Investigation of the association between the genetic polymorphisms of the co-stimulatory system and systemic lupus erythematosus

CD28 and CTLA4 polymorphisms associated with ankylosing spondylitis: a study in the context of HLA-B27

BACKGROUND

The human leukocyte antigen (HLA)-B27 gene is highly associated with ankylosing spondylitis (AS). However, not everyone who carries the HLA-B27 antigen develops AS, indicating that factors beyond the HLA-B27 gene contribute to the disease's onset. AS is an autoimmune disease in which co-stimulatory systems have been widely explored. Therefore, we aimed to analyze the association between single-nucleotide polymorphisms (SNPs) in co-stimulatory/inhibitory molecules and AS to identify other key factors involved in developing the disease.

RESULTS

This study recruited 32 patients with AS and 32 controls. DNA was extracted from whole blood, and PCR amplification was performed to target the promoter regions of the CTLA4, CD28, and PDCD1 genes. Chi-square and Fisher's exact tests were used under various genetic models to assess differences in genotype and allele distribution between cases and controls. The results showed that rs201801072 of the CD28 gene (TT + CT vs. CC, p = 0.001) and rs11571319 of the CTLA4 gene were associated with AS (GG vs. AG + AA, p = 0.001). Logistic regression analysis showed that rs201801072 (CD28) and rs11571319 (CTLA4) were independently associated with AS. A significant positive interaction was observed between these SNPs and HLA-B27 positivity, further increasing the risk of AS (T-allele: OR = 6.15; G-allele: OR = 13.30, both p < 0.001). HLA-B27 carriers exhibited an extremely high risk of AS (OR = 65.0, p = 1.19E-06).

CONCLUSIONS

The elevated frequencies of specific alleles in AS patients compared to controls highlight the potential involvement of these SNPs as key factors in the pathogenesis of AS, offering new insights into the genetic mechanisms underlying the disease.

How Co-Stimulatory/Inhibitory Molecules Vary Across Immune Cell Subtypes in the Severity of Systemic Lupus Erythematosus Compared to Controls

BACKGROUND

Co-stimulatory and co-inhibitory molecules are critical to T cell responses and involved in the pathogenesis of systemic lupus erythematosus (SLE). This study aimed to comprehensively analyze the surface expression of these molecules in various phenotypic immune cells, comparing the differences between various levels of the severity in SLE and control groups.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll-Paque from blood samples of severe SLE patients (treatment with immunosuppressants), mild SLE patients (excluding those with persistent proteinuria or thrombocytopenia), and healthy controls (n = 10 each). PBMCs were stimulated for 48 h. The cells were stained with anti-CD3, CD4, CD28, PD-1, and CTLA-4 antibodies and analyzed by flow cytometry. Differences between groups were assessed using the Kruskal-Wallis test and Mann-Whitney U-test, with median values and statistical significance (p < 0.05) reported.

RESULTS

The results showed that CD28 expression was significantly higher in SLE patients compared to controls, with the highest levels in mild SLE. However, CD3+ CD28+ and CD4+ CD28+ cells were more prevalent in controls (p = 0.032 and 0.017, respectively). Mild SLE patients exhibited the highest CTLA-4 expression, with significant differences from severe SLE and controls (p = 0.030 and 0.037, respectively). PD-1 expression was lowest in severe SLE but highest in mild SLE within CD3+ CD4+ cells (p = 0.001). After 48 h of activation, CD4+ CTLA4+ and CD3+ CTLA4+ expression levels were significantly higher in controls compared to SLE groups.

CONCLUSIONS

Our study highlighted that the expression of CD28, CTLA-4, and PD-1 in lymphocytes and specific T cell subsets was various according the severity of SLE in patients, underscoring their roles in disease pathogenesis.

The susceptibility of single nucleotide polymorphisms located within co-stimulatory pathways to systemic lupus erythematosus

Introduction

Autoimmune diseases result from the loss of immune tolerance, and they exhibit complex pathogenic mechanisms that remain challenging to effectively treat. It has been reported that the altered expression levels of co-stimulatory/inhibitory molecules will affect the level of T/B cell activation and lead to the loss of immune tolerance.

Methods

In this study, we evaluated the gene polymorphisms of the ligand genes corresponding co-stimulatory system that were expressed on antigen-presenting cells (CD80, CD86, ICOSLG, and PDL1) from 60 systemic lupus erythematosus (SLE) patients and 60 healthy controls.

Results

The results showed that rs16829984 and rs57271503 of the CD80 gene and rs4143815 of the PDL1 gene were associated with SLE, in which the G-allele of rs16829984 (p=0.022), the A-allele of rs57271503 (p=0.029), and the GG and GC genotype of rs4143815 (p=0.039) may be risk polymorphisms for SLE.

Discussion

These SNPs are in the promoter and 3'UTR of the genes, so they may affect the transcription and translation activity of the genes, thereby regulating immune function and contributing to the development of SLE.

Association of STAT3 gene polymorphisms with systemic lupus erythematosus in a Chinese Han population

OBJECTIVE

Evidence supports the important role of STAT3 in SLE; however, association between STAT3 gene polymorphisms and SLE risk needs discussion.

METHODS

Three hundred SLE patients and 380 healthy controls from Chinese Han population were included. DNA is extracted from peripheral blood mononuclear cells and the clinical characteristics of patients are collected. STAT3 gene polymorphisms (rs6503695, rs744166, rs9912773, and rs12601982) were genotyped by the Kompetitive Allele-Specific PCR (KASP) method. SPSS 26.0 was utilized to analyze the genetic susceptibility of SLE and STAT3 gene polymorphisms.

RESULTS

Frequencies of genotypes CT, TT, and TT+CT were significantly lower in SLE patients compared with those in healthy controls with respect to rs6503695 (p = .007, p < .001, p = .001). Frequencies of rs744166 genotypes AG, AA, and AA+AG were decreased in SLE patients as compared to those in healthy controls (p = .034, p = .006, p = .009). The recessive models (CC vs GG+GC) for rs9912773 and (AA vs GG+GA) for rs12601982 were significantly related to SLE patients (p = .014, p = .035). Moreover, allele C of rs6503695 was related to optic nerve damage in SLE patients (p = .036). rs744166 allele G was correlated with positive rash and albuminuria in SLE patients (p = .006, p = .014). For rs9912773, SLE patients carrying genotype GG had higher serum C3 and C4 levels compared to genotype GC+CC (p = .029, p = .028). The rs12601982 allele G was strongly associated with positive hypocomplementemia in SLE patients (p = .034). SLE patients carrying genotypes GG, GC, and CC had different SLEDAI score for rs12601982 (GG vs GC vs CC, p = .003).

CONCLUSION

STAT3 gene polymorphisms associated with SLE susceptibility.

Finding the Common Single-Nucleotide Polymorphisms in Three Autoimmune Diseases and Exploring Their Bio-Function by Using a Reporter Assay

In clinical practice, it is found that autoimmune thyroid disease often additionally occurs with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). In addition, several studies showed that eye-specific autoimmune diseases may have a strong relationship with systemic autoimmune diseases. We focused on Graves' disease (GD) with ocular conditions, also known as Graves' ophthalmopathy (GO), trying to find out the potential genetic background related to GO, RA, and SLE. There were 40 GO cases and 40 healthy controls enrolled in this study. The association between single-nucleotide polymorphisms (SNPs) of the co-stimulatory molecule genes and GO was analyzed using a chi-square test. It showed that rs11571315, rs733618, rs4553808, rs11571316, rs16840252, and rs11571319 of CTLA4, rs3181098 of CD28, rs36084323 and rs10204525 of PDCD1, and rs11889352 and rs4675379 of ICOS were significantly associated with GO based on genotype analysis and/or allele analysis (p < 0.05). After summarizing the GO data and the previously published SLE and RA data, it was found that rs11571315, rs733618, rs4553808, rs16840252, rs11571319, and rs36084323 were shared in these three diseases. Furthermore, the bio-function was confirmed by dual-luciferase reporter assay. It was shown that rs733618 T > C and rs4553808 A > G significantly decreased the transcriptional activity (both p < 0.001). This study is the first to confirm that these three diseases share genetically predisposing factors, and our results support the proposal that rs733618 T > C and rs4553808 A > G have bio-functional effects on the transcriptional activity of the CTLA4 gene.

ICOS gene polymorphisms in systemic lupus erythematosus: A case-control study

The inducible T-cell costimulator (ICOS) may play an important role in adaptive immunity by regulating the interaction between T cells and antigen-presenting cells. Disruption of this molecule can lead to autoimmune diseases, in particular systemic lupus erythematosus (SLE). In this study, we aimed to explore the possible association between ICOS gene polymorphisms and SLE as well as their influence on disease susceptibility and clinical outcomes. A further objective was to assess the potential impact of these polymorphisms on RNA expression. A case-control study, including 151 patients with SLE, and 291 unrelated healthy controls (HC) matched in gender, and geographical origin, was performed to genotype two polymorphisms located in the ICOS gene: rs11889031 (-693 G/A) and rs10932029 (IVS1 + 173 T/C); using the polymerase chain reaction (PCR)-restriction fragment length polymorphism method. The different genotypes were validated by direct sequencing. The expression level of ICOS mRNA was assessed by quantitative PCR in peripheral blood mononuclear cells of SLE patients and HC. The results were analysed using Shesis and spss.20. Our results revealed a significant association between ICOS gene rs11889031 > CC genotype and SLE disease (codominant genetic model 1, (C/C vs. C/T), p = .001, odds ratio [OR] = 2.18 IC [1.36-3.49]); codominant genetic model 2, (C/C vs. T/T) p = .007, OR = 15.29 IC [1.97-118.5]); dominant genetic model, (C/C vs. C/T + T/T) p = .0001, OR = 2.44 IC [1.53-3.9]). Besides, there was a marginal association between rs11889031 > TT genotype and T allele with a protective role from SLE (recessive genetic model, p = .016, OR = 0.08 IC [0.01-0.63] and p = 7.6904E - 05, OR = 0.43 IC = [0.28-0.66], respectively). Moreover, statistical analysis indicated that the rs11889031 > CC genotype was linked with clinical and serological manifestations of SLE, including blood pressure, and anti-SSA antibodies production in SLE patients. However, the ICOS gene rs10932029 polymorphism was not associated with susceptibility to SLE. On the other side, we did not note any effect of the two selected polymorphisms on the level of ICOS mRNA gene expression. The study showed a significant predisposing association of the ICOS rs11889031 > CC genotype with SLE, in contrast to a protective effect of rs11889031 > TT genotype in Tunisian patients. Our results suggest that ICOS rs11889031 may act as a risk factor for SLE and could be used as a genetic susceptibility biomarker.

Exploring the Bio-Functional Effect of Single Nucleotide Polymorphisms in the Promoter Region of the TNFSF4, CD28, and PDCD1 Genes

In a prior study, we discovered that hematopoietic stem cell transplantation (HSCT) and/or autoimmune diseases, such as systemic lupus erythematosus, were associated with the rs1234314 C/G and rs45454293 C/T polymorphisms of TNFSF4, the rs5839828 C > del and rs36084323 C > T polymorphisms of PDCD1, and the rs28541784C/T, rs200353921A/T, rs3181096C/T, and rs3181098 G/A polymorphisms of CD28. However, the association does not imply causation. These single nucleotide polymorphisms (SNPs) are all located in the promoter region of these genes, so we used the dual-luminescence reporter assay to explore the effect of single nucleotide polymorphisms (SNPs) on transcriptional activity. For each promoter–reporter with a single SNP mutation, more than 10 independent experiments were carried out, and the difference in transcription activity was compared using one-way ANOVA and Tukey’s honestly significant difference test. The results showed that the G-allele of rs1234314 had 0.32 ± 0.09 times the average amount of relative light units (RLU) compared to the C-allele (p = 0.003), the T-allele of rs45454293 had 4.63 ± 0.92 times the average amount of RLU compared to the C-allele (p < 0.001), the del-allele of rs5839828 had 1.37 ± 0.24 times the average amount of RLU compared to the G-allele (p < 0.001), and the T-allele of rs36084323 had 0.68 ± 0.07 times the average amount of RLU compared to the C-allele (p < 0.001). The CD28 SNPs studied here did not affect transcriptional activity. In conclusion, the findings of this study could only confirm that the SNP had a bio-functional effect on gene expression levels. According to the findings, several SNPs in the same gene have bio-functions that affect transcriptional activity. However, some increase transcriptional activity while others decrease it. Consequently, we inferred that the final protein level should be the integration result of the co-regulation of all the SNPs with the effect on transcriptional activity.