Cav3.2 channel regulates cerebral ischemia/reperfusion injury:a promising target for intervention

Calcium influx into neurons triggers neuronal death during cerebral ischemia/reperfusion injury.Various calcium channels are involved in cerebral ischemia/reperfusion injury.Cav3.2 channel is a main subtype of T-type calcium channels.T-type calcium channel blockers,such as pimozide and mibefradil,have been shown to prevent cerebral ischemia/reperfusion injury-induced brain injury.However,the role of Cav3.2 channels in cerebral ischemia/reperfusion injury remains unclear.Here,in vitro and in vivo models of cerebral ischemia/reperfusion injury were established using middle cerebral artery occlusion in mice and high glucose hypoxia/reoxygenation exposure in primary hippocampal neurons.The results showed that Cav3.2 expression was significantly upregulated in injured hippocampal tissue and primary hippocampal neurons.We further established a Cav3.2 gene-knockout mouse model of cerebral ischemia/reperfusion injury.Cav3.2 knockout markedly reduced infarct volume and brain water content,and alleviated neurological dysfunction after cerebral ischemia/reperfusion injury.Additionally,Cav3.2 knockout attenuated cerebral ischemia/reperfusion injury-induced oxidative stress,inflammatory response,and neuronal apoptosis.In the hippocampus of Cav3.2-knockout mice,calcineurin overexpression offset the beneficial effect of Cav3.2 knockout after cerebral ischemia/reperfusion injury.These findings suggest that the neuroprotective function of Cav3.2 knockout is mediated by calcineurin/nuclear factor of activated T cells 3 signaling.Findings from this study suggest that Cav3.2 could be a promising target for treatment of cerebral ischemia/reperfusion injury.

T cell-depleting nanoparticles ameliorate bone loss by reducing activated T cells and regulating the Treg/Th17 balance

Estrogen deficiency is one of the most frequent causes of osteoporosis in postmenopausal women.Under chronic inflammatory conditions caused by estrogen deficiency,activated T cells contribute to elevated levels of proinflammatory cytokines,impaired osteogenic differentiation capabilities of bone marrow mesenchymal stem cells(BMMSCs),and disturbed regulatory T cell(Treg)/Th17 cell balance.However,therapeutic strategies that re-establish immune homeostasis in this disorder have not been well developed.Here,we produced T cell-depleting nanoparticles(TDNs)that ameliorated the osteopenia phenotype and rescued the osteogenic deficiency of BMMSCs in ovariectomized(OVX)mice.TDNs consist of monocyte chemotactic protein-1(MCP-1)-encapsulated mesoporous silica nanoparticles as the core and Fas-ligand(FasL)as the corona.We showed that the delicate design of the TDNs enables rapid release of MCP-1 to recruit activated T cells and then induces their apoptosis through the conjugated FasL both in vitro and in vivo.Apoptotic signals recognized by macrophages help skew the Treg/Th17 cell balance and create an immune tolerant state,further attenuating the osteogenic deficiency of BMMSCs and the osteopenia phenotype.Mechanistically,we found that the therapeutic effects of TDNs were partially mediated by apoptotic T cell-derived extracellular vesicles(ApoEVs),which promoted macrophage transformation towards the M2 phenotype.These findings demonstrate that TDNs may represent a promising strategy for treating osteoporosis and other immune disorders.

Transplantation Expression of 4-1BB molecule on peripheral blood T cells in liver transplanted patients and its clinical implication

OBJECTIVE: To investigate the gene expression of 4-1BB in peripheral blood mononuclear cells (PBMCs) and its possible significance in clinical liver transplantation. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene expression of 4-1BB in PBMCs from 22 patients receiving liver transplantation, 13 patients with primary liver carcinoma (PLC), and 12 healthy controls. To determine whether 4-1BB molecule is also expressed on the surface of CD4^+ and CD8^+ T cell, flow cytometry was used to analyse the phenotype of T cell subsets from the blood of liver transplantation patients. RESULTS: 4-1BB mRNA was detected in PBMCs from stable survivors after liver transplantation, but almost not deteeted in PBMCs from PLC patients and healthy controls. Meanwhile, 4-1BB was almost not expressed on the surface of CD4^+ and CD8^+ T cells in healthy controls and PLC patients. A low level of 4-1BB expression, however, was found on the surface of CD4^+ and CD8^+ T cells from the stable survivors after liver transplantation. CONCLUSIONS: This study demonstrates that although patients are stable after liver transplantation, effector T-cells can also be activated through the signal of 4-1BB molecule and persistent irmmune response to grafts. Blockage of 4-1BB/4-1BBL pathway may benefitially reduce the clinical dosage of immunosuppressive agents and prolong the survival of grafts.

Expression characteristics of peripheral lymphocyte programmed death 1 and FoxP3+ Tregs in gastric cancer during surgery and chemotherapy

BACKGROUND Programmed death 1(PD-1)and CD4^(+)CD25^(+)FoxP3^(+)expression in peripheral blood T-cells has been previously reported in various types of cancer.However,the specific variation tendency during surgery and chemotherapy,as well as their relationship in gastric cancer patients,still remain unclear.Understanding this aspect may provide some novel insights for future studies on tumor recurrence and tumor immune escape,and also serve as a reference for determining the optimal timing and dose of clinical anti-PD-1 antibodies.AIM To observe and analyze the expression characteristics of peripheral lymphocyte PD-1 and FoxP3^(+)regulatory T cells(FoxP3^(+)Tregs)before and after surgery or chemotherapy in gastric cancer patients.METHODS Twenty-nine stomach cancer patients undergoing chemotherapy after a D2 gastrectomy provided 10 mL peripheral blood samples at each phase of the perioperative period and during chemotherapy.This study also included 29 agematched healthy donors as a control group.PD-1 expression was detected on lymphocytes,including CD4^(+)CD8^(+)CD45RO^(+),CD4^(+)CD45RO^(+),and CD8^(+)CD45RO^(+)lymphocytes as well as regulatory T cells.RESULTS We observed a significant increase of PD-1 expression on immune subsets and a larger number of FoxP3^(+)Tregs in gastric cancer patients(P<0.05).Following D2 gastrectomy,peripheral lymphocytes PD-1 expression and the number of FoxP3^(+)Tregs notably decrease(P<0.05).However,during postoperative chemotherapy,we only observed a decrease in PD-1 expression on lymphocytes in the CD8^(+)CD45RO^(+)and CD8^(+)CD45RO^(+)populations.Additionally,linear correlation analysis indicated a positive correlation between PD-1 expression and the number of CD4^(+)CD45RO^(+)FoxP3high activated Tregs(aTregs)on the total peripheral lymphocytes(r=0.5622,P<0.0001).CONCLUSION The observed alterations in PD-1 expression and the activation of regulatory T cells during gastric cancer treatment may offer novel insights for future investigations into tumor immune evasion and the clinical application of anti-PD-1 antibodies in gastric cancer.

Application of in Vitro Alternative Tests Based on AOP in Skin Sensitization Evaluation of Cosmetics

To evaluate and discuss two novels in vitro alternative tests which based on the 2nd and 4th event of the AOP in skin sensitization and their application in skin sensitization evaluation of cosmetics in vitro.The DSens(DSens method)and Jurkat(TCPA method)were used as the test models and 9 of reference chemicals and 12 kinds of cosmetic products were used to confirm and assess the application capability in skin sensitization.The results showed that the DSens method was more sensitive to the reference chemicals compare to the TCPA method.All the results of cosmetic products showed a high consistency between these two assays and h-CLAT or in vivo assay.As the new screening method for skin sensitization evaluation of cosmetics,the in vitro alternative tests based on AOP have certain effectiveness.The reasonable combination strategy can bring a bright future for the development and application of animal alternative test in China.

NFAT2 is implicated in corticosterone-induced rat Leydig cell apoptosis

Aim： To investigate the activation of the nuclear factor of activated T cells （NFAT） and its function in the corticosterone （CORT）-induced apoptosis of rat Leydig cells. Methods： NFAT in rat Leydig cells was detected by Western blotting and immunohistochemical staining. Cyclosporin A （CsA） was used to evaluate potential involvement of NFAT in the CORT-induced apoptosis of Leydig cells. Intracellular Ca^2＋ was monitored in CORT-treated Leydig cells using Fluo-3/AM. After the Leydig cells were incubated with either CORT or CORT plus CsA for 12 h, the levels of NFAT2 in the nuclei and in the cytoplasm were measured by semi-quantitative Western blotting. The role of NFAT2 in CORT- induced Leydig cell apoptosis was further evaluated by observing the effects of NFAT2 overexpression and the inhibition of NFAT2 activation by CsA on FasL expression and apoptosis. Results： We found that NFAT2 was the predominant isoform in Leydig cells. CsA blocked the CORT-induced apoptosis of the Leydig cells. The intracellular Ca^2＋ level in the Leydig cells was significantly increased after the CORT treatment. The CORT increased the level of NFAT2 in the nuclei and decreased its level in the cytoplasm. CsA blocked the CORT-induced nuclear translocation of NFAT2 in the Leydig cells. Both CORT-induced apoptosis and FasL expression in the rat Leydig cells were enhanced by the overexpression of NFAT2 and antagonized by CsA. Conclusion： NFAT2 was activated in CORT-induced Leydig cell apoptosis. The effects of NFAT2 overexpression and the inhibition of NFAT2 activation suggest that NFAT2 may potentially play a pro-apoptotic role in CORT-induced Leydig cell apoptosis through the up-regulation of FasL.

Combination of carboxyamidotriazole and 1-Methyl-L-tryptophan has synergistic inhibtory effects on programmed death 1 expression

OBJECTIVE To evaluate whether the IDO1 inhibitor 1-methyl-L-tryptophan(1-MT)combine calcium influx inhibitor carboxyamidotriazole(CAI)could further enhance the suppression of programmed death 1(PD-1)in CD8^+T cells and investigate the curative effect of the combined use.METHODS CD8^+T cells were isolated from normal mice spleen by negative selection using magnetic cell separation.The isolated CD8^+T cells were cultured in RPMI 1640 medium containing 10%FBS and 100 U·mL^(-1)IL-2 and activated by the addition of anti-CD3 and anti-CD28(1 g·L^(-1) each mabs).CD8^+T cells were pretreated for 48 h with drug and the fluo-3 as a marker of intracellular calcium concentration was detected by flow cytometry.The calcineurin(Ca N)levels were assayed with ELISA in CD8^+T cells after 48 h incubation with 10μm CAI.The nuclear translocations of NFAT and AHR were detected by immunofluorescent staining after 48 h of drug treatment.The expression of PD-1 in CD8^+T cells was analyzed by flow cytometry.RESULTS Intracellular fluorescent intensity was markedly debase due to CAI treatment(P<0.01).Meanwhile,the changes of CaN content had a resembled correlation(P<0.01).Immunofluorescence experiment showed that after combination therapy the transfer of NFAT and AHR in nuclear substantially reduced.Flow cytometry revealed that after the combination caused a significant decrease in PD-1 expression in CD8^+T cells.CONCLUSION CAI and 1-MT could inhibit markedly the expression of PD-1 in CD8^+T cells by inhibiting the nuclear translocation of NFAT and AHR,respectively and the combination of them has synergetic effect.

Role of RANTES and Its Receptor in Gastric Cancer Metastasis

This study examined the role of regulated upon activation normal T cell expressed and secreted（RANTES） and its receptor C-C chemokine receptor type 5（CCR5） in gastric cancer metastasis and the associated mechanism.The expression of RANTES and CCR5 was detected by using immunohistochemical staining and Western blotting in the gastric cancer tissues obtained from 60 gastric cancer patients with or without lymph node metastasis（n=30 in each）.The results showed that the expression levels of RANTES and CCR5 were higher in gastric cancer with lymph node metastasis than in that without metastasis（P0.05）.The expression levels of RANTES in 30 lymph nodes with cancerous invasion were higher than in 30 normal lymph nodes（P0.05）.Chemotactic test revealed that the number of migrating gastric cancer cells（n=295.0±54.6） induced by the protein of cancer-invading lymph nodes was greater than that by the protein mixture from cancer-invading lymph nodes and RANTES antibody（n=42.5±11.6）（P0.05）.RT-PCR showed that the expression levels of the main Th1 cytokines（IL-2,γ-IFN） were lower in gastric cancer with lymph node metastasis（2.22±0.90,3.26±1.15 respectively） than in that without metastasis（3.07±1.67,4.77±1.52 respectively）（P0.05）,but the expression level of the main Th 2 cytokine（IL-10） was higher in gastric cancer with lymph nodes metastasis（6.06±2.04） than in that without metastasis（4.88±1.87）（P0.05）.It was concluded that RANTES and its receptor CCR5 may contribute to gastric cancer metastasis through influencing the balance of Th1/Th2.RANTES and CCR5 may become a marker of gastric cancer metastasis.

THE ALTERNATIVE PATHWAY OF HUMAN T CELL ACTIVATION BY MONOCLONAL ANTIBODIES(A COMPARATIVE STUDY BETWEEN NORMAL INDIVIDUALS AND CANCER PATIENTS)

This paper described T cell proliferative response by an alternative pathway in normal subjects and In patients with malignant diseases. Two McAbs, Anti-CCTl and Lo-CD2-act recognizing two distinct epitopes on E-receptor (CD2) were used to costimulate PBMC. Proliferative responsiveness was measured by 3H-thymidine incorporation. It was found that 82% of 72 nonnal subjects gave proliferative response whereas only 23% of the 93 patients did. The average cpm±SD in patients with bladder cancer (118±2314), kidney cancer (1619±2719) or lymphoma (2518±4057) was significantly lower than that in normal subjects (4935±2314), (P<0.001). These results indicate that T cell proliferation through the alternative pathway was significantly depressed in patients with cancer, and this can be used as a new parameter to monitor the immune status of cancer patients.

Role of the Ca^2＋-Calcineurin-Nuclear Factor of Activated T cell Pathway in Mitofusin-2-Mediated Immune Function of Jurkat Cells

Background：Mitofusin-2 （MFN2）,a well-known mitochondrial fusion protein,has been shown to participate in innate immunity,but its role in mediating adaptive immunity remains poorly characterized.In this study,we explored the potential role of MFN2 in mediating the immune function of T lymphocytes.Methods：We manipulated MFN2 gone expression in Jurkat cells via lentiviral transduction of MFN2 small interfering RNA （siRNA） or full-length MFN2.After transduction,the immune response and its underlying mechanism were determined in Jurkat cells.One-way analysis of variance and Student＇s t-test were performed to determine the statistical significance between the groups.Results：Overexpression of MFN2 enhanced the immune response of T lymphocytes by upregulating Ca2＋ （359.280 ± 10.130 vs.266.940 ± 10.170,P =0.000）,calcineurin （0.513 ± 0.014 vs.0.403 ± 0.020 nmol/L,P =0.024）,and nuclear factor of activated T cells （NFATs） activation （1.040 ± 0.086 vs.0.700 ± 0.115,P =0.005）,whereas depletion of MFN2 impaired the immune function ofT lymphocytes by downregulating Ca2＋ （141.140 ± 14.670 vs.267.060 ± 9.230,P =0.000）,calcineurin （0.054 ± 0.030 nmol/L vs.0.404 ± 0.063 nmol/L,P =0.000）,and NFAT activation （0.500 ± 0.025 vs.0.720 ± 0.061,P =0.012）.Furthermore,upregulated calcineurin partially reversed the negative effects ofMFN2 siRNA on T cell-mediated immunity evidenced by elevations in T cell proliferation （1.120 ± 0.048 vs.0.580 ± 0.078,P =0.040）,interleukin-2 （IL-2） production （473.300 ± 24.100 vs.175.330 ± 12.900 pg/ml,P =0.000）,and the interferon-γ/IL-4 ratio （3.080 ± 0.156 vs.0.953 ± 0.093,P =0.000）.Meanwhile,calcineurin activity inhibitor depleted the positive effects of overexpressed MFN2 on T cells function.Conclusions：Our findings suggest that MFN2 may regulate T cell immune functions primarily through the Ca2＋-calcineurin-NFAT pathway.MFN2 may represent a potential therapeutic target for T cell immune dysfunction-related diseases.

Immunomodulatory Function of Pien Tze Huang in T Cell-Mediated Anti-tumor Activity against B16-F10,MC38 and Hep1-6 Tumor Models

Objective To investigate the anti-tumor effects of Pien Tze Huang(PZH)in mouse models of B16–F10 melanoma,MC38 colorectal cancer,Hep1-6 hepatocellular carcinoma and chemically induced hepatocellular carcinoma model.Methods Various tumor models,including B16–F10,MC38 and Hep1-6 tumor hypodermic inoculation models,B16–F10 and Hep1-6 pulmonary metastasis models,Hep1-6 orthotopic implantation model,and chemically induced hepatocellular carcinoma model,were utilized to evaluate the anti-tumor function of PZH.Tumor growth was assessed by measuring tumor size and weight of solid tumors isolated from C57BL/6 mice.For cell proliferation and death of tumor cells in vitro,as well as T cell activation markers,cytokine production and immune checkpoints analysis,single-cell suspensions were prepared from mouse spleen,lymph nodes,and tumors after PZH treatment.Results PZH demonstrated significant therapeutic efficacy in inhibiting tumor growth(P<0.01).Treatment with PZH resulted in a reduction in tumor size in subcutaneous MC38 colon adenocarcinoma and B16–F10 melanoma models,and decreased pulmonary metastasis of B16–F10 melanoma and Hep1-6 hepatoma(P<0.01).However,in vitro experiments showed that PZH only had slight impact on the cell proliferation and survival of tumor cells(P>0.05).Nevertheless,PZH exhibited a remarkable ability to enhance T cell activation and the production of interferon gamma,tumor necrosis factor alpha,and interleukin 2 in CD4^(+)T cells in vitro(P<0.01 or P<0.05).Importantly,PZH substantially inhibited T cell exhaustion and boosted cytokine production by tumor-infiltrating CD8^(+)T cells(P<0.01 or P<0.05).Conclusion This study has confirmed a novel immunomodulatory function of PZH in T cell-mediated anti-tumor immunity,indicating that PZH holds promise as a potential therapeutic agent for cancer treatment.

Nanoscale Precise Editing of Multiple Immune Stimulating Ligands on DNA Origami for T Cell Activation and Cell-Based Cancer Immunotherapy

The spatial arrangement of activating ligands is known to have great influence on T cell activation.However,independently studying each ligand’s spatial organization parameter that affects T cell activation remains a great challenge.Here,with DNA origami,we precisely organized the CD3ɛantibodies simulating T cell receptor(TCR)ligands and CD28 antibodies simulating co-stimulatory ligands to interrogate the independent role of TCR-ligand spacing and local copy numbers as well as the spacing between TCR ligands and co-stimulatory ligands on T cell activation.We found that T cell activation benefited fromlocally concentrated TCR ligands with a shorter spacing and was maximized by an∼38 nm spacing between TCR ligands and co-stimulatory ligands.The T cell expander constructed based on our findings could efficiently expand CD8+T cells for tumor immunotherapy.Thus,the DNA nanostructurebased ligands’precise arrangement can be a unique tool in studying immune cell activations and cellbased immunotherapies.

Neutrophils in Atlantic salmon(Salmo salar L.)are MHC class II^(+)and secret IL-12p40 upon bacterial exposure

Antigen-presentation via major histocompatibility complex(MHC)to T cells is the key event to initiate adaptive immune responses.In teleosts,as in mammals,the main types of professional antigen-presenting cells(APCs)are dendritic cells(DCs),monocytes/macrophages,and B cells.In the current study,flow cytometry,immunostaining and qPCR have been used to show that neutrophils in the teleost fish Atlantic salmon(Salmo salar L.)have antigen-presenting properties.The neutrophils were positive for MHC class II,CD83 and CD80/86,and upon in vitro bacterial exposure,gene expression analysis of purified neutrophils showed that IL-12p40,which is essential for proliferation of naïve T cells,was highly upregulated at both 6 and 24 h post bacterial exposure.Based on presence of MHC class II and upregulation of molecules involved in antigen presentation and T cell activation,we suggest that neutrophils in Atlantic salmon have potential to function as professional APCs.This work makes an important basis for further exploring the potential of using neutrophils to develop new,targeted immunoprophylactic measures.

Linker for activation of T cells contributes to airway inflammation in an asthmatic mouse model

Background Allergic asthma is associated with airway inflammation and hyperresponsiveness caused by dysregulated production of cytokines secreted by allergen-specific helper T-type 2 （Th2） cells. The linker for activation of T cells （LAT） is a membrane-associated adaptor protein, which has been shown to take part in regulating T cell receptor （TCR） signaling and T cell homeostasis. In this study, we established an asthmatic mouse model to examine the changes in LAT levels during allergic airway disease and the effects of LAT transgenic expression on airway inflammation. Methods T cells from mouse lung tissues were isolated from allergen challenged （ovalbumin （OVA）） and control mice, and the purity of these isolated T cells was examined by fluorescence-activated cell sorter （FACS）. Semi-quantitative RT-PCR and Western blotting were used to detect the expression of the LAT gene and LAT protein, respectively. After an intranasally administered mixture of pCMV-HA-LAT plasmid and Lipofectamine 2000, 24 hours before and 72 hours after allergen challenge, the BALF cell count and the differential cytologies were studied. In addition, IL-4 and IFN-γ levels in the BALF were determined by ELISA, and pathological changes in lung tissues were observed. Results LAT protein and mRNA expression were decreased in lung T cells in a mouse model of allergen-induced airway disease. After intranasal administration of pCMV-HA-LAT, histopathological examination of the lungs showed that intervention with LAT overexpression prevented mice from developing airway inflammation, and the number of total cells, eosinophils, neutrophils, and lymphocytes in the BALF was reduced significantly compared with the OVA sensitized and challenged group. In addition, the Th2 cytokine IL-4 decreased, while the Thl cytokine IFN-γ increased compared to the OVA sensitized and challenged group or the OVA sensitized group plus pCMV-HA treatment. Conclusion This study demonstrates that LAT might effectively diminish Th2 cytokine responses, lung histopathological changes and lung inflammation to allergen challenge in a model of expedmentally induced asthma.

Selective Function of PKC-θin T cells

T cell activation is a critical process in initiating adaptive immune response since only through this process the naive antigen specific T cells differentiate into armed effector T cells that mediate the actual immune response. During T cell activation, naive T cells undergo clonal expansion and acquire the capability to kill target cells infected with pathogens or produce cytokines essential for regulating immune response. Inappropriate activation or inactivation of T cells leads to autoimmunity or severe immunodeficiencies. PKC-θ is selectively expressed in T cells and required for mediating T cell activation process. Mice deficient in PKC-θ exhibit defects in T cell activation, survival and activation-induced cell death. PKC-θ selectively translocates to immunological synapse and mediates the signals required for activation of NF-κB, AP1 and NFAT that are essential for T cell activation. Furthermore, PKC-θ^-│- mice displayed multiple defects in the development of T cell-mediated immune responses in vivo. PKC-θ is thus a critical molecule that regulates T cell function at multiple stages in T cell-mediated immune responses in vivo.

MFSD2A potentiates gastric cancer response to anti-PD-1 immunotherapy by reprogramming the tumor microenvironment to activate T cell response

Background The efficacy of anti-programmed cell death protein 1(PD-1)immunotherapy in various cancers,including gastric cancer(GC),needs to be potentiated by more effective targeting to enhance therapeutic efficacy or identifying accurate biomarkers to predict clinical responses.Here,we attempted to identify molecules predicting or/and promoting anti-PD-1 therapeutic response in advanced GC(AGC).Methods The transcriptome of AGC tissues from patients with different clinical responses to anti-PD-1 immunotherapy and GC cells was analyzed by RNA sequencing.The protein and mRNA levels of the major facilitator superfamily domain containing 2A(MFSD2A)in GC cells were assessed via quantitative real-time polymerase chain reaction,Western blotting,and immunohistochemistry.Additionally,the regulation of anti-PD-1 response by MFSD2A was studied in tumor-bearing mice.Cytometry by Time-of-Flight,multiple immunohistochemistry,and flow cytometry assays were used to explore immunological responses.The effects of MFSD2A on lipid metabolism in mice cancer tissue and GC cells was detected by metabolomics.Results Higher expression of MFSD2A in tumor tissues of AGC patients was associated with better response to anti-PD-1 immunotherapy.Moreover,MFSD2A expression was lower in GC tissues compared to adjacent normal tissues,and its expression was inversely correlated with GC stage.The overexpression of MFSD2A in GC cells enhanced the efficacy of anti-PD-1 immunotherapy in vivo by reprogramming the tumor microenvironment(TME),characterized by increased CD8+T cell activation and reduced its exhaustion.MFSD2A inhibited transforming growth factorβ1(TGFβ1)release from GC cells by suppressing cyclooxygenase 2(COX2)-prostaglandin synthesis,which consequently reprogrammed TME to promote anti-tumor T cell activation.Conclusions MFSD2A potentially serves as a predictive biomarker for anti-PD-1 immunotherapy response in AGC patients.MFSD2A may be a promising therapeutic target to potentiate the efficacy of anti-PD-1 immunotherapy by reprogramming the TME to promote T cells activation.

Advanced subunit vaccine delivery technologies: From vaccine cascade obstacles to design strategies

Designing and manufacturing safe and effective vaccines is a crucial challenge for human health worldwide.Research on adjuvant-based subunit vaccines is increasingly being explored to meet clinical needs.Nevertheless,the adaptive immune responses of subunit vaccines are still unfavorable,which may partially be attributed to the immune cascade obstacles and unsatisfactory vaccine design.An extended understanding of the crosstalk between vaccine delivery strategies and immunological mechanisms could provide scientific insight to optimize antigen delivery and improve vaccination efficacy.In this review,we summarized the advanced subunit vaccine delivery technologies from the perspective of vaccine cascade obstacles after administration.The engineered subunit vaccines with lymph node and specific cell targeting ability,antigen cross-presentation,T cell activation properties,and tailorable antigen release patterns may achieve effective immune protection with high precision,efficiency,and stability.We hope this review can provide rational design principles and inspire the exploitation of future subunit vaccines.

T Lymphocyte Co-Signaling Pathways of the B7-CD28 Family

The past years have witnessed significant advance in our understanding of critical roles of T cell co-signals in B7-CD28 family molecules in regulating T cell activation and tolerance.New co-signaling molecules have been identified and their functions have been delineated.These co-signaling pathways play overlapping and distinct regulatory roles at various stages of a T cell response.By expressing in appropriate time and location,these pathways have different regulatory functions through independent receptors or on different subsets of lymphocytes.Precise understanding of these pathways will allow the development of novel approaches to treatment of human diseases such as cancer,viral infection,autoimmune diseases and transplantation rejection. Cellular & Molecular Immunology.2004;1(1):37-42.

Distinct Overexpression of Fas Ligand on T Lymphocytes in Aplastic Anemia

Increased expression of Fas by hematopoietic progenitors in aplastic anemia(AA)suggests that Fas/Fas ligand (FasL)system plays a key role in the formation of severe pancytopenia.To further confirm the above hypo- thesis,T cells from 8 patients with AA were systematically studied for their FasL's distribution pattern, releasing manner and proapoptotic activity,compared with normal resting T cells and artificially activated T cell blasts.The results demonstrated that AA T cells abnormally expressed low levels of membrane-bound FasL and contained high levels of intracellular FasL which could be triggered to release by high-dose phyto- hemagglutinin(PHA)pulse-stimulation.The supernatants from the PHA-stimulated AA T cells had apparent cytotoxicity against FasL-sensitive Jurkat cells,which could be significantly inhibited by monocional antibody against FasL in a dose-dependent manner,or nearly completely abrogated by ultracentrifugation.The above phenomena also appeared on artificially activated T cell blasts,but this was not the case on normal resting T cells.These results indicate that AA T cell is a type of“preactivated”T lymphocyte,characterized by over- expression of FasL,especially intracellular FasL which can be stimulated to release in bioavtive exosomes- bound form.Taken together,our data provide further and direct evidence for the hypothesis that T cells might mediate the destruction of hematopietic progenitor in AA through Fas/FasL system.Cellular & Molecular Immunology.2004;1(2):142-147.

Deubiquitinases as pivotal regulators of T cell functions

T cells efficiently respond to foreign antigens to mediate immune responses against infections but are tolerant to self-tissues. Defect in T cell activation is associated with severe immune deficiencies, whereas aberrant T cell activation contributes to the pathogenesis of diverse autoimmune and inflammatory diseases. An emerging mechanism that regulates T cell activation and tolerance is ubiquitination, a reversible process of protein modification that is counter-regulated by ubiquitinating enzymes and deubiquitinases （DUBs）. DUBs are isopeptidases that cleave polyubiquitin chains and remove ubiquitin from target proteins, thereby controlling the magnitude and duration of ubiquitin signaling. It is now well recognized that DUBs are crucial regulators of T cell responses and serve as potential therapeutic targets for manipulating immune responses in the treatment of immunological disorders and cancer. This review will discuss the recent progresses regarding the functions of DUBs in T cells.