Iranian Journal of Immunology最新文献

Background: Neutrophilic asthma is characterized by the predominant infiltration of neutrophils in airway inflammation.

Objective: To explore the therapeutic potential of an antibody against the inducible T cell co-stimulator ligand (ICOSL) in a mouse model of neutrophilic asthma.

Methods: Female BALB/c mice were randomly assigned to different groups. They were then injected with ovalbumin (OVA)/lipopolysaccharides (LPS) to induce neutrophilic asthma. The mice were then treated with either anti-ICOSL (the I group), control IgG (the G group), or no treatment (the N group). Additionally, a control group of mice received vehicle PBS and was labeled as the C group (n=6 per group). One day after the last allergen exposure, cytokine levels were measured in plasma and bronchoalveolar lavage fluid (BALF) using ELISA. After analyzing and categorizing BALF cells, the lung tissues were examined histologically and immunohistochemically.

Results: Administering anti-ICOSL resulted in a significant decrease in the total number of inflammatory infiltrates and neutrophils found in BALF. Moreover, it led to a decrease in the levels of interleukin (IL)-6, IL-13, and IL-17 in both BALF and plasma. Additionally, there was an increase in IFN-γ levels in the BALF of asthmatic mice (p<0.05 for all). Treatment with anti-ICOSL also reduced lung interstitial inflammation, mucus secretion, and ICOSL expression in asthmatic mice.

Conclusion: The treatment of anti-ICOSL effectively improved lung interstitial inflammation and mucus secretion in mice with neutrophilic asthma by restoring the balance of Th1/Th2/Th17 responses. These findings indicate that blocking the ICOS/ICOSL signaling could be an effective way to manage neutrophilic asthma.

Background: Understanding the effects of epigenetic factors on the pathogenesis of rheumatoid arthritis (RA) is important for the early diagnosis and therapeutic intervention of this disease. MicroRNA-150 (miR-150) exerts an important influence on the development and function of lymphocytes. However, the role of miR-150 in the pathogenesis of RA remains unclear.

Objective: To explore the role of miR-150 in the pathogenesis of RA and the related immune mechanism.

Methods: In this study, we used miR-150 knock-out (miR-150KO) and created animal models of RA. Flow cytometry, immunohistochemistry, and real-time RT-PCR were employed to assess the frequency of T cell subsets and cytokines expression.

Results: Compared to wild-type (WT) mice, the onset of RA was postponed and the incidence of RA was reduced in miR-150KO mice. The expression of IL-4 and IFN-γ significantly increased while the expression of IL-17 decreased significantly in NKT and CD4+ T cells of KO mice compared to that of WT mice after RA induction. In addition, the expression of IL-4 and IFN-γ increased while the expression of IL-17 decreased significantly in the joint tissues of KO mice compared to that of WT mice. Furthermore, the mRNA expression of TNF-α and IL-17 decreased significantly in the synovial fluid cells of KO mice compared to that of the WT mice after RA induction.

Conclusion: MiR-150 deficiency decreases the expression of IL-17 in T cells and joint tissues, and alleviates the occurrence and progression of RA in mice.

Background: Since the outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several vaccine candidates have been developed within a short period of time. Although the potency of these vaccines was evaluated individually, their comparative potency was not comprehensively evaluated.

Objective: To compare the immunogenicity and neutralization efficacy of four approved COVID-19 vaccines in Iran, including: PastoCovac Plus, Sinopharm, SpikoGen, and Noora in BALB/c mice.

Methods: Different groups of female BALB/c mice were vaccinated with three doses of each vaccine. The serum levels of antibodies against the viral receptor binding domain (anti-RBD) and spike (anti-spike) protein as well as the vaccine formulation (anti-vaccine) were evaluated using enzyme-linked immunosorbent assay (ELISA). The neutralization efficacy of these four vaccines was assessed through four neutralization assays: conventional virus neutralization test (cVNT), pseudotype virus neutralization test (pVNT), surrogate virus neutralization test (sVNT), and inhibition flow cytometry.

Results: All four vaccines induced seroconversion in vaccinated animals. All vaccines successfully induced high levels of anti-vaccine antibody; however, PastoCovac Plus and Sinopharm vaccines induced significantly higher levels of anti-RBD antibody titer compared to Noora and SpikoGen. Moreover, the results of the antibody response were corroborated by the virus neutralization tests, which revealed very weak neutralization potency by Noora and SpikoGen in all tests.

Conclusion: Our results indicate significant immunogenicity and neutralization efficacy induced by PastoCovac Plus and Sinopharm, but not by Noora and SpikoGen. This suggests the need for additional comparative assessment of the potency and efficacy of these four vaccines in vaccinated subjects.

Background: Tumor-infiltrating lymphocytes (TILs) and brain stromal cells produce immunosuppressive cytokines, contributing to an immunosuppressive tumor microenvironment (TME). Interleukin-38 (IL-38) is a novel anti-inflammatory cytokine and a natural modulator of the innate and adaptive immune system. However, its biological roles in brain tumors are not well defined.

Objective: To assess the serum levels of IL-38 and the percentages of TILs in the tumor tissues of patients with primary brain tumors and to determine their associations with the pathological features of the disease.

Methods: IL-38 was evaluated in sera using the enzyme-linked immunosorbent assay (ELISA). Hematoxylin and eosin (H&E)-stained sections were scored to determine the percentages of TILs in four different areas: the invasive margin, central tumor, perivascular and perinecrotic areas.

Results: IL-38 serum levels were significantly higher in low- and high-grade tumors than in healthy individuals, meanwhile, its levels remained consistent between these two grades. Although no significant difference was found in IL-38 serum levels between different histological subtypes of brain tumors, its levels were significantly higher in intra-axial brain tumors than in extra-axial ones. Additionally, a significant positive correlation was observed between serum levels of IL-38 and tumor size in patients with low-grade tumors. TILs were detected in at least one of the four examined areas; however, no statistically significant correlation was found between IL-38 levels and TILs.

Conclusion: Our data may suggest a connection between IL-38 and immune suppression and tumor progression in primary brain tumors. Further investigation is needed to uncover the role of IL-38 in the brain tumor microenvironment.

Background: The imbalance between M1 and M2 macrophage activation is closely associated with the pathogenesis of inflammatory bowel diseases (IBDs). Sulforaphane (SFN) plays an important role in the treatment of inflammatory diseases.

Objective: To investigate the effect of SFN on macrophage polarization and its underlying regulatory mechanism.

Methods: Mouse bone marrow-derived macrophages (BMDMs) were treated with SFN and an Nrf2 inhibitor, Brusatol. M1 macrophages were induced by LPS and IFN-γ stimulation, whereas M2 macrophages were induced by stimulation with IL-4 and IL-13. LPS-stimulated BMDMs were co-cultured with Caco-2 cells. Flow cytometry, qRT-PCR, and Western blot were performed to assess macrophage polarization. Cell function was assessed using CCK8 assay, transepithelial electrical resistance (TEER) assay, and biochemical analysis.

Results: Higher concentrations of SFN resulted in better intervention effects, with an optimal concentration of 10 μM. SFN decreased the levels of IL-12, IL-6, and TNF-α, as well as the percentages of CD16/32 in M1 BMDMs. At the same time, SFN increased the levels of YM1, Fizz1, and Arg1 as well as the percentages of CD206+ cells in M2 BMDMs. In addition, SFN enhanced the accumulation of Nrf2, NQO1, and HO-1 in M1 BMDMs, and the downregulation of Nrf2 reversed the regulatory effect of SFN on M1/M2 macrophages. LPS-stimulated BMDMs induced Caco-2 cell damage, which was partially alleviated by SFN.

Conclusion: Our findings indicate that SFN may act as an Nrf2 agonist to regulate macrophage polarization from M1 to M2. Furthermore, SFN may represent a potential protective ingredient against IBD.

Background: Endometriosis is a medical condition that can cause infertility in women. Women with endometriosis experience a decrease in NK cell cytotoxic activity against endometrial cells, ultimately contributing to the spread of these cells.

Objective: To assess the frequency of NK cells and the expression of the NKP46 receptor in endometrial tissue from patients with endometriosis using immunohistochemistry.

Methods: 30 endometrial tissue specimens were collected from three groups of cases with mild (n=11), moderate (n=10), and severe endometriosis (n=9), respectively. Additionally, 20 normal endometrial tissue specimens were collected as the control group. Immunohistochemical staining was carried out using specific human monoclonal antibodies against CD56 and NKP46 molecules.

Results: Cases with severe endometriosis had a significantly higher number of CD56+ uterine NK cells (26.19±2.50) compared to fertile women (15.02±0.622) and women with mild to moderate endometriosis (p<0.001). However, there was no significant difference between the mild to moderate patients compared with the healthy women (p>0.05). Endometrial NKp46 expression was lower in women with severe endometriosis (0.447±0.0829) compared to fertile women (0.987±0.115, p=0.03). The NKp46+/CD56+ cell ratio was also lower in women with severe endometriosis (0.019±0.003) compared to fertile women (0.072±0.011, p=0.01).

Conclusion: Women with severe endometriosis demonstrated an increased rate of infiltrated uterine NK cells and a significant decrease in NKP46 expression compared to fertile women. Therefore, NK cells and the NKp46 receptor may be involved in the development of endometriosis.

Background: Pulmonary neutrophils may play a crucial role in the development of bronchiolitis obliterans (BO) following measles virus infection. IL-27 could potentially have a negative regulatory effect on the release of reactive oxygen species and cytotoxic granules in neutrophils.

Objective: To investigate the levels of IL-27 in the bronchoalveolar lavage fluid (BALF) of children with post-infectious bronchiolitis obliterans (PIBO) and analyze the relationship between IL-27 levels and neutrophil proportions.

Methods: A total of 24 children with PIBO were recruited for the experimental group, while 23 children with bronchial foreign bodies were included in the control group. Bronchoscopic alveolar lavage was performed in both groups. The levels of IL-27 in BALF were measured using enzyme-linked immunosorbent assay (ELISA). The proportions of neutrophils in BALF were determined by smear staining. The relationship between the levels of IL-27 in BALF and the neutrophil proportions was analyzed by the Pearson test.

Results: The levels of IL-27 in BALF were significantly lower in children with PIBO compared to children with bronchial foreign bodies (p<0.05). Additionally, the proportions of neutrophils in BALF were significantly higher in children with PIBO compared to children with bronchial foreign bodies (p<0.05). The levels of IL-27 were negatively correlated with the neutrophil proportions in BALF in children with PIBO (p<0.05), but not in children with bronchial foreign bodies (p>0.05).

Conclusion: The present study suggests that a decrease in IL-27 may be associated with an increase in neutrophils in BALF and may contribute to the pathogenesis of PIBO.

Background: Natural killer (NK) cells play a role in the pathogenesis of various metabolic diseases related to obesity. While our initial findings have indicated a potential involvement of NK cells in the pathogenesis of type 2 diabetes mellitus, the precise mechanism underlying NK cell-mediated development of this form of diabetes remains inadequately comprehended.

Objective: To investigate the impact and the underlying mechanism of high glucose and elevated levels of free fatty acids (FFAs) on immune and inflammatory responses and oxidative stress in NK92 cells.

Methods: In this experiment, the CCK8 cytotoxicity assay was used to select the 44.4 mM and 1.5 mM concentrations of high glucose and high FFAs, respectively, to treat NK92 cells for 4 days. The concentrations of superoxide dismutase (SOD) and glutathione (GSH) were determined using a biochemical analyzer. Intracellular reactive oxygen species (ROS) levels, cytokines concentrations (TNF-α, IFN-γ, IL-6, and IL-10), and the expression levels of intracellular molecules (perforin and granzyme B) were assessed by flow cytometry.

Results: The number of NK92 cell clumps was significantly reduced in the high-FFA (HF) group. In addition, the production of ROS and levels of cytokines (TNF-α, IFN-γ, IL-6, and IL-10) significantly decreased in the HF group but showed no significant change in the high-glucose (HG) group. This observation was consistent with the expression levels of perforin and granzyme B that decreased in the HF group.

Conclusion: High FFAs induced morphological changes and serious damage to oxidative stress and inflammatory response in NK92 cells.

Cell-mediated immunity (CMI) is crucial in controlling the highly aggressive and progressive SARS-CoV-2 infection. Despite extensive researches on severe COVID-19 infection, the etiology and/or mechanisms of lymphopenia, decreased T cell-mediated responses in patients, cytokine release storms (CRS), and enhanced pro-inflammatory mediators are not fully understood. Several T cell subpopulations, including innate-like lymphocytes (ILLs) and conventional T cells, are involved in COVID-19 infection; however, their contribution to immunity and complications remains to be more elucidated. CD16+ T cells are among the effective players in the development of T helper1 (Th1) responses in COVID-19 infection, while their robust cytolytic properties contribute to lung tissue damage. While CD56-CD16bright NK cells play a protective role, natural killer T (NKT) cells, mucosal-associated invariant T (MAIT) cells, and γδ T cells and their roles in COVID-19 require further investigation. The involvement of the other T cell subsets, such as Th17, along with neutrophils, adds to the complexity of the situation. In this review, we presented and discussed the findings of recent studies on T cell responses and the contribution of each type of immune cells to COVID-19.