 release assay.
Results—TNF-α was produced mainly by the CD8+ Tcells in the intraepithelial lymphocytes (IEL) and the CD4+ T cells inthe lamina propria lymphocytes in response to CD2 stimulation: 478(94)and 782 (136) pg/ml, respectively. TNF-α (1 ng/ml or greater) augmented proliferation of IEL in response to interleukin 2 (IL-2), IL-7, or antibody to CD3 due to increased activation that did notinvolve IL-2 production or receptor generation. Conversely, antibody toTNF-α reduced IEL proliferation in response to IL-2 or IL-7. TNF-αalso induced calcium mobilisation and chemokinesis (by 2.8 (0.5) foldover spontaneous migration). TNF-α had no effect on lymphokineactivated killer cell activity.
Conclusions—TNF-α increases the proliferationand migration of IEL, which may expand their number in the epithelium.

     

Induction of various cytokines and development of severe mucosal inflammation by cagA gene positive Helicobacter pylori strains

Background—Helicobacter pyloristrains possessing the cagA gene are thought to induceinterleukin 8 (IL-8) in gastric mucosa. However, it is still unclearwhether a relation exists between the cagA gene and theexpression patterns of cytokines other than IL-8.
Aims—To investigate therelation between the cagA gene and the productionof various cytokine proteins using an enzyme linked immunosorbentassay (ELISA).
Patients and methods—In 184 patients,the cagA gene was detected by polymerase chain reaction(PCR), and levels of production of IL-1β, IL-6, IL-7, IL-8, IL-10,and tumour necrosis factor α (TNF-α) in antral biopsy specimenswere measured by ELISA.
Results—Mucosal levels of IL-1β, IL-6,IL-8, and TNF-α were significantly higher in H pyloripositive than in H pylori negative patients.Furthermore, the mucosal levels of IL-1β and IL-8 were significantly higher in specimens infected with cagApositive strains than in those infected with cagAnegative strains. In H pylori positivepatients, the mucosal level of IL-8 was closely correlated withthat of IL-1β (p<0.0001), and the mucosal level of IL-6was closely correlated with that of TNF-α (p<0.0001).
Conclusion—These findings suggest that theability to induce cytokines differs among the strains;cagA⁺ strains induce various kinds ofcytokines and may cause severe inflammation, whereascagA strains induce IL-8 and IL-1β onlyweakly and may cause only mild inflammation. However, as most patientsinfected with the cagA⁺ strains havegastritis, these strains may not be equivalent to ulcerogenic strains.

Keywords:cytokines; Helicobacter pylori; cagA gene; interleukin 8; interleukin 1β

     

Prophylactic effect of dietary glutamine supplementation on interleukin 8 and tumour necrosis factor α production in trinitrobenzene sulphonic acid induced colitis

Background—It is well established that glutaminesupplemented elemental diets result in less severe intestinal damage inexperimental colitis. However, few studies have examined the mode ofaction of glutamine in reducing intestinal damage.
Aims—To examine the effects of glutaminesupplemented elemental diets on the potent inflammatory cytokinesinterleukin 8 (IL-8) and tumour necrosis factor α (TNF-α) intrinitrobenzene sulphonic acid (TNBS) induced colitis which presentswith both acute and chronic features of ulcerative colitis.
Methods—Sprague-Dawley rats were randomised intothree dietary groups and fed 20% casein (controls), or 20% caseinsupplemented with either 2% glutamine (2% Gln) or 4% glutamine (4%Gln). After two weeks they received intracolonic TNBS to inducecolitis.
Results—Both Gln groups of rats gained more weight thanthe control group (p<0.05) which had progressive weight loss. Colon weight, macroscopic, and microscopic damage scores for the Gln groupswere lower than in the control group (p<0.05). IL-8 and TNF-αconcentrations in inflamed colonic tissues were lower in the Gln groupsthan in the control group (p<0.05), and correlated well with diseaseseverity. Bacterial translocation was lower both in incidence (p<0.05)and in the number of colony forming units (p<0.05) for the Gln groups,than in the control group. With respect to all indices studied, the 4%Gln group performed better than did the 2% Gln group.
Conclusion—Prophylactic glutamine supplementationmodulates the inflammatory activities of IL-8 and TNF-α in TNBSinduced colitis.

Keywords:glutamine; trinitrobenzene sulphonic acid; inflammatory bowel disease; rats; interleukin 8; tumour necrosis factorα

     

Increased secretion of pro-inflammatory cytokines by circulating polymorphonuclear neutrophils and regulation by interleukin 10 during intestinal inflammation

Background—Concentrations of pro-inflammatorycytokines are increased in the intestinal mucosa of patients withactive inflammatory bowel disease (IBD). Polymorphonuclear neutrophilgranulocytes (PMN) are the most abundant cell type in intestinallesions in IBD. Interleukin 10 (IL-10) is an importantcontra-inflammatory cytokine which induces downregulation ofpro-inflammatory cytokines.
Aims—To investigate whether PMN from patients withIBD or infectious colitis, respectively, secrete increased amounts ofpro-inflammatory cytokines and can be regulated by IL-10.
Methods—Secretion (ELISA) as well as correspondingmRNA levels (semiquantitative RT-PCR) of pro-inflammatory cytokines(IL-1β, TNF-α) and of IL-1 receptor antagonist were assessed inperipheral PMN.
Results—PMN from patients with IBD are primed tosecrete enhanced amounts of pro-inflammatory cytokines accompanied bydetection of corresponding mRNAs in comparison with normal controls.This finding is not specific for IBD but rather reflects intestinal inflammation in general. IL-10 markedly inhibited pro-inflammatory cytokine secretion as well as corresponding mRNA concentrations.
Conclusions—PMN are an important source ofpro-inflammatory cytokines in patients with intestinal inflammation andcan be downregulated by IL-10.

Keywords:granulocytes; interleukin 1β; interleukin 10; inflammatory bowel disease; intestinal immunity; inflammation; neutrophils; tumour necrosis factor α

     

Cytokine production in whole blood cell cultures of patients with rheumatoid arthritis

OBJECTIVE—The measurement of cytokine production of activated lymphocytes and monocytes in the whole blood cell (WBC) culture system may provide a sensitive tool for evaluating the actual ongoing immune response of patients with rheumatoid arthritis (RA).
METHODS—Lipopolysaccharide (LPS) up to 250 pg/ml was used for the stimulation of monocytes for measuring the production of tumour necrosis factor α (TNFα), interleukin 6 (IL6) and IL12, while the anti-CD3 (1 µg/ml) and anti-CD28 (5 µg/ml) combination was used for T cell stimulation with the measuring of IL4 and interferon gamma (INFγ) production. Twenty seven patients with RA and 23 healthy controls were studied.
RESULTS—The results showed a decreased IL6 (LPS stimulus 4-6 pg/ml) and IL12 (LPS stimulus 16-62 pg/ml) production in the RA patients. The maximal production of both cytokines was comparable with the normal controls. T cell stimulation showed a significant decreased INFγ production in the RA patients.
CONCLUSIONS—These findings obtained in the WBC culture system are highly suggestive for a decreased TH-1 derived cytokine production by a diminished IL12 production in RA patients. Another possibility is that both IL12 and INFγ production in WBCs are inhibited by eventual circulating serum factors.

     

Expression of inducible nitric oxide synthase activity in human colon epithelial cells: modulation by T lymphocyte derived cytokines

Background—Nitricoxide (NO) synthesis and inducible nitric oxide synthase (iNOS)expression are increased in colonic biopsy specimens from patients withulcerative colitis, but the cellular source of NO production is not known.
Aims—To examine thedistribution of iNOS in human colonic mucosa and to explore the abilityof T lymphocyte derived cytokines to regulate iNOS expression andactivity in human colonic epithelial cells.
Methods—iNOSexpression was examined using immunohistochemistry in colonic biopsysamples from 12 patients with ulcerative colitis and three withinfectious colitis and compared with 10normal controls. In vitro iNOSexpression and activity were determined in HT-29 cell cultures; nitritelevels were measured using a fluorescent substrate, iNOS mRNAexpression by northern blot analysis, and iNOS protein expression bywestern blot analysis.
Results—No iNOSexpression was detected (10 of 10) in non-inflamed mucosa derived fromnormal controls. In 11 of 12 cases of newly diagnosed ulcerativecolitis, iNOS protein was expressed in the epithelial cells, while noother positive cells were found in the lamina propria. Similar iNOSlabelling was found in colonic biopsy samples from patients withinfectious colitis in the acute phase, but when re-examined in samplesfrom patients in total remission, no iNOS staining was observed. Bothinterleukin (IL)-13 and IL-4, but not IL-10, are potent inhibitors ofiNOS expression and activity induced by an optimal combination ofcytokines, namely IL-1α, tumour necrosis factor α and interferonγ.
Conclusions—The datasuggest that the epithelium is the major source of iNOS activity inulcerative colitis and that IL-13 and IL-4 may act as intrinsicregulators of NO generation in intestinal inflammation.

Keywords:interleukin 13; nitric oxide; inducible nitric oxidesynthase; colonic epithelial cells; ulcerative colitis

     

TCRβ spectratyping in RA: evidence of clonal expansions in peripheral blood lymphocytes

OBJECTIVE—To compare the TCRβ repertoire of peripheral blood CD8 enriched (CD8+) and depleted (CD8−) T cells in rheumatoid arthritis (RA) patients and controls using CDR3 length analysis (spectratyping).
METHODS—CD8+ and CD8− T cells were separated from 14 RA patients and 12 controls, using magnetic beads coated with anti-CD8 monoclonal antibodies. cDNA was prepared as the template for amplification with 22 Vβ-Cβ primer pairs. The products were resolved by electrophoresis in an ABI373 sequencer using GENESCAN software. Expansions were identified as dominant CDR3 lengths, where the area underlying the corresponding peak exceeded the sum of the areas of the two adjacent peaks. This method was validated by sequencing 10 samples displaying dominant peaks. The expansion frequencies in RA patients and controls were compared using the χ² test statistic.
RESULTS—Dominant peaks were evident in several Vβ families. They were more frequent in RA patients in both the CD8+ subset (RA normalised frequency 10.6; control normalised frequency 8.0; p=0.03) and the CD8− subset (RA normalised frequency 2.9; control normalised frequency 1.5; p=0.02). Sequencing of 10 samples exhibiting dominant peaks revealed an unequivocal clonal expansion in nine (90%).
CONCLUSIONS—RA patients exhibited a significantly increased frequency of T cell expansions both in the CD8+ and CD8− subsets. This phenomenon may reflect the proliferation of autoreactive cells, a non-specific expansion of memory T cells in response to pro-inflammatory cytokines or a defect of T cell regulation that predates the onset of RA and may itself predipose to disease.

Keywords: rheumatoid arthritis; T cell; clonal expansion     

Correlations between skin lesions induced by anti-tumor necrosis factor-α and selected cytokines in Crohn’s disease patients

AIM:To investigate the correlation between the appearance of skin lesions and concentration of interleukin(IL)-17A,IL-23 and interferon-γ(IFN-γ)in Crohn’s disease(CD)patients during anti-tumor necrosis factor-α(TNF-α)therapy METHODS:A prospective study included 30 adult patients with CD of Caucasian origin(19 men and 11women;mean age±SD 32.0±8.6 years)during biological therapy with anti-TNF-αantibodies from January2012 to March 2013.Eighteen patients were treated with infliximab,seven with adalimumab and five withcertolizumab.Inclusion criteria were exacerbation of the underlying disease,Crohn’s Disease Activity Index over 300 and the ineffectiveness of previously used non-biological therapies.Patients with a history of psoriasis,atopic dermatitis and other autoimmune skin lesions were excluded from the study.The control group consisted of 12 healthy subjects.A diagnostic survey was carried out,blood tests and careful skin examination were performed,and the serum levels of IL-17,IL-23 and IFN-γwere measured using an enzyme-linked immunosorbent assays technique.Dermatoses that have developed in the course of biological therapy in patients who had no pre-existing skin lesions of similar character were qualified as skin lesions induced by antiTNF-αtherapy.RESULTS:Skin manifestations occurred in 18 of CD patients during the anti-TNF-αtherapy(60%),in the average time of 10.16±3.42 mo following the beginning of the 52-wk treatment cycle.Skin lesions observed in CD patients during biological therapy included psoriasiform lesions(44.4%),and eczema forms lesions(22.2%).In CD patients with drug induced skin lesions significantly higher levels of hemoglobin(13.3±1.5 g/dL vs 10.8±1.9 g/dL,P=0.018)and hematocrit(39.9%±4.5%vs 34.3%±5.4%,P=0.01),as well as a significantly lower level of platelets(268±62×103/μL vs 408±239×103/μL,P=0.046)was observed compared with CD patients without skin manifestations.The concentrations of IL-17A and IL-23in CD patients with skin lesions developed under antiTNF-αtherapy were significantly higher compared to those in patients without lesions(IL-17A:39.01±7.03pg/mL vs 25.71±4.90 pg/mL,P=0.00004;IL-23:408.78±94.13 pg/mL vs 312.15±76.24 pg/mL,P=0.00556).CONCLUSION:Skin lesions in CD patients during bio-logical therapy may result from significantly increased concentrations of IL-17A and IL-23,which are strongly associated with TNF-α/Th1 immune pathways.     

Hyaluronan production in human rheumatoid fibroblastic synovial lining cells is increased by interleukin 1β but inhibited by transforming growth factor β1

OBJECTIVES—To investigate the regulatory roles of interleukin 1β (IL1β), tumour necrosis factor α (TNFα), interferon γ (IFNγ) or transforming growth factor β1 (TGFβ1) on hyaluronan (HA) synthesis by human fibroblastic synovial lining cells.
METHODS—Concentrations of HA in culture supernatants of fibroblastic synovial lining cell line (RAMAK-1 cell line) with or without stimulation by IL1β, TNFα, IFNγ or TGFβ1 were measured by sandwich binding protein assay. Levels of HA synthase mRNA of the cells with or without stimulation were detected by reverse transcribed polymerase chain reaction. Molecular weights of HA in the culture supernatants of the cells with or without stimulation were measured using high performance gel permeation liquid chromatography.
RESULTS—HA synthesis by the cells was not significantly augmented by TNFα or by IFNγ. It was significantly stimulated by IL1β but inhibited by TGFβ1. Molecular weights of HA in the culture supernatants of the cells were unchanged by stimulation with TNFα. They were remarkably increased by stimulation with IL1β and IFNγ, but reduced with TGFβ1.
CONCLUSION—IL1β is an up regulator of HA synthesis, while TGFβ1 is a down regulator. HA production in the synovial lining cells of inflamed joints (for example, rheumatoid arthritis) might be regulated by the balance of these cytokines.

Keywords: synovial lining cells; hyaluronan, interleukin 1β; transforming growth factor β1