Structural characterisation of the distal 5' flanking region of the human interleukin-10 gene

Breast cancer associated CD169+ macrophages possess broad immunosuppressive functions but enhance antibody secretion by activated B cells

CD169⁺ resident macrophages in lymph nodes of breast cancer patients are for unknown reasons associated with a beneficial prognosis. This contrasts CD169⁺ macrophages present in primary breast tumors (CD169⁺ TAMs), that correlate with a worse prognosis. We recently showed that these CD169⁺ TAMs were associated with tertiary lymphoid structures (TLSs) and T_regs in breast cancer. Here, we show that CD169⁺ TAMs can be monocyte-derived and express a unique mediator profile characterized by type I IFNs, CXCL10, PGE₂ and inhibitory co-receptor expression pattern. The CD169⁺ monocyte-derived macrophages (CD169⁺ Mo-M) possessed an immunosuppressive function in vitro inhibiting NK, T and B cell proliferation, but enhanced antibody and IL6 secretion in activated B cells. Our findings indicate that CD169⁺ Mo-M in the primary breast tumor microenvironment are linked to both immunosuppression and TLS functions, with implications for future targeted Mo-M therapy.

Interleukin-10 polymorphisms and susceptibility to ARV associated hepatotoxicity

Interleukin-10 (IL-10) is an anti-inflammatory cytokine associated with the inhibition of HIV replication. IL-10 polymorphisms were found to be linked to drug-induced hepatotoxicity. Hence we examined the prevalence of IL-10 (-819C/T,-1082A/G) polymorphisms in a total of 165 HIV patients which included 34 patients with hepatotoxicity, 131 without hepatotoxicity and 155 healthy controls by the PCR-RFLP method. In HIV patients with hepatotoxicity, the IL-10-819TT genotype increased the risk of ARV associated hepatotoxicity severity (OR = 1.61, P = 0.35). IL-10-819TT genotype was overrepresented in patients with hepatotoxicity as compared to healthy controls (26.5% vs. 13.5%, OR = 1.61, P = 0.46). IL-10 -819CT genotype was associated with advance HIV disease stage (OR = 0.49, P = 0.045). In HIV patients without hepatotoxicity, the IL-10-819TT genotype was more prevalent in patients consuming tobacco as compared to non-users (OR = 1.60, P = 0.41). In HIV patients without hepatotoxicity using both alcohol + efavirenz along with IL-10 -819CT genotype resulted in increased risk for the acquisition of ARV associated hepatotoxicity (OR = 4.00, P = 0.36). In multivariate logistic regression, taking nevirapine was associated with the risk hepatotoxicity severity (OR = 0.23, P = 0.005). In conclusion, an insignificant association between IL-10 polymorphisms and susceptibility to ARV associated hepatotoxicity.

Interleukin 10 (IL10) proximal promoter polymorphisms beyond clinical response in classical Hodgkin lymphoma: Exploring the basis for the genetic control of the tumor microenvironment

Interleukin-10 (IL10) is an immune regulatory cytokine. Single nucleotide polymorphisms (SNPs) in IL10 promoter have been associated with prognosis in adult classical Hodgkin lymphoma (cHL). We analyzed IL10 SNPs -1082 and -592 in respect of therapy response, gene expression and tumor microenvironment (TME) composition in 98 pediatric patients with cHL. As confirmatory results, we found that -1082AA/AG; -592CC genotypes and ATA haplotype were associated with unfavourable prognosis: Progression-free survival (PFS) was shorter in -1082AA+AG (72.2%) than in GG patients (100%) (P = 0.024), and in -592AA (50%) and AC (74.2%) vs. CC patients (87.0%) (P = 0.009). In multivariate analysis, the -592CC genotype and the ATA haplotype retained prognostic impact (HR: 0.41, 95% CI 0.2-0.86; P = 0.018, and HR: 3.06 95% CI 1.03-9.12; P = 0.044, respectively). Our analysis further led to some new observations, namely: (1) Low IL10 mRNA expression was associated with -1082GG genotype (P = 0.014); (2) IL10 promoter polymorphisms influence TME composition;-1082GG/-592CC carriers showed low numbers of infiltrating cells expressing MAF transcription factor (20 vs. 78 and 49 vs. 108 cells/mm², respectively; P< 0.05); while ATA haplotype (high expression) associated with high numbers of MAF+ cells (P = 0.005). Specifically, -1082GG patients exhibited low percentages of CD68+MAF+ (M2-like) intratumoral macrophages (15.04% vs. 47.26%, P = 0.017). Considering ours as an independent validation cohort, our results give support to the clinical importance of IL10 polymorphisms in the full spectrum of cHL, and advance the concept of genetic control of microenvironment composition as a basis for susceptibility and therapeutic response.

Interleukin 10 gene single nucleotide polymorphisms in Polish patients with chronic hepatitis C: Analysis of association with severity of disease and treatment outcome

It is suggested that interleukin 10 (IL-10), as a modulator of immune response, is likely to influence the elimination of hepatitis C virus (HCV), the progression of chronic hepatitis C (CHC) and the response to interferon-based therapy in CHC patients. The aim of the study was to analyze the association of single nucleotide polymorphisms (SNPs) of IL-10 gene with severity of liver disease (degree of inflammation and stage of fibrosis) and outcome of pegylated interferon alpha and ribavirin combined therapy (sustained virological response (SVR) and relapse) in 196 Polish CHC patients infected with HCV genotype 1. The analysis included IL-10 promoter SNPs: -1082(A/G) rs1800896, -819(C/T) rs1800871, -592(C/A) rs1800872 and SNP in the 3' UTR of IL-10 gene: +4529(A/G) rs3024498. Genotyping was performed using PCR-RFLP and HRM analysis. It was demonstrated that the -592C allele is associated with mild hepatic inflammation. Moreover, it was found that the -819C allele might be associated with SVR and that the ACCA haplotype and intermediate IL-10 producer ACC haplotype are associated with SVR and non-relapse. It can be concluded that IL-10 SNPs are associated with severity of disease and response to therapy and may be considered as potential prognostic and predictive markers in CHC.

Family-based association study of interleukin 10 (IL10) and interleukin 10 receptor alpha (IL10RA) functional polymorphisms in schizophrenia in Polish population

Schizophrenia is a heterogeneous disorder and its etiology remains incompletely elucidated. Among possible causes, immunological factors have been implicated in its pathogenesis and course. Interleukin-10 (IL10) and it's receptor IL10RA may play an important role for immunological aspects in etiologies of major psychiatric disorders including schizophrenia. The aim of this study was to perform a transmission disequilibrium test (TDT) on a group of 146 schizophrenia trios from the Polish population. Functional polymorphisms from IL10 (rs1800872, rs1800871, rs1800896, rs1800890, and rs6676671) and IL10RA (rs3135932 and rs2229113) genes were analyzed. A lack of association with schizophrenia was detected for IL10 and IL10RA single polymorphisms and haplotypes.

Phorbol ester-mediated re-expression of endogenous LAT adapter in J.CaM2 cells: a model for dissecting drivers and blockers of LAT transcription

Linker for activation of T cells (LAT) is a raft-associated, transmembrane adapter protein critical for T-cell development and function. LAT expression is transiently upregulated upon T-cell receptor (TCR) engagement, but molecular mechanisms conveying TCR signaling to enhanced LAT transcription are not fully understood. Here we found that a Jurkat subline J.CaM2, initially characterized as LAT deficient, conditionally re-expressed LAT upon the treatment with a protein kinase C activator, phorbol 12-myristate 13-acetate (PMA). We took advantage of the above observation for studying cis-elements and trans-acting factors contributing to the activation-induced expression of LAT. We identified a LAT gene region spanning nucleotide position −14 to +357 relative to the ATG start codon as containing novel cis-regulatory elements that were able to promote PMA-induced reporter transcription in the absence of the core LAT promoter. Interestingly, a point mutation in LAT intron 1, identified in J.CaM2 cells, downmodulated LAT promoter activity by 50%. Mithramycin A, a selective Sp1 DNA-binding inhibitor, abolished LAT expression upon PMA treatment as did calcium ionophore ionomycin (Iono) and valproic acid (VPA), widely used as an anti-epileptic drug. Our data introduce J.CaM2 cells as a model for dissecting drivers and blockers of activation induced expression of LAT.

Association Between IL-10 Gene Promoter Polymorphisms (-592 A/C, -819 T/C, -1082 A/G) and Susceptibility to HBV Infection in an Iranian Population

BACKGROUND

IL-10 can play a vital role in immune response against HBV. Three biallelic SNPs from the transcription start site control the transcription of the IL-10 gene. An association between susceptibility to HBV and IL-10 polymorphisms has been suggested in patients with HBV infection.

OBJECTIVES

The present study was designed to study the association between polymorphisms in interleukin-10 (-1082 A/G, -819 T/C and -592 A/C) promoter gene and chronic hepatitis B virus (HBV) infection.

PATIENTS AND METHODS

221 chronically infected patients and 200 healthy control subjects were enrolled in the study. Three biallelic (-1082 A/G, -819 T/C and -592 A/C) polymorphisms in the IL-10 promoter gene were determined by PCR-RFLP method.

RESULTS

Persistent HBV infection was associated with IL-10-1082 AG (P = 0.001) and GG (P = 0.004) genotypes and G (P = 0.000) allele. IL-10-819 T/C and -592 A/C genotype and allele frequencies did not show any correlation with the risk of chronic hepatitis B infection.

CONCLUSIONS

These results suggest that polymorphisms in interleukin-10 gene promoter influence clinical outcome of HBV infection and susceptibility to HBV infection.

Association study of functional polymorphisms in interleukins and interleukin receptors genes: IL1A, IL1B, IL1RN, IL6, IL6R, IL10, IL10RA and TGFB1 in schizophrenia in Polish population

Schizophrenia has been associated with a large range of autoimmune diseases, with a history of any autoimmune disease being associated with a 45% increase in risk for the illness. The inflammatory system may trigger or modulate the course of schizophrenia through complex mechanisms influencing neurodevelopment, neuroplasticity and neurotransmission. In particular, increases or imbalance in cytokine before birth or during the early stages of life may affect neurodevelopment and produce vulnerability to the disease. A total of 27 polymorphisms of IL1N gene: rs1800587, rs17561; IL1B gene: rs1143634, rs1143643, rs16944, rs4848306, rs1143623, rs1143633, rs1143627; IL1RN gene: rs419598, rs315952, rs9005, rs4251961; IL6 gene: rs1800795, rs1800797; IL6R gene: rs4537545, rs4845617, rs2228145, IL10 gene: rs1800896, rs1800871, rs1800872, rs1800890, rs6676671; IL10RA gene: rs2229113, rs3135932; TGF1B gene: rs1800469, rs1800470; each selected on the basis of molecular evidence for functionality, were investigated in this study. Analysis was performed on a group of 621 patients with diagnosis of schizophrenia and 531 healthy controls in Polish population. An association of rs4848306 in IL1B gene, rs4251961 in IL1RN gene, rs2228145 and rs4537545 in IL6R with schizophrenia have been observed. rs6676671 in IL10 was associated with early age of onset. Strong linkage disequilibrium was observed between analyzed polymorphisms in each gene, except of IL10RA. We observed that haplotypes composed of rs4537545 and rs2228145 in IL6R gene were associated with schizophrenia. Analyses with family history of schizophrenia, other psychiatric disorders and alcohol abuse/dependence did not show any positive findings. Further studies on larger groups along with correlation with circulating protein levels are needed.

Variants of the IL-10 gene associate with muscle strength in elderly from rural Africa: a candidate gene study

Recently, it has been shown that the capacity of the innate immune system to produce cytokines relates to skeletal muscle mass and strength in older persons. The interleukin-10 (IL-10) gene regulates the production capacities of IL-10 and tumour necrosis factor-α (TNF-α). In rural Ghana, IL-10 gene variants associated with different production capacities of IL-10 and TNF-α are enriched compared with Caucasian populations. In this setting, we explored the association between these gene variants and muscle strength. Among 554 Ghanaians aged 50 years and older, we determined 20 single nucleotide polymorphisms in the IL-10 gene, production capacities of IL-10 and TNF-α in whole blood upon stimulation with lipopolysaccharide (LPS) and handgrip strength as a proxy for skeletal muscle strength. We distinguished pro-inflammatory haplotypes associated with low IL-10 production capacity and anti-inflammatory haplotypes with high IL-10 production capacity. We found that distinct haplotypes of the IL-10 gene associated with handgrip strength. A pro-inflammatory haplotype with a population frequency of 43.2% was associated with higher handgrip strength (P = 0.015). An anti-inflammatory haplotype with a population frequency of 7.9% was associated with lower handgrip strength (P = 0.006). In conclusion, variants of the IL-10 gene contributing to a pro-inflammatory cytokine response associate with higher muscle strength, whereas those with anti-inflammatory response associate with lower muscle strength. Future research needs to elucidate whether these effects of variation in the IL-10 gene are exerted directly through its role in the repair of muscle tissue or indirectly through its role in the defence against infectious diseases.

Association between IL-10 gene promoter polymorphism and hepatitis B viral infection in an Egyptian population

Cytokines play critical roles in the pathogenesis of hepatitis B virus infection (HBV). This work was designed to study the effect of IL-10 gene polymorphisms (-1082G/A and -819C/T) on susceptibility of Egyptians to HBV. Genotyping was performed using single-stranded polymorphism-polymerase chain reaction in 118 Egyptian hepatitis B patients and 119 healthy controls, and IL-10 serum levels were measured using ELISA. The frequency of IL-10 -1082G/G was significantly higher in HBV patients than in healthy controls, and G/A and A/A were not significantly different between groups. The distribution of IL-10 -819 genotypes was not significantly different between the HBV and healthy control groups. Although AT was significantly different between controls and patients, the distribution of the other haplotypes was not. IL-10 levels were significantly lower among hepatitis B patients. Our data stress the importance of IL-10 gene polymorphism in HBV infection. Depending on our preliminary work, IL-10 -1082G/G may act as a host genetic factor in the susceptibility to HBV infection in Egyptians.

Is interleukin-10 gene polymorphism a predictive marker in HCV infection?

The clinical outcome of hepatitis C virus (HCV) infection varies between individuals - from spontaneous viral clearance and persistence without complication, to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Also patterns of response to interferon-based anti-HCV therapy are different from person to person. This diversity may be affected by host genetic factors, including alterations in genes encoding cytokines. Interleukin-10, as an anti-inflammatory cytokine and immune response modulator, may influence on HCV infection susceptibility as well as spontaneous and treatment-induced HCV eradication. Moreover, it is stated that IL-10 has antifibrotic properties and play a role in progression of liver disease. This review summarized studies on interleukin-10 gene polymorphisms (mainly promoter SNPs at positions -1082(G/A), -819(C/T) and -592(C/A)), which may determine IL-10 production, regarding susceptibility to HCV infection, course of HCV-related liver disease (fibrosis, cirrhosis, hepatocellular carcinoma, ALT abnormalities), spontaneous viral elimination as well as hepatitis C treatment outcomes. Analysis of hereby summarized studies shows that it is difficult to unambiguously determine the importance of IL-10 polymorphism as a predictor of clinical outcome of hepatitis C and response to anti-HCV therapy before its beginning. Thus, future larger studies need to address these issues. Continuation of studies on interleukin-10 polymorphisms as well as identification of other candidate predictive markers in HCV infection has important practical implications and there is a chance that may contribute to reduce the scale of hepatitis C problem.

Interleukin-19: multiple roles in immune regulation and disease

First reported in 1999, IL-19 remains a mystery in many ways. Despite appearing in many genome scans and candidate gene studies, and having been searched for specifically as part of the IL-10 family, its function is still to be defined. Nonetheless, a pattern of Th2 promotion is coalescing from this nebulous body of work, supported by increasing evidence for a role in asthma. Similarly, a clear but less intuitive role as a subtle immunomodulator is emerging in psoriasis and chronic inflammatory disorders in general. Indeed, several human diseases and their animal models have highlighted a role for IL-19. Key questions remain, relating to the nature of its receptor, its function (if any) on leukocytes and how its effects are distinguished by the cell from those of IL-20 and IL-24. In this review, I shall attempt to bring together a summary of the known work - disparate as it may be - as well as presenting a picture of these two important clinical disorders and the potential involvement of this somewhat enigmatic cytokine.

Cell type-specific regulation of IL-10 expression in inflammation and disease

IL-10 plays an essential part in controlling inflammation and instructing adaptive immune responses. Consequently, dysregulation of IL-10 is linked with susceptibility to numerous infectious and autoimmune diseases in mouse models and in humans. It has become increasingly clear that appropriate temporal/spatial expression of IL-10 may be the key to how IL-10 contributes to the delicate balance between inflammation and immunoregulation. The mechanisms that govern the cell type- and receptor-specific induction of IL-10, however, remain unclear. This is due largely to the wide distribution of cellular sources that express IL-10 under diverse stimulation conditions and in a variety of tissue compartments. Further complicating the issue is the fact that human IL-10 expression patterns appear to be under genetic influence resulting in differential expression and disease susceptibility. In this review, we discuss the cellular sources of IL-10, their link to disease phenotypes and the molecular mechanisms implicated in IL-10 regulation.

Association of TNFA (-308G>A) and IL-10 (-819C>T) promoter polymorphisms with risk of cervical cancer

Etiology of cervical cancer is associated with excessive inflammation mediated tumorigenesis. Pro and anti-inflammatory cytokines (tumor necrosis factor alpha, TNFA and interleukin, IL-10) are involved in fighting against the tumorigenesis. Therefore, the present study was designed to evaluate the association of TNFA (-308G>A) and IL-10 (-819C>T) gene polymorphism with risk of cervical cancer. One hundred fifty histopathologically confirmed patients with cervical cancer and 162 age, ethnically-matched cervical cytology negative healthy controls were genotyped for TNFA (-308 G>A) and IL-10 (-819 C>T) polymorphisms using PCR-RFLP. Individuals with combination of TNFA -308GA+AA genotype and A allele were at elevated risk of cervical cancer (odds ratio (OR) = 2.24; P = 0.018 and OR, 2.05; P = 0.012). Frequency of IL-10 -819CT+TT genotype combination and T allele was slightly higher in cases as compared with controls but difference was not significant (OR = 1.52; P = 0.069 and OR = 1.38; P = 0.051). In association of genotypes with clinical characteristics, presence of TNFA -308GA+AA genotype conferred high risk for the stages (IB) (OR = 2.86, P = 0.039) and stages (III) (OR = 2.52; P = 0.015) of cervical cancer. In contrast, IL-10 -819TT genotype was not associated with higher risk of clinical characteristics of cervical cancer. In conclusion, individuals with TNFA -308*A allele carriers were at significantly higher risk of cervical cancer particularly early (IB) and advanced stages (III). However, IL-10 (-819C>T) polymorphism was not associated with risk of cervical cancer.

Characterization of two alternative Interleukin(IL)-10 5'UTR mRNA sequences, induced by lipopolysaccharide (LPS) stimulation of peripheral blood mononuclear cells

IL-10 production shows a broad-spectrum of individual response, suggesting a genetic component of approximately 75%. Different polymorphisms located close to, or within the IL-10 gene has been demonstrated to influence its transcription rate whereas the post-transcriptional regulation of IL-10 production has not well elucidated. The main responsible elements at this control level are both the 5'- and 3'-untranslated regions (UTR's) of mRNAs, and as the 3'-UTR regions are mainly involved in the stability and decay rate of mRNAs, the 5'-UTR regions mediate the binding rate of the molecule with ribosomal 40S subunit as a cis-acting element. Herein are report data on the identification of two IL10 mRNA that differ by the length of respective 5'UTR regions (160 and 288 nucleotides, respectively; EMBL accession nrs: EU751618 and EU751619) produced after stimulation of human blood samples with bacterial lipopolysaccharide (LPS). The longer 5'UTR is constitutively expressed in unstimulated PBMC cells cultured at 37 degrees C for 24h, while in LPS stimulated cells an additional IL-10 mRNA molecule, containing a shorter 5'UTR, is synthesized. RNADRAW software (http://www.rnadraw.com/) analysis have indicated that the secondary structures of the shorter 5'UTR IL-10 mRNA region is more available for the binding to the 40S ribosomal subunit. In conclusion, our data seem to suggest that LPS could influence the post-transcriptional control of IL-10 production inducing an alternative mRNA immediately available in response to the inflammatory stimulation.

Pro-inflammatory genetic background and zinc status in old atherosclerotic subjects

Inflammation and genetics are prominent mechanisms in the pathogenesis of atherosclerosis (AT) and its complications. In this review we discuss the possible impact on AT development of several genetic determinants involved in inflammation, oxidative stress and cytoprotection (IL-6, TNF-alpha, IL-10, CD14, TLR4, MT, HSP70). Genetic polymorphisms of these genes may affect a differential inflammatory response predisposing to AT. However, allelic polymorphisms of genes which increase the risk of AT frequently occur in the general population but, only adequate gene-environment-polymorphism interactions promote the onset of the disease. Zinc deficiency has been suggested as an environmental risk factor for AT. With advancing age, the incidence of zinc deficiency increases for several reasons. Among them, dietary intake, malabsorption and genetic background of inflammatory markers may be involved. A crucial contribution may also be played by increased oxidative stress which may lead to the appearance of dysfunctional proteins, including metallothioneins (MT) that are in turn involved in zinc homeostasis. The detection of candidate genes related to inflammation and promoting AT and their reciprocal influence/interaction with zinc status might allow earlier appropriate dietary interventions in genetically susceptible subjects.

Interleukin-10 (-819 C/T) and tumor necrosis factor-alpha (-308 G/A) gene variants influence gastritis and lymphoid follicle development

Helicobacter pylori (H. pylori) causes gastritis, development of lymphoid follicles and later monoclonal mucosa-associated lymphoid tissue (MALT) lymphoma. We evaluated the association of tumor necrosis factor (TNF)-alpha (-308 G/A) and IL-10 (-819 C/T) gene polymorphisms with gastritis and lymphoid follicle formation. H. pylori infection was detected using modified Giemsa staining and IgG anti-CagA enzyme-linked immunosorbent assay (ELISA). One hundred and thirty patients with non-ulcer dyspepsia (NUD) and 200 healthy age-matched controls were genotyped for TNF-alpha and IL-10 polymorphisms using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP). Subjects with IL-10 -819 T allele [patients (46.5%) versus controls (35.7%), p = 0.006, OR = 1.56, 95% CI = 1.14-2.15] were at risk of gastritis. Infection with H. pylori was more often associated with lymphoid follicles formation than its absence (46% versus 22%, p = 0.009). TNF-alpha polymorphism did not influence gastritis but patients with TNF-alpha -308 A allele carriers showed >2 fold risk of lymphoid follicle formation [presence (26%) versus absence (11.25%), p = 0.029, OR = 2.8; 95% CI = 1.09-7.08]. There was a trend towards association of lymphoid follicles and TNF-alpha -308 A allele carriers with H. pylori infection than without (58.5% versus 22.2%; p = 0.064). IL-10 -819 T and TNF-alpha -308 A alleles may increase risk of gastritis and lymphoid follicle formation.

Chemical inhibition of Src family kinases affects major LPS-activated pathways in primary human macrophages

Understanding the signalling mechanisms controlling inflammatory cytokine production is pivotal to the research of both acute and chronic immune disorders. Tyrosine phosphorylation is one of the earliest events to occur in response to an immune challenge yet the role of specific tyrosine kinases in inflammatory cytokine production has been difficult to ascribe due to conflicting literature. Here we show that the pyrazolo pyrimidine compound PP2, a selective inhibitor of Src family kinases (SFK), can inhibit LPS-induced TNF production as well as a number of other inflammatory cytokines. In addition, we show similar effects of PP2 on cytokine production when induced by other TLRs, (1, 2 and 5-8), indicating that SFK are important common regulators of TLR signalling. PP2 suppressed the activity of both TNF and IL-10 driven reporter genes, suggesting that this activity is mediated at the level of transcription. Interestingly, however, PP2 had no significant effect on the activation of NF-kappaB, or on p42/44 ERK, p46/54 JNK or p38 MAPK phosphorylation. In contrast, PP2 did inhibit AP-1 nuclear accumulation in response to LPS. Taken together, these findings show that the Src kinases are able to control inflammatory cytokine production at the transcriptional level independently of NF-kappaB, and highlight the role of the AP-1 family of transcription factors as downstream mediators of Src kinase action.

Interleukin-24, RANTES and CCR5 gene polymorphisms are not associated with chronic adult periodontitis

BACKGROUND AND OBJECTIVE

Cytokines, such as interleukin-10, and related genetic polymorphisms, have been implicated in the pathogenesis of chronic periodontitis. The aim of this study was to investigate a possible correlation between chronic periodontitis and genetic polymorphisms coding for two interleukin-10 related chemokines [interleukin-24 and regulated on activation, normal T cells expressed and secreted (RANTES)] as well as a RANTES receptor [CC chemokine receptor 5 (CCR5)].

MATERIAL AND METHODS

A single-blind, two-centre, case-controlled study was carried out with test patients from the Clinic of Periodontics, Göteborg University, and from the Department of Periodontology, Glasgow University, and control subjects from the undergraduate clinics of both schools. Blood samples were collected from 106 patients (56 women and 50 men, mean age 51.7 yr) with generalized, severe chronic periodontitis and from 69 periodontally healthy subjects (37 women and 32 men, mean age 53.3 yr). The polymerase chain reaction (PCR) was used to identify the genetic coding for interleukin-24, RANTES and CCR5. Genotype and allele frequencies were compared between the test and control groups using Fischer's exact test at the 5% level of significance.

RESULTS

There were no statistically significant differences between patients with chronic periodontitis and control subjects, regarding genotype distribution or allele frequency, irrespective of smoking status, in the combined Glasgow and Gothenburg cohort or in the specific location cohorts. The allele frequencies for healthy and control subjects for RANTES gave a p-value of 0.80 (allele G was 58.8% in healthy subjects and and 54.4% in subjects with periodontitis), for interleukin-24 the p-value was 0.90 (allele T was 56.2% in healthy subjects and and 54.9% in subjects with periodontitis) and for CCR5 the p-value was 0.90 (the wild-type allele was 85% in healthy subjects and and 82.7% in subjects with periodontitis).

CONCLUSION

The interleukin-24, RANTES and CCR5 polymorphisms investigated are not associated with chronic periodontitis.

Haplotype-independent costimulation of IL-10 secretion by SDF-1/CXCL12 proceeds via AP-1 binding to the human IL-10 promoter

Costimulation by the chemokine, stromal cell-derived factor-1 (SDF-1)/CXCL12, has been shown to increase the amount of IL-10 secreted by TCR-stimulated human T cells; however, the molecular mechanisms of this response are unknown. Knowledge of this signaling pathway may be useful because extensive evidence indicates that deficient IL-10 secretion promotes autoimmunity. The human IL-10 locus is highly polymorphic. We report in this study that SDF-1 costimulates IL-10 secretion from T cells containing all three of the most common human IL-10 promoter haplotypes that are identified by single-nucleotide polymorphisms at -1082, -819, and -592 bp (numbering is relative to the transcription start site). We further show that SDF-1 primarily costimulates IL-10 secretion by a diverse population of CD45RA(-) ("memory") phenotype T cells that includes cells expressing the presumed regulatory T cell marker, Foxp3. To address the molecular mechanisms of this response, we showed that SDF-1 costimulates the transcriptional activities in normal human T cells of reporter plasmids containing 1.1 kb of all three of the common IL-10 promoter haplotypes. IL-10 promoter activity was ablated by mutating two nonpolymorphic binding sites for the AP-1 transcription factor, and chromatin immunoprecipitation assays of primary human T cells revealed that SDF-1 costimulation enhances AP-1 binding to both of these sites. Together, these results delineate the molecular mechanisms responsible for SDF-1 costimulation of T cell IL-10 secretion. Because it is preserved among several human haplotypes and in diverse T cell populations including Foxp3(+) T cells, this pathway of IL-10 regulation may represent a key mechanism for modulating expression of this important immunoregulatory cytokine.

Cytokine gene polymorphisms can alter the effect of Bacillus Calmette-Guérin (BCG) immunotherapy

Various types of cancer are more frequent in men than women, and bladder cancer is one of the most common of these. Intravesical instillation of Bacillus Calmette-Guérin (BCG) after transurethral resection is the most effective treatment for superficial bladder cancers. The main aim of this study was to investigate for possible links between cytokine gene polymorphisms and different outcomes after BCG immunotherapy. Sixty patients who had been diagnosed with transitional cell cancer were investigated. All genotyping experiments were performed using polymerase chain reaction sequence-specific primers and a commercially available kit. The genes investigated were those that code for interleukin (IL)-1alpha, IL-1beta, IL-1R, IL-1RA, IL-4RA, IL-2, IL-4, IL-6, IL-10, IL-12, interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), and tumor necrosis factor-alpha (TNF-alpha). Analyses of the data identified TGF-beta codon 25 GG (92.85% vs. 64.44%, p=0.04, OR=7.17), IL-4 -1098 GG (16.6% vs. 0.0%, p=0.05, OR=18.33), IL-10 -1082 GG (28.5% vs. 6.8%, p=0.05, OR=5.47), and IL-10 -1082 GCC/GCC (28.57% vs. 4.5%, p=0.025, OR=8.4) polymorphisms as risk factors for progression of bladder cancer.

Genetic polymorphisms of inflammatory cytokines and myocardial infarction in the elderly

Cardiovascular diseases (CVD), such as myocardial infarction (MI), are major causes of disability and mortality in the elderly. The increasing burden of CVD in ageing industrialized populations requires intensive research in order to improve preventive and therapeutic strategies especially in old people and if possible slow the processes of cardiovascular disease generation and progression. Ageing is accompanied by an age-dependent up-regulation of the inflammatory response, due to chronic antigenic stress stimulation, which potentially triggers the onset of inflammatory diseases, especially CVD. However, the exact mechanisms are still poorly understood. Since CVD are caused by interactions between genetic and environmental factors, a possible approach to their prevention is to identify the potential genetic component of inflammatory cardiovascular risk factors, providing the basis for personalized lifestyle modification and improved pharmacological therapy. Some common gene polymorphisms associated with high production of inflammatory molecules have been associated with atherosclerosis. Therefore, controlling inflammation might play a protective role against CVD, especially in ageing. Although a large number of studies of pro- and anti-inflammatory gene variants in association with CVD and MI exists, the emerging data are quite conflicting and do not provide definitive evidence for a role of these polymorphisms in the pathogenesis of MI. In this paper we review the evidence for a possible role of genetic polymorphisms of the most important inflammatory cytokines (IL-6, TNF-alpha, IL-10) and immune receptors (CD14 receptor and TLR-4) in modulating the incidence or the prognosis of MI, with a special focus in ageing population.

Interleukin-10 −1082 promoter polymorphism is associated with schizophrenia in a Han Chinese sib-pair study

The interleukin-10 (IL-10) gene has been identified as a susceptibility gene for schizophrenia in Caucasians. A previous case-control study conducted by our group revealed a weak association between polymorphism, -592C/A, of the IL-10 gene promoter and schizophrenia. Our present study was aimed at confirming the association of the IL-10 promoter with schizophrenia using 197 Han Chinese sib-pair families. A family-based association test (FBAT) and haplotype analysis was undertaken using the FBAT v1.5.5. The global TDT was significant for a different polymorphism, -1082G/A (chi2=13.16, P=0.000285) and that the allele -1082G was preferentially transmitted to schizophrenia-affected children. Furthermore, haplotype TDT analysis showed that haplotype "GCC" was significantly associated with the disease (chi2=8.1, P=0.00443). Our results also indicate that the IL-10 gene may play a significant role in the etiology of schizophrenia among Han Chinese.

Distal enhancer elements transcribe intergenic RNA in the IL-10 family gene cluster

The IL-10 gene and homologs IL-19, IL-20, and IL-24 are expressed within a highly conserved 145-kb cytokine gene cluster. Like the Th2 IL-4 cytokine gene cluster, it is feasible that there is coordinate regulation of these cytokines by distal regulatory elements spanning the locus. We initiated a search to characterize regulatory elements within the IL-10 family locus and present data herein on a conserved 40-kb region between the IL-19 and IL-10 genes. We map the location of 17 DNase I-hypersensitive sites in different murine T cell populations and identify three enhancer elements, which function in T cells in vitro. Two of these enhancer elements, located 9 kb upstream and 6.45 kb downstream of IL-10, display cell-specific function in the Th1-Th2 cell clones AE7 and D10 and also exhibit basic promoter activity. The downstream element, IL-10CNS+6.45, binds AP-1 in the absence of NFAT and expresses intergenic RNA in a Th2-specific manner, further validating its role as a Th2-specific enhancer/promoter element. We show that the five most highly conserved noncoding sequences in the 40-kb region transcribe intergenic RNA; four of these regions possess promoter activity in vitro that could account for the expression of these transcripts. Hence, we speculate that these novel regulatory elements in the IL-10 family gene locus function via an intermediate regulatory RNA.

Allelic diversity in the TGFB1 regulatory region: characterization of novel functional single nucleotide polymorphisms

Altered TGF-beta1 expression due to polymorphisms affects a wide variety of normal cellular and disease processes such as T cell activation and proliferation, tumor progression, and asthma. In this study, a comprehensive examination of function and diversity was undertaken for the TGFB1 promoter region and exon 1 (-2,665 to +423). The known TGF-beta1 promoter was extended to encompass 463 bases by the identification of a strong enhancer activity for a distal segment (-2,665 to -2,204). Ten novel polymorphisms and 14 novel alleles were identified. Most single nucleotide polymorphisms (SNPs) appear to be randomly associated except c.-768_-769insC and c.+74G > C and a set of five novel polymorphisms present in a single allele in persons of African descent. The TGFB1 alleles clustered into three phylogenetic groups based on the common functional SNPs c.-1347C > T (commonly known as -509C-T) and c.+29T > C (commonly known as +869T-C) suggesting three phenotypic groups. Two SNPs unique to African-Americans affect the TGFB1 regulatory region. The c.-1287G > A SNP in the promoter alters the binding affinity of two unidentified transcription factor complexes which translates into a significant difference in reporter gene expression and the c.-387C > T SNP in the 5' UTR alters the binding of Stimulating protein 1 and 3. Thus, TGFB1 possesses a highly polymorphic, extensive regulatory region that likely impacts the pathogenesis of numerous TGF-beta1 related diseases.

Genes involved in immune response/inflammation, IGF1/insulin pathway and response to oxidative stress play a major role in the genetics of human longevity: the lesson of centenarians

In this paper, we review data of recent literature on the distribution in centenarians of candidate germ-line polymorphisms that likely affect the individual chance to reach the extreme limit of human life. On the basis of previous observations on the immunology, endocrinology and cellular biology of centenarians we focused on genes that regulate immune responses and inflammation (IL-6, IL-1 cluster, IL-10), genes involved in the insulin/IGF-I signalling pathway and genes that counteract oxidative stress (PON1). On the whole, data indicate that polymorphisms of these genes likely contribute to human longevity, in accord with observations emerging from a variety of animal models, and suggest that a common core of master genes and metabolic pathways are responsible for aging and longevity across animal species. Moreover, in the concern of our plan to discover new genetic factors related to longevity, we explored the possibility to by-pass the need of an a-priori choice of candidate genes, extending the search to genes and genomic regions of still unknown function. Alu sequences may be considered as good markers of highly variable and potentially unstable loci in functionally important genomic regions. We extensively screened Alu-rich genomic sites and found a new genomic region associated with longevity.

Mosaics of gene variations in the Interleukin-10 gene promoter affect interleukin-10 production depending on the stimulation used

Interleukin-10 (IL-10), a cytokine involved in many aspects of the immune response shows interindividual variations in their expression. However, genetic variations of the 5'-flanking region of the IL-10 gene (PIL-10) are poorly characterised with respect to different stimuli. New extended haplo- and genotypes are identified present at differing frequencies in three geographically separated populations. Their influence on IL-10 expression have been assessed in vitro after stimulation of leukocytes with lipopolysaccharide (LPS), dibutyryl-cAMP or following immortalisation with Epstein-Barr virus (lymphoblastoid cell line (LCL)). Interindividual differences of IL-10 production were found to be related to single-nucleotide polymorphisms (SNP) haplotype -6752/-6208 in LCLs (P<0.02), and for haplotypes comprising SNPs -6752/-6208/-3538 after LPS stimulation (P<0.03). Carriers of the IL10.G microsatellite with 22, 24 or 26 dinucleotide repeats linked with the -1087G SNP, exhibited the highest levels of IL-10 expression. Contrasting IL-10 secretion patterns were found for IL10.R microsatellite alleles characterised by 15 dinucleotide repeats: after LPS stimulation this allele was associated with high IL-10 production (P<0.007), but with low IL-10 levels in LCLs (P< 0.038). Thus, the effects of mosaics of genetic elements in the PIL-10 on the capacity of leukocytes to produce IL-10 depend on the agent inducing IL-10 expression.

IL-10 gene polymorphisms in infectious disease and SIDS

Interleukin-10 (IL-10) is a regulatory cytokine, and its principal role in vivo is to limit inflammatory response. IL-10 has been shown to influence both the susceptibility and course of various diseases, and the different polymorphisms in the IL-10 gene promoter have been associated with disease prevalence and severity. The genes involved in the immune system are also assumed to be of importance with regard to sudden infant death syndrome (SIDS), and specific haplotypes in the IL-10 gene promoter have been reported associated both with SIDS and sudden unexpected death due to infection.

Simultaneous analysis of interleukin-10 gene microsatellites and single-nucleotide polymorphisms in parallel with tumour necrosis factor and interferon-gamma short tandem repeats by fluorescence-based polymerase chain reaction

Different cytokine genotypes exist in the population, for example, as a result of selective pressure of infectious diseases. It may be that specific cytokine genotypes that are beneficial by creating a 'proinflammatory' phenotype predispose to severe inflammatory disease with worse clinical outcome. There is individual variation in the production of certain cytokines in relation to their genotypes. IL-10, IFN-gamma and TNF-alpha are key components in the regulation of immune responses and the balance of their expression levels is predictive in certain diseases. To describe cytokine genotypes, a one-tube PCR reaction was developed to analyse simultaneously DNA sequence variations of cytokine genes IL-10, IFN-gamma, and TNF. This multiplex PCR approach was used to provide genotypic data for two geographically independent donor groups from Germany and Gabon. Significant differences were obtained for the majority of sequence variations comparing both populations. However, the SNPs within the 5'-flanking region of the IL-10 gene at position -1087 and -6208 are comparable in their genic and genotypic behaviour. Comparing allelic and genotypic disequilibrium between pairs of loci revealed different association patterns for both populations according to the geographical polymorphism. This assay may improve immunogenetic studies in disease, characterized by disbalanced IL-10, IFN-gamma and TNF-alpha expression.

IL-10 and TNF-alpha polymorphisms and the recovery from HCV infection

Hepatitis C virus (HCV) infection becomes chronic in about 85% of infected individuals, whereas only 15% of infected people clear spontaneously the virus. It is conceivable that the host immunogenetic background influences the course of infection in term of recovery. Thus, in this study we have evaluated the effect of functionally relevant polymorphisms at tumor necrosis factor-alpha (TNF-alpha, i.e., 2 biallelic polymorphisms at nt -863 and nt-308 of the promoter) and interleukin-10 (IL-10) loci (i.e., 1 biallelic polymorphism at nt -1082 of the promoter), on the clearance of HCV infection. To this purpose, we compared 18 Sicilian patients who had spontaneously recovered from previous HCV infection with 42 Sicilian patients with current HCV infection and 135 Sicilian healthy patients. The results demonstrate a decreased frequency of the -863CC TNF-alpha promoter genotype (involved in high production of this pro-inflammatory cytokine) and an increased frequency of the -1082GG IL-10 promoter genotype (involved in high production of this anti-inflammatory cytokine) in patients recovered from HCV infection. The evaluation of combined TNF-alpha and IL-10 genotypes revealed a significant increase of the "anti-inflammatory genotype" (low-TNF/high-IL-10 producers) in resolved HCV infection group compared with patients with persistent HCV infection. On the whole, our findings suggest that a genetically determined control of the HCV-induced inflammatory response may play a role in the resolution of HCV infection.

Interleukin-10 promoter polymorphism in sporadic Alzheimer's disease

Proinflammatory cytokines and acute-phase proteins play an important role in Alzheimer's disease (AD) neurodegeneration, and common polymorphisms of genes controlling their high production have been shown to be associated with AD. Thus, AD patients display a proinflammatory genotype and the control of inflammation might play a protective role in AD development. By sequence-specific probes, we have evaluated the role of anti-inflammatory cytokine interleukin(IL)-10 in AD, by analysing in 132 AD patients and 213 healthy controls the prevalence of three different haplotypes, involving three single-nucleotide polymorphisms (SNPs) at -1082 (G-->A), -819 (C-->T) and -592 (C-->A) nucleotides of IL-10 promoter, associated with different IL-10 production. The percentage of -1082A carrier subjects was significantly increased among AD patients, and this increase was mainly due to the increase of ATA haplotype. Analysing these results according to the well-known genetic risk factor APOE-e4 allele, no significant differences were observed in SNP IL-10 allele distribution between AD patients carrying the genotype or not. So we may conclude that the presence of -1082A allele and in particular of -1082A/-819T/-592A haplotype, associated with a low production of anti-inflammatory cytokine IL-10, may be considered as an additive and independent genetic risk factor for AD.

Genetic polymorphisms in Spanish rheumatoid arthritis patients: an association and linkage study

HLA polymorphism accounts only for approximately one-third of the genetic predisposition to rheumatoid arthritis (RA). To investigate the role of other loci in the susceptibility to RA, we have performed an analysis of several polymorphisms in genes of immune-related function: IL-10 -1082, -819, -592 promoter single nucleotide polymorphisms (SNPs), IL-10G and IL-10R microsatellites, IL-6 -622 promoter SNP, FcgammaRIIIA Val/Phe-158 polymorphism, IL-1 receptor antagonist VNTR, and the IKBL+738 T/C mutation. The analysis has been performed on a case-control study and also on RA trios. IL-10G12 was found to be associated with RA in the case-control study (18% in RA patients vs 9% in controls: P=0.001; pc<0.05). This allele was also more often transmitted than not transmitted (10 vs 5). No other allele in the present study is found to be associated to RA. Our data suggest that most of the loci studied play no major role in the susceptibility to RA, the IL-10 gene being the sole exception.

Influence of interleukin-10 polymorphisms on interleukin-10 expression and survival in critically ill patients

OBJECTIVE

To determine the functionality of identified polymorphisms in the promoter and upstream regions of the interleukin-10 gene in terms of release of interleukin-10 from lipopolysaccharide-stimulated whole blood from healthy volunteers and to evaluate the relationship of interleukin-10 polymorphisms to interleukin-10 release, development of sepsis, and mortality in critically ill patients.

DESIGN

Observational study.

SETTING

The academic unit of anesthesia and intensive care, university laboratories, and ten-bed general intensive care unit in a university teaching hospital.

SUBJECTS

A total of 132 healthy volunteers plus 67 consecutive critically ill patients recruited within 24 hrs of admission to the intensive care unit, regardless of diagnosis.

MEASUREMENTS

Plasma interleukin-10 levels were measured by enzyme-linked immunosorbent assay. Single nucleotide polymorphisms were detected by restriction fragment length polymorphism analysis. Dinucleotide repeat polymorphisms were identified after polymerase chain reaction using a DNA size analyzer.

MAIN RESULTS

Stimulated interleukin-10 release in critically ill patients was significantly lower than in healthy subjects (p < .0001). In addition, in the patients who developed sepsis, interleukin-10 release at admission to the intensive care unit was significantly lower than in patients who did not subsequently develop sepsis (median [range] 1.47 [0.13-6.90] ng/mL compared with 4.93 [0.03-16.80] ng/mL, p = .001). The A allele of the single nucleotide polymorphism at -592 base pairs was associated with lower interleukin-10 release and higher mortality in critically ill patients. Other polymorphisms were not linked to interleukin-10 release, sepsis, or mortality.

CONCLUSIONS

The A allele of the -592 base pair single nucleotide polymorphism in the interleukin-10 gene is associated with lower stimulated interleukin-10 release and increased mortality. Further investigations are required to determine the nature of the functionality and the potential diagnostic and therapeutic aspects of this marker.

Association tests with systemic lupus erythematosus (SLE) of IL10 markers indicate a direct involvement of a CA repeat in the 5' regulatory region

Many lines of evidence suggest that IL10 is a strong candidate gene for systemic lupus erythematosus (SLE) susceptibility. In our previously reported study an allele (IL10.G-140bp) of the microsatellite IL10.G located at position -1100 was significantly increased in Italian SLE patients in comparison with controls. Starting from this observation, we tested if sequence variations in the vicinity of IL10.G were more strongly associated with SLE. We performed a comprehensive association study including 26 SNPs (of which four were newly identified in the present study by DHPLC analysis) spanning 8.5 Kb of the 5' flanking and the transcribed region of the IL10 gene. The association study was performed by the DNA pool method on an extended panel of Italian patients (205) and controls (631). Haplotypic associations were studied by individual typing of seven selected markers surrounding IL10.G. Gene, genotype and haplotype frequencies were not significantly different in patients and controls. Thus the IL10.G microsatellite remains to date the only IL10 marker associated with SLE in our population. A meta-analysis of all published results indicates a possible direct role of the IL10.G repeat number in SLE susceptibility.

Association between promoter polymorphic haplotypes of interleukin-10 gene and schizophrenia

BACKGROUND

Schizophrenia is one of the most severe psychiatric disorders, with a worldwide incidence of 1%. Several reports show abnormal cytokine levels in psychotic patients and indicate a possible role of the immune response system in the pathogenesis of schizophrenia. Increased concentrations of interleukin 10 (IL-10) have been found in plasma of schizophrenic patients, suggesting its potential role as a candidate gene for susceptibility to schizophrenia. IL-10 gene maps on chromosome 1 (q31-q32), a locus associated with genetic susceptibility to schizophrenia. Three functional haplotypes of the gene (GCC, ACC, ATA) have been described, derived from different combinations of three "single nucleotide polymorphisms" and directly related to the expression levels of the protein.

METHODS

We analyzed allele, genotype, and haplotype distributions in an association case-control study involving 106 schizophrenic patients and 143 unrelated healthy volunteers using polymerase chain reaction (PCR)-Single Strand Conformation Polymorphism and PCR Restriction Fragment Length Polymorphism methods.

RESULTS

Our results show a significant increase of GCC homozygotes (the high IL-10-producing haplotype) in schizophrenic patients compared to control subjects (chi(2) = 13, p =.023; odds ratio = 3.03; 95% confidence interval, 1.274-7.355).

CONCLUSIONS

These data could partly explain the abnormal secretion of IL-10 occurring in schizophrenic patients in response to infections or different stressors and suggest a potential role of IL-10 as a candidate gene for susceptibility to schizophrenia.

Gender-specific association between -1082 IL-10 promoter polymorphism and longevity

Ageing is characterized by a pro-inflammatory status, which could contribute to the onset of major age-related diseases. Thus, genetic variations in pro- or anti-inflammatory cytokines might influence successful ageing and longevity. IL-10 is an appropriate candidate because it exerts powerful inhibitory effects on pro-inflammatory function. IL-10 production is controlled by several polymorphic elements in the 5' flanking region of IL-10 gene on 1q32 locus, involving alleles at two microsatellite regions and several polymorphisms in promoter region. We analysed in 190 Italian centenarians (>99 years old, 159 women and 31 men) and in 260 <60 years old control subjects (99 women and 161 men), matched for geographical distribution, genotype frequencies for -1082G-->A, -819C-->T and -592C-->A IL-10 proximal promoter gene biallelic polymorphisms by sequence specific probes. -1082G homozygous genotype was increased in centenarian men (P < 0.025) but not in centenarian women. No difference was found between centenarians and control subjects regarding the other two polymorphisms. The presence of -1082GG genotype, suggested to be associated with high IL-10 production, significantly increases the possibility to reach the extreme limit of human lifespan in men. Together with previous data on other polymorphic loci (Tyrosine Hydroxylase, mitochondrial DNA, IL-6, haemochromatosis, IFN-gamma), this finding points out that that gender is a major variable in the genetics of longevity, suggesting that men and women follow different strategies to reach longevity. Concerning the biological significance of this association, we have not searched for functional proves that IL-10 is involved. Thus, we should conclude that our data only suggest that a marker on 1q32 genomic region may be involved in successful ageing in man. However, recent data on IL-6 and IFN-gamma genes suggest that longevity is negatively associated with genotypes coding for a pro-inflammatory profile. Thus, it is intriguing that the possession of -1082G genotype, suggested to be associated with IL-10 high production, is significantly increased in centenarians.