As a novel form of cell death, ferroptosis is mainly regulated by the accumulation of soluble iron ions in the cytoplasm and the production of lipid peroxides and is closely associated with several diseases, including acute kidney injury, ischemic reperfusion injury, neurodegenerative diseases, and cancer. The term "immunosuppression" refers to various factors that can directly harm immune cells' structure and function and affect the synthesis, release, and biological activity of immune molecules, leading to the insufficient response of the immune system to antigen production, failure to successfully resist the invasion of foreign pathogens, and even organ damage and metabolic disorders. An immunosuppressive phase commonly occurs in the progression of many ferroptosis-related diseases, and ferroptosis can directly inhibit immune cell function. However, the relationship between ferroptosis and immunosuppression has not yet been published due to their complicated interactions in various diseases. Therefore, this review deeply discusses the contribution of ferroptosis to immunosuppression in specific cases. In addition to offering new therapeutic targets for ferroptosis-related diseases, the findings will help clarify the issues on how ferroptosis contributes to immunosuppression.
Ferroptosis/immunology* ; Humans ; Immune Tolerance/immunology* ; Animals ; Immunosuppression Therapy ; Iron/metabolism* ; Neoplasms/immunology*

Sepsis is a leading life-threatening problem in intensive care medicine. The recent studies have given insights into the transition from inflammation to long-term immunosuppression in sepsis. This condition might cause physiological changes that comprise the lipopolysaccharide (LPS) tolerance. Most studies about the LPS tolerance focus on the reduced ability of macrophages to secrete pro-inflammatory cytokines. Although this method has identified various molecular changes, it remains ambiguous since changes in the whole cell population are measured as an average and markers are required for cell recognition. A fast and label-free method is in demand to detect cell tolerance and screen therapeutic agents that might reverse the process. In this study, direct current insulator-based dielectrophoresis (DC-iDEP) was used to characterize the biophysical properties (EKMr) of inflamed cells, LPS-tolerant cells, and cells treated with therapeutic agents. The results showed that the EKMr of these cells was 4.28×10⁸, 3.13×10⁸, and 4.25×10⁸ V/m², respectively, suggesting that the established method was useful in distinguishing LPS-tolerant cells. The device holds the promise to be applied in medical diagnosis and medicine screening.
Lipopolysaccharides/pharmacology* ; Animals ; Mice ; Macrophages/metabolism* ; Immune Tolerance/drug effects* ; RAW 264.7 Cells ; Drug Evaluation, Preclinical

Draconis Sanguis is a precious Chinese medicinal material for activating blood and resolving stasis, and its effective components are flavonoids. However, the structural diversity of flavonoids in Draconis Sanguis brings great challenges to the in-depth chara-cterization of its chemical composition profiles. To clarify the substance basis of Draconis Sanguis, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was used in this study to acquire MS data of Draconis Sanguis. The molecular weight imprinting(MWI) and mass defect filtering(MDF) were developed for rapid screening of flavonoids in Draconis Sanguis. Full-scan MS and MS~2 were recorded within the mass range m/z 100-1 000 in positive ion mode. Accor-ding to previous literature, MWI was employed to hunt for reported flavonoids in Draconis Sanguis, and the mass tolerance range of [M+H]~+ was set as ±10×10~(-3). A five-point MDF screening frame was further constructed to narrow the screening range of flavonoids from Draconis Sanguis. Combined with diagnostic fragment ions(DFI) and neutral loss(NL) as well as mass fragmentation pathways, 70 compounds were preliminarily identified from the extract of Draconis Sanguis, including 5 flavan oxidized congeners, 12 flavans, 1 dihydrochalcones, 49 flavonoids dimers, 1 flavonoids trimer and 2 flavonoid derivatives. This study clarified the chemical composition of flavonoids in Draconis Sanguis. Moreover, it also showed that high-resolution MS combined with data post-processing methods such as MWI and MDF could achieve rapid characterization of the chemical composition in Chinese medicinal materials.
Chromatography, High Pressure Liquid ; Flavonoids ; Immune Tolerance ; Molecular Weight ; Plant Extracts/chemistry*

To investigate the γ pass rate limit of plan verification equipment for volumetric modulated arc therapy (VMAT) plan verification and its sensitivity on the opening and closing errors of multi-leaf collimator (MLC), 50 cases of nasopharyngeal carcinoma VMAT plan with clockwise and counterclockwise full arcs were randomly selected. Eight kinds of MLC opening and closing errors were introduced in 10 cases of them, and 80 plans with errors were generated. Firstly, the plan verification was conducted in the form of field-by-field measurement and true composite measurement. The γ analysis with the criteria of 3% dose difference, distance to agreement of 2 mm, 10% dose threshold, and absolute dose global normalized conditions were performed for these fields. Then gradient analysis was used to investigate the sensitivity of field-by-field measurement and true composite measurement on MLC opening and closing errors, and the receiver operating characteristic curve (ROC) was used to investigate the optimal threshold of γ pass rate for identifying errors. Tolerance limits and action limits for γ pass rates were calculated using statistical process control (SPC) method for another 40 cases. The error identification ability using the tolerance limit calculated by SPC method and the universal tolerance limit (95%) were compared with using the optimal threshold of ROC. The results show that for the true composite measurement, the clockwise arc and the counterclockwise arc, the descent gradients of the γ passing rate with per millimeter MLC opening error are 10.61%, 7.62% and 6.66%, respectively, and the descent gradients with per millimeter MLC closing error are 9.75%, 7.36% and 6.37%, respectively. The optimal thresholds obtained by the ROC method are 99.35%, 97.95% and 98.25%, respectively, and the tolerance limits obtained by the SPC method are 98.98%, 97.74% and 98.62%, respectively. The tolerance limit calculated by SPC method is close to the optimal threshold of ROC, both of which could identify all errors of ±2 mm, while the universal tolerance limit can only partially identify them, indicating that the universal tolerance limit is not sensitive on some large errors. Therefore, considering the factors such as ease of use and accuracy, it is suggested to use the true composite measurement in clinical practice, and to formulate tolerance limits and action limits suitable for the actual process of the institution based on the SPC method. In conclusion, it is expected that the results of this study can provide some references for institutions to optimize the radiotherapy plan verification process, set appropriate pass rate limit, and promote the standardization of plan verification.
Humans ; Radiotherapy, Intensity-Modulated ; Immune Tolerance ; Nasopharyngeal Carcinoma ; ROC Curve ; Nasopharyngeal Neoplasms/radiotherapy*

The multiple myeloma (MM), the second most common hematologic malignancy, is malignant proliferative disease of plasma cells. Although the application of many targeted drugs has significantly prolonged the survival time of MM patients, it is still an incurable disease. In recent years, the immunosuppression caused by interaction between tumor microenvironment(TME) and tumor cells has attracted people's attention gradually. As a kind of immunosuppressive cells in TME, regulatory T cells (Treg) play an important role in the progress of MM. Treg is related to the proliferation and metastasis of tumors, and can lead to the progress of MM by promoting the angiogenesis and generating immunosuppressive TME. In this review, we briefly summarized the latest research progress on the impact of Treg on the pathogenesis of MM.
Humans ; Multiple Myeloma/pathology* ; T-Lymphocytes, Regulatory/pathology* ; Immune Tolerance ; Plasma Cells/pathology* ; Immunosuppression Therapy ; Tumor Microenvironment

Acute intestinal graft-versus-host disease is a refractory disease which can affect implantation and become a threat to life in severe cases. Autophagy is an intracellular degradation pathway necessary for maintaining cellular energy homeostasis. In recent years, a large number of studies have found that it is closely related to the pathogenesis and process of acute intestinal graft-versus-host disease. The main mechanisms may involve that inflammatory factor storm after pretreatment and infusion of donor cells induces disordered intestinal immune tolerance, and abnormal oxidative stress damages intestinal mucosal barrier, leading to intestinal rejection of acute graft-versus-host disease via mTOR signal pathway of autophagy, disordered mitophagy and other related pathways.
Autophagy ; Graft vs Host Disease ; Humans ; Immune Tolerance ; Oxidative Stress ; Signal Transduction

The COVID-19 pandemic is still raging across the world. Everyday thousands of infected people lost their lives. What is worse, there is no specific medicine and we do not know when the end of the pandemic will come. The nearest global pandemic is the 1918 influenza, which caused about 50 million deaths and partly terminate the World War Ⅰ. We believe that no matter the virus H1N1 for the 1918 influenza or 2019-nCoV for COVID-19, they are essentially the same and the final cause of death is sepsis. The definition and diagnostic/management criteria of sepsis have been modified several times but the mortality rate has not been improved until date. Over decades, researchers focus either on the immunosuppression or on the excessive inflammatory response following trauma or body exposure to harmful stimuli. But the immune response is very complex with various regulating factors involved in, such as neurotransmitter, endocrine hormone, etc. Sepsis is not a kind of disease, instead a misbalance of the body following infection, trauma or other harmful stimulation. Therefore we should re-think sepsis comprehensively with the concept of systemic biology, i.e. inflammationomics.
Betacoronavirus ; Coronavirus Infections ; complications ; epidemiology ; immunology ; Humans ; Immune Tolerance ; Inflammation ; complications ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; complications ; epidemiology ; immunology ; Pandemics ; Pneumonia, Viral ; complications ; epidemiology ; immunology ; Sepsis ; etiology

The active form of vitamin D3, 1,25-dihydroxyvitamin D₃ (aVD₃), is known to exert beneficial effects in the treatment of autoimmune diseases because of its immunosuppressive effects. However, clinical application of aVD₃ remains limited because of the potential side effects, particularly hypercalcemia. Encapsulation of aVD₃ within biodegradable nanoparticles (NPs) would enhance the delivery of aVD₃ to antigen presenting cells, while preventing the potential systemic side effects of aVD₃. In the present study, polymeric NPs containing ovalbumin (OVA) and aVD₃ (NP[OVA+aVD₃]) were prepared via the water-in-oil-in-water double emulsion solvent evaporation method, after which their immunomodulatory effects were examined. Bone marrow-derived immature dendritic cells (DCs) treated with NP(OVA+aVD₃) did not mature into immunogenic DCs but were converted into tolerogenic DCs, which express low levels of co-stimulatory molecules and MHC class II molecules, produce lower levels of pro-inflammatory cytokines while increasing the production of IL-10 and TGF-β, and induce the generation of Tregs. Intravenous injection with NP(OVA+aVD₃) markedly suppressed the generation of OVA-specific CTLs in mice. Furthermore, OVA-specific immune tolerance was induced in mice orally administered with NP(OVA+aVD₃). These results show that biodegradable NPs encapsulating both antigen and aVD₃ can effectively induce antigen-specific immune suppression.
Animals ; Antigen-Presenting Cells ; Autoimmune Diseases ; Cholecalciferol ; Cytokines ; Dendritic Cells ; Hypercalcemia ; Immune Tolerance ; Injections, Intravenous ; Interleukin-10 ; Methods ; Mice ; Nanoparticles ; Ovalbumin ; Polymers ; T-Lymphocytes, Regulatory ; Vitamins

Plasmacytoid dendritic cells (pDCs) are a unique subset of cells with different functional characteristics compared to classical dendritic cells. The pDCs are critical for the production of type I IFN in response to microbial and self-nucleic acids. They have an important role for host defense against viral pathogen infections. In addition, pDCs have been well studied as a critical player for breaking tolerance to self-nucleic acids that induce autoimmune disorders such as systemic lupus erythematosus. However, pDCs have an immunoregulatory role in inducing the immune tolerance by generating Tregs and various regulatory mechanisms in mucosal tissues. Here, we summarize the recent studies of pDCs that focused on the functional characteristics of gut pDCs, including interactions with other immune cells in the gut. Furthermore, the dynamic role of gut pDCs will be investigated with respect to disease status including gut infection, inflammatory bowel disease, and cancers.
Dendritic Cells ; Immune Tolerance ; Inflammatory Bowel Diseases ; Interferon Type I ; Lupus Erythematosus, Systemic ; Mucous Membrane

Systemic target therapeutic drugs, such as sorafenib, lenvatinib, or regorafenib are the only drugs that are known to be effective against advanced hepatocellular carcinoma (HCC). However, these agents show a limited efficacy in killing residual tumors. Immunotherapy is an alternative approach to this treatment and has been used to successfully treat different cancers, including HCC. HCC is an inflammation-induced cancer and represents a very interesting target for immunotherapeutics. Immunotherapies aim to reverse the immune tolerance and suppression found in tumor microenvironments and include approaches, such as adoptive cell therapy, immune checkpoint inhibition, and cancer vaccination. Adoptive cell therapy uses autologous natural killer or cytokine-induced killer cells by cultivating them ex vivo and subsequently reinfusing them into the patient. Immune checkpoint inhibitors reactivate tumor-specific T cells by suppressing checkpoint-mediated inhibitory signaling. Cancer vaccination induces a tumor-specific immune response by activating effector T lymphocytes. A wide range of potential immunotherapy-related adverse events occur; therefore, a multidisciplinary collaborative management is required across the clinical spectrum. This review summarizes the current status of immunotherapy for HCC and provides a perspective on its future applications.
Carcinoma, Hepatocellular ; Cell- and Tissue-Based Therapy ; Cytokine-Induced Killer Cells ; Homicide ; Humans ; Immune Tolerance ; Immunotherapy ; Neoplasm, Residual ; Oncolytic Viruses ; T-Lymphocytes ; Tumor Microenvironment ; Vaccination