Association of polymorphisms in IL-12/IFN-gamma pathway genes with susceptibility to pulmonary tuberculosis in Indonesia

Upon infection with mycobacteria the IL-12/IFN-gamma axis plays an essential role in the activation of cell-mediated immunity required for the elimination of pathogens. Mutations in genes of the IL-12/IFN-gamma axis are known to cause extreme susceptibility to infection with environmental mycobacteria, and subtle variations in these genes may influence susceptibility to more virulent mycobacteria. We analyzed the distribution of polymorphisms in four essential genes from the IL-12/IFN-gamma axis, IL12B, IL12RB1, IFNG and IFNGR1, in 382 pulmonary tuberculosis patients and 437 healthy controls from an endemic region in Jakarta, Indonesia. The IL12RB1 gene was sequenced in a subset of individuals. Nine known single nucleotide polymorphisms (SNPs) and two new silent variations, 135G>A and 1056C>T, were detected in IL12RB1. Six functional SNPs (-2C>T, 467G>A, 641A>G, 1312C>T, 1573G>A, 1781G>A) in IL12RB1, an IL12B promoter insertion/deletion polymorphism and CA repeats in IFNG and IFNGR1 were analyzed in the cohort. The IFNGR1 allele CA(12) (p=0.004) and genotype CA(12)/CA(12) (p=0.01; OR 0.5) were associated with protection from pulmonary tuberculosis. Interestingly, IL12B promoter heterozygosity was associated with protection from tuberculosis in BCG-vaccinated individuals (p=0.03; OR=0.6). This new finding supports the role that IL-23-of which IL12B encodes a subunit--plays in generation of memory T cells.     

Interleukin-12 receptor beta1 deficiency in a patient with abdominal tuberculosis.

Two siblings with interleukin-12 receptor beta1 (IL-12Rbeta1) deficiency but different clinical phenotypes were studied. Both are homozygous for an IL12RB1 missense mutation that prevents receptor expression and abolishes cellular responses to IL-12. Transfection of the patients' T cells with wild-type IL12RB1 restored IL-12Rbeta1 expression and function. One patient had the expected phenotype of disseminated bacille Calmette-Guérin (BCG) infection in early childhood, whereas the other did not develop BCG infection, despite 3 inoculations with live BCG. Abdominal tuberculosis was diagnosed in this second patient at age 18 years. To date, neither of them has had clinical disease caused by environmental mycobacteria. These observations show unexpected interfamilial and intrafamilial heterogeneity of the clinical phenotype associated with IL-12Rbeta1 deficiency. The patients may be resistant to BCG but remain vulnerable to Mycobacterium tuberculosis. A diagnosis of IL-12Rbeta1 deficiency should therefore be considered in selected patients with severe tuberculosis, despite their resistance to BCG and a lack of atypical mycobacteriosis.     

Associations between measles vaccine immunity and single-nucleotide polymorphisms in cytokine and cytokine receptor genes

BACKGROUND: Cytokines are key regulators of measles vaccine humoral and cellular immunity. Single-nucleotide polymorphisms (SNPs) that are associated with differences in cytokine levels should also influence measles vaccine-induced immunity. METHODS: We genotyped 118 measles-mumps-rubella-vaccinated subjects for SNPs from 6 cytokine genes (interleukin [IL]-2, IL-4, IL-10, IL-12A, IL-12B, and interferon [IFN]-gamma) and their receptors (IL-2RA, IL-2RB, IL-4RA, IL-10RA, IL-10RB, IL-12RB1, IL-12RB2, and IFN-gamma R). Associations of SNPs with measles-specific antibodies, lymphoproliferation, and secreted cytokines were determined using chi2 tests and analyses of covariance. RESULTS: We found significant associations (P<.05) between SNPs in the IL-2, IL-10, and IL-12RB genes and measles vaccine-induced immunity. The IVS1-100G (rs2069762) and the Ex2-34G (rs2069763) SNPs within the IL-2 gene were associated with high antibody and high lymphoproliferative responses, whereas SNPs within the IL-10 and IL-12R genes were associated with low antibody and lymphoproliferative responses to measles. SNPs within the IL-4RA and IL-12B genes varied significantly (P<.05) across immune response measures. Significant associations were also found between SNPs and secreted cytokine levels. CONCLUSIONS: Specific SNPs in the cytokine and cytokine receptor genes are significantly associated with variations in measures of the immune response to measles vaccination. These results need to be further validated in a larger cohort.     

Interleukin 12 (IL12B), interleukin 12 receptor (IL12RB1) and interleukin 23 (IL23A) gene polymorphism in systemic lupus erythematosus

OBJECTIVE: The aim of this study was to assess the possible association between the interleukin-12B (IL12B) and interleukin-12 receptor beta 1 (IL12RB1) gene polymorphisms with systemic lupus erythematosus (SLE). In addition, we have undertaken a systematic search for genetic variants of interleukin 23 (IL23A). METHODS: The study was conducted on 559 SLE patients and 603 ethnically matched healthy controls. Genotyping of the IL12B [IL12Bpro and IL12B 3' untranslated region (UTR)] and IL12RB1 (641A-->G, 1094T-->C and 1132G-->C) polymorphisms was performed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR-fluorescent methods, whereas IL23A genetic variants were realized with direct sequencing. RESULTS: No statistically significant differences in the distribution of the IL12B and the IL12RB1 genotypes and alleles were observed when comparing SLE patients and control subjects. Additionally, no differences in the genotype and allele distribution were found when SLE patients were stratified according to the presence or absence of lupus nephritis. Despite an extensive analysis in 30 individuals, variations located in the exons and in the 5' and 3' UTR regions of IL23A gene were not found in any case. CONCLUSIONS: These results suggest that polymorphisms located in IL12B, IL12RB1 and IL23A genes may not play a relevant role in the susceptibility or severity of SLE in the Spanish population.     

Correlation of polymorphic variation in the promoter region of the interleukin-1 beta gene with secretion of interleukin-1 beta protein

OBJECTIVE: Significant variation in interleukin-1 beta (IL-1 beta) protein secretion between subjects has been observed when using a lipopolysaccharide (LPS)/ATP-mediated ex vivo blood stimulation assay. To explore the potential relationships between genetic polymorphisms in the IL1B cytokine gene and cellular responses to inflammatory stimuli such as LPS, we investigated the hypothesis that polymorphisms within the promoter and exon 5 of the IL1B gene contribute to the observed differences in IL-1 beta protein secretion. METHODS: The IL1B gene polymorphisms C-511T, T-31C, and C3954T were tested for association with LPS-induced secretion of IL-1 beta protein as measured by an ex vivo blood stimulation assay. Samples from 2 independent study populations (n = 31 and n = 25) were available for use in the ex vivo assay after consent was obtained to analyze the DNA. RESULTS: A specific haplotype, composed of the T allele at -511 and the C allele at -31, was significantly associated with a 2-3-fold increase in LPS-induced IL-1 beta protein secretion. This association was observed in both of the independent study populations (P = 0.0084 and P = 0.0017). CONCLUSION: These data suggest that polymorphisms within the promoter region of the IL1B gene contribute to observed differences in LPS-induced IL-1 beta protein secretion.     

Ethnic-specific genetic associations with pulmonary tuberculosis

Several susceptibility-associated genetic polymorphisms have been proposed to explain differential susceptibility to tuberculosis (TB) disease progression in different populations. Here, polymorphisms in the natural resistance-associated macrophage protein 1 (NRAMP1), vitamin D receptor, tumor necrosis factor-alpha, interleukin (IL)-1, and IL-10 genes were evaluated in 358 Cambodian patients with pulmonary TB and 106 tuberculin-positive control subjects. Heterozygosity for the -1082 polymorphism of the IL-10 promoter and heterozygosity for 2 linked polymorphic NRAMP1 variants, D543N and 3' untranslated region, were associated with TB susceptibility and resistance, respectively. Other polymorphisms associated with differential susceptibility to TB were not associated with susceptibility or resistance to TB in Cambodians. The novel pattern of genetic associations with susceptibility and resistance to TB detected in Cambodia is consistent with the conclusion that unique environmental and natural selective factors have resulted in the development of ethnic-specific host genetic factors associated with TB susceptibility and resistance worldwide.     

Interleukin 1alpha,interleukin 1beta and interleukin 1 receptor gene polymorphisms in psoriatic arthritis

OBJECTIVES: To investigate polymorphisms of interleukin (IL) 1alpha, IL-1beta and IL-1 receptor R1 genes in patients with psoriatic arthritis (PsA), their relationship to the age of onset of psoriasis and the pattern of joint involvement. METHODS: One hundred and forty well-characterized patients with PsA were studied. One hundred healthy controls were recruited from primary care. All were genotyped for single-nucleotide polymorphisms in the genes for IL-1alpha (position -889), IL-1beta (position +3953) and IL-1R1 (position +970). The frequencies of the respective variants were compared between patients and controls and in relation to age of onset of psoriasis, to clinical subsets of the disease and to the presence of erosions. RESULTS: All three polymorphisms were in Hardy-Weinberg equilibrium in both patients and controls. The frequency of IL-1alpha -889 CC homozygotes was significantly increased in PsA patients compared with normal controls [58 vs 40%, odds ratio (OR) 2.06, 95%, confidence interval (CI) 1.22-3.47]. The frequency of the IL-1alpha -889 C allele was significantly increased in PsA patients compared with controls (75 vs 65%, OR 1.65, 95% CI 1.11-2.45). In subset analysis there were no other significant differences in allelic frequencies for the IL-1alpha -889 C/T, IL-1beta +3953 C/T and IL-1R1 +970 C/T polymorphisms. CONCLUSIONS: The IL-1 gene complex may play a role in the development of PsA and/or psoriasis or act as a marker for other genes on chromosome 2q12 to 2q13.     

Lack of an association between interleukin-12 receptor beta1 polymorphisms and tuberculosis in Koreans

BACKGROUND: The fact that only 10% of people infected with Mycobacterium tuberculosis develop clinical tuberculosis (TB) suggests the presence of genetic factors in the pathogenesis of TB. To date, a number of single nucleotide polymorphisms (SNPs) in several candidate genes have been proposed as genetic risk factors of TB; however, reports are conflicting. OBJECTIVES: We investigated whether SNPs in the interleukin (IL)-12 receptor beta1 gene are associated with TB in Koreans. METHODS: One hundred and fifteen patients with bacteriologically or pathologically confirmed TB and 151 healthy anonymous blood donors were enrolled. The genotypes of 5 SNPs on IL-12 receptor beta1 gene, +705A/G (Q214R), +1158T/C (M365T), +1196G/C (G378R), +1637G/A (A525T) and +1664 C/T (P534S), were determined by PCR-RFLP. RESULTS: No difference was observed between TB patients and controls in terms of the genotype frequencies of the 5 SNPs of the IL-12 receptor beta1 gene or of their haplotypes. CONCLUSIONS: In view of the finding that these SNPs have been reported to be associated with TB in the Japanese and Moroccan populations, our results may reflect racial differences in genetic susceptibility to TB.     

Polymorphism in IL1B: IL1B-511 association with tuberculosis and decreased lipopolysaccharide-induced IL-1beta in IFN-gamma primed ex-vivo whole blood assay

To determine whether variation in two interleukin 1 family genes (IL1B and interleukin 1 receptor antagonist, IL1RN) is associated with pulmonary tuberculosis (TB), two published polymorphisms at nucleotide positions -511 and +3953 in IL1B and one in the IL1RN 86 bp VNTR were genotyped in 335 smear positive Gambian TB patients, and 298 ethnically matched controls. All individuals were HIV negative. Decreased risk of pulmonary TB was associated with both heterozygosity and homozygosity for the IL1B-511-C allele (OR 0.66, P = 0.027, and OR 0.58, P = 0.015, respectively). Nonetheless, the C allele was present at a frequency of 0.66 in TB cases suggesting that whilst IL-1beta contributes to disease susceptibility, it is not the major factor. There was no association between the IL1B+3953-T/C polymorphism or the 86 bp IL1RN pentallelic repeat and TB in this population. Using an ex-vivo whole blood assay, healthy Gambian individuals who are homozygous for the IL1B-511-T allele failed to exhibit a significant increase in IL-1beta production in response to LPS after IFN-gamma priming.     

Lack of association of genetic polymorphisms in the interleukin-1beta, interleukin-1 receptor antagonist, interleukin-4, and interleukin-10 genes with risk of rheumatic heart disease in Taiwan Chinese

Inflammation and genetics may play a role in the pathogenesis of rheumatic heart disease (RHD). The aim of this study was to test whether interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1Ra), IL-4, or IL-10 gene polymorphisms could be used as markers of susceptibility to or severity of RHD among the Chinese population in Taiwan. A group of 115 patients with RHD diagnosed by echocardiography, and 163 age- and sex-matched normal control subjects were studied. IL-1beta promoter, IL-1beta exon 5, IL-1Ra, IL-4 promoter, IL-4 intron 3, and IL-10 gene polymorphisms were identified by polymerase chain reaction-based restriction analysis. There was no significant difference in the distribution of genotypes and allelic frequencies between RHD cases and controls for IL-1beta promoter, IL-1beta exon 5, IL-1Ra, IL-4 promoter, IL-4 intron 3, and IL-10 gene polymorphisms. Further categorization of the RHD patients into mitral valve disease and combined valve disease subgroups also revealed no statistical difference in these gene polymorphisms when compared with controls. These findings suggest that the IL-1beta, IL-1Ra, IL-4, or IL-10 gene polymorphisms are not suitable genetic markers for RHD in Taiwan Chinese.     

Effects of interleukin-1 gene polymorphisms on the development of coronary artery disease associated with Chlamydia pneumoniae infection

OBJECTIVES: This study was done to elucidate the effects of interleukin (IL)-1 gene polymorphisms on coronary artery disease (CAD) associated with Chlamydia pneumoniae (CP) infection. BACKGROUND: It was suggested that CP was associated with CAD. However, genetic factors involved in CAD associated with CP infection are unknown. METHODS: We evaluated CP immunoglobulin G (IgG) seropositivity and IL-1 beta (a C/T transition at -511) and IL-1 receptor antagonist (IL-1Ra) (a variable-number repeat in intron 2) gene polymorphisms in 292 patients undergoing coronary angiography. RESULTS: Seropositivity for CP was present in 61% of patients with CAD versus 51% without CAD (p = NS). The percentage of patients having IL-1 beta (-511) C/C genotype and/or IL-1Ra (intron 2) 2- or 3-repeat allele was higher in patients with CAD than without CAD (29 vs. 16%, p < 0.025). To clarify the effects of these CAD-associated variants (IL-1 beta C/C and/or IL-1Ra 2- or 3-repeat), patients were divided into four groups. A stepwise increase in CAD prevalence was observed depending on CP seropositivity and the variants. Odds ratios (ORs) for CAD were 1.4 in the group with seropositivity alone, 1.7 with the variants alone and 3.8 with seropositivity and the variants. Such variants were associated with CAD in both patients with and without seropositivity. Interestingly, high prevalence of myocardial infarction (MI) was confined to the group with seropositivity and the variants (OR, 2.8). The variants were associated with MI only in patients with CP seropositivity. CONCLUSIONS: The IL-1 gene polymorphisms were found to play a role in the development of CAD, especially MI, in patients with CP infection.     

Assessment of the interleukin 1 gene cluster and other candidate gene polymorphisms in host susceptibility to tuberculosis.

SETTING: A study of tuberculosis cases and healthy blood donor controls from the Western Region of The Gambia, West Africa. OBJECTIVE: To investigate the potential role of candidate gene polymorphisms in host susceptibility to tuberculosis. DESIGN: Single base change polymorphisms in interleukin 1 beta (IL1 beta), interleukin 10 (IL10) and fucosyltransferase-2 (FUT-2), microsatellite polymorphisms in interleukin 1 alpha (IL1 alpha) and IL10 and a minisatellite polymorphism in interleukin 1 receptor antagonist (IL1RA) were typed in over 400 tuberculosis cases and 400 healthy blood donor controls. RESULTS: IL1 gene cluster polymorphisms (IL1RA and possibly IL1 alpha) showed marginally significant association with tuberculosis. In particular IL1RA allele 2 heterozygotes were less frequent among tuberculosis cases than controls (P = 0.03). IL1 beta, IL10 and FUT-2 polymorphisms were not associated with tuberculosis. CONCLUSION: Genetic susceptibility to tuberculosis among Gambians may be partly determined by genes in the IL1 gene cluster on chromosome 2. Further association studies will be required on other population groups to confirm whether these results are of biological significance.     

Polymorphic variability in the interleukin (IL)-1beta promoter conditions susceptibility to severe malarial anemia and functional changes in IL-1beta production

Interleukin (IL)-1beta is a cytokine released as part of the innate immune response to Plasmodium falciparum. Because the role played by IL-1beta polymorphic variability in conditioning the immunopathogenesis of severe malarial anemia (SMA) remains undefined, relationships between IL-1beta promoter variants (-31C/T and -511A/G), SMA (hemoglobin [Hb] level <6.0 g/dL), and circulating IL-1beta levels were investigated in children with parasitemia (n= 566) from western Kenya. The IL-1beta promoter haplotype -31C/-511A (CA) was associated with increased risk of SMA (Hb level <6.0 g/dL; odds ratio [OR], 1.98 [95% confidence interval {CI}, 1.55-2.27]; P < .05) and reduced circulating IL-1beta levels (p <.05). The TA (-31T/-511A) haplotype was nonsignificantly associated with protection against SMA (OR, 0.52 [95% CI, 0.18-1.16]; p =.11) and elevated IL-1beta production ( p<.05). Compared with the non-SMA group, children with SMA had significantly lower IL-1beta levels and nonsignificant elevations in both IL-1 receptor antagonist (IL-1Ra) and the ratio of IL-1Ra to IL-1beta. The results presented demonstrate that variation in IL-1beta promoter conditions susceptibility to SMA and functional changes in circulating IL-1beta levels.     

Interleukin-12 Receptor β1 Polymorphisms and Nontuberculous Mycobacterial Lung Diseases

The pathway involving interferon-gamma and interleukin (IL)-12 plays an important role in host defense against mycobacterial infections. Recent studies have indicated that IL-12 receptor beta1 (IL-12Rbeta1) gene polymorphisms are associated with susceptibility to pulmonary tuberculosis. However, there have been no reports of an association between IL-12Rbeta1 gene polymorphism and lung disease caused by nontuberculous mycobacteria (NTM). The present study involved 128 patients with the nodular bronchiectatic form of NTM lung disease (75 patients with Mycobacterium avium-intracellulare complex infection and 53 patients with Mycobacterium abscessus infection) and 240 healthy controls. Single nucleotide polymorphisms of the IL-12Rbeta1 gene at positions +705A/G, +1158T/C, and +1196G/C were determined by direct sequencing of polymerase chain reaction products. Comparisons of the NTM lung disease patients with healthy controls did not identify any significant differences in relation to the genotype, allele, and haplotype frequencies of the IL-12Rbeta1 +705A/G, +1158T/C, and +1196G/C polymorphisms. These IL-12Rbeta1 gene polymorphisms do not appear to be responsible for host susceptibility to NTM lung disease, at least in this Korean population.     

Immunogenetics of CD4 lymphocyte count recovery during antiretroviral therapy: An AIDS Clinical Trials Group study

During antiretroviral therapy, CD4 lymphocyte count increases are modest in some patients despite virologic control. We explored whether polymorphisms in genes important for T cell expansion, survival, and apoptosis are associated with the magnitude of CD4 lymphocyte count recovery during antiretroviral therapy. We studied treatment-naive individuals who achieved sustained control of plasma viremia (<400 HIV-1 RNA copies/mL) for at least 48 weeks after initiation of antiretroviral therapy and compared genotypes among individuals who had an increase of either <200 or > or =200 CD4 cells/mm3 from baseline. A total of 137 single-nucleotide polymorphisms across 17 genes were characterized in 873 study participants. In multivariate analyses that controlled for clinical variables, polymorphisms in genes encoding tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), TNF- alpha , Bcl-2-interacting molecule (Bim), interleukin (IL)-15, and IL-15 receptor alpha chain (IL-15R alpha ) were associated with the magnitude of the increase in CD4 lymphocyte count, as were haplotypes in genes encoding interferon- alpha , IL-2, and IL-15R alpha (P < .05, for each). Multifactor dimensionality reduction identified a gene-gene interaction between IL-2/IL-15 receptor common beta chain and IL-2/IL-7/IL-15 receptor common gamma chain. Immune recovery during antiretroviral therapy is a complex phenotype that is influenced by multiple genetic variants. Future studies should validate these tentative associations and define underlying mechanisms.     

Genetic association studies of interleukin-13 receptor alpha1 subunit gene polymorphisms in asthma and atopy.

Interleukin (IL)-13 plays a central role in asthma pathogenesis by binding to the IL-13 receptor, which is a heterodimer composed of the IL-13 receptor alpha1 subunit (IL-13Ralpha1) and IL-4Ralpha. The genetic diversity at the IL-13Ralpha1 gene (IL13RA1) locus on chromosome Xq24 was characterised and the association of identified polymorphisms with asthma and atopy phenotypes examined. The promoter and coding region of IL13RA1 were screened for common genetic variants, and polymorphisms found were genotyped in a large cohort of 341 asthmatic Caucasian families (each containing at least two asthmatic siblings) and 182 nonasthmatic control subjects. Genetic association was determined using case-control and transmission disequilibrium test analyses. Two common polymorphisms were identified, a newly found thymidine (T) to guanine (G) transition of nucleotide -281 (-281T>G) single nucleotide polymorphism in the IL13RA1 promoter and the previously described 1365A>G variant in the IL13RA1 proximal 3' untranslated region. No significant association of either -281T>G or 1365A>G with risk of asthma or atopy phenotypes was found, apart from a suggestive association between the IL13RA1 -281T/1365A haplotype and raised total serum immunoglobulin E levels in adult female asthmatics. These findings indicate that the interleukin-13 receptor alpha1 subunit gene -281T>G and 1365A>G polymorphisms do not contribute to asthma susceptibility or severity, although the interleukin-13 receptor alpha1 subunit gene locus might be involved in the control of immunoglobulin E production.     

Genetic variation in the IL-10 pathway modulates severity of acute graft-versus-host disease following hematopoietic cell transplantation: synergism between IL-10 genotype of patient and IL-10 receptor beta genotype of donor

We have previously shown that the interleukin 10 (IL-10)/-592*A allele of the recipient is associated with less severe acute graft-versus-host disease (GVHD) and a lower risk of nonrelapse mortality after hematopoietic cell transplantation (HCT) from an HLA-identical sibling. In the present study, we examined variation in the IL-10 receptor beta gene as a further test of the hypothesis that the IL-10 pathway regulates the risk of acute GVHD. A single nucleotide polymorphism (A/G) at cDNA position 238 of the IL-10 receptor beta gene (IL10RB/c238) was genotyped in 953 HC transplant recipients and their HLA-identical sibling donors. IL-10/-592 and IL10RB/c238 genotypes were tested for association with GVHD by multivariable analysis. The IL-10/-592*A allele of the recipient and IL10RB/c238*G allele of the donor were significantly associated with a lower risk of grades III-IV acute GVHD (trend P < .001 and P = .02, respectively). The donor IL10RB/c238*G allele provided protection among patients with the IL-10/-592 A/C or A/A genotypes but not among patients with the high-risk IL-10/-592 C/C genotype. These data suggest an interaction of the patient IL-10/-592 and donor IL10RB/c238 genotypes on risk of GVHD, further supporting the hypothesis that the IL-10 pathway plays an important role in controlling the severity of acute GVHD.