Hyperexpression of tumor necrosis factor receptor 2 inhibits differentiation of myeloid-derived suppressor cells by instigating apolarity during ageing.

During the ageing process, TNF-α can promote the expansion of myeloid-derived suppressor cells (MDSCs). However, it remains unclear which receptor(s) of TNF-α are involved in and how they modulate this process. Here, we report that TNFR2 hyperexpression induced by either TNF-α or IL-6, two proinflammatory factors of senescence-associated secretory phenotype (SASP), causes cellular apolarity and differentiation inhibition in aged MDSCs. Ex vivo overexpression of TNFR2 in young MDSCs inhibited their polarity and differentiation, whereas in vivo depletion of Tnfr2 in aged MDSCs promotes their differentiation. Consequently, the age-dependent increase of TNFR2 versus unaltered TNFR1 expression in aged MDSCs significantly shifts the balance of TNF-α signaling toward the TNFR2-JNK axis, which accounts for JNK-induced impairment of cell polarity and differentiation failure of aged MDSCs. Consistently, inhibiting JNK attenuates apolarity and partially restores the differentiation capacity of aged MDSCs, suggesting that upregulated TNFR2/JNK signaling is a key factor limiting MDSC differentiation during organismal ageing. Therefore, abnormal hyperexpression of TNFR2 represents a general mechanism by which extrinsic SASP signals disrupt intrinsic cell polarity behavior, thereby arresting mature differentiation of MDSCs with ageing, suggesting that TNFR2 could be a potential therapeutic target for intervention of ageing through rejuvenation of aged MDSCs.

Antigen clearance at the peak of the primary immune response induces experimental autoimmune encephalomyelitis.

Autoimmune demyelinating diseases can be induced by an immune response against myelin peptides; however, the exact mechanism underlying the development of such diseases remains unclear. In experimental autoimmune encephalomyelitis, we found that the clearance of exogenous myelin antigen at the peak of the primary immune response is key to the pathogenesis of the disease. The generation of effector T cells requires continuous antigen stimulation, whereas redundant antigen traps and exhausts effector T cells in the periphery, which induces resistance to the disease. Moreover, insufficient antigenic stimulation fails to induce disease efficiently owing to insufficient numbers of effector T cells. When myelin antigen is entirely cleared, the number of effector T cells reaches a peak, which facilitates infiltration of more effector T cells into the central nervous system. The peripheral antigen clearance initiates the first wave of effector T cell entry into the central nervous system and induces chronic inflammation. The inflamed central nervous system recruits the second wave of effector T cells that worsen inflammation, resulting in loss of self-tolerance. These findings provide new insights into the mechanism underlying the development of autoimmune demyelinating diseases, which may potentially impact future treatments.

Programmed PPAR-α downregulation induces inflammaging by suppressing fatty acid catabolism in monocytes.

Inflammaging is associated with an increased risk of chronic disease. Monocytes are the principal immune cells for the production of inflammatory cytokines and contribute to inflammaging in the elderly. However, the underlying mechanisms remain largely unknown. Here, we found that monocytes from aged individuals contained high levels of lipid droplets (LDs), and this increase was correlated with impaired fatty acid oxidation. Downregulated peroxisome proliferator-activated receptor (PPAR)-α may be responsible for the pro-inflammatory phenotype of monocytes in aged individuals, as it was positively correlated with LD accumulation and increasing TNF-α concentration. Interestingly, interventions that result in PPAR-α upregulation, such as fenofibrate treatment, TNF-α neutralization, or calorie restriction, reversed the effect of aging on monocytes. Thus the downregulation of PPAR-α and LD levels in monocytes represents a novel biomarker for inflammaging. Furthermore, PPAR-α activation in the elderly may also alleviate long-term inflammaging, preventing the development of life-limiting chronic diseases.

[Oridonin ameliorates experimental autoimmune encephalomyelitis by inhibiting NF-κB signaling in T lymphocytes].

Objective To investigate the therapeutic effect and mechanism of oridonin on experimental autoimmune encephalomyelitis (EAE). Methods Female C57BL/6 mice were immunized with MOG/CFA to establish EAE model. The mice were randomly divided into EAE control and oridonin treatment groups. The mice were intraperitoneally injected with oridonin [15 mg/(kg.d)] on day 3, 5 and 7 post immunization, and the control group was injected with the same amount of PBS. EAE scores were recorded and the cell infiltration in the spinal cord was observed by HE staining at the peak of the disease. Flow cytometry analysis was used to detect the proliferation and apoptosis of MOG reactive CD4+ T cells, and the differentiation of pathogenic T helper type 1 (Th1) cells and Th17 cells. The expression of cytokine IFN-γ and IL-17 were detected by ELISA assay. The expression of nuclear factor κBp65 (NF-κBp65), phosphorylated NF-κBp65 (p-NF-κBp65), and phosphorylated IκB (p-IκB) were detected by Western blot analysis. Results Compared with the control group, the incidence and severity of EAE mice in the oridonin-treated groups was reduced, the onset time was delayed, and the immune cell infiltration in the spinal cord was reduced. In vitro and in vivo experiments showed that oridonin inhibited the proliferation of myelin antigen reactive CD4+ T cells and induced their apoptosis. Oridonin inhibited the differentiation of pathogenic Th1 cells and Th17 cells, and the expression of inflammatory cytokines IFN-γ and IL-17. Oridonin inhibited the phosphorylation of IκB and NF-κBp65. Conclusion Oridonin can ameliorate EAE by inhibiting the activation of NF-κB signaling pathway, thereby the proliferation and differentiation of T cells and the secretion of inflammatory factors are inhibited.

Circular RNA hsa_circ_0001178 facilitates the invasion and metastasis of colorectal cancer through upregulating ZEB1 via sponging multiple miRNAs.

Metastasis is the main cause of increasing cancer morbidity and mortality. However, the underlying mechanism of cancer metastasis remains largely unknown. In the present study, we identified one circular RNA (circRNA) closely related to the metastasis of colorectal cancer (CRC), namely hsa_circ_0001178. CRC patients with high hsa_circ_0001178 were more prone to have metastatic clinical features, advanced TNM stage and adverse prognosis. Stable knockdown of hsa_circ_0001178 significantly weakened CRC cell migratory and invasive capabilities in vitro as well as lung and liver metastases in vivo. Mechanistic study revealed that hsa_circ_0001178 acted as a competing endogenous RNA (ceRNA) for miR-382/587/616 to upregulate ZEB1 (a key trigger of epithelial-to-mesenchymal transition), thereby promoting CRC metastatic dissemination. Of note, ZEB1 could also increase hsa_circ_0001178 expression via physically binding to hsa_circ_0001178 promoter region. Collectively, our data uncover the crucial role of hsa_circ_0001178 in CRC metastasis, and targeted therapy based on this positive feedback ceRNA axis may be a promising treatment for metastatic CRC patients.

[Mechanism of immune tolerance induced by soluble myelin oligodendrocyte glycoprotein in mice with experimental autoimmune encephalomyelitis].

Objective To explore the mechanism of immune tolerance induced by soluble MOG35-55 (MOG) peptide in mice with experimental autoimmune encephalomyelitis (EAE). Methods EAE mice were randomly divided into three groups, MOG, OVA and control groups, which were injected intraperitoneally with MOG, OVA peptide and PBS, respectively, from day 6 to day 16 after EAE induction. Lymphocytes in the spleen and CNS were enumerated and their phenotypes and function were analyzed by flow cytometry to explore the role of T cell migration in MOG-induced EAE tolerance. Next, CD11b+ antigen presenting cells (APCs) in the spleen and CNS infiltration were analyzed by flow cytometry to evaluate their maturation, and the role of mature APCs in blocking MOG-CD4+ T cells trafficking to CNS was determined by immunofluorescence technique. Results MOG trapped effector T cells in the spleen and protected mice from EAE. MOG triggered the maturation of splenic APCs, while prevented the maturation of CNS-infiltrating APCs. MOG-loaded APCs could interact with MOG reactive CD4+ T cells and limit their migration. Conclusion MOG can protect mice from EAE by inducing the maturation of splenic APCs that interact with MOG-T cells and trap them in the periphery.

The immune response is a prerequisite for the development of CD4+Foxp3+ regulatory T cells in transplantation.

CD4+Foxp3+ regulatory T cells (Tregs) are critical in maintaining the peripheral tolerance and homeostasis of the immune system, yet their development and role in transplantation are poorly understood. Here we show that the levels of Tregs in neonatal transplant tolerant mice are similar to the levels in naive mice when they are kept in a state of homeostasis devoid of an immune response. An increased frequency of Tregs was observed only in recipients with allograft rejection, in naive mice that received alloantigens, or in tolerant mice adoptively transferred with alloreactive T cells. Even though an antigen-specific immune response is a prerequisite for the development of Tregs, both antigen-specific and nonspecific Tregs are generated in this process. We conclude that Tregs are induced and function in an inflammatory environment and in a negative feedback loop.

Determinant roles of gender and age on SII, PLR, NLR, LMR and MLR and their reference intervals defining in Henan, China: A posteriori and big-data-based.

OBJECTIVES: By now, there are few data of the reference intervals (RIs) of SII, PLR, NLR, LMR and MLR. We aimed to establish RIs of SII, PLR, NLR, LMR and MLR for healthy persons. METHODS: A retrospective analysis on a cohort of ostensibly healthy, aged no <18 years old physical examinees who took health examination from January to December in 2013 was conducted to explore influences of age and gender on SII, PLR, NLR, LMR and MLR and to establish their RIs. And another cohort of 450 persons in our hospital from January to July in 2016 is included for validations of RIs. RESULTS: NLR, LMR and MLR were significantly different between gender groups (P=.010; P<.001; P<.001, separately), while SII and PLR were not (P=.137; P=.267, separately). While SII was not changed much between age groups (P=.842), PLR, NLR, LMR and MLR were significantly different (all with P<.001). RIs of SII, PLR, NLR, LMR and MLR were: SII: [161,701]; PLR: 18-65 year-old: [61,179]/>65 year-old: [55,179]; NLR: 18-65 year-old male: [0.90,2.94]/18-65 year-old female: [0.85,3.06]/>65 year-old male: [0.95,3.57]/aged >65 year-old female: [0.83,3.30]; LMR: 18-65 year-old male: [2.50,7.50]/18-65 year-old female: [2.75,8.50]/>65 year-old male: [2.16,7.41]/>65 year-old female: [2.40,8.33]; MLR: 18-65 year-old male: [0.12,0.35]/18-65 year-old female: [0.10,0.32]/>65 year-old male: [0.12,0.41]/>65 year-old male: [0.11,0.33]. CONCLUSIONS: RIs of SII, PLR, NLR, LMR and MLR of people in central China were established and validated. It will benefit experimental design of the related studies and lead to better standardizations of SII, PLR, NLR, LMR and MLR for their clinical applications.

Antigen-oriented T cell migration contributes to myelin peptide induced-EAE and immune tolerance.

Treatment with soluble myelin peptide can efficiently and specifically induce tolerance to demyelination autoimmune diseases including multiple sclerosis, however the mechanism underlying this therapeutic effect remains to be elucidated. In actively induced mouse model of experimental autoimmune encephalomyelitis (EAE) we analyzed T cell and innate immune cell responses in the central nervous system (CNS) and spleen after intraperitoneal (i.p.) infusion of myelin oligodendrocyte glycoprotein (MOG). We found that i.p. MOG infusion blocked effector T cell recruitment to the CNS and protected mice from EAE and lymphoid organ atrophy. Innate immune CD11b(+) cells preferentially recruited MOG-specific effector T cells, particularly when activated to become competent antigen presenting cells (APCs). During EAE development, mature APCs were enriched in the CNS rather than in the spleen, attracting effector T cells to the CNS. Increased myelin antigen exposure induced CNS-APC maturation, recruiting additional effector T cells to the CNS, causing symptoms of disease. MOG triggered functional maturation of splenic APCs. MOG presenting APCs interacted with MOG-specific T cells in the spleen, aggregating to cluster around CD11b(+) cells, and were trapped in the periphery. This process was MHC II dependent as an MHC II directed antibody blocked CD4(+) T cell cluster formation. These findings highlight the role of myelin peptide-loaded APCs in myelin peptide-induced EAE and immune tolerance.

The platelet-to-lymphocyte ratio, superior to the neutrophil-to-lymphocyte ratio, correlates with hepatitis C virus infection.

OBJECTIVES: The platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) have been studied widely in cancer diseases. However, their correlation with hepatitis C virus (HCV) infection is unknown. The aim of this study was to investigate the correlation of PLR and NLR with disease severity in patients with HCV-related liver disease and the virological response in chronic hepatitis C (CHC) patients. METHODS: The clinical data of 120 HCV-infected patients and 40 healthy controls were analyzed. The clinical data of 24 CHC patients who had been followed up regularly were collected for the following time points: before treatment (week 0) and weeks 4, 48, and 72 during treatment. These data were also analyzed. All data were collected from the database of the hospital patient electronic medical record system. RESULTS: The HCV-related cirrhosis group and HCV-related hepatocellular carcinoma group were found to have lower PLRs (61±31 and 51±23) than the healthy controls (115±23). The PLR of the HCV cleared group (154±85) was significantly higher than that of the HCV untreated group and HCV uncleared group (90±28 and 88±40, respectively). Receiver operating characteristics curve analysis for the PLR showed an area under the curve of 0.772 (95% confidence interval 0.674-0.869, p<0.000); for NLR, the area under the curve was 0.612 (95% confidence interval 0.495-0.730, p=0.063). Furthermore, an increasing PLR in CHC patients indicated a good virological response, and a stable PLR or a downward trend in PLR could predict no rapid virological response being achieved by week 4, and even no sustained virological response by week 72. CONCLUSIONS: The PLR is closely related to disease severity in patients with HCV-related liver disease and to the virological response in CHC patients. Dynamic continuous monitoring of the PLR will contribute to disease surveillance, with an increasing tendency predicting a good virological response.

Oridonin suppresses transplant rejection by depleting T cells from the periphery.

Oridonin is a natural compound purified from Rabdosia rubescens that has remarkable anti-inflammatory and antitumor activities. Although oridonin has been used in traditional Chinese medicine for many years to treat inflammatory diseases, the underlying mechanisms of these activities are not well understood. In this paper, we explored whether oridonin could be used in transplantation and the mechanisms of its immunosuppression. Oridonin efficacy in transplantation is manifested by prolonged graft survival and decreased graft infiltration. Oridonin induces T cell apoptosis in a concentration- and time-dependent manner. In vivo, oridonin depleted large numbers of T cells from the spleen and peripheral blood. Decreased T cell numbers resulted from apoptosis, which was accompanied by increased phagocyte numbers in the periphery. Reduction in the number of thymocytes was observed in mice treated for 8days, and CD4+CD8+ cells were more sensitive to apoptosis induced by oridonin. Additionally, successive treatment with oridonin for 16days resulted in a considerable reduction in the total number of spleen cells and spleen volume. Thus, T cell depletion may play an essential role in prolonged graft survival and immunosuppression induced by oridonin.

A given number of effector T cells can only destroy a limited number of target cells in graft rejection.

Anti-donor T cells mediate graft rejection and the frequency of anti-donor T cells directly correlates with transplant outcome. It has long been noted that long-term tolerance was occasionally observed in minor mismatched recipients, little is known about the mechanisms underlying this phenomenon. To quantitatively analyze the relationship between anti-donor T cells and target cells, long-term tolerant C57BL/6 mice were established by infusing 3 x 10(7) F1 splenocytes during the neonatal period. The removal of anti-donor T cells in these mice was demonstrated by unresponsiveness in mixed-lymphocyte reaction. A total of 2 x 10(7) or 5 x 10(7) syngenic naive cells were transferred into long-term tolerant mice; the dose of 5 x 10(7) syngenic cells destroyed chimerism and the skin grafts, while the dose of 2 x 10(7) syngenic cells led to loss of chimerism but the survival of the skin grafts. On Day 20 after the transfusion, a portion of 5 x 10(7) syngenic cells still remained in the mice, while no syngenic cells were detected in mice that received a total of 2 x 10(7) syngenic cells suggesting that these cells were completely exhausted. Syngenic CD4+ T cells proliferated and activated in both groups, while syngenic cells in the low-dose group were more susceptible to apoptosis than those in the high-dose group. Our results suggest that a given number of effector T cells could only kill a limited number of target cells. When that limit was reached, the T cells died. This novel concept not only provides a reasonable explanation for long-term tolerance in minor mismatched transplantation but also provides new insight into tolerance induction that depleting alloreactive T cells in recipients by donor cells or agents is a prerequisite for reconstitution of thymus by donor cells, the establishment of central tolerance is the key for successful tolerance induction.