Cytotoxic T-lymphocyte-associated Protein 4 Gene Research Articles

Programmed Death 1 and Cytotoxic T-Lymphocyte-Associated Protein 4 Gene Expression in Peripheral Blood Mononuclear Cells Can Serve as Prognostic Biomarkers for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a highly aggressive form of liver cancer with poor prognosis. The lack of reliable biomarkers for early detection and accurate diagnosis and prognosis poses a significant challenge to its effective clinical management. In this study, we investigated the diagnostic and prognostic potential of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) expression in peripheral blood mononuclear cells (PBMCs) in HCC. PD-1 and CTLA-4 gene expression was analyzed comparatively using PBMCs collected from HCC patients and healthy individuals. The results revealed higher PD-1 gene expression levels in patients with multifocal tumors, lymphatic invasion, or distant metastasis than those in their control counterparts. However, conventional serum biomarkers of liver function do not exhibit similar correlations. In conclusion, PD-1 gene expression is associated with OS and PFS and CTLA-4 gene expression is associated with OS, whereas the serum biomarkers analyzed in this study show no significant correlation with survival in HCC. Hence, PD-1 and CTLA-4 expressed in PBMCs are considered potential prognostic biomarkers for patients with HCC that can facilitate prediction of malignancy, response to currently available HCC treatments, and overall survival.

Evaluation of CTLA-4 (+ 49A/G) polymorphism association with rheumatoid arthritis in Egyptian patients

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is an inhibitory molecule that has an essential role in T-cell homeostasis and self-tolerance because of its inhibitory signals. Genetic polymorphisms in the CTLA-4 gene have been associated with several autoimmune diseases. We aimed to assess the association between the CTLA-4 +49 A/G polymorphism (rs231775) and rheumatoid arthritis (RA) in Egyptian RA patients. The study included 104 RA patients and 81 apparently healthy control individuals. The polymorphism was assessed using restriction fragment-length polymorphism analysis. Genotype distribution was compared between patients and controls under different models of inheritance. Under the codominant model, RA patients showed a higher frequency of AG and GG genotypes compared to the control subjects (p=0.0092). Under the dominant model, RA patients showed a higher frequency of AG and GG genotypes grouped together compared to control subjects (p=0.0026). Under the over-dominant model, the AG genotype was more frequent in RA patients compared to control subjects (p= 0.0395). No association was observed between CTLA-4 polymorphism rs231775 and RA using the recessive model (p=0.1356). A significant association was observed between carrying the G allele and the presence of RA (p=0.0032). In conclusion, our findings showed a positive association between the CTLA-4 gene +49 A>G polymorphism and RA. However, discrepancies in literature reflect both ethnic variability in CTLA-4 gene polymorphisms as well as the complex pathogenesis of RA.

Cytotoxic T-lymphocyte associated protein 4 (CTLA4) polymorphisms are linked to systemic lupus erythematosus: an updated meta-analysis

ABSTRACT Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) molecule controls T cell immune response. Functional single nucleotide polymorphisms (SNPs) in the CTLA-4 gene have been associated with several autoimmune diseases, including systemic lupus erythematosus (SLE). However, the genetic association of the CTLA-4 variants with vulnerability to SLE remained contradictory. We have conducted a current meta-analysis by combining the findings of prior published articles in order to make a conclusive statement. Various literature databases were screened with appropriate keywords to obtain relevant articles, and eligible reports were obtained using well-defined inclusion and exclusion criteria. Meta-analysis was performed by Comprehensive Meta-analysis V 3.3, and various statistical parameters such as odds ratio, 95% confidence interval, and probability values were computed. A total of 3847 SLE patients and 5278 healthy controls were considered in the present meta-analysis from 26 individual reports. A significant association of CTLA-4 +49 A/G (G vs. A: p=0.03, OR=1.47) and -1722 T/C (p=0.02, OR=0.87) polymorphisms were observed with susceptibility and resistance against the development of SLE, respectively. However, the other two SNPs in the CTLA-4 gene (-318 C/T and -1661 A/G) failed to establish a connection. Interestingly, subgroup analysis revealed an association of CTLA-4 +49 A/G with a predisposition to SLE only in the Asian population (G vs. A: p=0.04, OR=1.26, GG vs. AA: p=0.02, OR=1.84, AG vs AA: p=0.01, OR=1.44, GG+AG vs AA: p=0.01, OR=1.52) and not in Caucasians. The current meta-analysis suggests a significant CTLA-4 +49 A/G variant association with susceptibility to SLE development in overall and Asian populations. In contrast, the other variant, -1722 T/C, is linked with protection against SLE. However, further case-control studies in diverse ethnic populations are requisite.

CTLA4 Methylation and its Expression as a Prognostic Biomarker in Tobacco Users with and without Oral Squamous Cell CarcinomaA Protocol for Cross-sectional Study

Introduction: Oral Squamous Cell Carcinoma (OSCC) is characterised by immunosuppression mediated by evasion of ‘immune checkpoints’ by tumour cells. Cytotoxic T Lymphocyte Associated Protein 4 (CTLA4) is one of the immune checkpoint molecule whose role in oral carcinogenesis remains to be elucidated. Deoxyribonucleic Acid (DNA) methylation of CTLA4 promoter region holds potential as a biomarker for diagnosis and assessment of individuals at risk of developing OSCC. Need for the study: Immunotherapy is an emerging treatment modality in some cancers. Thus, better understanding of role of CTLA4 methylation in OSCC paves a way for newer strategies in immunotherapeutic. Aim: To assess the DNA methylation pattern of promoter region of CTLA4 gene and evaluate its expression in tobacco users with and without OSCC so that it can contribute as biomarker for diagnosis and prognosis of OSCC. Materials and Methods: The proposed longitudinal crosssectional study will be conducted at Sharad Pawar Dental College and Hospital, Maharashtra, India. It will evaluate promoter methylation and protein expression of CTLA4 gene in Smokeless Tobacco (SLT) users. There will be three groups: group A OSCC patients; group B normal individuals with SLT habit without any oral lesion; and group C normal individuals without SLT habit. Formalin Fixed Paraffin Embedded (FFPE) tissue blocks will be prepared from the biopsy obtained from total thirty nine participants. DNA methylation of CTLA4 promoter will be assessed using Methylation-Specific PCR (MS-PCR). In addition, the quantitative expression of CTLA4 will also be assessed using Immunohistochemistry (IHC).

Decreased Expression of Cytotoxic T Lymphocyte-associated Protein 4: A Risk Factor of Myocardial Infarction.

Cardiovascular diseases are the most prevalent disease worldwide and pose a considerable threat to human health. Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) plays a crucial role in the maintenance of immune diseases; however, its role in the progression of cardiovascular disorders is still unknown. The present study aimed to evaluate the relationship between CTLA-4 and myocardial infarction (MI). The Kyoto encyclopedia of genes and genomes database and the pathway studio database has revealed the role of CTLA4 as an inhibitory receptor on activated T cells. The relative expression of the CTLA-4 gene was assessed on the peripheral blood cells in 80 MI patients and 80 healthy individuals using quantitative real-time polymerase chain reaction (qRT-PCR) and also receiver operating characteristic (ROC) analysis was performed to evaluate the sensitivity and specificity of CTLA-4. We noticed the decreased expression of CTLA-4 levels in patients, compared to the control group (2.73±1.55 vs. 5.36±1.34). The study revealed the sensitivity of 0.89, specificity of 0.83, the accuracy of 0.9, and the area under the ROC curve (AUC) of 0.901 (95% CI: 0.727-0.776) for CTLA-4. The results highlighted the critical role of CTLA-4 as an inhibitory receptor in the maintenance of cardiovascular risks.

Nicotinic Acetylcholine Receptor Subunit Alpha-7 Mediates PD-L1 and CTLA-4 Expression in HepG2 Cells

Background: The liver is the largest solid organ in the body and has several unique immunological roles. The alpha7 subtype of nicotinic acetylcholine receptor (α7nAChR) is expressed in the liver and has different immunoregulatory effects. Programmed death ligand 1 (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) are two major checkpoints that act as a negative regulator of the immune system. In this study, we examined the effects of activation (with nicotine) and inhibition (with specific siRNA) of α7nAChR on the PD-L1 and CTLA-4 genes expression. Methods: Human hepatocellular carcinoma (HepG2) cell line was used to investigate the effects of treatment with low dose (1 μM) and high dose (10 μM) of nicotine on the PD-L1 and CTLA-4 expression. In addition to this, the effects of treatment with 100 nM concentration of specific siRNA targeting α7nAChR (α7-siRNA) were examined using quantitative real-time PCR. Results: Compared to untreated cells, the HepG2 cells treated with nicotine exhibited significant dose-dependent decreases in PD-L1 expression. Furthermore, nicotine has a biphasic effect on the CTLA-4 expression and decreased its expression in 10 μM concentration. The qRT-PCR revealed that α7-siRNA significantly reduced the mRNA levels of α7nAChR (P < 0.01). Also, compared to control cells, α7-siRNA treated cells exhibited significant increases in both PD-L1 and CTLA-4 expression. Conclusion: These experiments determined that nicotine treatment leads to decreases in PD-L1 and CTLA-4 expression. These effects are reversed by treatment with α7-siRNA, which indicates the involvement of α7nAChR related mechanisms in these processes.

Influence of cytotoxic T lymphocyte antigen 4 genetic variants on acute rejection in kidney transplant patients: precision medicine perspective

The most effective and common treatment for end-stage renal disease is kidney transplantation.The personalized approach to kidney transplantation, which utilizes precision medicine principles, determines distinctive genomics characteristics of candidates/recipients that must be taken into account. Cytotoxic T lymphocyte associated protein 4 (CTLA4) may be a suitable candidate gene for studying allograft rejection. The aim of this study was to understand whether we can consider two common variants of the CTLA4 gene as a risk factor of transplant rejection in a group of Iranian population. Totally, 169 kidney transplant recipients, including acute rejections (N=39) and non-rejection (N=130) groups who underwent transplantation were included in this study. The genotyping of rs5742909 (-318C/T) and rs231775 (+49A/G) variants of the CTLA4 gene were performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The AG genotype frequency of rs231775 variant was the same in both patients with and without a history of rejection while, none of those groups had homozygote genotype. In rs5742909, both CT and TT frequencies of patients with rejected transplant were lower than patients with a normal outcome. The results of the presented study suggest that rs231775 and rs5742909 of CTLA4 genetic variants are not linked to acute rejection who underwent kidney transplantation. So, these variants cannot be considered as risk factors of acute allograft rejection in a group of Iranian renal transplantation recipients. However, the transplantation precision medicine may be an important area for the improvement of patients outcome as the precision medicine has already entered clinical practice in kidney transplantation.

The Association Between Single-Nucleotide Polymorphisms of Co-Stimulatory Genes Within Non-HLA Region and the Prognosis of Leukemia Patients With Hematopoietic Stem Cell Transplantation.

To avoid graft rejection, the hematopoietic stem cells with matched classical human leukocyte antigen (HLA) alleles are the primary choice for clinical allogeneic transplantation. However, even if the fully HLA-matched hematopoietic stem cells are used for transplantation, some patients still have poor prognosis after hematopoietic stem cell transplantation (HSCT), suggesting that the HLA system was not the only determinant of the outcomes of HSCT. In this study, we investigated whether the single-nucleotide polymorphisms (SNPs) of the co-stimulatory genes within non-HLA regions were related to the outcomes of HSCT. The genomic DNAs of 163 patients who had acute leukemia and received HSCT and their respective donors were collected for analysis. Thirty-four SNPs located in the four co-stimulatory genes including cytotoxic T-lymphocyte associated protein 4 (CTLA4), CD28, tumor necrosis factor ligand superfamily 4 (TNFSF4), and programmed cell death protein 1 (PDCD1) were selected to explore their relationship with the adverse outcomes after transplantation, including mortality, cytomegalovirus infection, graft-versus-host disease, and relapse. Our results revealed that nine SNPs in the CTLA4 gene, five SNPs in the PDCD1 gene, two SNPs in the TNFSF4 gene, and four SNPs in the CD28 gene were significantly associated with the occurrence of adverse outcomes post-HSCT. These SNPs may play important roles in immune response to allografts post-HSCT and can be the targets for developing strategy to identify appropriate donors.

Upregulation of Cytotoxic T-Lymphocyte-Associated Protein 4 and Forkhead Box P3 Transcripts in Peripheral Blood of Patients with Bladder Cancer.

Background: Regulatory T cells (Tregs) play a key role in the progression of tumors. These cells express forkhead box P3 (FOXP3) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4), which are the potential targets for cancer immunotherapy. The present study aimed to evaluate FOXP3 and CTLA4 transcripts in patients with bladder cancer (BC) compared with healthy individuals.Methods: Transcripts of CTLA4 and FOXP3 genes in the peripheral blood mononuclear cells (PBMCs) of 50 patients with histologically confirmed BC and 50 healthy individuals were assessed at the Institute for Cancer Research, Shiraz University of Medical Sciences (Shiraz, Iran) during 2014-2016. RNA was extracted from PBMCs, then cDNA was synthesized and subjected to quantitative real-time PCR (qRT-PCR) using appropriate primers. Statistical analysis was performed using SPSS software (version 21.0).Results: Significantly higher amounts of CTLA4 and FOXP3 gene transcripts were found in the peripheral blood of BC patients compared with healthy individuals. The expression of both genes was significantly higher in patients with non-invasive and grade I/II BC. The median of CTLA4 and FOXP3 transcript expressions was 3.74 and 5.39, respectively, in non-invasive BC patients, which was significant compared with the control group (P=0.0016 and P=0.009, respectively). The median of target gene mRNA expression in grade I/II BC patients was 2.9 for CTLA4 and 6.61 for FOXP3, which was significant compared with the controls (P=0.013 and P=0.0037, respectively).Conclusion: This study highlights the functional activity of Tregs in early stages of bladder cancer and showed the importance of CTLA4 and FOXP3, when it comes to screening BC.

Association between CTLA-4 gene polymorphism and risk of rheumatoid arthritis: a meta-analysis.

Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) gene polymorphisms may be involved in the risk of Rheumatoid arthritis (RA). However, evidence for the association remains controversial. Therefore, we performed a meta-analysis to confirm the relationship between CTLA-4 gene polymorphisms and RA. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of association. Stratified analysis was conducted by ethnicity. In total, 66 case-control studies including 21681 cases and 23457 controls were obtained. For rs3087243 polymorphism, significant association was detected in Asians (A vs. G: OR=0.77, 95%CI=0.65-0.90, P=0.001; AA vs. GG: OR=0.67, 95%CI=0.48-0.94, P=0.02) and Caucasians (A vs. G: OR=0.89, 95%CI=0.86-0.93, P<0.00001; AA vs. GG: OR=0.81, 95%CI=0.75-0.88, P<0.00001). For rs231775 polymorphism, significant association was observed in the overall (G vs. A: OR =1.16, 95%CI=1.08-1.25, P<0.0001; GG vs. AA: OR=1.29, 95%CI=1.12-1.50, P=0.0006), and in Asians (G vs. A: OR=1.27, 95%CI=1.10-1.47, P=0.001; GG vs. AA: OR=1.58, 95%CI=1.24-2.01, P=0.0002), but not in Caucasians. However, there was no association between rs5742909 polymorphism and RA. This meta-analysis confirmed that rs3087243 and rs231775 polymorphism were associated with the risk of RA in both overall population and ethnic-specific analysis, but there was no association between rs5742909 polymorphism and RA risk.

Expression of the immune checkpoint receptors CTLA-4, LAG-3, and TIM-3 in β-thalassemia major patients: correlation with alloantibody production and regulatory T cells (Tregs) phenotype.

Alloimmunization is a serious complication in β-thalassemia major patients as a result of repeated blood transfusion. The immune checkpoint receptors play an important role in regulating immune system homeostasis and the function of the immune cells. This study aimed to evaluate the expression of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), lymphocyte activation gene 3 (LAG-3), and T-cell immunoglobulin and mucin domain-containing protein-3 (TIM-3) immune checkpoint molecules in β-thalassemia major patients with and without alloantibody. For this purpose, 68 β-thalassemia major patients with (34 patients) and without (34 patients) alloantibody as well as 20 healthy controls were enrolled. The expression of these genes was evaluated in different groups of patients by SYBR Green real-time PCR method. Our results showed that the mean expression of LAG-3 was significantly increased in thalassemia patients compared to the control group (*P < 0.001). However, there was no significant difference in expression of the CTLA-4 and TIM-3 as well as LAG-3 genes between patients with and without alloantibody (P > 0.05). A positive correlation was observed between the level of LAG-3 expression with markers associated with Treg function includingFOXP3 and GDF-15 genes in β-thalassemia major patients. Taken together, the LAG-3 molecule might have a more prominent role in the abnormality of the immune system in thalassemia patients especially the function of regulatory T cells (Tregs), prior to the CTLA-4 and TIM-3 genes.

The Association Between CTLA-4, CD80/86, and CD28 Gene Polymorphisms and Rheumatoid Arthritis: An Original Study and Meta-Analysis.

Background: Rheumatoid arthritis (RA) is related to several pivotal susceptibility genes, including cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and costimulatory molecule (CD80/CD86) genes. Although the connection between polymorphisms of CTLA-4 and CD86 genes in different populations of RA have been studied extensively, the results are controversial.Objective: To clarify the correlation in the Chinese Han population between CTLA-4, CD80/86, and CD28 gene polymorphisms, and RA susceptibility.Methods: A case-control study (574 RA patients and 804 controls) was conducted to determine the correlation between CTLA-4 rs231775 and rs16840252 gene polymorphisms, CD86 rs17281995 gene polymorphisms, and the risk of RA for the Chinese Han population. Furthermore, an additional meta-analysis, including three single nucleotide polymorphisms (SNPs) (CTLA-4 rs231775, CTLA-4 rs3087243, and CTLA-4 rs5742909) from 32 citations, including 43 studies, 24,703 cases and 23,825 controls was performed to elucidate the relationship between known SNPs in the CTLA-4 genes and RA for more robust conclusions.Results: The results showed that CTLA-4 rs231775 gene polymorphism decreased the RA risk (GA vs. AA, OR = 0.77, P = 0.025), whereas CTLA-4 rs16840252 and CD86 rs17281995 gene polymorphisms were not related to RA susceptibility. Stratification analyses by RF, ACPA, CRP, ESR, DAS28, and functional class identified significant associations for CTLA-4 rs231775 and rs16840252 gene polymorphisms in the RF-positive and RF-negative groups. A meta-analysis of the literature on CTLA-4 gene polymorphisms and RA risk revealed that the risk of RA was decreased by CTLA-4 rs231775 gene polymorphisms.Conclusions: The CTLA-4 rs231775 gene polymorphism decreased the risk of RA, whereas CTLA-4 rs16840252 and CD86 rs17281995 gene polymorphisms were not related to RA risk. A meta-analysis indicated that CTLA-4 rs231775 and rs3087243 gene polymorphisms decreased the risk of RA. To support these analytical results, additional clinical cases should be investigated in further studies.

Association of the genetic polymorphisms in inhibiting and activating molecules of immune system with rheumatoid arthritis: A systematic review and meta-analysis.

Several studies have demonstrated that the genetic polymorphisms in the genes encoding immune regulatory molecules, namely cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and CD28, play a fundamental role in susceptibility to rheumatoid arthritis (RA). Several disperse population studies have resulted in conflicting outcomes regarding the genetic polymorphisms in these genes and RA risk. This systematic review and meta-analysis study was performed to reach a conclusive understanding of the role of single-nucleotide polymorphisms (SNPs) of CTLA4-rs231775, CTLA4-rs5742909, and CD28-rs1980422 in susceptibility to RA. Databases (ISI Web of Science, MEDLINE/PubMed, and Scopus) were searched to find the case–control studies surveying the association of CTLA4 gene rs231775, CTLA4 gene rs5742909, and CD28 gene rs1980422 polymorphisms and RA susceptibility in different population until August 2020. Association comparison between the polymorphisms and RA proneness was assessed using pooled odds ratio (OR) and their corresponding 95% confidence interval. This study was conducted on 16 population studies, comprising 1078 RA patients and 1118 healthy controls for CTLA4-rs231775, 2193 RA patients and 2580 healthy controls for CTLA4-rs5742909, and 807 RA patients and 732 healthy controls for CD28-rs1980422. Analysis indicated that G-allele, GG and GA genotypes, and dominant model for rs231775, recessive model for rs5742909, and C-allele, CC and CT genotypes, and recessive model for rs1980422 were significantly associated with increased RA risk. This meta-analysis showed that genetic polymorphisms of both immune inhibitory and activating genes, including CTLA4-rs231775, CTLA4-rs5742909, and CD28-rs1980422 polymorphisms, may increase susceptibility to RA.

Up-regulation of CD200/CD200R1 Immunomodulatory Axis of Allogenic Peripheral Blood Mononuclear Cells in a Co-culture with Adipose-derived Mesenchymal Stem Cells.

Co-inhibitory molecules modulate immune responses. Immunomodulatory properties of mesenchymal stem cells (MSCs) turn them into ideal candidates for cell therapy. This study was designed to investigate the immunomodulatory effect of adipose-derived stem cells (ASCs) on inflammatory environment of a co-culture of allogenic peripheral blood mononuclear cells (PBMCs) in a two-way mixed leukocyte reaction (twMLR) setting. ASCs were co-cultured with allogenic PBMCs in twMLR setting for four days. The proliferation of peripheral blood mononuclear cells (PBMCs), levels of interleukin (IL)-10, and expression of interferon-gamma (IFN-γ), B7-1, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed death-ligand 1 (PD-L1), +, and CD200R1 genes, as well as cell surface expression of CD200 and CD200R1, were measured in twMLR as control, and co-culture groups on days 0, 2 and 4 of the experiment. The proliferation of PBMCs was suppressed on days 2 and 4 of co-culture. The expression of CD200 (p=0.014), CD200R1, CTLA-4, and PD1 genes increased on days 2 and 4 of the co-culture compared to twMLR. CD200 expressing PBMCs decreased by 1.75% on day 2 of the co-culture but increased by 6.23% on day 4 of the co-culture (p=0.013) compared to the same days of twMLR. IL-10 levels increased in the co-culture supernatants on days 2 and 4 compared to twMLR (p<0.05). Our results showed that ASCs upregulate the CD200/CD200R1 axis more than PD-1/PD-L1 and CTLA-4/B7-1 pathways in the twMLR. Also, elevated expression of CD200R1 in the final day ofco-culture was similar to PD-1 expression pattern. This finding suggests a role for the CD200/CD200R1 axis in later modulation of the immune response.

Association of Rs231775 Genetic Variant of Cytotoxic T-lymphocyte Associated Protein 4 with Alopecia Areata Disease in Males: A Case–Control Study

ABSTRACT Background Alopecia Areata (AA) is a common inflammatory immune-mediated non-scarring hair loss; however, the exact genetic susceptibility remains to be clarified. Cytotoxic T-lymphocyte Associated Protein 4 (CTLA4) has emerged as a central and critically important modulator of immune responses and is believed to play a crucial rule in AA pathogenesis. Objectives To investigate the association of CTLA4 variant (rs231775) within codon 17 with AA risk and outcomes. Methods Genetic analyses of the rs231775 SNP of CTLA4 gene were performed in 186 males (93 AA patients and 93 controls). Results The rs231775 CTLA4 variant was significantly higher in AA patients in comparison with control subjects especially among heterozygous and dominant model. This association varied significantly with disease severity. Conclusions Individuals with homozygosity of rs231775 CTLA4 variant represented AA disease risk and increased severity than their counterparts. Abbreviations: AA: Alopecia areata; CTLA4: Cytotoxic T-lymphocyte Associated Protein 4; SNP: Single nucleotide polymorphism; LADA: Latent autoimmune diabetes in adults; SLE: Systemic lupus erythematosus; SCU: Suez Canal University; SALT: Severity of Alopecia Tool; DNA: Deoxyribonucleic acid; RT-PCR: Real-time polymerase chain reaction, HWE: Hardy–Weinberg equation; RA: rheumatoid arthritis.

Detection of CTLA- 4 and PTPN22 Genes Polymorphisms and Relationship with Hyperthyroidism Patients in Thi-Qar Province¬, Iraq.

This study was conducted to identify the genetic polymorphisms of the cytotoxic T-lymphocyte-associated protein 4 (CTLA4) gene and protein tyrosine phosphatase non-receptor 22 (PTPN22) gene to investigate the possible association of their polymorphism with the development or progression of hyperthyroidism. Two genetic loci covering two regions within the CTLA4 and PTPN22 genes were amplified by PCR. Next, a direct sequencing strategy was performed for the observed PCR amplicons to assess the pattern of genetic polymorphism in the screened specimens. Subsequently, the observed variants were localized according to their positions within the referring genomic DNA sequences. The results indicated a significant increase (P

Vitamin D Increases CTLA-4 Gene Expression in Patients with Mild to Moderate Ulcerative Colitis.

BACKGROUND Ulcerative colitis (UC) is a chronic inflammatory disorder of the large intestine. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a member of the immunoglobulin superfamily, which binds B7-1 and B7-2 on APCs (antigen-presenting cells), and induces APCs to produce an inhibitory signal to T cells. The aim of this study was to investigate the effect of vitamin D on CTLA-4 gene expression in whole blood samples of patients with UC. METHODS 90 patients with mild to moderate UC were randomized to receive either a single injection of 7.5 mg vitamin D3 or 1 mL normal saline. 90 days following the intervention fold changes in CTLA-4 mRNA expression were determined and statistical comparisons between the two groups were performed. RESULTS Serum vitamin D increased significantly only in the vitamin D group. CTLA-4 fold changes were significantly higher in the vitamin D group compared with the placebo group (median ± IQR: 1.21 ± 2.3 vs. 1.00 ± 1.5, respectively; p = 0.007). CONCLUSION The results of this study revealed that vitamin D administration in patients with UC enhances the CTLA-4 gene expression.

CTLA-4 Genetic Variants Predict Survival in Patients with Sepsis.

Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) is a coinhibitory checkpoint protein expressed on the surface of T cells. A recent study by our working group revealed that the rs231775 single nucleotide polymorphism (SNP) in the CTLA-4 gene was associated with the survival of patients with sepsis and served as an independent prognostic variable. To further investigate the impact of CTLA-4 genetic variants on sepsis survival, we examined the effect of two functional SNPs, CTLA-4 rs733618 and CTLA-4 rs3087243, and inferred haplotypes, on the survival of 644 prospectively enrolled septic patients. Kaplan–Meier survival analysis revealed significantly lower 90-day mortality for rs3087243 G allele carriers (n = 502) than for AA-homozygous (n = 142) patients (27.3% vs. 40.8%, p = 0.0024). Likewise, lower 90-day mortality was observed for TAA haplotype-negative patients (n = 197; compound rs733618 T/rs231775 A/rs3087243 A) than for patients carrying the TAA haplotype (n = 447; 24.4% vs. 32.9%, p = 0.0265). Carrying the rs3087243 G allele hazard ratio (HR): 0.667; 95% confidence interval (CI): 0.489–0.909; p = 0.0103) or not carrying the TAA haplotype (HR: 0.685; 95% CI: 0.491–0.956; p = 0.0262) remained significant covariates for 90-day survival in the multivariate Cox regression analysis and thus served as independent prognostic variables. In conclusion, our findings underscore the significance of CTLA-4 genetic variants as predictors of survival of patients with sepsis.

The CTLA-4 rs231775 GG genotype is associated with favorable 90-day survival in Caucasian patients with sepsis

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a surface protein on T cells, that has an inhibitory effect on the host immune reaction and prevents overreaction of the immune system. Because the functional single-nucleotide polymorphism (SNP) rs231775 of the CTLA-4 gene is associated with autoimmune diseases and because of the critical role of the immune reaction in sepsis, we intended to examine the effect of this polymorphism on survival in patients with sepsis. 644 septic adult Caucasian patients were prospectively enrolled in this study. Patients were followed up for 90 days. Mortality risk within this period was defined as primary outcome parameter. Kaplan-Meier survival analysis revealed a significantly lower 90-day mortality risk among GG homozygous patients (n = 101) than among A allele carriers (n = 543; 22% and 32%, respectively; p = 0.03565). Furthermore, the CTLA-4 rs231775 GG genotype remained a significant covariate for 90-day mortality risk after controlling for confounders in the multivariate Cox regression analysis (hazard ratio: 0.624; 95% CI: 0.399–0.975; p = 0.03858). In conclusion, our study provides the first evidence for CTLA-4 rs231775 as a prognostic variable for the survival of patients with sepsis and emphasizes the need for further research to reveal potential functional associations between CTLA-4 and the immune pathophysiology of sepsis.

Correlation between CTLA4 genetic polymorphisms, its serum protein level and the susceptibility to recurrent spontaneous abortion: A case-control study.

Present study was aimed to detect the influence of cytotoxic T-lymphocyte associated protein 4 (CTLA4) gene polymorphisms for the risk of recurrent spontaneous abortion (RSA), as well as the serum level of CTLA4 protein in RSA patients.One hundred thirty-three RSA patients and 146 healthy persons were recruited in this case–control study. PCR-RFLP was used to genotype the CTLA4 gene polymorphisms both in case and control groups. Serum level of CTLA4 was detected by ELISA kit. Quantitative variables were compared by t test or Mann–Whitney U test between groups. Qualitative variables were evaluated by χ2 test or Fisher exact test. Association strength was expressed by odds ratios (ORs) and 95% confidence intervals (95% CIs).G allele of rs4553808 (P = .027, OR = 0.570, 95% CI = 0.345–0.942) and T allele of rs5742909 (P = .027, OR = 0.570, 95% CI = 0.345–0.942) were distinctly associated with reduced susceptibility of RSA. Distinctly negative association has been discovered between rs231775 AA genotype and RSA susceptibility (P = .040, OR = 0.427, 95% CI = 0.188–0.973). CTLA4 protein had significantly higher serum level in RSA patients than in healthy controls (P = .028). In RSA patients, AA genotype carriers had higher CTLA4 serum level than that GG genotype carriers (17.83 ± 6.35 ng/mL vs 10.41 ± 7.28 ng/mL, P = .039).Minor alleles of CTLA4 polymorphisms might inhibit the RSA susceptibility via upregulated the protein expression level.