IL-1 genes in myasthenia gravis: IL-1A -889 polymorphism associated with sex and age of disease onset

Single-cell RNA-Seq reveals transcriptional heterogeneity and immune subtypes associated with disease activity in human myasthenia gravis

Myasthenia gravis (MG) is a rare autoimmune disease. Although the impact of immune cell disorder in MG has been extensively studied, little is known about the transcriptomes of individual cells. Here, we assessed the transcriptional profiles of 39,243 cells by single-cell sequencing and identified 13 major cell clusters, along with 39 subgroups of cells derived from patients with new-onset myasthenia gravis and healthy controls. We found that B cells, CD4⁺ T cells, and monocytes exhibited more heterogeneity in MG patients. CD4⁺ T cells were expanded in MG patients. We reclustered B cells and CD4⁺ T cells, and predict their essential regulators. Further analyses demonstrated that B cells in MG exhibited higher transcriptional activity towards plasma cell differentiation, CD4⁺ T cell subsets were unbalanced, and inflammatory pathways of monocytes were highly activated. Notably, we discovered a disease-relevant subgroup, CD180⁻ B cells. Increased CD180⁻ B cells in MG are indicative of a high IgG composition and were associated with disease activity and the anti-AChR antibody. Together, our data further the understanding of the cellular heterogeneity involved in the pathogenesis of MG and provide large cell-type-specific markers for subsequent research.

The role of single nucleotide polymorphisms, contained in proinflammatory cytokine genes, in the development of congenital infection with human cytomegalovirus in fetuses and neonates

PURPOSE

The research project targeted the distribution of genotypes, alleles and haplotypes in single nucleotide polymorphisms (SNPs) within the interleukin (IL) 1A, IL1B, IL6, IL12B and TNFA genes, in fetuses and neonates, congenitally infected with human cytomegalovirus (HCMV), and among uninfected controls.

METHODS

The study included 20 fetuses and neonates with congenital HCMV infection and 31 control individuals. The genotypes in SNPs of the studied cytokine genes were identified by a self-designed nested PCR-RFLP assays. Selected genotypes, representing distinct variants in analyzed polymorphisms, were confirmed by sequencing. The relationship between the genetic status of the studied polymorphisms and congenital infection development was estimated, using a logistic regression model.

RESULTS

The CT haplotype, composed of C allele determined in IL1A -889 C > T and T allele in IL1B +3954 C > T SNP, increased the risk of congenital HCMV infection, as well as the onset of disease related symptoms (P ≤ 0.0001). Considering disease outcome, the risk of development of symptoms, was increased among the CT heterozygotes in IL1A -889 C > T polymorphism (OR 2.86, 95% CI 0.24-33.90; P = 0.045). Moreover, multiple-SNP variants CCGAG in the range of all the SNPs, analyzed in the study, increased the risk of congenital infection with HCMV (OR 7.94, 95% CI 1.38-45.69; P = 0.026).

CONCLUSIONS

Polymorphisms within the proinflammatory cytokine genes may contribute to the development of congenital infection with HCMV.

Implications of cytokine gene polymorphisms on the orchestration of the immune response: lessons learned from oral diseases

Over the past 10 years, a plethora of information concerning the influence of gene polymorphisms on cytokine expression has been made available in the literature. Significant contribution to this field has come from studies of oral diseases, one of the widest spread health problems in the world, affecting hundreds of millions worldwide. Here we will discuss the importance of studies of gene polymorphism towards the identification of susceptible groups or prognostic indicators of oral disease. Additionally, we will highlight the differences in data obtained from genetically diverse populations and review the application of cytokine gene polymorphisms studies in oral diseases in autoimmune processes and parasitic infections.

IL1A alleles associate with a virological response to antiretroviral therapy in HIV patients beginning therapy with advanced disease

Among Australians treated for advanced HIV disease, a suboptimal virological response was associated with allele 2 at interleukin 1 alpha (IL1A)-889 and IL1A+4845. This is confirmed and investigated using patients from AIDS Clinical Trials Group study 384 (n=532). Among non-African-American patients with CD4 T-cell count of< or = 100 cells/microl at baseline, IL1A+4845(*)TT was associated with poor virological outcome (P=0.03). Differences were smaller with higher baseline CD4 T-cell counts. IL1A-889 and IL1A+4845 were not in linkage disequilibrium in African-American patients, and IL1A+4845(*)T did not affect outcome.

Polymorphisms of interferon-γ, interleukin-10, and interleukin-12 genes in myasthenia gravis

To assess the involvement of polymorphisms in genetic susceptibility to myasthenia gravis (MG), this study analyzed four polymorphisms of interferon (IFN)-gamma, interleukin (IL)-10, and IL-12 genes in 115 patients and 204 healthy controls (HC). IFNG +874T carriers were less frequent in MG, in patients with anti-acetylcholine receptor (AChR) (63%) and anti-titin (56.2%) antibodies compared with HC (p = 0.01 for all, OR: 0.5, 0.5, and 0.4, respectively). The presence of thymoma was also associated with lower frequency of IFNG +874T allele (p = 0.018, OR = 0.34). At IL10, -2763A allele was found to be slightly more frequent in MG and in patients with anti-AChR than in HC group (p = 0.05, OR = 1.7, p = 0.036, OR = 1.83). However, these associations did not remain significant after correction for multiple comparisons. IL12B allele distribution was not different among groups. These data suggest that some cytokine gene polymorphisms may contribute to susceptibility to or antibody production in MG. These findings need to be replicated in further studies.

The IL1A (?889) gene polymorphism is associated with chronic periodontal disease in a sample of Brazilian individuals

BACKGROUND AND OBJECTIVE

It has been proposed that genotypes reflective of polymorphisms in cytokine genes can predispose individuals to disease by enhancing inflammatory processes. The C/T polymorphism at position -889 of the IL1A gene influences interleukin-1alpha expression, with the T allele inducing higher expression. The aim of this study was to evaluate the association of the IL1A (-889) gene polymorphism in Brazilian individuals with different clinical forms of periodontitis and severity of disease.

MATERIAL AND METHODS

DNA was obtained from oral swabs of 163 Brazilian individuals and was amplified using the polymerase chain reaction (PCR). Products were submitted to digestion and were analyzed by electrophoresis to distinguish the C and T alleles.

RESULTS

A significant difference in the genotype distribution was observed when comparing the chronic periodontitis group with the control group, evaluating only nonsmokers (chi-squared analysis = 9.91; p = 0.007), as well as when smokers were included (chi-squared analysis = 6.36; p = 0.04). Moreover, we observed a higher incidence of the T allele in the chronic periodontitis group (37.8%) when compared with the control group (18.4%) in nonsmokers (p = 0.006, odds ratio = 2.69, confidence interval = 1.27-5.68) and also when smokers were included (p = 0.03, odds ratio = 1.87, confidence interval = 0.98-3.56). No statistical difference was observed when the aggressive periodontitis group was compared with the control group. With regard to severity of disease, no statistical difference was observed.

CONCLUSION

These data show an association of the IL1A (-889) polymorphism with chronic periodontitis in Brazilian individuals.

Correlation between single nucleotide polymorphisms in a calprotectin subunit gene and risk of periodontitis in a Chinese population

S100A8, the light subunit of calprotectin, has been known to be associated with periodontal inflammation. The present study looked to detect whether three polymorphisms in the upstream region of the S100A8 gene are correlated with periodontitis. Three hundred and twenty one subjects, including chronic periodontitis (CP) patients, aggressive periodontitis (AgP) patients and periodontally healthy controls, were recruited. The SNPs rs3795391, rs3806232 and rs3885688 were analyzed by PCR-RFLP analysis. No person carried the rs3885688 polymorphism in this cohort. For the other two polymorphisms, the combined effects of genotype/allele and gender were shown to be associated with the risk of periodontitis using multivariate logistic regression analysis. The G+ genotype/G allele may be considered to exert a significant protective effect in males against AgP (Genotype: rs3795391: P= 0.032, rs3806232: P= 0.017; Allele: rs3795391: P= 0.024, rs3806232: P= 0.013). Although the combined effects of genotype and gender on CP susceptibility were not observed for these two polymorphisms, there does seem to be increased risk of CP in males with allele A compared to females with allele A (rs3795391: P= 0.008; rs3806232: P= 0.009). Hence we found an important association between polymorphisms in the S100A8 gene and periodontitis in a Chinese population.

Association study of genetic variants of pro-inflammatory chemokine and cytokine genes in systemic lupus erythematosus

Background

Several lines of evidence suggest that chemokines and cytokines play an important role in the inflammatory development and progression of systemic lupus erythematosus. The aim of this study was to evaluate the relevance of functional genetic variations of RANTES, IL-8, IL-1α, and MCP-1 for systemic lupus erythematosus.

Methods

The study was conducted on 500 SLE patients and 481 ethnically matched healthy controls. Genotyping of polymorphisms in the RANTES, IL-8, IL-1α, and MCP-1 genes were performed using a real-time polymerase chain reaction (PCR) system with pre-developed TaqMan allelic discrimination assay.

Results

No significant differences between SLE patients and healthy controls were observed when comparing genotype, allele or haplotype frequencies of the RANTES, IL-8, IL-1α, and MCP-1 polymorphisms. In addition, no evidence for association with clinical sub-features of SLE was found.

Conclusion

These results suggest that the tested functional variation of RANTES, IL-8, IL-1α, and MCP-1 genes do not confer a relevant role in the susceptibility or severity of SLE in the Spanish population.

The chemokine CXCL13 is a key molecule in autoimmune myasthenia gravis

Myasthenia gravis (MG) is associated with ectopic germinal centers in the thymus. Thymectomy and glucocorticoids are the main treatments but they induce operative risks and side effects, respectively. The aim of this study was to propose new therapies more efficient for MG. We hypothesized that molecules dysregulated in MG thymus and normalized by glucocorticoids may play a key role in thymic pathogenesis. Using gene chip analysis, we identified 88 genes complying with these criteria, the most remarkable being the B-cell chemoattractant (CXCL13). Its expression was increased in thymus and sera of glucocorticoid-untreated patients and decreased in response to treatment in correlation with clinical improvement. Normal B cells were actively chemoattracted by thymic extracts from glucocorticoid-untreated patients, an effect inhibited by anti-CXCL13 antibodies. In the thymus, CXCL13 was preferentially produced by epithelial cells and overproduced by epithelial cells from MG patients. Altogether, our results suggest that a high CXCL13 production by epithelial cells could be responsible for germinal center formation in MG thymus. Furthermore, they show that this gene is a main target of corticotherapy. Thus, new therapies targeting CXCL13 could be of interest for MG and other autoimmune diseases characterized by ectopic germinal center formation.

IL-1 receptor antagonist-mediated therapeutic effect in murine myasthenia gravis is associated with suppressed serum proinflammatory cytokines, C3, and anti-acetylcholine receptor IgG1

In myasthenia gravis (MG), TNF and IL-1beta polymorphisms and high serum levels of these proinflammatory cytokines have been observed. Likewise, TNF and IL-1beta are critical for the activation of acetylcholine receptor (AChR)-specific T and B cells and for the development of experimental autoimmune myasthenia gravis (EAMG) induced by AChR immunization. We tested the therapeutic effect of human recombinant IL-1 receptor antagonist (IL-1ra) in C57BL/6 mice with EAMG. Multiple daily injections of 0.01 mg of IL-1ra administered for 2 wk following two AChR immunizations decreased the incidence and severity of clinical EAMG. Furthermore, IL-1ra treatment of mice with ongoing clinical EAMG reduced the clinical symptoms of disease. The IL-1ra-mediated suppression of clinical disease was associated with suppressed serum IFN-gamma, TNF-alpha, IL-1beta, IL-2, IL-6, C3, and anti-AChR IgG1 without influencing total serum IgG. Therefore, IL-1ra could be used as a nonsteroidal drug for the treatment of MG.

Association analysis between interleukin-1 family polymorphisms and generalized aggressive periodontitis in a Chinese population

BACKGROUND

It has been suggested that aggressive periodontitis (AgP) has a genetic basis, but this theory has not been confirmed. The intent of this investigation was to study whether specific interleukin (IL)-1 genotypes and/or alleles could be used to predict susceptibility to generalized AgP (GAgP) in Chinese.

METHODS

The GAgP group consisted of 122 patients, and the control group included 95 healthy subjects. Single nucleotide polymorphisms at IL-1A (+4845) and IL-1B (-511, +3954) were analyzed by standard polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The polymorphism of a variable number tandem repeat (VNTR) in intron 2 of IL-1RN was detected by PCR amplification and fragment size analysis.

RESULTS

There was no significant association of IL-1 polymorphisms with GAgP in the unstratified subjects. However, when cases were stratified by gender, the frequencies of A2+ genotype and allele 2 at IL-1A +4845 were significantly increased in male patients compared to male controls (genotype: odds ratio [OR] 5.58, 95% confidence interval [CI]: 1.09 to 28.68, P = 0.039; allele: OR 4.97, 95% CI: 1.01 to 24.50, P = 0.049; adjusted for age and smoking status). The frequency of IL-1B -511 A1/A2 heterozygote was significantly increased in male GAgP group compared to male controls (adjusted OR 3.16, 95% CI: 1.01 to 9.89, P = 0.048). In females, no significant differences were found between patients and controls in corresponding analyses at all polymorphic loci. A possible combined effect of IL-1B -511 polymorphism and smoking on the elevated risk to GAgP was observed. The OR of GAgP for combined A2+ genotype and smoking was 12.45 (95% CI: 1.43 to 108.06, P = 0.022), and for combined allele 2 and smoking was 18.25 (95% CI: 2.32 to 143.86, P = 0.006).

CONCLUSIONS

The polymorphisms of IL-1A +4845 and IL-1B -511 may play an important role in determining GAgP susceptibility in Chinese males. Furthermore, a possible combined effect of the polymorphism of IL-1B -511 and smoking on GAgP susceptibility was suggested.

Interleukin-1 gene cluster polymorphisms and susceptibility to clinical malaria in a Gambian case-control study

Interleukin-1 (IL1) is a potent endogenous pyrogen and inducer of the acute phase response, and these innate immune responses are an important part of the human host's initial reaction to infection by the malaria parasite. In addition, several single-nucleotide polymorphisms (SNPs) in this region have previously been demonstrated to be associated with susceptibility to infectious disease. Therefore, a possible association with malaria susceptibility was investigated. A total of 13 polymorphic markers were used in a two-stage screening strategy to genotype a Gambian case-control study group by either restriction endonuclease digestion or the Sequenom MassARRAY assay. This involved an initial screen of 188 severe cases and 188 mild controls, and if there was a significant association with a malaria phenotype (P<0.05); this was followed by screening of the remaining 1044 samples. Two markers showed significant association with malaria: interleukin-1 alpha +4845 G --> T (P=0.035 for mild malaria versus controls) and interleukin-1 beta +3953 C --> T (P=0.030 for mild malaria versus severe malaria). Haplotypes constructed using the SNPHAP programme were not associated with any of the malaria phenotypes investigated. In summary, if IL1 variants are involved in malaria susceptibility in the Gambia at all, then the effects are small.