Coagulation and Inflammation in COVID-19: Reciprocal Relationship between Inflammatory and Coagulation Markers.

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), formerly known as 2019-nCoV. Numerous cellular and biochemical issues arise after COVID-19 infection. The severe inflammation that is caused by a number of cytokines appears to be one of the key hallmarks of COVID-19. Additionally, people with severe COVID-19 have coagulopathy and fulminant thrombotic events. We briefly reviewed the COVID-19 disease at the beginning of this paper. The inflammation and coagulation markers and their alterations in COVID-19 illness are briefly discussed in the parts that follow. Next, we talked about NETosis, which is a crucial relationship between coagulation and inflammation. In the end, we mentioned the two-way relationship between inflammation and coagulation, as well as the factors involved in it. We suggest that inflammation and coagulation are integrated systems in COVID-19 that act on each other in such a way that not only inflammation can activate coagulation but also coagulation can activate inflammation.

The effect of 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase gene overexpression in the kynurenine pathway on the expression levels of indoleamine 2,3-dioxygenase 1 and interferon-γ in inflammatory conditions: an in vitro study.

BACKGROUND: The kynurenine pathway (KP) can be involved in the pathogenesis of neurodegenerative diseases and excessive neurotoxic metabolite production. This study aimed to evaluate the effects of overexpression of murine 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase (Acmsd) gene in inflammatory conditions in RAW 264.7 cell line to present more information about the effect of this gene on inflammatory conditions and the KP cycle. METHODS AND RESULTS: The coding sequence of the Acmsd gene was cloned into pCMV6-AC-IRES-GFP expression vector with a green fluorescent protein (GFP) marker. To simulate inflammatory conditions, RAW 264.7 macrophage cells were stimulated by Lipopolysaccharide (LPS) 24 h before transfection, and transfected by Polyethyleneimine (PEI) with constructed plasmids expressing the Acmsd gene. The effect of Acmsd gene expression level on murine Interferon-gamma (Ifn-γ) and murine Indoleamine 2,3-dioxygenase 1 (Ido1) gene expression level was investigated by Real-Time PCR. According to the results of this study, good transfection efficiency was observed 72 h after transfection, and Acmsd expression level increased 29-fold (P < 0.001) in transfected LPS-stimulated cells compared to the control group (LPS-stimulated cells that were not transfected). Additionally, increased Acmsd expression level significantly down-regulated Ifn-γ (P < 0.001) and Ido1 (P < 0.01) expression level in transfected LPS-stimulated cells compared to LPS-stimulated cells. CONCLUSIONS: Acmsd gene overexpression in inflammatory conditions can reduce the expression levels of the Ido1 gene, and its regulator, Ifn-γ. Consequently, it may be considered as a novel regulatory factor in the KP balance.

The effects of probiotic Bacillus subtilis on the cytotoxicity of Clostridium perfringens type a in Caco-2 cell culture.

BACKGROUND: Some Bacillus strains have recently been identified for potential use as probiotics and food additives. The present study evaluated the antimicrobial effects of Bacillus subtilis ATCC 6633 and its metabolite on the enterotoxin and vegetative cells, spore and germinated spore of Clostridium perfringens type A in Caco-2 cells. RESULTS: We used flow cytometry and MTT assays to evaluate the cytotoxicity effect of treatments. According to the results, the most cell survival was found in the 4% crude antimicrobial substance (CAS) with the vegetative form of C. perfringens among co-cultured groups. Furthermore, the apoptosis and necrosis in co-cultured groups were significantly decreased (P < 0.05). CONCLUSION: The present results suggested the crucial role of the current probiotic in the control of various forms of C. perfringens type A which was investigated for the first time. Also, the majority of treatments showed higher cell viability in flow cytometry compared to the MTT assay.

Evaluation of red cell membrane cytoskeletal disorders using a flow cytometric method in South iran.

OBJECTIVE: The diagnosis of hereditary red blood cell (RBC) membrane disorders, and in particular hereditary spherocytosis (HS) and Southeast Asian ovalocytosis (SAO), is based on clinical history, RBC morphology, and other conventional tests such as osmotic fragility. However, there are some milder cases of these disorders that are difficult to diagnose. The application of eosin-5'-maleimide (EMA) was evaluated for screening of RBC membrane defects along with some other anemias. We used EMA dye, which binds mostly to band 3 protein and to a lesser extent some other membrane proteins, for screening of some membrane defects such as HS. MATERIALS AND METHODS: Fresh RBCs from hematologically normal controls and patients with HS, SAO, hereditary elliptocytosis, hereditary spherocytosis with pincered cells, severe iron deficiency, thalassemia minor, and autoimmune hemolytic anemia were stained with EMA dye and analyzed for mean fluorescent intensity (MFI) using a flow cytometer. RESULTS: RBCs from patients with HS and iron deficiency showed a significant reduction in MFI compared to those from normal controls (p<0.0001 and p<0.001, respectively), while macrocytic RBCs showed a significant increase in MFI (p<0.01). A significant correlation was shown between mean corpuscular volume and MFI, with the exceptions of HS and thalassemia minor. CONCLUSION: Our results showed that the flow cytometric method could be a reliable diagnostic method for screening and confirmation, with higher sensitivity and specificity (95% and 93%, respectively) than conventional routine tests for HS patients prior to further specific membrane protein molecular tests.

Investigating the Expression Levels of Bax and Bcl-2 Genes in Peripheral Blood Lymphocytes of Industrial Radiation Workers in the Asaluyeh Region.

Background: Industrial radiography uses gamma or X-ray radionuclide sources to investigate the safety of industrial materials. Industrial radiation workers receive the highest occupational radiation doses. Objective: The present study investigates the relationship between Bax and Bcl-2 gene expression variables in industrial radiation workers. Material and Methods: In this case-control study, data was collected using blood sampling from 40 workers, including two groups of non-radiation and radiation workers employed at the location. Expression levels of Bax and Bcl-2 genes were assessed in the laboratory. The environmental and absorbed doses of workers were measured using environmental and pen dosimeters. Results: Statistical analysis showed that the radiation group's Bcl-2 gene expression level was significantly higher. Findings also demonstrated a correlation between Bcl-2 gene expression and the number of workdays. Also, the Bax gene expression did not show a significant change, and the expression ratio of Bax/Bcl-2 was insignificant in the two groups. Conclusion: Exposure to low doses of radiation could promote an adaptive response in cells by increasing Bcl-2 gene expression.

Generation of large numbers of highly purified dendritic cells from bone marrow progenitor cells after co-culture with syngeneic murine splenocytes.

Dendritic cells (DCs) are called the sentinels of the human immune system because of their function as antigen presenting cells (APCs) that elicit a protective immune response. Given that DCs have been used for many years as target cells in a great number of experiments, it became essential to devise a new method for producing DCs in higher quantities and of greater purity. Here we report a novel technique for obtaining more dendritic cells, and with higher purity, from in-vitro co-culture of bone marrow (BM) cells with splenocytes. From a total of 20 × 10(6) BM cells and 120 × 10(6)splenocytes, 3 × 10(6) BM cells along with 20 × 10(6)splenocytes were co-cultured in petri dishes for DC generation; 120 × 10(6) splenocytes from one C57BL/6 mouse were also co-cultured in petri dishes for DC generation. BM cells were the control group cultured in the same conditions except for the presence of splenocytes. Purity and maturation state of DCs were checked by lineage surface markers (CD11c, CD11b, CD8α, and F4/80) and the expression levels of MHCII as well as co-stimulatory molecules (CD86, CD80, and CD40). Endocytosis and thymidine uptake capacity were also used to test the functionality of DCs. The levels of IL-12p70, IL-23, and IL-10 were also checked in the supernatant of cultured cells by ELISA. The number of DCs derived from co-culture of BM and splenocytes (DCs(TME)) was at least twice that of BM-derived DCs in the absence of splenocytes. In addition, the purity of DCs after co-culture of BM and splenocytes was greater than that of DCs in the control culture (90.2% and 77.2%, respectively; p<0.05). While functional assays showed no differences between co-culture and control groups, IL-10 levels were significantly lower in DCs(TME) compared to BM-derived DCs in the absence of splenocytes (193 pg/ml and 630 pg/ml, respectively; p<0.05). The results of the present study show that the generation of DCs from BM progenitors is accelerated in the presence of syngeneic splenocytes. Given the larger number of generated DCs, and with higher purity, in this technique, DCs(TME) could be more advantageous for DC-based immunotherapy and vaccination techniques.

Comparison of Commercial Low Molecular Weight Heparin and Homemade Anti-Xa Calibrators to a Commercial Specific Anti-Xa Calibrator for Plasma Rivaroxaban Quantification by Anti-Xa Oral Anticoagulant Plasma Concentration Chromogenic Assay.

OBJECTIVE: The main concern about measuring the concentration of rivaroxaban by anti-Xa assay in some laboratories is the lack of a commercial specific calibrator in emergencies. Therefore, this study aimed at providing a homemade anti-Xa calibrator and commercial low molecular weight heparin (LMWH) anti-Xa calibrator. METHODS: The anti-Xa plasma concentration of rivaroxaban was measured in 70 patients using a commercial specific anti-Xa calibrator, a commercial LMWH anti-Xa calibrator, and a homemade anti-Xa calibrator. RESULTS: We demonstrated a significant correlation and agreement (P < .001) between LMWH-calibrated anti-Xa and the commercial specific calibrator. A significant correlation (P < .001) was found between homemade calibrated anti-Xa made by normal pooled plasma and that calibrated with a commercial specific drug. The nonspecific homemade and LMWH calibrators had excellent agreement (P < .001) and can be used interchangeably. CONCLUSION: Our data showed that for estimating rivaroxaban concentrations, the LMWH calibrator could be used as an alternative calibrator in the anti-Xa assay.

A study on the effect of JNJ-10397049 on proliferation and differentiation of neural precursor cells.

The orexin 2 receptor plays a central role in maintaining sleep and wakefulness. Recently, it has been shown that sleep and wakefulness orchestrate the proliferation and differentiation of oligodendrocytes. Here, we explored the role of a selective orexin 2 receptor antagonist (JNJ-10397049) in proliferation and differentiation of neural progenitor cells (NPCs). We evaluated the proliferation potential of NPCs after exposure to different concentrations of JNJ-10397049 by using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide and neurosphere assays. Moreover, the expression of differentiation markers was assessed by immunocytochemistry and real-time polymerase chain reaction. JNJ-10397049 significantly increased the proliferation of NPCs at lower concentrations. In addition, orexin 2 receptor antagonist facilitated progression of differentiation of NPCs towards oligodendroglial lineage by considerable expression of Olig2 and 2',3'-cyclic-nucleotide 3'-phosphodiesterase as well as decreased expression of nestin marker. The results open a new avenue for future investigations in which the production of more oligodendrocytes from NPCs is needed.

G Protein Coupled Receptors Potentially Involved in Oligodendrogenesis: A Gene Expression Analysis.

Background: Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system characterized by infiltration of inflammatory leukocytes to the CNS followed by oligodendrocyte cell death, myelin sheath destruction, and axonal injury. A logical incidence occurring after demyelination is remyelination. G-protein coupled receptors (GPCRs) activate internal signal transduction cascades through binding to different ligands. This family of receptors are targeted by more than 40% of currently marketed drugs. GPCRs can be successfully targeted for induction of remyelination. GPCRs highly enriched in oligodendrocyte progenitor cells compared to oligodendrocytes are proposed to hamper oligodendrocyte differentiation and therefore their inhibition might induce remyelination. This study aimed to investigate the expression of GPCRs in silico and in vitro. Methods: We performed gene expression analysis using DAVID and Panther websites on a RNA-seq dataset (GSE52564 accession number). Primary embryonic neural stem/progenitor cell isolation and culture were performed and subsequently NSPCs were characterized by Immunocytochemistry with Anti-Nestin antibody. Expression of GPR37L1, EDNRB, PDGFRα, CNPase and GFAP were assessed using real-time PCR. All the experiments were conducted at Shiraz University of Medical Sciences (SUMS), Shiraz, Iran, in the year 2018. Results: The 14 most highly expressed GPCRs in oligodendrocyte progenitor cells (OPCs) compared to Oligodendrocytes were presented in our study. Conclusion: The investigation of the most highly expressed GPCRs in OPCs compared to oligodendrocyte in silico and in vitro presents the significant role of GPCRs in remyelination induction. Among the 14 GPCRs mentioned in this study, GPR37L1 is a potential remyelinating drug target and is suggested for further studies.

Efficacy of Mesenchymal Stem Cells Therapy in Parasitic Infections: Are Anti-parasitic Drugs Combined with MSCs More Effective?

PURPOSE: Mesenchymal stem cells (MSCs) are mesodermal-origin postnatal stem cells that are able to self-renew and differentiate into several cell lineages. MSCs possess anti-inflammatory and anti-apoptotic activity, immunomodulatory action, as well as regenerative properties. Since MSCs also have antimicrobial properties, it has been suggested that they should be utilized for treating infectious diseases. In this study, the last pre-clinical advances in the efficacy of MSCs' therapy against parasitic diseases were reviewed. METHODS: Data about the effects of MSCs' therapy on experimental and pre-clinical parasitic infections were collected by searching relevant articles and reviewing them. RESULTS: In the present study, empirical findings on the impacts of MSCs' therapy against parasitic diseases were recapitulated. Studies have reported that the administration of MSCs reduces the burden of the parasite and modulates the levels of inflammatory and anti-inflammatory cytokines in parasitic diseases, including schistosomiasis, malaria, cystic echinococcosis, toxocariasis, leishmaniasis, and trypanosomiasis. Also, the administration of MSCs combined with anti-parasitic drugs enhanced anti-parasitic effects and immunomodulatory actions. CONCLUSION: Based on this review, empirical studies have revealed the beneficial effects of MSCs against some parasitic infections. This new therapeutic strategy showed both anti-parasitic and immunomodulatory effects. Also, the combination of anti-parasitic drugs with MSCs' therapy promoted anti-parasitic and immunomodulatory activities against parasitic infections.

Maximizing the recovery of the native p28 bacterial peptide with improved activity and maintained solubility and stability in Escherichia coli BL21 (DE3).

p28 is a natural bacterial product, which recently has attracted much attention as an efficient cell penetrating peptide (CPP) and a promising anticancer agent. Considering the interesting biological qualities of p28, maximizing its expression appears to be a prominent priority. The optimization of such bioprocesses might be facilitated by utilizing statistical approaches such as Design of Experiment (DoE). In this study, we aimed to maximize the expression of "biologically active" p28 in Escherichia coli BL21 (DE3) host by harnessing statistical tools and experimental methods. Using Minitab, Plackett-Burman and Box-Behnken Response Surface Methodology (RSM) designs were generated to optimize the conditions for the expression of p28. Each condition was experimentally investigated by assessing the biological activity of the purified p28 in the MCF-7 breast cancer cell line. Seven independent variables were investigated, and three of them including ethanol concentration, OD600 of the culture at the time of induction, and the post-induction temperature were demonstrated to significantly affect the p28 expression in E. coli. The cytotoxicity, penetration efficiency, and total process time were measured as dependent variables. The optimized expression conditions were validated experimentally, and the final products were investigated in terms of expression yield, solubility, and stability in vitro. Following the optimization, an 8-fold increase of the concentration of p28 expression was observed. In this study, we suggest an optimized combination of effective factors to produce soluble p28 in the E. coli host, a protocol that results in the production of a significantly high amount of the biologically active peptide with retained solubility and stability.

Serum Expression of Seven MicroRNAs in Chronic Lymphocytic Leukemia Patients.

PURPOSE: MicroRNAs are small single-strand noncoding RNAs that can be deregulated in a variety of cancers. Over the past few years, multiple markers have been discovered in chronic lymphocytic leukemia (CLL). Among these, miRNAs seem to have important roles in the pathogenesis of CLL. The development and validation of miRNA-expression patterns as biomarkers should have a significant impact in cancer diagnosis, therapeutic success, and increasing the life expectancy of patients. In this study, to specify the utility of circulatory miRNA expression as noninvasive and useful biomarkers for CLL, we analyzed the dysregulation of seven miRNAs: miR30d, miR25-3p, miR19a-3p, miR133b, miR451a, miR145, and miR144 in CLL-patient sera. METHODS: Thirty untreated patients with flow-cytometry confirmation of CLL were chosen. Serum samples were collected from 30 newly diagnosed CLL patients. Fifteen healthy samples were taken for comparison as controls. RNA was extracted using Trizol. RNA from CLL patient specimens was compared to controls with real-time PCR. RESULTS: Seven miRNAs were differently expressed between CLL and normal specimens using the comparative 2-ΔΔCt method. miRNAs 133b, 25-3p, 451a, 145, 19a-3p, and 144 were overexpressed in sera obtained from CLL patients, and miRNA-30d was underexpressed in patient samples. Among these seven miRNAs, miR19a-3p and miR25-3p showed the most deregulation in CLL patients. CONCLUSION: Real-time PCR is an applied means to perform high-throughput investigation of serum-RNA samples. We assessed the expression of seven miRNAs in CLL patients by this method. The results demonstrated that the use of miRNA-expression profiling may have an impressive role in the diagnosis of CLL. In addition, miRNA 19a-3p and 25-3p are known oncogenes with therapeutic and potential biomarkers.

Bone marrow dendritic cells deficient for CD40 and IL-23p19 are tolerogenic in vitro.

OBJECTIVES: In addition to pro-inflammatory role, dendritic cells (DCs) can also be anti-inflammatory when they acquire tolerogenic phenotype. In this study we tested the role of CD40 and IL-23p19 in antigen presenting function of bone marrow-derived DCs (BMDCs) by comparing BMDCs derived from CD40 knockout (CD40KO-DCs) and IL-23p19 (IL-23p19KO-DCs) knockout mice with those from C57BL/6 mice (Cont-DCs). We have focused on CD40 and IL-23, as these molecules have well established pro-inflammatory roles in a number of autoimmune and inflammatory diseases. MATERIALS AND METHODS: The expression of maturation markers MHC II and co-stimulatory molecules CD40, CD80, and CD86 was analyzed by flow cytometry, while the expression of CD40 and IL-23p19 was measured by RT-PCR. The capacity of BMDCs to activate CD4+ T cells was evaluated by 3H-thymidine incorporation, and the capacity of BMDCs to uptake antigen was evaluated using fluorescent OVA and flow cytometry. RESULTS: The lack of CD40 or IL-23p19 had no effect on uptake of FITC-OVA by the DCs, confirming their immature phenotype. Moreover, CD40KO-DCs had significantly reduced capacity to stimulate proliferation of CD4+ T cells. CD4+ T cells activated by CD40KO-DCs and IL-23p19KO-DCs produced significantly less IFN-γ (P-value ≤0.05), while CD4+ T cells stimulated by IL-23p19KO-DCs produced less GM-CSF and more IL-10 than Cont-DCs. CONCLUSION: This study shows that CD40KO-DCs and IL-23p19KO-DCs have a marked tolerogenic potency in vitro. Future in vivo studies should determine if and to what extent DCs lacking CD40 or IL-23 have a potential to be useful in therapy of autoimmune inflammation.

Expression of transforming growth factor-beta and interferon gamma biomarkers after whole body gamma irradiation.

CONTEXT: There are plenty of evidence that suggest that the potential high doses of radiation result in severe health effects to exposed individuals, although there is no consensus about the health impact of low dose of ionizing radiation (IR). AIMS: This study aimed to discuss the effect a range of IR doses on the changes of gene expression and serum protein levels of two immune factors transforming growth factor-ß (TGF-ß) and interferon gamma (IFN-γ) in rats. Findings from this study can be useful to develop a suitable biomarker for biological dosimetry applications. SUBJECTS AND METHODS: After 24 h of irradiation of rats with the doses of 1000, 500, 100, 50, and 20 mGy, the gene expression of TGF-ß and IFN-γ in lymphocytes was assessed using quantitative polymerase chain reaction. Besides, the protein level of these two factors in blood plasma was determined by enzyme-linked immunosorbent assay (ELISA) kits. STATISTICAL ANALYSIS USED: One-way analysis of variance Tukey-Kramer Multiple Comparisons Test was used. P <0.05 was considered statistically significant. RESULTS: Significant increases in the expression levels of TGF-ß and IFN-γ genes were observed by increasing the dose from 100 to 500 mGy and then 1000 mGy compared to the control (P < 0.05). The ELISA tests showed significant differences in the serum level of TGF-ß cytokine in the dose of 1000 mGy, while the serum level of IFN-γ cytokine showed significant differences in doses of 20 mGy and 1000 mGy compared to the control (P < 0.05). CONCLUSIONS: The results of this study showed the changes in the expression of TGF-ß and IFN-γ genes after irradiation more than 100 mGy in lymphocytes compared to the control group; the changes in the serum levels of these cytokines only occurred in the specific doses compared to the control group.

Delivery of plasmid encoding interleukin-12 gene into hepatocytes by conjugated polyethylenimine-based nanoparticles.

In the present investigation, polyethylenimine (PEI) was conjugated with succinic anhydride at four substitution degrees and the efficiency of the modified PEI derivatives in transferring the plasmid encoding interleukin-12 gene was evaluated. The results revealed that the conjugated PEI derivatives enhanced the transfection efficiency by up to 3-fold relative to unmodified PEI, with the highest increase occurring at conjugation degrees around 30%. The results demonstrated the ability of the modified PEI derivatives in condensation of the plasmid into the nanoparticles in the size range of approximately 100 nm. Also, the PEI derivatives exhibited substantial decrease in cell-induced toxicity.

Evaluation of the immunomodulatory effect of curdlan on maturation and function of mouse spleen-derived dendritic cells.

BACKGROUND: T helper 1 and T helper 17 cells play important roles in immunity against foreign invaders. Differentiation of these Th subsets is affected by state of maturation and cytokines that are produced by dendritic cells (DCs). Curdlan is a linear (1→3)-ß-glucan and has shown activity against tumors and infectious agents. OBJECTIVE: This study aims to investigate whether curdlan plays its role through affecting the maturation and cytokine production by DCs. METHODS: DCs were isolated from the spleen of BALB/c mice by MACS method. After an overnight culture of DCs in the presence of curdlan, the expression levels of CD40, CD86, and MHC-II molecules were determined by flow cytometry. The production of cytokines involved in Th1 and Th17 cell differentiation (IL-12 and IL-6, respectively) was also evaluated by ELISA. Lipopolysaccharide (LPS) treated and untreated cells were considered as positive and negative controls, respectively. RESULTS: The results of this study did not show a significant difference in the levels of surface expression of CD40 (p=0.82), CD86 (p=0.79), and MHC class II (p=0.84) molecules upon exposure to curdlan. However, LPS increased the intensity of CD40 expression on dendritic cells (p=0.04). In addition, it was revealed that curdlan-exposed DCs are not able to produce a significant amount of IL-6 and IL-12 cytokines. Conversely, LPS-treated DCs were able to make a significant amount of IL-12 (p=0.005). CONCLUSION: The results of the present study suggest that curdlan has no effect on Th1 or Th17 differentiation while LPS may induce Th1 deviation by induction of CD40 expression and IL-12 production.

Generation of immunogenic and tolerogenic clinical-grade dendritic cells.

Immunotherapy with dendritic cells (DCs), which have been manipulated ex vivo to become immunogenic or tolerogenic, has been tested in clinical trials for disease therapy. DCs are sentinels of the immune system, which after exposure to antigenic or inflammatory signals and crosstalk with effector CD4(+) T cells express high levels of costimulatory molecules and cytokines. Upregulation of either costimulatory molecules or cytokines promotes immunologic DCs, whereas their downregulation generates tolerogenic DCs (TDCs), which induce T regulatory cells (Tregs) and a state of tolerance. Immunogenic DCs are used for the therapy of infectious diseases such as HIV-1 and cancer, whereas tolerogenic DCs are used in treating various autoimmune diseases and in transplantation. DC vaccination is still at an early stage, and improvements are mainly needed in quality control of monitoring assays to generate clinical-grade DC products and to assess the effect of DC vaccination in future clinical trials. Here, we review the recent work in DC generation and monitoring approaches for DC-based trials with immunogenic or tolerogenic DCs.

Analysis of cytotoxic T lymphocyte associated antigen 4 gene polymorphisms in patients with ulcerative colitis.

BACKGROUND AND AIM: Ulcerative colitis (UC) is a multifactorial disease associated with dysregulated immunity. Recently, cytotoxic T lymphocyte associated antigen 4 (CTLA-4) gene polymorphisms have been reported in association with several autoimmune diseases in several populations. In the present study, the possible implication of the CTLA-4 gene as a risk factor for UC in the Iranian population was investigated. METHODS: One hundred UC patients and 100 healthy subjects were studied. CTLA-4 exon 1 position 49 (A/G: codon 17: Thr/Ala) polymorphisms were investigated by polymerase chain reaction single strand confirmation polymorphism method. Four of the patients and one of the healthy controls were excluded from the study because of incomplete DNA extraction. RESULTS: The allele frequencies of A and G in 96 patients (A: 66.1%; G: 33.9%) were not significantly different from the 99 control subjects (A: 63.1%; G: 36.9%, P > 0.05). No significant differences in the distribution of genotype frequencies were observed between A + 49G gene polymorphisms and UC in the Iranian population (P > 0.05). CONCLUSION: CTLA-4 polymorphism is not associated with UC in the Iranian population.

Cytotoxic T lymphocyte antigen-4 gene in breast cancer.

The exon 1 polymorphism (49A/G) of ctla-4 gene corresponds to an amino acid exchange (threonine to alanine) in the leader peptide of the expressed protein. There are reports concerning the higher level of G allele in subjects with various autoimmune diseases, which has resulted in the hypothesis that CTLA-4 may play a role in regulating self-tolerance by the immune system and in the pathogenesis of autoimmune disorders. This study was undertaken to investigate the correlation of exon 1 (49A/G) polymorphism in the ctla-4 gene and breast cancer. The ctla-4 49A/G polymorphism was studied in 197 women with primary breast cancer and 151 age/sex matched normal individuals. The results indicated a significant difference between frequency of ctla-4 genotypes in patients and controls. The frequency of GG genotype was significantly decreased in breast cancer patients compared to controls (4.6% v.s. 12.6%, P = 0.012). There was also a significant positive correlation between tumor size and the existence of AA genotype in patients (P = 0.016). In addition, a positive correlation between AA genotype and lymph node involvement was observed (P = 0.042). The observed decrease in the frequency of GG genotype in the breast cancer patients is contrary to the frequently reported increase of GG genotype in autoimmune diseases. In addition, the data implies that polymorphism of ctla-4 exon 1 contributes in tumor progression.