Tumor-infiltrating T-Lymphocyte immunity-related immune tolerance and anti–programmed cell death protein 1/ligand of programmed cell death protein 1 therapy for advanced hepatocellular carcinoma

Systemic therapy has become the standard treatment for patients with advanced hepatocellular carcinoma(HCC)whose treatment options are limited.However,the long-term patient response to drugs and the survival outcomes remain a concern.With increasing exploration of the HCC microenvironment,particularly in terms of T lymphocyte immunity,a new era of immunomolecular targeted therapy,based on molecular signaling,has arrived for advanced HCC.In the study of immune tolerance of the intrinsic HCC microenvironment,we found that multiple immunosuppressive mechanisms and immune checkpoint inhibitors,such as anti–programmed cell death protein 1/ligand of programmed cell death protein 1 therapy,have improved clinical outcomes in some patients with advanced HCC.Furthermore,various combination therapies have been investigated,and HCC types have been categorized into different types based on anti–programmed cell death protein 1(PD-1)/ligand of programmed cell death protein 1(PD-L1)treatment.In this paper,we first discuss the tumor-infiltrating T lymphocyte immunity and immune tolerance of HCC.We then clarify the basic mechanism of anti–PD-1/PD-L1 therapy and discuss the types of HCC based on anti–PD-1/PD-L1 therapy.Thereafter,we explain the relevant studies and mechanisms of combination therapy of anti–PD-1/PD-L1 with antiangiogenesis drugs or multikinase kinase inhibitors,anti–T lymphocyte–related signaling pathways in HCC,and other anti-CD8+T cell immune checkpoints.In this way,this review offers a deeper understanding of anti–PD-1/PD-L1 immunotherapy for advanced HCC,in order to provide better individualized treatments for patients with advanced HCC.

Liver immunity,autoimmunity,and inborn errors of immunity

The liver is the front line organ of the immune system.The liver contains the largest collection of phagocytic cells in the body that detect both pathogens that enter through the gut and endogenously produced antigens.This is possible by the highly developed differentiation capacity of the liver immune system between self-antigens or non-self-antigens,such as food antigens or pathogens.As an immune active organ,the liver functions as a gatekeeping barrier from the outside world,and it can create a rapid and strong immune response,under unfavorable conditions.However,the liver's assumed immune status is anti-inflammatory or immuno-tolerant.Dynamic interactions between the numerous populations of immune cells in the liver are key for maintaining the delicate balance between immune screening and immune tolerance.The anatomical structure of the liver can facilitate the preparation of lymphocytes,modulate the immune response against hepatotropic pathogens,and contribute to some of its unique immunological properties,particularly its capacity to induce antigen-specific tolerance.Since liver sinusoidal endothelial cell is fenestrated and lacks a basement membrane,circulating lymphocytes can closely contact with antigens,displayed by endothelial cells,Kupffer cells,and dendritic cells while passing through the sinusoids.Loss of immune tolerance,leading to an autoaggressive immune response in the liver,if not controlled,can lead to the induction of autoimmune or autoinflammatory diseases.This review mentions the unique features of liver immunity,and dysregulated immune responses in patients with autoimmune liver diseases who have a close association with inborn errors of immunity have also been the emphases.

Research progress of ICOSL/ICOS pathway in maternal-fetal immune tolerance

Co-signaling molecules are molecules whose ligands on the surface of cells interact with receptors on the surface of T cells to convey stimulatory or inhibitory signals to regulate immune responses.Co-signaling molecules play an important role in tumor and autoimmune diseases.Lately,studies have shown that co-signaling molecules are also involved in the regulation of maternal-fetal immune tolerance,and abnormalities of co-signaling molecules may lead to the imbalance of maternal-fetal immune tolerance,resulting in recurrent abortion,eclampsia and other pregnancy complications.ICOSL/ICOS is a ligand and receptor of costimulatory signals,which regulates maternal and fetal immune tolerance by participating in T cell differentiation and Th1 and Th2 cytokine secretion.Therefore,this article reviews the structure of ICOSL/ICOS,the distribution of ICOSL/ICOS at the maternal-fetal interface and its immune regulation during pregnancy,in order to provide new ideas for the future study of immunotherapy of pregnancy complications caused by abnormal co-signaling molecules.

Gastric cancer liver metastasis will reduce the efficacy of immunotherapy

Immune checkpoint inhibitors augment the antitumor activity of T cells by inhibiting the negative regulatory pathway of T cells,leading to notable efficacy in patients with non-small cell lung cancer,melanoma,and other malignancies through immunotherapy utilization.However,secondary malignant liver tumors not only lower the liver's sensitivity to immunotherapy but also trigger systemic immune suppression,resulting in reduced overall effectiveness of immune therapy.Patients receiving immunotherapy for non-small cell lung cancer and melanoma experience reduced response rates,progression-free survival,and overall survival when secondary malignant tumors develop in the liver.Through Liu's retrospective analysis,valuable insights are provided for the future clinical management of these patients.Therefore,in patients with gastric cancer(GC),the occurrence of liver metastasis might be indicative of reduced efficacy of immuno-therapy.Overcoming liver immune tolerance mechanisms and their negative impacts allows for the potential benefits of immunotherapy in patients with GC and liver metastasis.INTRODUCTION Gastric cancer(GC)ranks among the prevalent malignancies affecting the digestive system globally.Based on the latest epidemiological data[1,2],it holds the fifth position for incidence and the fourth position for mortality among all malignant tumors.GC cases and fatalities in China make up roughly half of the worldwide figures.Earlier investigations[3]have demonstrated that the median overall survival(mOS)among advanced GC patients left untreated typically ranges from 3 to 4 months.Systemic chemotherapy recipients often experience a mOS of around one year,accompanied by a marked improvement in the quality of life among patients with advanced GC.The mainstay of treatment for advanced GC patients involves chemotherapeutic medications such as fluoropyrimidines,platinum compounds,and taxanes.However,their efficacy in tumor control is constrained by acquired resistance and primary resistance.The rise of personalized precision therapy has propelled immunotherapy into the spotlight as a crucial component of comprehensive treatment[4].By blocking the negative regulatory pathways of T cells,immune checkpoint inhibitors(ICIs)boost the anti-tumor effect of T cells.Immunotherapy has brought about significant therapeutic benefits for patients diagnosed with non-small cell lung cancer,melanoma,and related illnesses[5,6],instilling newfound hope in those with advanced GC[7].However,phase III clinical trial data[8-12]reveals that the incorporation of immunotherapy into chemotherapy regimens improves overall survival(OS)outcomes for patients with advanced GC.The liver's immune-exempt nature renders it less responsive to immunotherapy when secondary malignant tumors are present,fostering systemic immune suppression and yielding unfavorable outcomes in immune therapy[13-15].In retrospective research[16-20]pertaining to non-small cell lung cancer and melanoma,it has been observed that the presence of secondary liver malignancies may lower the response rate,progression-free survival(PFS),and OS rates in patients treated with immunotherapy,independent of factors such as tumor mutation burden and PD-L1 expression.Despite this,there is a paucity of studies examining whether the existence of secondary malignant liver tumors affects the effectiveness of immunotherapy in patients diagnosed with advanced HER-2 negative GC.

Consideration on immunotherapy of liver metastases of malignant tumors

In this editorial,we comment on the article“Analysis of the impact of immuno-therapy efficacy and safety in patients with gastric cancer and liver metastasis”by Liu et al that was published in the recent issue of the World Journal of Gastroin-testinal Surgery.It has prompted us to think and summarize some thoughts on immunotherapy for malignant tumor liver metastasis.Immunotherapy plays a crucial role in the treatment of malignant tumors;however,the presence of liver metastases in advanced tumors may impact its efficacy.Although patients with liver metastases can still benefit from immunotherapy,multiple clinical studies have indicated that,compared to other sites of metastasis,liver metastases may diminish the effectiveness of immunotherapy.The efficacy of immune checkpoint inhibitors in patients with liver metastases often fails to reach the ideal level,primarily due to the liver metastases exploiting the host's peripheral immune to-lerance mechanisms to promote systemic CD8(+)T cell exhaustion,resulting in a systemic immune-tolerant environment.This article aims to summarize the reasons for the decreased efficacy of immunotherapy following liver metastasis in various malignant tumors and propose potential clinical strategies for manage-ment.

Impact of liver metastasis on immunotherapy in gastric carcinoma

The editorial discusses the impact of liver metastasis on immunotherapy efficacy in gastric cancer(GC)patients.Liver metastasis can hinder the effectiveness of immunotherapy by altering the immune microenvironment,leading to systemic loss of T-cells and reduced treatment response.Studies suggest that liver meta-stases serve as a negative baseline factor for immunotherapy efficacy,resulting in poorer progression-free survival and objective response rates.Strategies such as liver-mediated radiotherapy may help improve treatment outcomes by reshaping the liver’s immune microenvironment and reducing T-cell depletion.Understand-ing the complex interplay between liver metastasis and immunotherapy response is crucial for optimising patient care in GC.

Immunology demystified: A guide for transplant hepatologists

Liver transplantation has become standard practice for treating end-stage liver disease.The success of the procedure relies on effective immunosuppressive medications to control the host's immune response.Despite the liver's inherent capacity to foster tolerance,the early post-transplant period is marked by significant immune reactivity.To ensure favorable outcomes,it is imperative to identify and manage various rejection types,encompassing T-cell-mediated,antibody-mediated,and chronic rejection.However,the approach to prescribing immunosuppressants relies heavily on clinical judgment rather than evidencebased criteria.Given that the majority of patients will require lifelong immunosuppression as the mechanisms underlying operational tolerance are still being investigated,healthcare providers must possess an understanding of immune responses,rejection mechanisms,and the pathways targeted by immunosuppressive drugs.This knowledge enables customization of treatments and improved patient care,even though a consensus on an optimal immunosuppressive regimen remains elusive.

Establishment of Nasal Tolerance to Heat Shock Protein-60 Alleviates Atherosclerosis by Inducing TGF-β-dependent Regulatory T Cells

Mounting evidence supports that a newly identified regulatory T cell (Treg),CD4+LAP+ Treg,is associated with oral tolerance induction and following inhibition of atherosclerosis,but little is described about whether nasal tolerance to antigen likewise induces the novel Tregs production and the relevant antiatherosclerotic benefit.We investigated the effect of nasal administration of heat shock protein-60 (HSP60) on atherogenesis.HSP60 or phosphate buffer solution (PBS) was nasally adminis-tered to six-week-old male ApoE-/-mice.At the 10th week after the nasal administration,there was a significant decrease in atherosclerotic plaque areas of aortic roots in the HSP60-treated mice as com-pared with those in the PBS-treated mice.Atherosclerosis suppression was accompanied with a signifi-cant increase in CD4+LAP+ and CD4+CD25+Foxp3+ Tregs and a concurrently increased production of TGF-β in the HSP60-treated mice.The protective effect of HSP60 was offset by injection of anti-TGF-βantibody.It is concluded that nasal administration of HSP60 can inhibit atherosclerotic formation through immune tolerance which is established by Tregs depending on the induction of anti-inflammatory cytokine TGF-β.Immune tolerance induced by nasal administration of HSP60 may provide an alternative therapeutic method for atherosclerosis.

Clinical operational tolerance in liver transplantation:state-of-the-art perspective and future prospects

BACKGROUND:Liver transplantation is the definite treatment for end-stage liver diseases with satisfactory results.However,untoward effects of life-long immunosuppression prevent the development of alternative strategies to achieve better longterm outcome.Achieving clinical operational tolerance is the ultimate goal.DATA SOURCES:A PubMed and Google Scholar search using terms:"immune tolerance","liver transplantation","clinical trial","operational tolerance" and "immunosuppression withdrawal" was performed,and relevant articles published in English in the past decade were reviewed.Full-text publications relevant to the field were selected and relevant articles from reference lists were also included.Priority was given to those articles which are relevant to the review.RESULTS:Because of the inherent tolerogenic property,around 20%-30% of liver transplantation recipients develop spontaneous operational tolerance after immunosuppression withdrawal,and the percentage may be even higher in pediatric living donor liver transplantation recipients.Several natural killer and γδT cell related markers have been identified to be associated with the tolerant state in liver transplantation patients.Despite the progress,clinical operational tolerance is still rare in liver transplantation.Reprogramming the recipient immune system by creating chimerism and regulatory cell therapies is among newer promising means to achieve clinical liver transplantation tolerance in the future.CONCLUSION:Although clinical operational tolerance is still rare in liver transplantation recipients,ongoing basic research and collaborative clinical trials may help to decipher the mystery of transplantation tolerance and extend the potential benefits of drug withdrawal to an increasing number of patients in a more predictable fashion.

Ragweed pollen induces allergic conjunctivitis immune tolerance in mice via regulation of the NF-κB signal pathway

AIM:To investigate the feasibility and mechanism of immune tolerance in allergic conjunctivitis.METHODS:The allergic conjunctivitis immune tolerance mice model was established by ragweed pollen(RW)and the related cytokines were detected.The mice were divided into 9 groups and the maslinic acid(MA)or PBS were given for different group after modeling.The expression levels of chemokine ligand 5(CCL5)and P-65 in the conjunctival tissue were analyzed by immunohistochemistry,quantitative reverse transcription polymerase chain reaction(q RT-PCR)and Western blot.The percentage of interleukin-17(IL-17)and CD4+CD25+in the splenocyte supernatant was analyzed by flow cytometry.Fur thermore,the serum and splenocyte supernatant concentration of total-IgE,interleukin-10(IL-10),and IL-17 was analyzed by enzyme linked immune response(ELISA).RESULTS:After the model was established,symptoms of conjunctivitis were alleviated,the level of P-65,CCL5,IL-17,and total-IgE was raised,while the expression of IL-10,CD4+CD25+was decreased.This result fully demonstrated that a typical IL-17/regulatory-T-cells(Treg cells)imbalance and NF-κB activation.When the NF-κB signal pathway was suppressed,it showed that there was a further relief of conjunctivitis in mice.At the same time,the expression of total-IgE,IL-17,and CCL5 was decreased and the expression of anti-inflammatory factor(IL-10,CD4+CD25+)was increased.CONCLUSION:In the state of immune tolerance,symptoms of conjunctivitis in mice are alleviated,the Th-17 cells of allergic conjunctivitis mice are inhibited,and Treg cells activity is enhanced.

Immunological tolerance of human hepatocyte xenograft induced by adenovirus vector-mediated CTLA4Ig gene transfer

BACKGROUND:Systemic administration of CTLA4Ig has been applied in inducing immunological tolerance of hepatocyte implants,but has potential for systemic immune inhibition.This study was designed to induce hepatocyte immunological tolerance by locally expressing CTLA4Ig in an attempt to improve the effectiveness of cell transplantation.METHODS:A normal human liver cell line(L02) was transfected with adenovirus vector containing the CTLA4Ig gene(Ad-CTLA4Ig-EGFP) in vitro,and the expression of CTLA4Ig by transfected cells was assessed by fluorescent imaging and immunocytochemical staining.Transfected cells then were injected into the spleen of Sprague-Dawley rats,the survival of cells was determined by immunohistochemistry,and the immune status was examined through CD4 + and CD69 + T cellcounts and ELISA detection of IL-2 in peripheral blood.RESULTS:L02 cells expressed CTLA4Ig in the cytoplasm for >4 weeks.Surviving L02 cells were observed in the experimental group at 3 and 4 weeks post-transplantation,while none was detected in the control group.Furthermore,the percentages of CD4 + and CD4 + CD69 + T cells in the CTLA4-transfected group were 24.5% and 45.1%,markedly lower than those in the control group at 4 weeks post-transplantation(P<0.01).Furthermore,the IL-2 level was also lower in the CTLA4transfected group than in the control group.CONCLUSION:Adenovirus-mediated CTLA4Ig gene transfer into human hepatocytes has the potential to become an effective method of inducing immunological tolerance in hepatocyte transplantation.

Diverse Roles of Immune Cells in Transplant Rejection and Immune Tolerance

Organ transplant rejection(OTR)is a complex immune reaction involving multiple cells,and it determines graft survival and patient prognosis.At present,most transplant recipients are administered a combination of immunosuppressive and biological agents to protect them from OTR.However,immunosuppressive agents negatively impact the immune system of the patients,causing them to suffer from serious complications,such as chronic infection and malignant tumors.Therefore,a thorough understanding of the mechanisms involved in immune tolerance and immune rejection with regard to organ transplant(OT)is essential for developing better treatment options and improving patient outcomes.This article reviews the role of immune cells in OTR and organ transplant tolerance(OTT),including the novel cell therapies that are currently under clinical trials for transplant recipients.

IMMUNE TOLERANCE INDUCED BY GAMMA-RAY IRRADIATION

Objective: To detect the existence of immune tolerance induced by gamma-ray irradiation. Methods: Peritoneal cells were harvested from mice subjected to 5 Gy 60Co gamma-ray total body irradiation at 3d, 7d, 15d and 30d, then their counts, morphological changes and IL-12 gene expression were investigated. Results: After irradiation, the peritoneal cells were sharply reduced, the cell morphology shifted from round-like to polymorphic and fusiform with some processes, expression of IL-12 p35 was seriously suppressed, while that of IL-12 p40 greatly enhanced. Conclusion: Our data highly suggest that the gamma-ray irradiation could potentially induce dendritic cell (DC) commitment and immune tolerance.

Anti-tumor Immunity Elicited by Adenovirus Encoding AdhTrp2 or AdmTrp2 without Vitiligo

To compare the difference in tumor immunity and autoimmunity elicited by adenovirus （Ad） encoding human or murine tyrosinase-related protein 2 （AdhTRP2 or AdmTRP2）, and to find the most effective way to induce immunity by AdhTRP2 or AdmTRP2, C57BL/6 mice were immunized with AdhTRP2 or AdmTRP2 intramuscularly at different doses of 10^5, 10^6, 10^7 and 10^8 separately （ 10 mice for each dose）. Two weeks after the immunization, in vivo CTL assay and intracellular staining （ICS） of IFN-γ were carried out to analyze the dose-effect relationship. Tumor growth and vitiligo （as an sign of autoimmunity） were observed until 3 months after challenge with 10^5 B 16F10 tumor cells. The results showed that Ad encoding AdmTrp2 induced weak tumor immune response. Similar immunization with AdhTrp-2 elicited stronger protective immunity. CTL activity and IFN-γ-produced CD8＋T cells were directly proportional to dose of AdhTrp2 or AdmTrp2. Moreover, AdhTrp2 group showed tumor rejection in 100% of challenged mice till the end of 3rd month while 60% of mice immunized with AdmTrp2 were protected against tumor. In the whole process of this experiment, no vitiligo was observed in mice immunized either with AdhTrp2 or AdmTrp2. It is concluded that anti-melanoma responses induced by genetic vaccination expressing xenoantigens breaks immune tolerance effectively and is able to elicit strong antigen-specific cytotoxic T cell response without vitiligo.

Nerve allograft regeneration and immunological tolerance of rats with sciatic nerve transplantation after intragastric pretreatment with ultraviolet B-irradiated donor splenocytes

BACKGROUND： Nerve allograft rejection is an unavoidable problem for nerve allografts. Traumatic peripheral nerve injuries are commonly reconstructed using autogenous nerve grafts. However, this form of reconstruction is limited by insufficient autologous nerves for large gap repairs and by morbidity at the nerve donor site. OBJECTIVE： To examine sciatic nerve regeneration and immune tolerance reaction after intragastric administration of ultraviolet B-irradiated （UVB） donor splenocytes. DESIGN, TIME AND SETTING： A complete randomized grouping design and controlled experiment. The experiments were conducted in the Department of Orthopedics, the First Affiliated Hospital to Shanxi Medical University, China, between March and October 2007. MATERIALS： Fourteen adult male SD rats and fourteen male Wistar rats, weighing 250-300 g, were randomly matched as donors and acceptors. A further seven male SD rats （weight 250-300 g, age 12-16 weeks） were used for nerve isografts. Immune preparations and the Epics XL flow cytometer were purchased from B-D Company, USA. A computer-assisted electromyograph machine was provided by Keypoint P, Dantel Company, Denmark. METHODS： Splenocytes from Wistar rats were isolated, purified, and cultured, and then irradiated with ultraviolet B. In the first control group （Group 1）, the SD rats received a syngeneic SD nerve isograft. In the second control group （Group 2）, the SD rats received a nerve allograft from Wistar rats without pretreatment. In the oral-tolerance treated group （Group 3）, the SD recipient rats were inoculated with 2.5×10^7 Lewis UVB-irradiated donor splenocyte cells by intestinal tract administration at seven days before transplantation. MAIN OUTCOME MEASURES： （1） The recent end and the middle and distal end of the transplanted nerve were cut at 8 and 12 weeks after operation. Recovery of nerve regeneration was measured with HE staining using the total number, density, and diameter of the nerve fibers. （2） The level of CD25＋T lymphocytes in peripheral blood was detected with the Epics XL flow cytometer at one week after operation. （3） The bilateral sciatic nerves were exposed from the sciatic notch up to 0.5 mm beyond the distal graft site at eight weeks post-engraftment. Bipolar platinum stimulating electrodes were placed under the sciatic nerve proximally and the mean conduction velocity was recorded with recording electrodes on the posterior tibial nerve at 0.3 cm distal to the nerve graft. RESULTS： Eight weeks after operation, total axon number and fiber density in Group 3 were higher than that in Group 1 （P 〈 0.05）, neural regeneration in Group 3 was lower than that in Group 1 （P 〈 0.05） , The level of CD25＋T lymphocytes in peripheral blood of Group 3 was significantly lower than that of Group 2 （P 〈 0.05）. There was no significant difference between Group 3 and Group 1 （P 〉 0.05）. At eight weeks post-engraftment the mean conduction velocity of Group 3 approximated that of Group 1. The untreated allografts in Group 2 demonstrated no measurable recovery of conduction velocity. CONCLUSION： Pretreatment with a single intragastric dose of UVB-modified donor antigen specifically induced tolerance to peripheral nerve allografts in rats.

Sinomenine promotes differentiation of induced pluripotent stem cells into immature dendritic cells with high induction of immune tolerance

BACKGROUND Immature dendritic cells(imDCs)play an important role in the induction of donor-specific transplant immunotolerance.However,these cells have limitations,such as rapid maturation and a short lifespan in vivo.In previous studies,induced pluripotent stem cells(iPSCs)differentiated into imDCs,and sinomenine(SN)was used to inhibit the maturation of imDCs.AIM To study the capacity of SN to maintain iPSC-derived imDCs(SN-iPSCs-imDCs)in an immature state and the mechanism by which SN-iPSCs-imDCs induce immunotolerance.METHODS In this study,mouse iPSCs were induced to differentiate into imDCs in culture medium without or with SN(iPSCs-imDCs and SN-iPSCs-imDCs).The imDCrelated surface markers,endocytotic capacity of fluorescein isothiocyanate Dextran and apoptosis were analyzed by flow cytometry.The effects of iPSCs-imDCs and SNiPSCs-imDCs on T-cell stimulatory function,and regulatory T(Treg)cell proliferative function in vitro were analyzed by mixed lymphocyte reaction.Cytokine expression was detected by ELISA.The apoptosis-related proteins of iPSCs-DCs and SN-iPSCs-DCs were analyzed by western blotting.The induced immunotolerance of SN-iPSCs-DCs was evaluated by treating recipient Balb/c skin graft mice.Statistical evaluation of graft survival was performed using Kaplan–Meier curves.RESULTS Both iPSCs-imDCs and SN-iPSCs-imDCs were successfully obtained,and their biological characteristics and ability to induce immunotolerance were compared.SN-iPSCs-imDCs exhibited higher CD11c levels and lower CD80 and CD86 levels compared with iPSCs-imDCs.Reduced major histocompatibility complex II expression,worse T-cell stimulatory function,higher Treg cell proliferative function and stronger endocytotic capacity were observed with SN-iPSCs-imDCs(P<0.05).The levels of interleukin(IL)-2,IL-12,interferon-γin SN-iPSCs-imDCs were lower than those in iPSCs-imDCs,whereas IL-10 and transforming growth factor-βlevels were higher(P<0.05).The apoptosis rate of these cells was significantly higher(P<0.05),and the expression levels of cleaved caspase3,Bax and cleaved poly(ADP-ribose)polymerase were higher after treatment with lipopolysaccharides,but Bcl-2 was reduced.In Balb/c mice recipients immunized with iPSCsimDCs or SN-iPSCs-imDCs 7 d before skin grafting,the SN-iPSCs-imDCs group showed lower ability to inhibit donor-specific CD4+T-cell proliferation(P<0.05)and a higher capacity to induce CD4+CD25+FoxP3+Treg cell proliferation in the spleen(P<0.05).The survival span of C57bl/6 skin grafts was significantly prolonged in immunized Balb/c recipients with a donor-specific pattern.CONCLUSION This study demonstrated that SN-iPSCs-imDCs have potential applications in vitro and in vivo for induction of immunotolerance following organ transplantation.

Molecular mechanism of different viruses associated with autoimmunity

Different kinds of human chronic diseases may develop the mechanism of autoimmune diseases.As a group of disorders,in the Western world autoimmunity possess as the third most prevalent morbidity and mortality.However,the mechanism of most autoimmune diseases is still under investigation.Viral infection is the principal factor involved in the induction of autoimmune diseases other than genetic factors and cytokine activity.Different mechanisms have been proposed by which viral infection might interrupt tolerance to self and induce autoimmune cascade which eventually leads to the destruction of a specific type of cell or a whole-body organ.The autoimmune attack can be understood through the different immune systems and other possible mechanisms such as molecular mimicry,bystander activation and epitope spreading.In addition to genetic and viral factors,other environmental factors are also involved including bacterial,parasitic and fungal infections.However,different animal models have been studied which provide strong evidence that viruses induced AIDs as well as accelerated and increased lesions in conditions where self-tolerance is interrupted.In the current review,we discussed the virus-induced autoimmunity and the molecular mechanism which is associated with this phenomenon.Here we also discussed the different viruses such as rubella virus,enteroviruses,measles virus,human T-lymphotropic virus type1,human cytomegalovirus,human herpes virus-6,Epstein-Barr virus,rotavirus and some other viruses which modulate the development of AIDs.

Influence of mycophenolate mofetil (MMF) upon thematuration and allo-stimulatory activity of cultured progenitors of dendritic cells and the effectson the tolerance induction in allograft recipients

To investigate the influence of mycophenolate mofetil (MMF) upon the maturation and the allo-stimulatory activity of cultured progenitors of dendritic cells (DCp), and to evaluate the effects of the pre-treated dentritic cells of recipients with MMF on the tolerance induction as well as its possible mechanism, GM-CSF and MMF were added to the in vitro cultured progenitor cells, and the immuno-phenotypical analysis was performed by means of flow cytometry. The secretion of IL-12 was detected by ELISA and the stimulatory activities of DCp on allogeneic T cells were observed by mixed lymphocyte reaction. Twenty-four C57BL/6 mice were divided into 3 groups (each with 8 mice), in which group A of mice accepted allografts of heart from BALB/c mice, group B of mice had received untreated DCp from donors of BALB/c mice 7 days before transplantation, and C57BL/6 mice in group C were treated by injection with MMF-treated allografts of heart from BALB/c mice 7 days before transplantation. The survival times of allografts and the changes of the cytokine levels in sera of the recipient mice were observed after transplantation. The experimental results showed that MMF could significantly inhibit the expressions of the co-stimulatory molecules CD80 and CD86 on DCs and the secretion of IL-12 and the allo-stimulatory activities of DCs were also markedly inhibited. The survival times of allografts in group B of mice were longer than those in group A, while the group C showed the longest survival times of allografts, with a marked reduction in the production of the Th1 type cytokines. It is evident that MMF has a suppressive effect on the maturation and allo-stimulatory activities of the cultured dendritic cell progenitors, thus leading to a donor specific tolerance in heart-transplanted recipients.

Complex regulatory effects of gut microbial short-chain fatty acids on immune tolerance and autoimmunity

Immune tolerance deletes or suppresses autoreactive lymphocytes and is established at multiple levels during the development,activation and effector phases of T and B cells.These mechanisms are cell-intrinsically programmed and critical in preventing autoimmune diseases.We have witnessed the existence of another type of immune tolerance mechanism that is shaped by lifestyle choices,such as diet,microbiome and microbial metabolites.Short-chain fatty acids(SCFAs)are the most abundant microbial metabolites in the colonic lumen and are mainly produced by the microbial fermentation of prebiotics,such as dietary fiber.This review focuses on the preventive and immunomodulatory effects of SCFAs on autoimmunity.The tissue-and disease-specific effects of dietary fiber,SCFAs and SCFA-producing microbes on major types of autoimmune diseases,including type I diabetes,multiple sclerosis,rheumatoid arthritis and lupus,are discussed.Additionally,their key regulatory mechanisms for lymphocyte development,tissue barrier function,host metabolism,immunity,autoantibody production,and inflammatory effector and regulatory lymphocytes are discussed.The shared and differential effects of SCFAs on different types and stages of autoimmune diseases are discussed.

Facing challenges with hope:universal immune cells for hematologic malignancies

Many patients have achieved a favorable overall survival rate since allogenic hematopoietic stem cell transplantation(allo-HSCT)has been widely implemented to treat hematologic malignancies.However,graft-versus-host disease(GVHD)and complications of immunosuppressive drugs after allo-HSCT are the main causes of non-relapse mortality and a poor quality of life.In addition,GVHD and infusion-induced toxicity still occur with donor lymphocyte infusions(DLIs)and chimeric antigen receptor(CAR)T-cell therapy.Because of the special immune tolerance characteristics and anti-tumor ability of universal immune cells,universal immune cell therapy may strongly reduce GVHD,while simultaneously reducing tumor burden.Nevertheless,widespread application of universal immune cell therapy is mainly restricted by poor expansion and persistence efficacy.Many strategies have been applied to improve universal immune cell proliferation and persistence efficacy,including the use of universal cell lines,signaling regulation and CAR technology.In this review we have summarized current advances in universal immune cell therapy for hematologic malignancies with a discussion of future perspectives.