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Background: Thymocyte selection-associated high mobility group box protein (TOX) and members of the nuclear receptor 4A (NR4A) are known as transcription factors involved in T cell exhaustion., Objective: To evaluate the mRNA expression of TOX and NR4A1-3 in CD8+ T cells in acute leukemia., Methods: Blood samples were obtained from 21 ALL and 6 AML patients as well as 20 control subjects. CD8+ T cells were isolated using MACS. Relative gene expression of TOX and NR4A1-3 was then evaluated using qRT-PCR., Results: Comparison of mRNA expression of TOX in CD8+ T cells showed no significant difference among the study groups (p>0.05), while the expression of NR4A1 was significantly lower in AML patients than in the control group (p=0.0006). Also, the expression of NR4A2 and NR4A3 was significantly lower in both ALL (p=0.0049 and p=0.0005, respectively) and AML (p=0.0019 and p=0.0055, respectively) patients., Conclusion: NR4As expressions were found to be lower in CD8+ T cells from patients with AML and ALL compared to controls, whereas the mRNA expression of TOX showed no significant difference. Although TOX and NR4As are associated with CD8+ T cell exhaustion in solid tumors, they might play different roles in acute leukemia, which requires further investigation.

Background: Innate Lymphoid Cells (ILCs) promote tissue homeostasis, contribute to the immune defense mechanisms, and play important roles in the initiation of immune responses and chronic inflammation., Objective: To understand the roles of innate lymphoid cells in the pathophysiology of colorectal cancer (CRC) in the mouse model., Methods: CRC was induced using azoxymethane (AOM) and dextran sulfate sodium (DSS) in Balb/c mice (the chemically induced group=18 mice), or orthotopic injection of CT-26 cell line into the colon of another set of Balb/c mice (the orthotopic group=14mice). Normal saline was injected into 18 mice, as the sham group. After 80 days, the chemically induced group was divided into two subgroups, dysplasia (8 mice) and reparative change (10 mice), based on pathological examinations. The frequencies of ILC1, 2, and 3 were then measured in colon tissues using flow cytometry by four markers including an anti-mouse lineage cocktail (FITC anti-mCD3/FITC anti-mGr-1/FITC anti-mCD11b/ FITC anti-mCD45R (B220)/FITC anti-mTer-119), PE/Cy7 anti-mouse CD45, PE anti-mouse CD117 (c-kit), and APC anti-mouse IL-33 Rα (ST2)., Results: The total ILC population was significantly higher in the chemically induced reparative change compared with the sham group. ILC1 percentage in the chemically induced reparative change was significantly higher compared to those in the other three groups (Sham, chemically induced dysplasia and orthotopic dysplasia). The orthotopic dysplasia group showed more ILC3 percentage than the other groups., Conclusion: ILC1 and ILC3 subgroups increased significantly in reparative and dysplastic experimental CRC respectively. Thus ILC1 may have an inhibitory effect on tumor growth whereas ILC3 promotes tumor progression.

Background: Ulcerative colitis (UC) and Crohn's disease (CD) are the two forms of inflammatory bowel disease (IBD). Adaptive immune responses involving helper T cells play an important role in developing IBDs. Programmed death (PD)-1 and its ligands namely PD-L1 and PD-L2 are negative costimulatory molecules that control T cell motility and formation of an immune synapse between T cells and antigen-presenting cells (APCs)., Objective: To investigate the role of PD-L1 and PD-L2 in patients with UC to clarify the mechanism of IBD development., Methods: Biopsy specimens were obtained from 50 UC patients and 45 sex- and age-matched control subjects. Total RNA was extracted from all samples and applied for cDNA synthesis. Relative expression of PD-L1 and PD-L2 mRNA was determined using Taqman qRT-PCR., Results: Relative gene expression levels of both PD-L1 and PD-L2 were higher in UC patients than the control groups (p<0.05 and p<0.01, respectively). Furthermore, both PD-L1 and PD-L2 expressions were positively correlated in all study subjects (r=0.339, p<0.001). However, among the groups with disease severity, the relative gene expression levels of PD-L1 and PD-L2 showed no significant difference., Conclusions: During IBD, the occurrence of PD-L1 and PD-L2 up-regulation may modulate the chronic inflammation of colonic mucosa.

Background: Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western world. This health problem is caused due to the accumulation of mature B-lymphocytes in the peripheral blood and bone marrow. In the course of cancer, CD4+ T cells become "exhausted" and characterized with poor effector functions and the expression of multiple inhibitory receptors., Objective: To investigate the frequency and functional properties of exhausted CD4+ T lymphocytes in patients with CLL., Methods: Peripheral blood mononuclear cells were obtained from 25 untreated CLL patients and 15 healthy volunteers. CLL patients were clinically classified according to the Rai staging system. The frequency of CD4+/Tim-3+/PD-1+ cells was obtained by flow cytometry. To evaluate cell proliferation and cytokine production, CD4+ T cells were isolated and stimulated with phytohemagglutinin and PMA/ionomycin. Concentrations of IL-2, IFN-γ, TNF-α, and IL-10 were measured in the culture supernatants of stimulated cells by the ELISA technique., Results: The percentage of CD4+/Tim-3+/PD-1+ cells was significantly higher in CLL patients than that of healthy controls. CD4+ T cells from CLL patients showed lower proliferative responses, a lower production of IL-2, IFN-γ, and TNF-α, and a higher production of IL-10, compared to healthy controls. CD4+ T cells from CLL patients in advanced clinical stages showed more exhaustion features than those of early stages., Conclusion: Given that the exhaustion phase of T cells can be reversible, targeted blocking of immune inhibitory molecules could be a promising tool to restore the host immune responses against leukemic cells in CLL.

Background: Regulatory T Cells (Tregs) and Myeloid-Derived Suppressor Cells (MDSCs) are two main regulatory cells modulating the immune responses in inflammation and cancer., Objective: To investigate and compare Tregs and MDSCs in peptic ulcer and gastric cancer., Methods: Patients with dyspepsia were selected and divided into three groups of non-ulcer dyspepsia (NUD, n=22), peptic ulcer disease (PUD, n=25), and gastric cancer (GC, n=27) according to their endoscopic and histopathological examinations. Helicobacter pylori infection was diagnosed by rapid urease test and histopathology. The number of peripheral blood CD4+CD25+FoxP3+Tregs and CD14+HLA-DR- MDSCs were determined in all patients, by flow cytometry. The number of FoxP3+ regulatory T cells was also determined by immunohistochemistry (IHC)., Results: The percentage of peripheral blood Treg cells in both PUD (0.81 ± 0.39, p<0.001) and GC groups (0.98 ± 0.65, p<0.001) were significantly higher than in NUD group (0.46 ± 0.10). These results were also confirmed by IHC. A significantly higher percentage of MDSCs in patients with PUD (0.73 ± 0.19, p<0.001) and GC (0.73 ± 0.16, p<0.001) was also observed when compared to NUD group (0.46 ± 0.16). There was no difference in the percentages of these two cell types between the PUD and GC groups. The percentages of Tregs and MDSCs in patients with PUD and GC were not significantly correlated., Conclusions: Both Tregs and MDSCs showed higher frequencies in PUD and GC. These results suggest that immune-modulation by the Tregs and MDSCs may play a role in the pathogenesis of PUD and GC.

Background: CD1d presents glycolipid antigens to invariant natural killer T (iNKT) cells. The role of CD1d in the development of peptic ulcer and gastric cancer has not been revealed, yet., Objective: To clarify the expression of alternatively spliced variants of CD1d in peptic ulcer and gastric cancer., Methods: Patients with dyspepsia were selected and divided into three groups of non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC), according to their endoscopic and histopathological examinations. H. pylori infection was diagnosed by rapid urease test and histopathology. The expression levels of V2, V4, and V5 spliced variants of CD1d molecule were determined by quantitative Reverse Transcriptase PCR., Results: Relative gene expression levels of V4 were higher in GC patients (n=37) than those in NUD (n=49) and PUD (n=51) groups (p<0.05 and p<0.01, respectively). Moreover, GC patients showed higher expression levels of V5 compared to NUD and PUD groups (p<0.001 and p<0.001, respectively). Positive correlation coefficients were attained between V4 and V5 expression in patients with PUD (r=0.734, p<0.0001) and GC (r=0.423, p<0.01), but not in patients with NUD. Among NUD patients, the expression levels of V4, but not V5, were higher in H. pylori-positive patients than in H. pylori-negative ones (p<0.01)., Conclusion: Collectively, both membrane-bound (V4) and soluble (V5) isoforms of CD1d were over-expressed in gastric tumor tissues, suggesting that they are involved in anti-tumor immune responses.

Background: Immune reactions have been reported to be involved in the destruction of retinal ganglion cells (RGCs) in glaucoma., Objective: To investigate the role of major histocompatibility complex class I-related chain A and B (MICA and MICB) molecules in the pathogenesis of glaucoma., Methods: Aqueous humor and serum samples from 15 glaucoma patients and 45 patients with cataract, undergoing ocular surgery, were obtained. The concentrations of MICA and MICB molecules in all samples were measured using ELISA., Results: Both MICA and MICB concentrations were higher in the aqueous humor of patients with glaucoma compared to those with cataract (p=0.013 and p=0.004, respectively); however, in the serum samples, no significant differences were observed., Conclusions: Increased intraocular pressure may be associated with increased expression of the MICA and MICB molecules, which could initiate the destruction of RGCs and consequent development of glaucoma.

Background: The pathogenesis of migraine involves immune-mediated mechanisms in the vascular endothelium. Toll like receptor 4 (TLR-4) is a signaling receptor of innate immunity which plays a role in various neuropathologies related to neuron inflammation., Objective: This case/control study is aimed to investigate whether TLR-4 896A/G variation is related to migraine headaches in an Iranian population., Methods: A total of 170 migraine patients (130 females, mean age 33.24 ± 11 years) and 170 age, sex, and ethnicity matched healthy controls (118 females, mean age of 31 ± 10 years) were recruited. Genotyping was carried out using the tetra primer amplification refractory mutation system (ARMS)-PCR., Results: The frequency of G allele was higher in migraine patients than the controls (15% vs. 4.7%; p<0.0001). Interestingly, the distribution of heterozygous 896A/G genotype statistically differed between migraineurs and controls (25.3% vs. 8.2%, p=0.00002, OR 3.87, 95% CI; 2.02-7.4). Multivariate logistic regression analysis indicated that G allele in affected female migraineurs is an independent factor associated with increased risk of migraine (OR 3.2, 95% CI 1.23-8.24, p=0.01)., Conclusion: Our results showed TLR-4 polymorphism as a genetic risk factor for migraine. However, further studies in different populations are required to elucidate the precise role of TLR-4 896A/G mutation in susceptibility to migraine.