Analysis of CD28 and CTLA-4 gene polymorphisms in Turkish patients with Behcet's disease

The CD28 IVS3 + 17 T/C polymorphism and the GVHD occurrence in Tunisian patients receiving an HLA-identical sibling HSCs transplant

Graft-versus-host disease (GVHD) is a potentially serious complication ofallogeneic hematopoietic stem cell transplantation (HSCT). Graft-contaminating T cells (donor T cells) arecrucial for the development ofGVHD since they are able to react against the recipient's antigens. In this study we aim toevaluatethepotentialassociation between the IVS3 + 17 T/C gene variation in the CD28 molecule, a T cells costimulatory factor, and the GVHD occurrence in a Tunisian group of recipients of allo-HSCTs. Results show that there is an association between the presence of this polymorphism and the occurrence of grades II-IV acute GVHD (OR: 2.470, I.C: 1.027-5.938, p = 0.043). As for the chronic GVHD, it seems that the studied gene variation has no impact on the occurrence of this complication, which appeared likely to be affected by the HSCT graft source (PBSC: peripheral blood stem cells) (OR: 5.141, I.C: 1.590-16.620, p = 0.006). Based on these data, we believe that the CD28 IVS3 + 17 T/C polymorphism is a significant factor in the pathogenesis of acute GVHD.

A Darwinian View of Behçet's Disease

Behçet's disease (BD) is a multisystem inflammatory disorder of unknown etiology, characterized by oral and genital ulceration, with other complications including eye, skin, joint, and central nervous system (CNS) lesions. Diagnosis is based on clinical findings, which may differ between patients. There is a strong genetic basis for BD; however, only a few genes have been associated with the disease across the geographical spread of BD. In this article, we discuss the history and combination of genes involved in this complex disease in relation to the geographical range and present our view that the disease has developed from a Darwinian perspective, with different gene polymorphisms that affect the same biological pathway. Moreover, these mutations individually are protective mechanisms against the disease relevant to each region, which affected both archaic and modern humans.

Cytotoxic T Lymphocyte Antigen 4 Gene +49 A/G (rs231775) Polymorphism and Susceptibility to Systemic Lupus Erythematosus

AIM

To assess the probable role of +49AG polymorphism in susceptibility to SLE in an Egyptian population.

BACKGROUND

Systemic lupus erythematosus (SLE) is a compound inflammatory chronic disease distinguished through the release of autoantibodies. Cytotoxic T lymphocyte associated antigen-4 is a main down controller of T-cell response; its dysregulation could affect SLE pathogenesis by altered T cells activation to self-antigens.

OBJECTIVES

To evaluate the CTLA-4 +49AG allelic and genotype frequency in a sample of the Egyptian population and correlate them with disease susceptibility and clinical severity.

MATERIALS AND METHODS

Including 100 patients with SLE and 100 healthy controls (age and gender matched), CTLA-4 exon 1 49 A>G Genotyping was done using Real-Time PCR.

RESULTS

No difference was noticed in genotype or allele distributions of the studied polymorphism between both groups. Similar genotypes and allele frequencies were established for the 2 groups after their stratification by the age of disease onset, clinical course, or severity.

CONCLUSION

CTLA-4 +49AG gene polymorphism is not linked with the liability to develop SLE in the studied Egyptian population. Yet it is significantly related to disease severity.

The potential for immune checkpoint modulators in cerebrovascular injury and inflammation

Introduction: Neuroinflammation has been linked to poor neurologic and functional outcomes in many cerebrovascular disorders. Immune checkpoints are upregulated in the setting of traumatic brain injury, intracerebral hemorrhage, ischemic stroke, central nervous systems vasculitis, and post-hemorrhagic vasospasm, and are potential mediators of pathologic inflammation. Burgeoning evidence suggests that immune checkpoint modulation is a promising treatment strategy to decrease immune cell recruitment, cytokine secretion, brain edema, and neurodegeneration.Areas covered: This review discusses the role of immune checkpoints in neuroinflammation, and the potential for therapeutic immune checkpoint modulation in inflammatory cerebrovascular disorders. A search of Pubmed and clinicaltrials.gov was performed to find relevant literature published within the last 50 years.Expert opinion: The clinical success of immune-activating checkpoint modulators in human cancers has shown the immense clinical potential of checkpoint-based immunotherapy. Given that checkpoint blockade can also precipitate a pathologic pro-inflammatory or autoimmune response, it is plausible that these pathways may also be targeted to quell aberrant inflammation. A limited but growing number of studies suggest that immune checkpoints play a critical role in regulating the immune response in the central nervous system in a variety of contexts, and that immune-deactivating checkpoint modulators may be a promising treatment strategy for acute and chronic neuroinflammation in cerebrovascular disorders.

CD28 gene polymorphisms and acute cellular rejection after liver transplantation

The co-stimulatory molecule CD28 plays an important role in T-cell-mediated immune response like acute cellular liver transplant rejection. The aim of the retrospective case- control study was to examine whether the single nucleotide polymorphisms (SNPs) rs3116487, rs3116494, and rs3116496 of the CD28 gene are associated with acute cellular liver transplant rejection. The mentioned SNPs were genotyped in 147 liver transplant recipients without acute cellular rejection and 144 liver transplant recipients with acute cellular rejection by real-time endpoint genotyping. The genotype and allele frequencies of the SNPs did not show any significant differences between both groups. Haplotype analyzes of the SNPs also showed no association. Our data suggest that the analyzed SNPs are not major contributors to the susceptibility of acute cellular liver transplant rejection.

Association of CTLA-4 and CD28 Gene Polymorphisms with Type 1 Diabetes in South Indian Population

Each functional gene illustrates the complexity of genetic predisposition to disease; however, it is difficult to bring out these traits with reference to autoimmune diseases like type 1 diabetes (T1D). To find out the genetic contribution of CTLA-4 + 49A/G, CTLA-4 -318C/T and CD28 + 17T/C polymorphisms toward T1D, the present study was performed with 124 T1D patients, 54 siblings and 125 parents including 39 trios in South Indian population. The association and linkage of CTLA-4 + 49A/G, CTLA-4 -318C/T and CD28 + 17T/C polymorphisms with T1D were analyzed and transmission disequilibrium test was performed. CTLA-4 G allele carrying genotypes (GG+AG) showed a higher risk association and can be considered as susceptible to develop T1D among patients with age at diagnosis from 0 to 10 years as compared to siblings (OR = 2.9; p_c = 0.047) and parents (OR = 2.7; p_c = 0.036). On the other hand, a strong protection against the disease (age at diagnosis; 0-10 years) was observed with CTLA-4 + 49AA genotype (OR = 0.37; p_c = 0.036) and combined AA/CC genotype (OR = 0.31; p_c = 0.034) of CTLA-4 + 49A/G and CTLA-4 -318C/T polymorphisms. However, a significant association was not observed between CTLA-4 -318C/T and CD28 + 17T/C polymorphisms and T1D. This family-based study reports a strong association between possible genotypes of CTLA-4 gene polymorphism and T1D in South Indian population, particularly in younger individuals.

Genetics and Epigenetics Mechanism in the Pathogenesis of Behçet's Disease

BACKGROUND

Behçet's Disease (BD) is characterized by numerous systemic manifestations and is known for its ability to affect both, arteries and the veins. However, the etiology of BD is only partially understood, and previous studies have demonstrated a role for genetic and epigenetic factors that contribute to disease pathophysiology. Several studies have implicated T cells and monocytes in the pathogenesis of BD especially when these cells are stimulated by heat shock proteins and streptococcal antigen. Furthermore, during disease exacerbations adenosine deaminase has an important role in activating lymphocyte proliferation, maturation, and differentiation in BD. This article presents a review of the published literature mainly from the last 20 years. The topics of main concern were the role of genetic and epigenetic factors as contributing factors in disease pathophysiology.

RESULT AND CONCLUSION

The authors used MeSH terms "Behçet's disease" with "pathophysiology," "pathogenesis," "genetic" or "epigenetic" to search the PubMed database. All the relevant studies identified were included and are described according to the aforementioned subheadings.

Association Between the CD28 c.17 +3 T>C Polymorphism (rs3116496) and Cancer Risk: An Updated Meta-Analysis

BACKGROUND Numerous studies have been conducted on whether CD28 rs3116496 polymorphism affected cancer susceptibility, and these findings have been controversial. Thus, the purpose of this study was to assess the relationship between rs3116496 and susceptibility to cancer. MATERIAL AND METHODS The research published as of October 25, 2018 were comprehensively searched in PubMed, Embase, Cochrane Library and Chinese Wanfang database, CNKI, CBM. Statistical calculations performed using Stata12.0. RESULTS Overall analyses found that rs3116496 was a risk factor for cancer (C versus T, OR=1.14, 95% CI: 1.01-1.29, PH=0.003), and the heterogeneity was moderate (I²=53.3%). In subgroup analysis results by cancer types, the analysis showed that rs3116496 was a risk factor for breast cancer and leukemia. In the subgroup analysis by ethnicity, rs3116496 was a risk factor for cancer in the Asian population. After PHWE<0.05 was deleted, the analysis showed that rs3116496 might be related to the increased risk of colorectal cancer. CONCLUSIONS Our meta-analysis confirmed that rs3116496 was significantly related to cancer risk, especially in an Asian population, and was strongly correlated with the increased risk of breast cancer, leukemia and colorectal cancer.

Genetic Variation of Costimulatory Molecules, Including Cytotoxic T-Lymphocyte Antigen 4, Inducible T-Cell Costimulator, Cluster Differentiation 28, and Programmed Cell Death 1 Genes, in Iranian Patients With Leukemia

OBJECTIVES

There are limited studies about the possible relationship between genetic variations of costimulatory genes and susceptibility to hematologic malignancies like leukemia and lymphoma.

MATERIALS AND METHODS

This cross-sectional study included 59 leukemia patients. The polymorphisms of costimulatory molecules, including the CTLA-4 gene (-318 C/T, -1722 T/C, -1661 A/G, +49 A/G), PD-1 gene (1.3 A/G, 1.9 C/T), ICOS gene (1720 C/T), and CD28 gene (17 C/T), were analyzed by polymerase chain reaction-restriction fragment length polymorphism methods.

RESULTS

Our results showed that the TT genotype and T allele of the CTLA-4 -318 T/C polymorphism, the AA genotype of CTLA-4 +49 A/G polymorphism, and the CT genotype of PD-1 1.9 C/T polymorphism were significantly higher in healthy controls (P < .05). However, the AG genotype of the CTLA-4 +49 A/G, the CC genotype of the PD-1 1.9 C/T, and the CT genotype of the CD28 +17C/T polymorphism were significantly increased in patients with leukemia (P < .05). When the genotype frequency of costimulatory genes was compared between different leukemia groups, we observed that the A allele of the CTLA-4 +49 A/G and the CC genotype and C allele of the CD28 +17 C/T polymorphism were significantly higher in patients with acute leukemia than in those with chronic leukemia (P < .05). Among leukemia patients, the AA genotype of CTLA-4 +49A/G polymorphism was significantly increased in patients with acute myeloid leukemia, whereas the AG genotype was more prevalent in patients with acute lymphoblastic leukemia (P < .05).

CONCLUSIONS

We show for the first time that genetic variations of costimulatory molecules CTLA-4, CD28, and PD-1 may be associated with susceptibility of Iranian patients to leukemia.

A non-conserved amino acid variant regulates differential signalling between human and mouse CD28

CD28 superagonistic antibodies (CD28SAb) can preferentially activate and expand immunosuppressive regulatory T cells (Treg) in mice. However, pre-clinical trials assessing CD28SAbs for the therapy of autoimmune diseases reveal severe systemic inflammatory response syndrome in humans, thereby implying the existence of distinct signalling abilities between human and mouse CD28. Here, we show that a single amino acid variant within the C-terminal proline-rich motif of human and mouse CD28 (P²¹² in human vs. A²¹⁰ in mouse) regulates CD28-induced NF-κB activation and pro-inflammatory cytokine gene expression. Moreover, this Y²⁰⁹APP²¹² sequence in humans is crucial for the association of CD28 with the Nck adaptor protein for actin cytoskeleton reorganisation events necessary for CD28 autonomous signalling. This study thus unveils different outcomes between human and mouse CD28 signalling to underscore the importance of species difference when transferring results from preclinical models to the bedside.

CD28 transmits co-stimulatory signals for the activation of both mouse and human T cells, but in vivo hyperactivation of CD28 has opposite effects on system immunity. Here, the authors show that a single amino acid difference between mouse and human CD28 dictates this function distinction via differential recruitment of Nck.

Inducible T-cell costimulator (ICOS) and CD28 polymorphisms possibly play a role in the pathogenesis of chronic autoreactive urticaria

BACKGROUND

Clinical experience emphasizes the coexistence of chronic spontaneous urticaria (CSU) and autoimmune disturbances. In chromosome 2q33-34, there is a cluster of homologous genes that are considered promising candidate genes for susceptibility to autoimmune diseases.

AIM

To examine the possible role of polymorphisms in the genes for CD28 and inducible T-cell costimulator (ICOS) in the background of CSU.

METHODS

In total, 149 patients with CSU with positive autologous serum skin test were enrolled in the study. The healthy control (HC) group consisted of 100 healthy volunteers. In all subjects, the CD28 rs2140148 and rs3116496 and the ICOS rs6726035 polymorphisms were analysed. Disease severity was assessed by means of Urticaria Activity Score.

RESULTS

We found a statistically significantly lower prevalence of the ICOS rs6726035 TT genotype among patients with CSU compared with HCs. Furthermore, the haplotype rs2140148A, rs3116496T and rs6726035C presented a possible association with CSU. We did not find any association between the examined polymorphisms and either urticaria severity or age of disease onset.

CONCLUSIONS

Our results underline the role of autoimmune components in the pathogenesis of chronic autoreactive urticaria, and indicate it as a potentially genetically related disorder.

Association of killer cell immunoglobulin-like receptor (KIR) genes and their HLA ligands with susceptibility to Behçet's‎ disease

OBJECTIVES

Behçet's disease (BD) is a systemic inflammatory disorder with remissions and exacerbations. It is thought that defects in the natural killer (NK) cell repertoire may be involved in BD through killer cell immunoglobulin-like receptors (KIRs). This study aimed to evaluate KIR and HLA genes, their interactions in BD patients, and their associations with clinical manifestations.

METHOD

The presence or absence of KIR and HLA alleles and genotypes was analysed by polymerase chain reaction sequence-specific primer on genomic DNA of 397 BD patients and 300 healthy controls.

RESULTS

None of the KIR genes showed significant effects on BD susceptibility. HLA-C1^Asn80 showed a protective effect against BD, whereas HLA-C2^Lys80, HLA-B-Bw4^Ile80, HLA-B5, and HLA-B51 were associated with a susceptibility risk for BD. In the combination of KIR and HLA genes, the frequencies of HLA genotypes no. 2, 3, 5, and 8, and inhibitory KIR no. 4 were significantly higher in patients than in controls. The frequencies of KIR genotype no. 3 and HLA genotypes no. 1, 4, 6, 7, and 9 were significantly lower in patients than in controls. There were many associations between KIR and HLA genes with clinical features of BD.

CONCLUSION

Differences in the frequency of HLA genes, KIR-HLA interactions, and genotypes between BD and healthy controls and their associations with clinical manifestations indicate that NK cells are involved in BD pathogenesis. The observed differences indicated an NK cell activity imbalance in BD patients, and suggest a role of the KIR-HLA repertoire in the development of BD.

CTLA4 and CD28 Gene Polymorphisms with Respect to Affective Symptom Domain in Schizophrenia

BACKGROUND

Accumulating evidence indicates that immune alterations in schizophrenia are due to genetic underpinnings. Here, we aimed at investigating whether polymorphisms in CTLA4 and CD28 genes, encoding molecules that regulate T-cell activity, influence schizophrenia symptomatology.

METHOD

We recruited 120 schizophrenia patients and 380 healthy age- and sex-matched controls. We divided the patients into two groups: one with no co-occurrence between psychotic and affective symptoms and the second one with psychotic symptoms dominating in the clinical manifestation, although also with occasional affective disturbances in the course of illness.

RESULTS

Among the patients with co-occurring affective symptoms, there were significantly more CTLA4 c.49A>G[A] alleles (p = 0.018, odds ratio (OR) 2.03, 95% confidence interval (CI) 1.2-3.66) and more CTLA4 g.319C>T[T] alleles (p = 0.07, OR 1.93, 95% CI 0.94-4.13) in comparison to the second group. Additionally, we have shown that CD28 c.17 + 3T>C[C+] were more significantly overrepresented among patients with co-occurring psychotic and affective symptoms (p = 0.0003, OR 3.36, 95% CI 1.69-6.68) than in patients without co-occurence between these symptoms (p = 0.012, OR 1.88, 95% CI 1.15-3.10).

CONCLUSION

CTLA4 and CD28 gene polymorphisms may not only act in immune deregulation observed in schizophrenia, but may also influence the course of the illness by modifying the susceptibility to the co-occurrence of psychotic and affective symptoms.

Behçet syndrome: from pathogenesis to novel therapies

Behçet syndrome is a chronic disease hallmarked by inflammation of the blood vessels that is related to an autoimmune reaction caused by inherited susceptibility due to specific genes and environmental factors, probably components of infectious microorganisms, which turn on or get going the disease in genetically susceptible subjects. The more common clinical expression of the disease is represented by a triple-symptom complex of recurrent oral aphthous ulcers, genital ulcers, and uveitis, sometimes associated with inflammatory arthritis, phlebitis, iritis, as well as inflammation of the digestive tract, brain, and spinal cord. The treatment strategies used to manage the manifestations of Behçet syndrome have gradually progressed, and a number of new therapeutic resources have been implemented in recent years, allowing better control of pathogenic mechanisms, reducing symptoms and suffering, and ameliorating patient's outcome.

The role of CTLA-4 exon-1 49 A/G polymorphism and soluble CTLA-4 protein level in egyptian patients with Behçet's disease

This study analyzed the association of the A/G SNP at position +49 of exon-1 in the CTLA-4 gene to the susceptibility and clinical manifestations of Behcet's disease (BD). It was performed on 60 Egyptian BD patients and 95 age- and sex-matched healthy controls. The genotypes for the +49 A/G polymorphism of the CTLA-4 gene were determined by PCR-RFLP, while the serum level of CTLA-4 protein was measured by ELISA. CTLA-4 +49 A allele (P < 0.001, OR = 3.084, and CI (95%) = 1.90-4.99) and A/A genotype (P < 0.001, OR = 6.643, and CI (95%) = 2.58-17.10) frequency distribution was significantly more increased in patients than in the controls, with no significant differences between males and females with regard to the genotype or allele frequency distribution. A/A genotype was associated with a more reduced expression of sCTLA-4 protein in patients than in the controls (1.76 ± 0.19 versus 1.91 ± 0.30, resp; P < 0.0007). In addition, it is associated with the occurrence of ocular and vasculitic manifestations of BD in the patient group. The CTLA-4 gene could be considered as a susceptibility and a disease-modifying gene to BD in Egyptian population that needs further confirmatory studies on larger cohorts.

Mevalonate kinase gene mutations and their clinical correlations in Behçet's disease

AIM

Genetics is suggested to play a role in the development of Behçet's disease (BD). Shared phenotipic features requires an approach to differential diagnosis from periodic febrile syndromes. We planned to study for mevalonate kinase (MVK) as a candidate for a susceptibility gene for Behçet's disease.

METHOD

Consecutive Behçet patients and apperently healthy subjects were included. Severity score of Behçet disease was calculated. Genotyping of mevalonate kinase gene was performed by polymerase chain reaction/sequence-based typing technique.

RESULTS

Fifty BD patients (median age: 38.30 ± 11.06 years) and 51 controls (median age: 33.88 ± 12.47 years) were recruited. Three types of mutations have been found: first, a single nucleotide polymorphism (SNP) c.769-38C>T (rs35191208) in 21 of 50 BD patients and in 15 of 51 controls. Both groups were comparable for the frequency of c.769-38C>T (P > 0.05). In all of the cases with c.769-38C>T, a second SNP, c885+24G>A (rs2270374) was also present (previously reported to be in linkage disequilibrium with the first SNP). A third SNP, c.769-7T>G (rs104895331) was found in three of 50 BD patients and in one of the control group. We found this SNP together with c769-38C>T and c.885+24G>A. The neurological involvement was found to be more frequent in the BD patients with c.769-3C>T when compared to the BD patients without this polymorphism (P = 0.012).

CONCLUSION

Our results suggested that the effects of MVK mutations in Behçet's disease could be an additional genetic susceptibility factor for the patients with neurological involvement. However, these results need confirmation in larger study populations and in different ethnic groups.

Interleukin-2 gene polymorphism in Turkish patients with Behçet's disease and its association with ocular involvement

Behçet's disease (BD) is a chronic immune-mediated systemic disease, characterized by oral and genital lesions and ocular inflammation. Several cytokine genes may play crucial roles in host susceptibility to BD, because the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphisms. The association of the interleukin (IL)-2 gene polymorphisms with the susceptibility to BD was investigated in this study. DNA samples were obtained from a Turkish population of 97 patients with BD and 76 healthy control subjects. Polymorphisms of IL-2 gene at position -330 and +166 were determined using the polymerase chain reaction with sequence-specific primers. In the patients with BD, there was a significantly increased frequency of IL-2 -330 GT genotype. Interestingly, we demonstrated that the frequencies of IL-2 -330 GT and IL-2 + 166 GG genotypes were increased in BD patients with ocular involvement, whilst IL-2 -330 TT genotype was significantly decreased. Also, analysis of allele frequency demonstrated that the presence of G allele at position +166 of IL-2 seems to be a risk factor for ocular involvement. These results reveal that IL-2 -330 GT genotype may be a susceptibility factor for BD, whereas IL-2 -330 TT genotype seems to display a protective association with BD. Additionally, IL-2 gene polymorphisms might be associated with ocular involvement in BD.

Association between Rho-kinase (ROCK2) gene polymorphisms and Behçet's disease

Behçet's disease (BD) is a multi-systemic vasculitis. The aim of this study was to investigate the association between Rho-kinase (ROCK2) gene polymorphisms and patients with BD in a Turkish population. A total of 194 BD patients and 276 healthy controls with similar age and sex were included to this study. Polymorphisms were analyzed in genomic DNA using a BioMark 96.96 dynamic array system. mRNA from blood samples was extracted, and real-time polymerase chain reaction was performed for ROCK2 gene expression. There were marked changes in both genotype (TT, 41.8%; TA, 30.3%) and allele (T, 57%; A, 43%) frequencies for the rs35768389 (Asp601Val) polymorphism in patients compared with controls (TT, 64.6%; TA, 9.4%, P < 0.0001; T, 69.3%; A, 30.7%, P = 0.0004). Although CC genotype (52.0%) of rs1515219 polymorphism were more frequent, CT genotype (27.7%) were less frequent among the patients than controls (CC, 31.7%, CT, 44.6%, P = 0.0001). There was an increase in C allele (65.8% vs 54.0%) and decrease in T allele frequencies (34.2% vs 46.0%, P = 0.001) in patients. However, no associations were found with rs726843, rs2290156, rs965665, rs10178332, rs2230774, rs6755196, rs10929732, and rs34945852 polymorphisms. There was an increase in peripheral blood mRNA ROCK2 expressions in patients. This is the first study to examine the involvement of ROCK2 gene variation in the risk of incident BD. The results strongly suggest that ROCK2 gene polymorphisms may modify individual susceptibility to BD in the Turkish population.

CTLA-4 exon 1 +49A/G polymorphism is associated with renal involvement in pediatric Henoch-Schönlein purpura

BACKGROUND

Henoch-Schönlein purpura (HSP) is a multisystemic vasculitis of unknown etiology. Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and CD28 have been reported to be important candidate genes for conferring susceptibility to autoimmunity. In this study, we investigated the correlation of CTLA-4 and CD28 gene polymorphisms with HSP in children with and without renal involvement.

METHODS

The CTLA-4 exon 1 +49A/G, promoter -318C/T and CD28 IVS3 +17T/C single nucleotide polymorphisms (SNPs) were genotyped in 110 children with HSP and 90 ethnically matched healthy controls through restriction fragment-length polymorphism (RFLP).

RESULTS

The CTLA-4 (+49) GG genotype and G allele (GG + AG genotype) were more common in HSP patients with renal involvement (n = 52) than in HSP patients without renal involvement (n = 58) (P = 0.019 and 0.001, respectively). There were no significant differences in the prevalence of CTLA-4 (+49 A/G), (-318C/T) and CD28 IVS3 (+17 /T/C) polymorphisms between HSP patients and controls.

CONCLUSIONS

Our findings suggest that the CTLA-4 +49 GG genotype and G allele may contribute to increased risk for the development of renal damage in HSP patients.

Investigation of CD28 gene polymorphisms in patients with sporadic breast cancer in a Chinese Han population in Northeast China

Background

CD28 is one of a number of costimulatory molecules that play crucial roles in immune regulation and homeostasis. Accumulating evidence indicates that immune factors influence breast carcinogenesis. To clarify the relationships between polymorphisms in the CD28 gene and breast carcinogenesis, a case-control study was conducted in women from Heilongjiang Province in northeast of China.

Methodology/Principal Findings

Our research subjects consisted of 565 female patients with sporadic breast cancer and 605 age- and sex-matched healthy controls. In total, 12 single nucleotide polymorphisms (SNPs) in the CD28 gene were successfully determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The relationship between the CD28 variants and clinical features, including histological grade, tumor size, lymph node metastasis, human epidermal growth factor receptor 2 (C-erbB2), estrogen receptor (ER), progesterone receptor (PR), and tumor protein 53 (P53) status were analyzed. A statistically significant association was observed between rs3116496 and breast cancer risk under different genetic models (additive P = 0.0164, dominant P = 0.0042). Different distributions of the rs3116496 ‘T’ allele were found in patients and controls, which remained significant after correcting the P value for multiple testing using Haploview with 10,000 permutations (corrected P = 0.0384). In addition, significant associations were observed between rs3116487/rs3116494 (D’ = 1, r² = 0.99) and clinicopathological features such as C-erbB2 and ER status, in breast cancer patients.

Conclusions/Significance

Our findings indicate that CD28 gene polymorphisms contribute to sporadic breast cancer risk and have a significant association with clinicopathological features in a northeast Chinese Han population.

New insights into the pathogenesis of Behçet's disease

Behçet's disease (BD) is a recurrent systemic inflammatory disorder of unknown origin characterized by oral and genital mucous ulcer, uveitis, and skin lesions. Involvement of large vessels, central nervous system (CNS), gastrointestinal tract and thrombotic events are less frequent but can be life threatening. The aim of this review is to provide new insights into the pathogenesis of BD. Over the past year substantial advances have been done in the understanding of the genetic [1,2] and immunology [3] of BD. BD is at the crossroad between autoimmune and autoinflammatory syndromes. In common with autoimmune diseases BD shares class I MHC association. However, in contrast to autoimmune disorders, BD has clinical features that seem to be mostly autoinflammatory. The pathogenesis of BD is still unknown, but major determinants of the genetic and immune system abnormalities have been reported recently. Triggering infectious factors are supposed to participate in the outbreak of BD in genetically predisposed patients. Two recent large genome-wide association study (GWAS) conducted in Turkey and Japan reported association between single nucleotide polymorphism (SNP) of interleukin (IL)-10 and IL-23R/IL-12RB2 genes and BD. New insights into the perturbations of T cell homeostasis of BD recently emerged. We have recently demonstrated the promotion of Th17 responses and the suppression of regulatory T cells (Tregs) that were driven by interleukin (IL)-21 production and that correlates with BD activity. Inflammatory cells within BD inflammatory lesions included mostly neutrophils, Th1 and Th17 cells, and cytotoxic CD8+ and γδ T cells. Altogether, the recent progresses in the knowledge of BD pathogenesis pave the way for innovative therapy.

Relationships between genetic polymorphisms of triggering receptor expressed on myeloid cells-1 and inflammatory bowel diseases in the Korean population

AIMS

Triggering receptor expressed on myeloid cells-1 (TREM-1) has been shown to play a crucial role in the propagation of inflammatory responses. Recent studies have reported that TREM-1 expression is up-regulated in patients with inflammatory bowel disease (IBD). Therefore, we investigated the associations between TREM-1 genetic polymorphisms and IBD development and its phenotypes in the Korean population.

MAIN METHODS

Three TREM-1 single nucleotide polymorphisms (SNPs, rs2234237, rs3789205, and rs9471535) were genotyped by Taqman technology on 202 Crohn's disease (CD), 265 ulcerative colitis (UC), 138 with intestinal Behcet's disease (BD), and 234 healthy controls and the relationships between these SNPs and IBD development and phenotypes were evaluated.

KEY FINDINGS

We found that TREM-1 SNPs are significantly associated with the development of intestinal Behcet's disease (rs9471535: odds ratio [OR]=1.637, P=0.025; rs3789205: OR=1.668, P=0.019; rs2234237: OR=1.691, P=0.016), and in particular with skin involvement (rs9471535: OR=2.723, P=0.009; rs3789205: OR=2.477, P=0.017; rs2234237: OR=2.278, P=0.030) and the risk of azathioprine use (rs9471535: OR=2.722, P=0.021; rs3789205: OR=2.493, P=0.032; rs2234237: OR=2.638, P=0.026). However, TREM-1 SNPs were not significantly associated with the development of Crohn's disease or ulcerative colitis.

SIGNIFICANCE

The results of our study suggest that TREM-1 SNPs may play a significant role in the development of intestinal Behcet's disease and may have modest effects on disease severity.

Altered expression of costimulatory molecules in Behçet's disease according to clinical activity

BACKGROUND

The reduced expression of molecules limiting excessive immune responses has been considered a pathogenic mechanism associated with autoimmune diseases.

OBJECTIVES

To understand the implications of costimulatory molecules in Behçet's disease (BD), the expression of CTLA-4 and PD-1 on T-cell subsets and of their ligands CD80, CD86 and PD-L1 on antigen-presenting cells (APCs) was investigated.

METHODS

Peripheral blood mononuclear cells (PBMC) from 11 patients with active BD, eight patients with inactive BD, eight patients with recurrent aphthous ulcers and 10 healthy volunteers as healthy controls (HC) were stimulated with phorbol myristate acetate and ionomycin. The expression of costimulatory molecules was then analysed by flow cytometry. Soluble CTLA-4 (sCTLA-4) concentrations were determined by enzyme-linked immunosorbent assay and the transcript level of PD-L1 was measured by real-time polymerase chain reaction. The PD-L1 expression in skin lesions of patients with BD was evaluated by immunohistochemistry.

RESULTS

Compared with the HC group, reduced expression of CTLA-4 in CD4+ T cells after stimulation was observed in the active BD group, with no difference in the production of sCTLA-4. CD86 expression, in the resting APCs, was reduced in the active BD group compared with the HC group. PD-L1 expression in the APCs was decreased in the active BD group with or without stimulation of cells. Concordantly, the mRNA levels of PD-L1 in PBMC, and PD-L1 expression in the cutaneous lesions, were low in the active BD group.

CONCLUSIONS

The results of this study suggest that altered expression of PD-L1, CTLA-4 and CD86 may be involved in the pathogenesis of BD.

CTLA-4 +49A>G polymorphism is associated with the risk but not with the progression of colorectal cancer in Chinese

PURPOSE

Colorectal cancer (CRC) is one of the most common malignancies in the world and a multipathway disease. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a potent immunoregulatory molecule that suppresses antitumor response by down-regulating T-cell activation. The most studied +49A>G polymorphism of CTLA-4 gene has been associated with several autoimmune or cancer diseases. Our aim was to investigate the association between this genetic variant and the risk as well as progression of colorectal cancer in Chinese.

METHODS

We conducted a case-control study of 124 colorectal cancer cases and 407 healthy controls. DNA was extracted from blood specimens, and +49A>G polymorphism in the CTLA-4 gene was genotyped by polymerase chain reaction-ligation detection reaction (PCR-LDR).

RESULTS

In our study group, the frequency of AG or GG or carrying at least one G allele at position +49 was significantly different in colorectal cancer patients and the control group, indicating that the risk of CRC was significantly higher among subjects with the AG or GG genotype or carrying at least one G allele at position +49 than among the subjects with the AA genotype. However, we observed no association between CTLA-4 +49A>G polymorphism and the progression of CRC. Interestingly, the CTLA-4 +49A allele was in non-significantly higher numbers in CRC patients with distant metastasis.

CONCLUSIONS

Our results suggested that CTLA-4 +49A>G polymorphism was associated with an increased risk of colorectal cancer, but this polymorphism did not play an important role in the progression of CRC in Chinese.

The skin pathergy test: innately useful?

Pathergy is the term used to describe hyper-reactivity of the skin that occurs in response to minimal trauma. A positive skin pathergy test (SPT), characterised by erythematous induration at the site of the needle stick with a small pustule containing sterile pus at its centre, is among the criteria required for a diagnosis of Behçet's disease (BD) and in certain population has been shown to be highly specific for this condition. Problems with standardising the induction manoeuvre for the SPT as well as the method of assessment of the response have limited the usefulness of the SPT in the clinical setting. Extensive investigation into histopathological and immunological aspects of pathergy has led to a number of hypotheses relating to the aetiology of the skin pathergy reaction and the disease itself, but the cause is considered to be unknown. Pathergy lesions, the development of new skin lesions or the aggravation of existing ones following trivial trauma, are also reported in pyoderma gangrenosum and has been noted in other neutrophilic dermatoses such as Sweet's syndrome. The response of such patient groups to the systematic application of the SPT has not been described. We propose that a new way of considering the pathergy reaction is to see it as an aberration of the skin's innate reactivity from a homeostatic reactive mode closely coupled to tissue healing to an abnormal destructive/inflammatory mode. Our understanding of BD and other similar conditions would profit by more detailed mechanistic knowledge of skin homeostasis to minimal trauma in both health and disease through a more structured and systematic use of the SPT.

HLA-B51/B5 and the risk of Behçet's disease: a systematic review and meta-analysis of case-control genetic association studies

OBJECTIVE

To quantify by meta-analysis the genetic effect of the HLA-B5 or HLA-B51 (HLA-B51/B5) allele on the risk of developing Behçet's disease (BD) and to look for potential effect modifiers.

METHODS

Relevant studies were identified using the PubMed Medline database and manual searches of the literature. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by using the random-effects model. Subgroup meta-analyses and meta-regression analyses were undertaken to investigate the effects of selected study-level parameters on the pooled OR. Heterogeneity was assessed using the I2 statistic. Pooled results were used to calculate population-attributable risks (PAR) for BD in relationship to HLA-B51/B5.

RESULTS

A total of 4,800 patients with BD and 16,289 controls from 78 independent studies (published 1975-2007) were selected. The pooled OR of HLA-B51/B5 allele carriers to develop BD compared with noncarriers was 5.78 (95% CI 5.00-6.67), with moderate between-study heterogeneity (I2 = 61%). The subgroup analyses stratifying studies by geographic locations (Eastern Asia, Middle East/North Africa, Southern Europe, Northern/Eastern Europe) yielded consistent OR ranges (5.31-7.20), with I2 ranges of 52-70%. Univariate random-effects meta-regression indicated the percentage of male BD cases (P = 0.008) as a source of heterogeneity. The PAR within the various geographic areas were estimated at 32-52%.

CONCLUSION

The strength of the association between BD and HLA-B51/B5, and its consistency across populations of various ethnicities, lends further support to this allele being a primary and causal risk determinant for BD. Variations according to sex support an interaction of this allele with BD characteristics.

Investigation of CTLA-4 and CD28 gene polymorphisms in a group of Turkish patients with colorectal cancer

Colorectal cancer (CRC), also called colon cancer or bowel cancer, includes cancerous growths in the colon, rectum and appendix. The immune system is an important defence mechanism against cancer and is often dysfunctional in patients with malignancies. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and CD28 genes encode receptors that provide negative and positive signals, respectively. Polymorphisms in these genes can affect their functions. In this study, we aimed to investigate the association of cancer with the frequencies and roles of CTLA-4/+49A > G (exon 1) and -318C > T (promoter), and CD28/IVS3 + 17T > C (intron 3 position + 17). These polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 218 Turkish subjects (56 patients with CRC and 162 healthy controls). No statistically significant differences in the genotype distributions of CTLA-4/+49GG (1.8% vs. 6.8%, odds ratio (OR) = 0.250, P = 0.305) and CTLA-4/-318TT (0% vs. 0.6%, OR = 1.006, P = 1.000), and CD28/IVS3 + 17CC (8.9% vs. 3.7%, OR = 0.2411, P = 0.155) between patients with CRC and healthy controls, were observed. We also found that there were no significant differences in the frequencies of CTLA-4/+49G (18.8% vs. 20.1%, OR = 0.920, P = 0.891) and CTLA-4/-318T (7.1% vs. 4.3%, OR = 1.653, P = 0.314), and CD28/IVS3 + 17C alleles (25.9% vs. 19.1%, OR = 1.353, P = 0.139) between two study groups. Present results suggested that CTLA-4 and CD28 gene polymorphisms did not play an important role in Turkish patients with CRC.

CTLA-4 +49 A/G genotype and HLA-DRB1 polymorphisms in Turkish patients with Henoch-Schönlein purpura

The pathogenesis of Henoch-Schönlein purpura (HSP) remains unknown; however, it is generally considered to be an immune complex-mediated disease. Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) is expressed on activated T cells, and, thus, it is critically involved in the immune response. We aimed to investigate the possible influence of CTLA-4 polymorphisms for susceptibility to HSP and determine if there were associations with human leukocyte antigen (HLA)-DRB1 genotypes. Using polymerase chain reaction-based DNA genotyping, we investigated the polymorphisms located in the genes encoding CTLA-4 in 100 patients with HSP and 156 ethnically matched healthy controls. When CTLA-4 +49 A/G polymorphism of HSP patients and control group was compared, no associations with joint, gastrointestinal or renal manifestations, or susceptibility to HSP, were observed. However, patients with nephrotic proteinuria had higher HLA-DRB1*13 positivity [odds ratio (OR) = 3.76, 95% confidence interval (95%CI) = 1.25-11.23, P = 0.025]. When the patients were stratified according to CTLA-4 polymorphism, a significant association between nephrotic proteinuria patients and carriage of the AG genotype was also found (OR = 15.42, 95%CI = 1.59-148.82, P = 0.008). These results suggested that CTLA-4 +49 A/G polymorphism does not contribute to susceptibility to HSP; however, the presence of CTLA-4 AG genotype and HLA-DRB1*13 could be a risk factor for developing nephrotic-range proteinuria in these patients.

Behçet's disease

PURPOSE OF REVIEW

To summarize recent scientific developments in the epidemiology, genetics, pathogenesis and treatment of Behçet's disease.

RECENT FINDINGS

Important genetic and immunologic studies were performed. Tumor necrosis factor-alpha-1031C allele was associated with disease susceptibility. Polymorphisms in interleukin-10, IL-8 and CD28 genes were also associated with Behçet's disease. Association with endothelial nitric oxide synthase gene polymorphism was confirmed but was ethnic related. Significant T helper type 1 immune reaction was reconfirmed in recent studies, especially during active phases, but T helper type 2 reaction may also play a role. Interleukin-12B heterozygosity is associated with Behçet's disease susceptibility and plays an important role in mediating T helper type 1 antistreptococcal immune response. Selenium binding protein may be a target antigen in Behçet's uveitis. Pathergy reaction is most frequently positive in the forearm; multiple needle pricks increase positive rate. Experience with anti-tumour necrosis factor therapy for various manifestations is increasing. Cyclosporin A treatment may be associated with new onset of neuro-Behçet. There is a high prevalence of headaches with moderate or severe disability. Cardiac manifestations include left ventricular dysfunction and coronary flow abnormalities. Anti-Saccharomyces cerevisiae antibodies may be especially common in intestinal Behçet's disease and are also increased in healthy relatives of patients.

SUMMARY

Considerable progress has been made, particularly in understanding the immunologic and genetic basis of the disease. The importance of novel serological markers and autoantigens merits further investigations.

Relationship between periodontal findings and specific polymorphisms of interleukin-1alpha and -1beta in Turkish patients with Behçet's disease

Genetic factors predispose individuals to Behçet's disease (BD) and periodontal disease. IL-1 has been implicated in the pathogenesis of both BD and periodontal disease. The relationship between periodontitis and pathogenesis of BD has not yet been determined. Since IL-1 has been implicated in the pathogenesis of both BD and periodontal disease, we aimed to investigate the possible relation of the periodontal scores and SNPs of IL-1alpha-889C/T, IL-1beta-511C/T, and IL-1beta+3962T/C with BD compared to healthy controls (HC) and recurrent aphtous stomatitis (RAS). A total of 155 Turkish individuals were enrolled in this study. The periodontal status of all subjects was evaluated according to the WHO community periodontal index of treatment needs. For genotyping, CTS-PCR-SSP was employed. IL-1alpha-889C allele was significantly higher in BD patients (p = 0.03) and RAS (p = 0.02) compared to HC. The frequency of IL-1beta+3962T allele was significantly higher in RAS patients compared to HC (p = 0.015). Male gender (p = 0.04), age (p = 0.02) and carrying IL-1beta-511T allele (p = 0.01) were found to be a significant risk factors for higher periodontal scores in Turkish population. We can speculate that susceptibility to the development of periodontal disease could be influenced by IL-1 SNPs. Periodontitis-induced autoinflammatory response also may play a role in the development/severity of BD and RAS via IL-1 gene alteration.

No association of KIR genes with Behcet's disease

Behcet's disease (BD) is thought to be caused by multiple genetic, environmental and immunological factors, one of the most prominent being the strong association with human leucocyte antigen (HLA)-Bw51, an HLA-Bw4-associated allele. We examined the presence/absence of 14 killer cell immunoglobulin-like receptors (KIRs) and their ligands in 134 Turkish individuals with BD and compared the results with those of 154 ethnically matched controls. Although KIR3DL1 with its ligand (HLA-Bw4) was significantly increased in the patients with BD (P = 0.0003), this no longer applied when the patients and controls were categorised by HLA-Bw51 status. Thus, no association was identified between presence or absence of any of the 14 KIR genes studied and BD. In addition, we did not find any associations of KIR with various manifestations of the disease nor with gender or age of onset.