The purpose of this study was to investigate the changes in postoperative plasma IL-10 levels in allogeneic lung transplant recipients and its relationship with death due to bacterial infection. To this end, plasma samples were collected from healthy volunteers and lung transplantation recipients who either deceased, survived or lived with a good long-term prognosis. For the deceased group, the immune cell distributions in peripheral blood were analyzed by routine blood analysis. The pathogenic infection status was examined by imaging and the type of pathogenic infection was analyzed by in vitro bacteria culture and by high-throughput genomic sequencing of pathogenic microorganisms. In addition, the concentration of multiple cytokines in all plasma samples was monitored by Luminex multifactor detection. The results showed that in the deceased recipients, postoperative white blood cell count (WBC), absolute neutrophil count (NEUT) and percentage (NEUT%), CRP concentration, and neutrophil-lymphocyte ratio (NLR) were all increased, while red blood cell count (RBC) and platelet count (PLT) were decreased. Moreover, some high-density shadows were observed in the postoperative lungs along with multiple bacterial infections in the blood, bronchoalveolar lavage fluid (BALF), and sputum. Dynamic monitoring of cytokines concentration showed that plasma IL-10 concentration and IL-10/IFN-γ ratio were all significantly increased (all P＜0.000 1) in the deceased recipients after allogeneic lung transplantation compared to those of survived recipients, recipients with good prognosis and healthy volunteers. Altogether, this work suggests, for the first time, that the change in plasma IL-10 level is highly related with increased bacterial infection and mortality in lung transplantation recipients.
To investigate the effect of CD47 knockdown on the migration, proliferation, and chemokine secretion of ovarian cancer cells, small interfering RNA (siRNA) targeting CD47 was transfected to ovarian cancer cells and the knockdown efficiency was confirmed by Western blotting, qRT-PCR, and flow cytometry. Cell proliferation, migration, and invasion were examined using CCK-8, wound healing assay, and the Transwell assay, respectively. qRT-PCR was used to detect the expressions of CD47, C-X-C motif chemokine ligand 1（CXCL1）, CXCL8, C-C motif chemokine ligand 20（CCL20）and IL-6. ELISA was used to determine the release of IL-6 and CXCL8. Transwell was employed to study macrophage invasion of CD47 knockdown ovarian cancer cells. The results showed that the expressions of chemokines CXCL1, CXCL3, CXCL8, CCL20, and IL-6 in ovarian cancer cells were reduced when CD47 was knocked down, along with the reduction of the migration capacity of macrophages towards ovarian cancer cells. CD47 knockdown did not affect the proliferation, migration, or invasion of ovarian cancer cells. Our findings suggest that CD47 in ovarian cancer cells can affect the migration ability of macrophages by regulating their chemokine expression.
To explore the effect and mechanism of Annexin A1 (ANXA1) peptidomimetic Ac2-26 on hemodynamics and myocardial mitochondrial damage in the acute heart failure (AHF) model, rats were divided into control group, model group, and Ac2-26 group (fifteen rats per group). AHF model was established in the model group and Ac2-26 group. Rats in Ac2-26 group were also intravenously injected with Ac2-26 once a day for fourteen days, whereas the control group and model group were treated with the same volume of saline. Color doppler ultrasound was used to detect the hemodynamic indexes. H-E staining was used to evaluate the pathological damage of myocardial tissue. TUNEL staining was used to detect the apoptosis of cardiomyocytes. Transmission electron microscope (TEM) was used to observe the mitochondrial structure. Changes in mitochondrial membrane potential were also evaluated. Macrophage marker CD68, M1 marker iNOS, and M2 marker CD206 were detected by immunohistochemistry. mRNA expressions of TNF-α, IL-6, TGF-β, IL-10 and recombinant human Arginase 1 (Arg-1) and protein expression levels of IL-10, Arg-1 and CD206 were evaluated by qRT-PCR and Western blotting, respectively. Compared with the model group, the left ventricular systolic pressure （LVSP）and maximum increase rate of left ventricular pressure (+LV dp/dtmax) of rats in the Ac2-26 group were increased, left ventricular end-diastolic pressure （LVEDP）and maximum decrease rate of left ventricular pressure (－LV dp/dtmax) were decreased, and heart rate (HR) was increased; The number of cardiomyocytes in the myocardial tissue was large, and the inter-cellular space was narrowed, and the infiltration of inflammatory cells and macrophages was also relieved; The positive rate of TUNEL staining was decreased, the damage of myocardial mitochondria was relieved, the structure was relatively intact, and the mitochondrial membrane potential was increased; The positive expression of iNOS in myocardial tissue was decreased, and the positive expressions of CD68 and CD206 were increased; The relative mRNA expressions of TNF-α and IL-6 were both down-regulated, while those of TGF-β, IL-10 and Arg-1 were all up-regulated. Meanwhile, the protein levels of IL-10, Arg-1, and CD206 were also up-regulated, and all the differences were statistically significant (all P＜0.05). In conclusion, Ac2-26 treatment has improved hemodynamics and alleviated mitochondrial damage, leading to the recovery of cardiac function in AHF rats. The mechanism may be related to macrophage polarization change from M1 to M2.
To explore the mechanism of γδT cell receptor in global cerebral ischemia-reperfusion injury after cardiopulmonary-cerebral resuscitation (CPCR) in mice, adult male C57BL/6 mice were randomly divided into three groups: blank group, CPCR group, and CPCR+γδT receptor antagonist group. The model of global cerebral ischemia-reperfusion injury in mice after CPCR was established by asphyxia and then paraffin sections of mouse brain tissue were made. H-E staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) were used to observe the injury and apoptosis of cerebral tissue. Western blotting and immunohistochemistry were used to evaluate the protein expression levels of IL-17A and IL-23p19. The mRNA expression levels of IL-17A and IL-23p19 were evaluated by RT-PCR. The results showed that compared to those of the blank group, large numbers of cells in the central area of cerebral ischemia foci in the CPCR group were dead or showed irregular state of enlargement, rupture of nuclear membrane, and disappearance of cell structure. And the apoptosis in the CPCR group was more severe than that in blank group. In contrast, all the above manifestations were less severe in CPCR+γδT receptor antagonist group. Compared to those in the blank group, the brain injury score, apoptosis rate, IL-17A and IL-23p19 expressions were significantly increased in the CPCR group (P<0.01). Compared to the CPCR group, the CPCR+ γδT receptor antagonist group had significantly lower brain injury score, apoptosis rate, IL-17A and IL-23p19 expressions (P<0.05). These results suggest that the γδT cell receptor plays a proinflammatory role in the pathogenesis of global cerebral ischemia-reperfusion injury after CPCR in mice by regulating the levels of IL-17A and IL-23p19 in γδT cells.
To investigate the effect and mechanism of paeoniflorin (PF) on human bronchial epithelial cells (BEAS-2B), THP-1 cells were induced to differentiate into macrophages by phorbol 12-myristate 13-acetate, and the toxicity of PF to THP-1 macrophages was detected by CCK-8 assay. THP-1 macrophages were cultured with 1 μg/mL LPS to induce inflammation, and treated with 1, 10, and 30 μmol/L PF for 24, 48, and 72 h, respectively. Cell viability was detected by CCK-8 assay, and the optimal concentration and treating time of PF were determined. BEAS-2B cells were inoculated in the upper chamber of Transwell and THP-1 macrophages were inoculated in the lower chamber of Transwell. THP-1 macrophages were divided into 4 groups: control group, LPS group, PF group, and LPS+PF group. The survival rate of BEAS-2B cells was detected by CCK-8 assay, the apoptosis rate of BEAS-2B cells was detected by FACS, the levels of inflammatory cytokines IFN-γ, IL-4, IL-17C, and IL-10 were detected by ELISA, and the expression levels of CD63, CD9, and apoptosis-linked gene 2-interaction protein X (Alix) were detected by Western blotting. The expressions of M1 and M2 markers CD80 and CD206 in THP-1 macro-phages were detected by FACS. The results showed that the optimal concentration and treating time of PF were 10 μmol/L and 48 h. Compared to those in the control group, the cell survival rate, IL-4 and IL-10 levels and the proportion of M2-type macrophages in the LPS group were significantly decreased (P<0.01). On the other hand, the apoptosis rate, IFN-γ and IL-17C levels, CD63, CD9, Alix protein expression levels and the proportion of M1-type macrophages were significantly increased (P<0.01). Compared to those in the LPS group, the cell survival rate, IL-4 and IL-10 levels and the proportion of M2-type macrophages in the LPS+PF group were significantly increased (P<0.01), while the apoptosis rate, IFN-γ and IL-17C levels, CD63, CD9, Alix protein expression levels and the proportion of M1-type macrophages were significantly decreased (P<0.01). These results suggest that PF can improve the survival rate of BEAS-2B cells, reduce apoptosis, and inhibit exosome secretion and inflammatory response. The underlying mechanism may be related to PF induced M2-type polarization of macrophages.
The aim of this research was to investigate the pharmaceutical effect of polydatin (PD) on the amelioration of acute myocardial infarction (AMI)-induced myocardial fibrosis in rat model. To this end, SD rats were randomly divided into control group (Ct), model group (Model), low-dose PD treatment group (PD-L, 40 mg/kg), high-dose PD treatment group (PD-H, 100 mg/kg), captopril treatment group (CTP, 20 mg/kg), and PD-H+TGF-β agonist group (100 mg/kg+30 mg/kg). AMI was induced by left anterior descending coronary artery ligation in all rats except those in the Ct group. Myocardial function and tissue structure were evaluated by animal ultrasound system and Masson staining of the heart. The collagen sedimentation in the myocardial tissue was evaluated by immunohistochemistry and the levels of IL-6 and TNF-α were measured by ELISA kits. The protein expressions of TGF-β1, p-Smad2/3, and p-ERK1/2 were assessed by Western blotting. Compared to those in the Ct group, rats in the model group exhibited worse myocardial function with severe myocardial fibrosis and systematic inflammatory responses (all P＜0.05). Notably, PD treatment significantly ameliorated AMI-induced myocardial injury in a dose-dependent manner, evidenced by improved myocardial function, less fibrotic collagen deposition, less inflammatory factors secretion along with the inhibition of the TGF-β/Smad/ERK signaling pathway (all P＜0.05). Moreover, the therapeutic effect of high-dose PD was comparable to that of positive control captopril whereas SRI-011381 (a type of TGF-β agonist) remarkedly abrogated the rescue effect of PD on the AMI-induced myocardial fibrosis. In conclusion, our study demonstrates that PD may relieve the degree of myocardial inflammatory infiltration and improve AMI-induced myocardial fibrosis in rats by inhibiting the TGF-β/Smad/ERK signaling pathway, which may promote damaged myocardium repairments.
This study aims to develop a method to efficiently and stably induce the differentiation and expansion of human myeloid-derived suppressor cells (MDSC) in vitro and provide new experimental technology for the study of the function and mechanism of human MDSC. For this purpose, PBMC of healthy volunteers were isolated with Ficoll density gradient centrifugation. Next, monocytes were separated by anchoring technique. PBMC or monocytes were stimulated with GM-CSF and IL-6 (10, 20, 40, 80 ng/mL each) for 4, 7, 14, and 21 days before co-culturing with PBMC for 3 days. The proliferation of CD33+ MDSC and T cells and the proportion of CD3+IFN-γ+ T cells were detected by FACS. The results showed that the PBMC or monocytes were induced to differentiate to less CD33+MDSC by conventional methods. However, by improved methods, the monocytes cultured with GM-CSF and IL-6 (each 80 ng/mL) for 14 days (refreshing the culture solution every 4-5 days) were induced to differentiate more efficiently into a higher proportion of CD33+MDSC, which showed significant inhibition of T cell proliferation and IFN-γ secretion. This study suggests that with the improved method, the monocytes are efficiently induced to differentiate into CD33+ MDSC, which has significant suppressive function.
To explore the clinical characteristics of DNA topoisomerase type Ⅰ (AC-29) in human laryngeal carcinoma cell line 2 (HEp-2) cells, four cases of AC-29 from Children's Hospital of Nanjing Medical University were retrospectively reported. From January 2020 to December 2021, a total of 14 213 serum samples with auto-antibodies had been tested in this Hospital. Among them, four had the anti-nuclear antibody (ANA) karyotype shaped AC-29 tested by indirect immunofluorescence assay. AC-29 is a newly defined karyotype in recent years. Correct identification of AC-29 has potential significance for early diagnosis of disease.
Immunotherapy has become one of the main modalities for tumor treatment. CTLA-4 and PD-1 are the two main players in tumor immune escape. However, the low response rate of PD-1 and CTLA-4 treatments is the main challenge facing tumor immunotherapy at present. Lymphocyte activation gene 3 (LAG-3), a new-generation inhibitory immune checkpoint, plays an important regulatory role in the human immune system. LAG-3 is highly expressed on various types of TIL and mediates tumor immune escape through multiple mechanisms. LAG-3 can also be co-expressed with PD-1 in TIL. Combined blockade of LAG-3 and PD-1 synergistically inhibits immune escape, increases antitumor response, and enhances T cell proliferation. It has become one of the most promising immunotherapies to improve the current deficiencies in tumor immunotherapy. Therefore, it is of great significance to deeply understand the biological characteristics of LAG-3 and further explore its mechanism of action. In addition, the structure and function of LAG-3 as well as its research progress in tumor immunity are reviewed.
Systemic lupus erythematosus (SLE), also known as typeⅠIFN signature disease, is a chronic systemic autoimmune disease of unknown etiology. The main features of the disease are the overactive immune response and overexpression of typeⅠIFN. In the course of innate immune response, the overactive immune reaction of nucleic acid receptor to pathogen and nucleic acid in vivo is one of the reasons that lead to the typeⅠIFN abnormality in patients. Regulating the overactive immune response and the overexpression of typeⅠIFN play important roles in alleviating the disease. Autophagy, as an important process regulating body homeostasis, can inhibit the typeⅠIFN response. In this review, we discuss how the selective autophagic receptors tripartite motif 21 (TRIM21), stimulator of interferon genes (STING), and p62 affect typeⅠIFN response by mediating autophagy of key regulators in multiple pathways.
Radiation-induced bystander effect (RIBE) is one of the mechanisms of ionizing radiation-induced biological effects, which may be mediated by a variety of pathways. Exosomes are 30~150 nm diameter bilayer lipid membrane-rounding vesicles actively released by living cells and were widely distributed in body fluids. They carry signal molecules including nucleic acids and proteins to play important roles in inter-cellular communications. Recently, it has been found that exosomes can participate in the formation of RIBE and mediate the occurrence of immune responses due to ionizing radiation. The immune system is one of the main targets for ionizing radiation, and the damage of the immune system is also the main cause of the most common diseases and life quality decline of patients suffering from nuclear accidents. Therefore, it has persisted a hotspot in the field of radiation biology to comprehensively reveal the mechanism of RIBE in the ionizing radiation-induced immune effect. This review discusses the role of RIBE in the ionizing radiation-induced immune effect from the perspective of exosome and summarizes the biological mechanisms of exosome in this process in order to form a scientific basis for further study of the mechanism of radiation biological effects and for the exploration of radiation injury prevention and treatment strategies.
Neutrophils are one of the most important effector cells in innate immunity and the defense at the frontline against invading pathogens. With the continuous advances, people have realized that neutrophils not only participate in the inflammatory response and tissue damage repair, tumor-associated neutrophils also act as anti- or pro-tumorigenic factors depending on specific tumor microenvironment (TME) status. Neutrophils with different functions may have different phenotypes and also some plasticity. This review begins with the biological properties of neutrophils, and then summarizes the diverse phenotypes of neutrophils with different functions in the TME, the possible mechanisms of immunosuppressive neutrophils regulating tumor immunity, and the clinical application of neutrophils in cancer research.
More and more studies have shown that the occurrence of atherosclerosis is closely related to pyroptosis, especially gasdermin D（GSDMD）-mediated pyroptosis. In atherosclerosis, inflammatory cells such as macrophages, vascular endothelial cells, and vascular smooth muscle cells undergo pyroptosis, leading to plaque rupture and thrombosis, and finally to acute coronary syndrome. In the development of atherosclerosis, arterial wall endothelial injury and lipid deposition are the main initiating factors, which activate Caspase-1 and Caspase-11/4/5, respectively, and in turn cause the cleavage of the GSDMD protein and mediate classical and non-classical cell pyroptosis. The N-terminus of the GSDMD protein migrates to the cell membrane and oligomerizes to form pores through which the inflammatory factors IL-1β and IL-18 are released into the interstitium. The release of inflammatory factors further promotes the death of intravascular cells, after which their contents, cytokines, and proteases enter the extracellular matrix, aggravating the local inflammatory response, leading to atherosclerotic plaque rupture and cardiovascular disease. Based on the above mechanism, the development of drugs that directly target GSDMD and signal molecules in the pyroptosis signaling pathway induced by GSDMD, such as inflammasomes, Caspase-1, IL-1β, and IL-18, provides a theoretical basis and new ideas for the treatment of atherosclerosis.
During the global pandemic of COVID-19, memory T cells have drawn increasing research attention because of their superior antiviral capacity. The latest research demonstrates that certain APC and cytokines in the microenvironment are required for the differentiation and effector responses of memory CD4+ T cells via tightly modulated intracellular transcription factors and energy metabolism. This review summarizes and discusses the key mechanisms underlying the development, long-term maintenance, and secondary immune responses of memory CD4+ T cells. Precise regulation of their number and functions in different types of diseases will be a big challenge in the future.