Iranian journal of immunology
Volume:20 Issue: 2, Spring 2023

The functions of dendritic cells (DCs) are influenced by their intracellular metabolism, in which liver kinase B1 (LKB1) plays an important role. However, due to the difficulty in isolating the DCs, the roles of LKB1 in DC maturation and functions in tumor settings have been poorly characterized. To investigate the roles of LKB1 in DC functions including phagocytosis and presentation of antigens, activation, T cell differentiation, and ultimately tumor eradication. Genetic modification of Lkb1 in the DCs was made by lentiviral transduction, and their impacts on T cell proliferation, differentiation, activity, or B16 melanoma metastasis were examined by flow cytometry, qPCR, or lung tumor nodule counting. LKB1 did not affect antigen uptake and presentation by the DCs, but facilitated the stimulation of T cell proliferation. Interestingly, following T cell activation, Foxp3-expressing regulatory T cells (Treg) were increased (P=0.0267) or decreased (P=0.0195) in mice injected with Lkb1 knockdown DCs or overexpressing DCs, respectively. Further exploration revealed that LKB1 inhibited OX40L (P=0.0385) and CD86 (P=0.0111) expression, and these co-stimulatory molecules enhanced Treg proliferation, and downregulated immune suppressive cytokine IL-10 (P=0.0315). Moreover, we found that the injection of the DCs with limited LKB1 expression before tumor inoculation could reduce their production of granzyme B (P<0.0001) and perforin (P=0.0042) from CD8+T cells, thereby impairing their cytotoxicity and promoting tumor growth. Our data suggest that LKB1 can enhance DC-mediated T cell immunity by restraining Treg development and thereby suppressing tumor growth.

One of the inflammatory diseases of the respiratory system is asthma. Teucrium polium (TP) has anti-inflammatory and anti-allergic properties and its anti-asthmatic effects have not been investigated yet. RORγt is an inflammatory transcription factor for Th17 differentiation. By secreting IL-17, Th17 leads to neutrophilic inflammation in the lungs. As an anti-inflammatory cytokine, IL-10 reduces the dissemination of inflammatory elements in the airways. To evaluate the effect of TP extract in asthma treatment. Thirty female Balb/c mice were distributed into 5 groups (n=6) including the control, treated with ovalbumin (OVA), and OVA+ various doses of TP (50, 150, and 300 mg/kg). All groups except the control group were sensitized to OVA solution on days 0, 7, and 14 by subcutaneous injection. The challenge was performed on days 18 to 21 by the inhalation of 1% OVA and the treatment was done with TP extract in the treatment groups, half an hour before the challenge. On day 22, the serum and spleen samples were collected to determine IL-10 serum levels and RORγt gene expression, respectively. In the treatment groups, the expression of RORγt significantly decreased when using OVA+ Tp extract (150 mg/kg and 300 mg/kg), and IL-10 serum levels significantly increased when using OVA+ TP extract (150 mg/kg) compared with the OVA group. It is possible that TP extract can be effective in improving asthma by reducing inflammation.

Molecular markers are involved in atopic dermatitis (AD) pathogenesis. The estrogen receptor (ESR)-1 gene, encoding ERα, is reported to express aberrantly in AD patients. To detect the biological functions of ESR1 in 2,4 dinitrochlorobenzene (DNCB)-treated mice. The DNCB-treated mice received a topical application of emulsion containing the 1,3-bis(4 hydroxyphenyl)-4-methyl-5-[4-(2-piperidinyl ethoxy) phenol]-1H-pyrazole dihydrochloride (MPP; an ESR1-selective antagonist) to dorsal skins and ears. Then the dermatitis scores, histopathological changes, and cytokine levels were evaluated. MPP specifically downregulated ESR1 expression in DNCB-applied mice. Functionally, application of MPP abolished the DNCB-induced promotion in dermatitis score. Additionally, MPP administration protected against DNCB-induced dermatitis severity, suppressed mast cell infiltration and reduced production of immunoglobulin E (IgE) and thymus and activation-regulated chemokine (TARC). Moreover, MPP treatment inhibited DNCB- induced production of Th2 cytokines and infiltration of CD4+ T cells. ESR1 facilitates Th2-immune response and enhances Th2 cytokines in AD mice.

Ki67 and P53 are important diagnostic and prognostic biomarkers expressed in several cancers. The current standard method for evaluating Ki67 and P53 in cancer tissues is immunohistochemistry (IHC), and having highly sensitive monoclonal antibodies against these biomarkers is necessary for an accurate diagnosis in the IHC test. To generate and characterize novel monoclonal antibodies (mAbs) against human Ki67 and P53 antigens for IHC purposes. Ki67 and P53-specific mAbs were produced by the hybridoma method and screened by enzyme-linked immunosorbent assay (ELISA) and IHC techniques. Selected mAbs were characterized using Western blot and flow cytometry, and their affinities and isotypes were determined by ELISA. Moreover, using the IHC technique in 200 breast cancer tissue samples, we assessed the specificity, sensitivity, and accuracy of the produced mAbs. Two anti-Ki67 (2C2 and 2H1) and three anti-P53 mAbs (2A6, 2G4, and 1G10) showed strong reactivity to their target antigens in IHC. The selected mAbs were also able to recognize their targets by flow cytometry as well as Western blotting using human tumor cell lines expressing these antigens. The specificity, sensitivity, and accuracy calculated for clone 2H1 were 94.2%, 99.0%, and 96.6%, and for clone 2A6 were 97.3%, 98.1%, and 97.5%, respectively. Using these two monoclonal antibodies, we found a significant correlation between Ki67 and P53 overexpression and lymph node metastasis in patients with breast cancer. The present study showed that the novel anti-Ki67 and anti-P53 mAbs could recognize their respective antigens with high specificity and sensitivity and therefore can be used in prognostic studies.

Suppressor APC domain containing 2 (SAPCD2) is involved in cell cycle regulation and its mRNA levels are higher in cancer tissues. But, the function of SAPCD2 in cancer development remains unclear. To generate mouse monoclonal antibodies (mAbs) specific to SAPCD2 and thus clarify the function of SAPCD2 in the development of gastric carcinoma (GC). Purified SAPCD2-GST immunized BALB/c mouse spleen cells were collected and fused with myeloma cells to obtain monoclonal antibody hybridoma. A group of monoclonal antibodies exhibiting high specificity and sensitivity against SAPCD2 has been generated and characterized by IHC, WB, IP, IF, and ELISA. By immunohistochemical analysis, the SAPCD2 expression was evaluated in 228 clinical samples of gastric mucosal lesions, including precancerous lesions and GC samples. We identified a highly specific and sensitive clone of s12 in eukaryotic cells and performed an IHC analysis. We found that 81.3% of 107 GC tissues were SAPCD2-positive, compared with the 26.2% in the matched adjacent normal-appearing tissues (P<0.001). Furthermore, among the 121 gastritis tissues, SAPCD2 was overexpressed in precancerous gastric lesions such as dysplasia (Dys, 78.9%), intestinal metaplasia (IM, 44.7%), and chronic atrophic gastritis (CAG, 6.1%) compared with that in chronic non-atrophic gastritis (CNAG, 3.2%) (P<0.001). The SAPCD2-positivity rate was 81.3% in GC, suggesting that the expression of SAPCD2 increased with the severity of the lesion (P<0.001). In summary, we have described novel monoclonal antibodies against SAPCD2, which are highly expressed in GC tissues and may serve as the basis for an early clinical marker for GC development.

Retinopathy of diabetes is a chronic diabetes mellitus complication affecting retinal vessels, and some ocular complications’ molecular mechanisms remain obscure. To evaluate the expression of HLA-G1, HLA-G5, miRNA-181a, and miRNA-34a in the lens epithelial cells of patients with retinopathy of diabetes. In a case-control study, 30 diabetic patients with retinopathy, 30 diabetic patients without retinopathy, and 30 cataract patients without diabetes mellitus as the control group were enrolled after a full description with details about the study methods and objectives. The expression of HLA G1, HLA G5, miRNA-181a, and miRNA-34a in lens epithelial cells was assessed by quantitative RT PCR. Moreover, the levels of HLA-G protein in aqueous humor were evaluated by the ELISA method. HLA-G1 expression was significantly upregulated in the retinopathy group (P=0.003). The aqueous humor of diabetic retinopathy patients contained significantly higher levels of HLA-G protein compared with the non-diabetic patients (P=0.001). miRNA-181a was significantly downregulated in the diabetic retinopathy group compared with the patients without diabetes (P=0.001). In addition, miRNA-34a was upregulated in the retinopathy group (P=0.009). Taken together, the present results showed that HLA-G1 and miRNA-34a can be valuable markers for diabetic retinopathy. Our data offers new perspectives for improving the control of inflammation in the lens epithelial cells by considering HLA-G and miRNA.

Experimental autoimmune encephalomyelitis (EAE), as an autoimmune disease in the central nervous system (CNS), is an animal model for multiple sclerosis (MS) mediated by T lymphocytes. To investigate ginger extract’s effect on reducing inflammation and improving the symptoms in the EAE model. The EAE was induced by injecting MOG35-55 and pertussis toxin into eight-week-old female C57BL6 mice. The mice were treated with an intraperitoneal injection of 300 mg/kg/day of hydroalcoholic extract of ginger for 21 days. The disease severity and weight changes were measured daily. Then, the mice spleens were removed; the gene expressions of interleukin (IL)-17, transforming growth factor beta (TGF-β), interferon-γ (IFN-γ), and tumor necrosis factor α (TNF-α) were analyzed by Real-time PCR and the percentage of regulatory T lymphocytes (Treg cells) was determined by flow cytometry. Serum nitric oxide and antioxidant capacity were measured, and brain tissue sections were prepared to investigate the leukocyte infiltration and plaque formation. The severity of symptoms in the intervention group was lower than in the control. The gene expression levels of inflammatory cytokines, including IL-17 (P=0.04) and IFN-γ (P=0.01), were reduced. The Treg cells increased significantly, and the serum nitric oxide level was lower in the ginger-treated group. There was no significant difference in lymphocyte infiltration in the brain between the two groups. The present study indicated that ginger extract could effectively reduce inflammatory mediators and modulate immune responses in EAE.

Low-dose naltrexone (LDN) is involved in the treatment of inflammatory and immune system diseases and can affect immune cells. Mesenchymal stem cells (MSCs) are known for their immunomodulatory effects and the potential for the treatment of certain types of autoimmune diseases. To investigate the long-term effects of LDN on human adipose-derived mesenchymal stem cells (ASCs) to see how their immunomodulatory properties are affected and also how LDN-treated ASCs interact with other immune cells present in peripheral blood mononuclear cells (PBMCs). After 14 days of treatment, the ability of LDN-treated ASCs to modulate PBMC proliferation in a two-way mixed lymphocyte reaction (MLR) model was assessed using XTT. The relative expression of IDO, PD-L1, COX-2, HGF genes, and the level of IL-6 and TGF-β cytokines were measured in IFN-γ stimulated and unstimulated ASCs (treated and not treated cells) using real-time PCR and ELISA respectively. Unstimulated ASCs treated with 10-8 M Naltrexone (10-8 M NTX) showed higher levels of TGF-β, compared with the controls (P<0.05). Stimulated ASCs treated with 10-6 M NTX showed elevated expression of IDO, PD-L1 genes, and IL-6 level (P<0.05). Our results demonstrated that various LDN concentrations have dissimilar effects on ASCs’ immunomodulatory properties. A higher LDN concentration induced an alteration in the immunomodulatory features of ASCs.

Individuals with Selective Immunoglobulin-A Deficiency (SIgAD) are often asymptomatic, and symptomatic SIgAD patients often have autoimmune comorbidities. A 48-year-old Han Chinese man presented with abdominal discomfort, hematochezia, and a large tumor in the anogenital region. The primary diagnosis of SIgAD was based on the patient’s age, serum IgA concentration (0.067 g/L), and the evidence of chronic respiratory infection. No other immunoglobulin deficiency or evidence of immunosuppression was present. The primary diagnosis of giant condyloma acuminatum was based on human papilloma virus-6-positive laboratory results and histological characteristics. The tumor and adjacent skin lesions were resected. Hemoglobin concentration fell to 5.50 g/dL, and an emergency erythrocyte transfusion was performed. The body temperature increased to 39.8 ºC, suggesting a transfusion reaction, and 5 mg dexamethasone was administered intravenously. Hemoglobin concentration stabilized at 10.5 g/dL. The clinical signs and laboratory results indicated autoimmune hemolytic anemia, systemic lupus erythematosus, and Hashimoto’s thyroiditis. Abdominal discomfort and hematochezia subsided. Though uncommon, the manifestation of multiple autoimmune comorbidities can occur in SIgAD patients. Further research is needed regarding the causes of SIgAD and the autoimmune disorders that often occur as comorbidities.

Immune Checkpoint Inhibitors (ICIs) have dramatically revolutionized the therapeutic approaches by which we treat a series of cancers accompanied by immune-related adverse events (irAEs). Herein, we reported an intrahepatic cholangiocarcinoma male patient with a history of ankylosing spondylitis developing pulmonary arterial hypertension (PAH) under ICI combined therapy with pembrolizumab and lenvatinib. The indirect measurement of cardiac ultrasound showed a pulmonary artery pressure (PAP) of 72mmHg after 21 three-week cycles of ICI combined therapy. The patient partially responded to the treatment of glucocorticoid and mycophenolate mofetil. The PAP decreased to 55mmHg 3 months after the ICI combined therapy was discontinued, but increased to 90mmHg after the ICI combined therapy was rechallenged. We treated him with adalimumab -an antitumor necrosis factor-alpha (ani-TNF-α) antibody- combined with glucocorticoid and immunosuppressants under lenvatinib monotherapy. The patient responded again with PAP decreasing to 67mmHg after 2 two-week cycles of adalimumab. Accordingly, we diagnosed him to have irAE-related PAH. Our findings supported the use of glucocorticoid disease-modifying antirheumatic drugs (DMARDs) as a treatment option in refractory PAH.