Indoleamine 2,3-dioxygenase (IDO) is essential for dendritic cell activation and chemotactic responsiveness to chemokines

Indoleamine 2, 3-dioxygenase (IDO) is a rate-limiting enzyme for the tryptophan catabolism. In human and murine cells, IDO inhibits antigen-specific T cell proliferation in vitro and suppresses T cell responses to fetal alloantigens during murine pregnancy. In mice, IDO expression is an inducible feature of specific subsets of dendritic cells (DCs), and is important for T cell regulatory properties. However, the effect of IDO and tryptophan deprivation on DC func- tions remains unknown. We report here that when tryptophan utilization was prevented by a pharmacological inhibitor of IDO, 1-methyl tryptophan (1MT), DC activation induced by pathogenic stimulus lipopolysaccharide (LPS) or inflam- matory cytokine TNF-α was inhibited both phenotypically and functionally. Such an effect was less remarkable when DC was stimulated by a physiological stimulus, CD40 ligand. Tryptophan deprivation during DC activation also regu- lated the expression of CCR5 and CXCR4, as well as DC responsiveness to chemokines. These results suggest that tryptophan usage in the microenvironment is essential for DC maturation, and may also play a role in the regulation of DC migratory behaviors.

Aberrant activation of nuclear factor of activated T cell 2 in lamina propria mononuclear cells in ulcerative colitis

AIM:To investigate the role of nuclear factor of activated T cell 2(NFAT2),the major NFAT protein in peripheral T cells,in sustained T cell activation and intractable inflammation in human ulcerative colitis(UC). METHODS:We used two-dimensional gel-electrophoresis, immunohistochemistry,double immunohistochemical staining,and confocal microscopy to inspect the expression of NFAT2 in 107,15,48 and 5 cases of UC, Crohn's disease(CD),non-specific colitis,and 5 healthy individuals,respectively. RESULTS:Up-regulation with profound nucleo- translocation/activation of NFAT2 of lamina propria mononuclear cells(LPMC)of colonic mucosa was found specifically in the affected colonic mucosa from patients with UC,as compared to CD or NC(P<0.001,Kruskal- Wallis test).Nucleo-translocation/activation of NFAT2 primarily occurred in CD8+T,but was less prominent in CD4+T cells or CD20+B cells.It was strongly associated with the disease activity,including endoscopic stage (τ=0.2145,P=0.0281)and histologic grade(τ=0.4167, P<0.001). CONCLUSION:We disclose for the first time the nucleo-translocation/activatin of NFAT2 in lamina propria mononuclear cells in ulcerative colitis.Activation of NFAT2 was specific for ulcerative colitis and highly associated with disease activity.Since activation of NFAT2is implicated in an auto-regulatory positive feedback loop of sustained T-cell activation and NFAT proteins play key roles in the calcium/calcineurin signaling pathways,our results not only provide new insights into the mechanism for sustained intractable inflammation,but also suggest the calcium-calcineurin/NFAT pathway as a new therapeutic target for ulcerative colitis.

Novel function of perforin in negatively regulating CD4^＋ T cell activation by affecting calcium signaling

Perforin is a pore-forming protein engaged mainly in mediating target T cell death and is employed by cytotoxic T lymphocytes （CTLs） and natural killer cells. However, whether it also plays a role in conventional CD4^＋ T cell function remains unclear. Here we report that in perforin-deficient （PKO） mice, CD4^＋ T cells are hyperproliferative in response to T cell receptor （TCR） stimulation. This feature of hyperproliferation is accompanied by the enhancement both in cell division and in IL-2 secretion. It seems that the perforin deficiency does not influence T cell development in thymus spleen and lymph node. In vivo, perforin deficiency results in increased antigen-specific T cell proliferation and antibody production. Furthermore, PKO mice are more susceptible to experimental autoimmune uveitis. To address the molecular mechanism, we found that after TCR stimulation, CD4^＋ T cells from PKO mice display an increased intracellular calcium flux and subsequently enhance activation of transcription factor NFAT1. Our results indicate that perforin plays a negative role in regulating CD4^＋ T cell activation and immune response by affecting TCR-dependent Ca^2＋ signaling.

The phenotype and activation status of regulatory T cells during Friend retrovirus infection

The suppressive capacity of regulatory T cells （Tregs） has been extensively studied and is well established for many diseases.The expansion,accumulation,and activation of Tregs in viral infections are of major interest in order to find ways to alter Treg functions for therapeutic benefit.Tregs are able to dampen effector T cell responses to viral infections and thereby contribute to the establishment of a chronic infection.In the Friend retrovirus （FV） mouse model,Tregs are known to expand in all infected organs.To better understand the characteristics of these Treg populations,their phenotype was analyzed in detail.During acute FV-infection,Tregs became activated in the spleen and bone marrow,as indicated by various T cell activation markers,such as CD43 and CD103.Interestingly,Tregs in the bone marrow,which contains the highest viral loads during acute infection,displayed greater levels of activation than Tregs from the spleen.Treg expansion was driven by proliferation but no FV-specific Tregs could be detected.Activated Tregs in FV-infection did not produce Granzyme B （GzmB） or tumor necrosis factor α （TNFα）,which are thought to be a potential mechanism for their suppressive activity.Furthermore,Tregs expressed inhibitory markers,such as TIM3,PD-1 and PD-L1.Blocking TIM3 and PD-L1 with antibodies during chronic FV-infection increased the numbers of activated Tregs.These data may have important implications for the understanding of Treg functions during chronic viral infections.

Treg/Th17 cell balance and phytohaemagglutinin activation of T lymphocytes in peripheral blood of systemic sclerosis patients

AIM To investigate T-cell activation, the percentage of peripheral T regulatory cells(Tregs), Th17 cells and the circulating cytokine profile in systemic sclerosis(SSc).METHODS We enrolled a total of 24 SSc patients and 16 healthy controls in the study and divided the patients as having diffuse cutaneous SSc(dc SSc, n = 13) or limited cutaneous SSc(lc SSc, n = 11). We performed a further subdivision of the patients regarding the stage of the disease-early, intermediate or late. Peripheral venous blood samples were collected from all subjects. We performed flow cytometric analysis of the activationcapacity of T-lymphocytes upon stimulation with PHA-M and of the percentage of peripheral Tregs and Th17 cells in both patients and healthy controls. We used ELISA to quantitate serum levels of human interleukin(IL)-6, IL-10, tissue growth factor-β1(TGF-β1), and IL-17 A.RESULTS We identified a decreased percentage of CD3+CD69+ cells in PHA-stimulated samples from SSc patients in comparison with healthy controls(13.35% ± 2.90% vs 37.03% ± 2.33%, P < 0.001). However, we did not establish a correlation between the down-regulated CD3+CD69+ cells and the clinical subset, nor regarding the stage of the disease. The activated CD4+CD25+ peripheral lymphocytes were represented in decreased percentage in patients when compared to controls(6.30% ± 0.68% vs 9.36% ± 1.08%, P = 0.016). Regarding the forms of the disease, dc SSc patients demonstrated lower frequency of CD4+CD25+ T cells against healthy subjects(5.95% ± 0.89% vs 9.36% ± 1.08%, P = 0.025). With regard to Th17 cells, our patients demonstrated increased percentage in comparison with controls(18.13% ± 1.55% vs 13.73% ± 1.21%, P = 0.031). We detected up-regulated Th17 cells within the lc SSc subset against controls(20.46% ± 2.41% vs 13.73% ± 1.21%, P = 0.025), nevertheless no difference was found between dc SSc and lc SSc patients. Flow cytometric analysis revealed an increased percentage of CD4+CD25-Foxp3+ in dc SSc patients compared to controls(10.94% ± 1.65% vs 6.88% ± 0.91, P = 0.032). Regarding the peripheral cytokine profile, we detected raised levels of IL-6 [2.10(1.05-4.60) pg/m L vs 0.00 pg/m L, P < 0.001], TGF-β1(19.94 ± 3.35 ng/m L vs 10.03 ± 2.25 ng/m L, P = 0.02), IL-10(2.83 ± 0.44 pg/m L vs 0.68 ± 0.51 pg/m L, P = 0.008), and IL-17 A [6.30(2.50-15.60) pg/m L vs 0(0.00-0.05) pg/m L, P < 0.001] in patients when compared to healthy controls. Furthermore, we found increased circulating IL-10, TGF-β, IL-6 and IL-17 A in the lc SSc subset vs control subjects, as it follows: IL-10(3.32 ± 0.59 pg/m L vs 0.68 ± 0.51 pg/m L, P = 0.003), TGF-β1(22.82 ± 4.99 ng/m L vs 10.03 ± 2.25 ng/m L, P = 0.031), IL-6 [2.08(1.51-4.69) pg/m L vs 0.00 pg/m L, P < 0.001], and IL-17 A [14.50(8.55-41.65) pg/m L vs 0.00(0.00-0.05) pg/m L, P < 0.001]. Furthermore, circulating IL-17 A was higher in lc SSc as opposed to dc SSc subset(31.99 ± 13.29 pg/m L vs 7.14 ± 3.01 pg/m L, P = 0.008). Within the dc SSc subset, raised levels of IL-17 A and IL-6 were detected vs healthy controls: IL-17 A [2.60(0.45-9.80) pg/m L vs 0.00(0.00-0.05) pg/m L, P < 0.001], IL-6 [2.80(1.03-7.23) pg/m L vs 0.00 pg/m L, P < 0.001]. Regarding the stages of the disease, TGF-β1 serum levels were increased in early stage against late stage, independently from the SSc phenotype(30.03 ± 4.59 ng/m L vs 13.08 ± 4.50 ng/m L, P = 0.017).CONCLUSION It is likely that the altered percentage of Th17 and CD4+CD25-Fox P3+ cells along with the peripheral cytokine profile in patients with SSc may play a key role in the pathogenesis of the disease.

HIV-1 fusion inhibitor VIR576 interferes with T-cell activation by targeting TCR

Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were estalished to investigate the potential effect of FP16, VIR576 on the proliferation of A2b cells in response to MOG35-55. A fluorescence-based binding assay using Rhodamine （Rho）-conjugated VIR576 was estalished to e- valuate the potential interaction between VIR576 and TCR-TMD. Fluorescence confocal microscopy was used to to study whether VIR576 could colocalize with CD4 molecule in the CD4 ＋ T cell membrane to interact with TCR. Re- suits The effects of VIR576 on the proliferation of MOG-specific A2b T cells in response to the stimulation of MOG 35 -55 peptide wasevaluated. VIR576 itself could directly inhibit antigen-specific T-cell activation. Further studies confirmed that VIR576 also inhibited the proliferation of splenocytes and primary CD4 ＋ CD25- T cells iso- lated from the spleens of DOll. 10 OVA Tg mice in response to OVA stimulation in vitro. However, VIR576 had no effect on the proliferation of normal mouse splenocytes and T lymphocytes stimulated with Con A or anti-CD3 anti- body. The FRET assay confirmed that VIR576 effectively binds to the core peptide （CP） , corresponding to the N- terminal 9-residue region of TCR-TMD. Confocal microscopy revealed that VIR576 colocalizes with CD4 on the ac- tivated CD4 ＋ T-cell membrane, particularly within the activation cluster including re-assembled CD4 and TCR mol- ecules. Conclusion These results suggest that VIR576 is effective in suppressing antigen-specific T-cell activa- tion, but it has no effect on non-specific T-cell proliferation, and VIR576 has the ability to down-regulate antigen- specific T-cell activation by interaction with TCR transmembrane domain.

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.

ACTIVATION OF TCELLS BY SYNTHETIC PEPTIDES OF SUPERANTIGEN TSST-1 UNDER ASSISTANCE OF ASSITANT MOLECULES

根据以往对超抗原ＴＳＳＴ－１分子的Ｔ细胞表位预测结果，从ＴＳＳＴ－１分子中选择了一段序列，合成了两个交叠肽，Ｔ３４和Ｔ５８；观察它们在辅助分子辅助下的促Ｔ细胞增殖能力。结果发现：Ｔ３４和Ｔ５８单独虽均不能活化人的ＰＢＭＣ或小鼠脾细胞，但在ＣＤ２８的共刺激或ＰＭＡ的辅助下却可活化人的ＰＢＭＣ和小鼠的脾细胞。提示：Ｔ３４和Ｔ５８不具备ＭＨＣ结合位，但含有Ｔ细胞表位，两者的Ｔ细胞表位可能位于两肽的共同序列内，即ＴＳＳＴ－１（１２５～１５８）。

Estradiol regulates T cell activation by influencing co-stimulatory molecules transcription

To investigate whether estradiol （E2） plays a role in cell-contact-dependent regulatory mechanism of T cell activation, we studied the role of E2 in regulating gene transcription of CTLA-4, ICOS, B7-1, B7-2 and B7h in vitro. The splenic cells of normal female BALB/c mice were activated by ConA. Then the cells were cultured with E2 （100 pg/ml or 50 ng/ml） for 24 h or 48 h, respectively. The cell proliferation was measured by MTF assay and the expression of the co-stimulatory molecules mRNA was examined by RT-PCR analysis. We found that E2 （100 pg/ml, physiological level） stimulated the acti- vated spleen cells proliferation; inhibited CTLA-4, ICOS, TGF-β and IL-10 gene transcription; promoted B7-1 and B7-2 gene transcription. E2 （50 ng/ml, pregnant level） inhibited the proliferation of the activated splenic cells; promoted CTLA-4, B7-1, IL-10 but inhibited B7-2 and TGF-β gene transcription. Therefore, we conclude that the effects of E2 on T cell activation are partially through its regulation on the co-stimulatory molecules. The co-stimulatory molecules are crucial components of the cell-contact dependent regulatory mechanism, and E2 may regulate T cell activation by this mechanism.

BAFF调节免疫性血小板减少症模型小鼠的Th17/Treg平衡的研究

目的:探讨B细胞激活因子(BAFF)对免疫性血小板减少症模型小鼠体内辅助性T细胞17(Th17)/调节性T细胞(Treg)平衡的调节作用和潜在机制。方法:制备豚鼠抗小鼠血小板抗血清(GP-APS),并将150只无特定病原级别的成年雄性BALB/c小鼠(7~8周龄)随机分为5组,每组30只。分别为对照组(空白对照)和ITP组(GP-APS诱导),ITP+rhBAFF组(ITP组联合静脉注射50μg/kg/50μL重组人BAFF蛋白),并在ITP+rhBAFF组处理的基础上分别联合Notch1的抑制剂(DAPT)或PI3K/Akt的抑制剂Polygalacin D(PGD),设立ITP+rhBAFF+DAPT组和ITP+rhBAFF+PGD组,除对照组和ITP组外,均为静脉注射给药,DAPT注射剂量100μg/kg;PGD注射剂量25μg/kg,静脉注射总体积均为50μL,每日1次。1周后取小鼠1mL外周血并分离血清和单个核细胞。用免疫荧光化学检测单个核细胞中BAFF和Notch1的定位。对外周血中的血小板进行计数。酶联免疫吸附法(ELSIA)检测小鼠外周血血清BAFF的水平。Western blot检测小鼠外周血单个核细胞中PI3K、AKT、Notch1、p-Akt(Thr308)、p-Akt(Ser473)的蛋白表达。流式细胞术检测单个核细胞中Th17/Treg的比例变化。结果:ITP小鼠外周血单个核细胞的BAFF与Notch1共定位在细胞膜。与对照组比较,ITP组BAFF、Notch1、p-Akt(Thr308)、p-Akt(Ser473)的表达增加,血小板数目和Treg比例减少,Th17比例增加(P<0.05)。与ITP组比较,ITP+rhBAFF组BAFF、Notch1、p-Akt(Thr308)、p-Akt(Ser473)的表达增加,血小板数目和Treg比例减少,Th17比例增加(P<0.05)。与ITP+rhBAFF组比较,ITP+rhBAFF+DAPT组BAFF、Notch1、p-Akt(Thr308)、p-Akt(Ser473)的表达降低,血小板数目和Treg比例增加,Th17比例降低(P<0.05)。与ITP+rhBAFF组比较,ITP+rhBAFF+PGD组BAFF、Notch1、p-Akt(Thr308)、p-Akt(Ser473)的表达降低,血小板数目和Treg比例增加,Th17比例降低(P<0.05)。结论:BAFF通过激活Notch1/PI3K/Akt信号通路促进免疫性血小板减少症模型小鼠体内Th17比例增加及Treg比例减少。

T细胞活化谱对脓毒症患者病原菌类型的鉴别效果

目的探讨T细胞活化谱鉴别脓毒症不同病原菌感染中的临床价值。方法选取2020年9月至2022年6月于西安交通大学第一附属医院接受治疗的100例脓毒症患者作为脓毒症组,选取同期于门诊进行体检的37例健康志愿者作为对照组。脓毒症组根据患者入院病原学检查结果分为革兰氏阴性菌组(简称阴性菌组,46例)和革兰氏阳性菌组(简称阳性菌组,54例)。通过流式细胞仪检测患者外周血中T淋巴细胞的活化状态及其表面共刺激分子的表达情况。采用受试者操作特征(ROC)曲线评估CD38^(+)HLA-DR^(+)T细胞区分革兰氏阴性菌脓毒症和革兰氏阳性菌脓毒症的能力。结果阴性菌组和阳性菌组的外周血中CD4^(+)CD38^(+)CD69^(+)T细胞和CD8^(+)CD38^(+)CD69^(+)T细胞计数比较差异无统计学意义(P>0.05),但均高于对照组(P<0.05)。与对照组相比,脓毒症各亚组外周血中CD4^(+)CD38^(+)HLA-DR^(+)、CD8^(+)CD38^(+)HLA-DR^(+)T细胞计数显著增加(P<0.05),并且阴性菌组大于阳性菌组(P<0.05)。鉴别革兰氏阴性菌脓毒症和革兰氏阳性菌脓毒症时,CD4^(+)CD38^(+)HLA-DR^(+)T细胞的ROC曲线下面积(AUC)为0.901(95%CI 0.837~0.965),特异度为0.867,敏感度为0.836;CD8^(+)CD38^(+)HLA-DR^(+)T细胞的AUC为0.927(95%CI 0.872~0.982),特异度为0.778,敏感度为0.933。结论人白细胞DR抗原(HLA-DR)参与了脓毒症患者外周血中T细胞活化的关键免疫反应,并能区分脓毒症不同病原菌感染。

川崎病患儿血清CaN、NFATc1水平与免疫球蛋白治疗反应的相关性

目的探讨川崎病患儿血清钙调神经磷酸酶(CaN)、活化T细胞核因子c1(NFATc1)水平与免疫球蛋白(IVIG)治疗反应的相关性,以期为临床改善治疗效果提供理论参考。方法采用前瞻性研究,选取平顶山市第一人民医院2018年1月至2023年1月100例川崎病患儿作为研究对象,检测入院时患儿的血清CaN、NFATc1水平,同时收集患儿的一般资料,根据IVIG治疗反应情况分为IVIG治疗敏感组与IVIG治疗无反应组。比较两组患儿的血清CaN、NFATc1水平及一般资料,采用点二列相关性检验血清CaN、NFATc1水平与IVIG治疗反应之间的关系,并采用logistic回归性检验二者对IVIG治疗反应的影响。结果100例患儿中有20例为IVIG治疗无反应,占比为20%(20/100)。IVIG治疗无反应组患儿入院时血清CaN、NFATc1及C反应蛋白(CRP)水平高于IVIG治疗敏感组(P<0.05)。经点二列相关性检验显示血清CaN、NFATc1水平与川崎病患儿IVIG治疗无反应存在正相关关系(r>0,P<0.05)。经logistic回归性分析检验显示高水平血清CaN、血清NFATc1是导致患儿IVIG治疗无反应的影响因素(P<0.05)。结论川崎病患儿IVIG治疗无反应发生风险较高,且与血清CaN、血清NFATc1存在关系,二者的高水平表达是导致IVIG治疗无反应的影响因素。

免疫检查点T细胞激活抑制物免疫球蛋白可变区结构域、人内源性逆转录病毒-H长端重复相关蛋白2在子宫内膜癌中的表达及临床意义

目的分析免疫检查点T细胞激活抑制物免疫球蛋白可变区结构域(VISTA)、人内源性逆转录病毒-H长端重复相关蛋白2(HHLA2)在子宫内膜癌(EC)中的表达及临床意义。方法选取2017年9月至2019年10月唐山市妇幼保健院收治的120例的EC患者作为研究对象,收集其的EC组织和癌旁正常组织。检测EC组织和癌旁正常组织VISTA、HHLA2的表达;采用Spearman分析免疫检查点VISTA、HHLA2的相关性;Kaplan-Meier分析VISTA、HHLA2与预后的关系;Cox回归分析影响EC患者预后的危险因素。结果EC组织中VISTA、HHLA2阳性表达率显著高于正常癌旁组织(P<0.05)。Spearman相关性结果显示EC组织中VISTA与HHLA2表达呈正相关性(r=0.587,P<0.05)。EC组织中VISTA、HHLA2表达与临床病理特征有关(P<0.05)。Kaplan-Meier曲线结果显示VISTA阳性表达患者3年生存率低于阴性表达患者(χ^(2)=11.864,P<0.05),HHLA2阳性表达患者3年生存率低于阴性表达患者(χ^(2)=4.975,P<0.05)。Cox回归分析结果显示VISTA和HHLA2是影响EC患者预后的危险因素(P<0.05)。结论免疫检查点VISTA、HHLA2在EC中高表达,其是影响EC预后的危险因素,二者可能是有价值的预后标志物。

T cell immune response is correlated with fibrosis and inflammatory activity in hepatitis B cirrhotics

AIM： TO explore the relationship among interferon-γ （IFN-γ） activity, fibrogenesis, T cell immune responses and hepatic inflammatory activity. METHODS： Peripheral blood samples from a total of 43 hepatitis B cirrhotic patients （LC） and 19 healthy controls （NC） were collected to measure their serum levels of IFN-γ, interleukin-2 （IL-2）, soluble interleukin-2 receptor （sIL-2R）, interleukin-10 （IL-10） and three serological markers of fibrosis including hyaluronic acid （HA）, procollagen type III peptide （PIIIP）, and type iV collagen were measured using a double antibody sandwich ELISA. Also, serum total bilirubin （TB） and alanine aminotransferase （ALT） were measured by routine measures. RESULTS： The concentrations of serological markers of fibrosis in patients with active cirrhosis （ALC） were significantly higher than those in stationary liver cirrhosis （SLC） or NC groups. The levels of serological markers in HBeAg-positive patients were significantly higher than those in HBeAg-negative patients. In SLC and ALC patients, a negative linear correlation was found between IFN-γ levels and the serological markers of fibrosis. IFN-γ and IL-2 levels in the ALC group were significantly higher than those in the SLC and NC groups, but the statistical difference was not significant between the latter two. In contrast, IL-10 levels in the SLC group were significantly higher than that in the NC group, but no significant difference was found between SLC and ALC groups. The sIL-2R level was elevated gradually in all these groups, and the differences were significant. Positive linear correlations were seen between IFN-γ activity and ALT levels （r = 0.339, P 〈 0.05）, and IL-2 activity and TB levels （r = 0.517, P 〈 0.05）. sIL-2R expression was positively correlated with both ALT and TB levels （r = 0.324, 0.455, P 〈 0.05）, whereas there was no statistically significant correlation between IL-10 expression and serum ALT and TB levels （r = -0.102, -0.093, P 〉 0.05）. Finally, there was a positive correlation between IFN-γ and IL-2 levels. CONCLUSION： T cell immune responses are correlated with fibrosis and hepatic inflammatory activity and may play an important role in liver cirrhosis.

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.

Downregulation of CD4+CD25+ regulatory T cells may underlie enhanced Th1 immunity caused by immunization with activated autologous T cells

Regulatory T cells （Treg） play important roles in immune system homeostasis, and may also be involved in tumor immunotolerance by suppressing Th1 immune response which is involved in anti-tumor immunity. We have previously reported that immunization with attenuated activated autologous T cells leads to enhanced anti-tumor immunity and upregulated Thl responses in vivo. However, the underlying molecular mechanisms are not well understood. Here we show that Treg function was significantly downregulated in mice that received immunization of attenuated activated autologous T cells. We found that Foxp3 expression decreased in CD4＋CD25＋ T cells from the immunized mice. Moreover, CD4＋CD25＋Foxp3＋ Treg obtained from immunized mice exhibited diminished immunosuppression ability compared to those from naive mice. Further analysis showed that the serum of immunized mice contains a high level ofanti-CD25 antibody （about 30 ng/ml, p〈0.01 vs controls）. Consistent with a role ofanti-CD25 response in the downregulation of Treg, adoptive transfer of serum from immunized mice to naive mice led to a significant decrease in Treg population and function in recipient mice. The triggering of anti-CD25 response in immunized mice can be explained by the fact that CD25 was induced to a high level in the ConA activated autologous T cells used for immunization. Our results demonstrate for the first time that immunization with attenuated activated autologous T cells evokes anti-CD25 antibody production, which leads to impeded CD4＋CD25＋Foxp3＋ Treg expansion and function in vivo. We suggest that dampened Treg function likely contributes to enhanced Thl response in immunized mice and is at least part of the mechanism underlying the boosted anti-tumor immunity.

BIOLOGICAL FEATURES OF HUMAN T-ACTIVATED KILLER CELLS

Objective: To investigate the immunobiological essence of T-activated killer (T-AK) cells induced by anti-CD3 monoclonal antibody (CD3McAb) and recombinant interleukin-2 (rIL-2) co-stimulation. Methods: The cytomorphology, phenotype and cytotoxicity of T-AK cells generated from human peripheral blood mononuclear cells (PBMC) were determined. Results: T-AK cells were similar to activated lymphoblasts in morphology, more than 90% of T-AK cells expressed the phenotypes of T-lymphocytes (CD3 +, CD8 +, and 20%～50% of the cells were NK-like phenotype (CD16 +, CD56 +, some of them expressed IL-2 receptor (CD25 +), CD38 antigen (CD38 +) and MHC-II antigen (HLA-DR+) characteristic marks for the activated T lymphocytes. T-AK cells attacking targets were morphologically large volumes with granules and mainly contained CD8 + and CD56 + cells. T-AK cells possessed high tumoricidal activities against NK-sensitive K562 cells and NK-resistant Raji cells, the cytotoxicity was composed of mainly CD3McAb-activated CD3AK activity (～50%), IL-2 induced LAK activity (～30%), NK activity (～10%) and the activities of inhibitory factors in T-AK supernatant (～10%). Conclusion: T-AK cells are a heterogeneous cell population consisting of mainly activated T lymphocytes and NK-like cells, the main part of T-AK cytotoxicity is the common activities of CD3AK cells and LAK cells.

Establishment of a Human Malignant T Lymphoma Cell Line Carrying a Retrovirus-like Particles with RT Activity

We have established an IL-2 independent malignant lymphoma line (CM-1) from peripheral T lymphocytes donated by a femalc patient with nervous systcm disease, the binlogical characteristics of CM-1 cells was studied in this paper. Another T lymphocytes,such as peripheral T lymphocytes donated by a maIe patient with multiple sclerosis, could be transformed into a malignant lymphoma line by using filtered supernatant of the CM-1 cultured medium, thus the CM-2 cell line u'as estabIished. The CM-1 and CM-2 cells were transplanted by subcutaneous inoculation into nude mice, and could cause the occurrenceof typical maIignant lymphoma. The observation of eIectron micrographs suggested the existence of virions in the CM-1 and CM-2 cells, and these virions were similar toretrovirus in the ultra-structure characteristics. lt was found that this virus possesses reverse transcriptase activity. ResuIts obtained from serological assay, molecular hybridization and PCR excluded the existence of other human viruses, which were commonly usedin our laboratory. The unknown virus possesses strong transformation activity, and probably is a new retro virus. Meanwhile, the work on the clone and sequence analysis ofthis virus are being carried out.

2型糖尿病合并骨质疏松患者血清miR-9-5p和NFAT5的表达及其与骨折的关系

目的:2型糖尿病(type 2 diabetes mellitus,T2DM)是一种多病因代谢性疾病,骨质疏松(osteoporosis,OP)和骨折是其常见并发症。本研究旨在探讨T2DM合并OP患者血清中微RNA(microRNA,miR)-9-5p和核转录因子5(nuclear factor of activated T-cells 5,NFAT5)的表达水平,以及其与骨折的关系。方法:收集郑州市第七人民医院就诊的T2DM合并OP患者184例(OP组),另纳入同时间段单纯T2DM患者184例(T2DM组)。实时聚合酶链反应检测血清miR-9-5p、NFAT5表达水平。随访2年,根据新发骨折情况,将T2DM合并OP患者分为骨折组(43例)与无骨折组(141例)。Pearson法分析血清miR-9-5p、NFAT5分别与空腹血糖(fasting plasma glucose,FPG)、I型前胶原N末端前肽(procollagen I N-terminal propeptide,PINP)、空腹胰岛素(fasting insulin,FINS)、胰岛素抵抗指数(insulin resistance index,HOMA-IR)、骨密度T值、I型胶原羧基端β降解产物(type I collagen hydroxy terminal peptideβdegradation products,β-CTX)相关性,以及miR-9-5p与NFAT5的相关性;采用受试者操作特征(receiver operator characteristic,ROC)曲线评估血清miR-9-5p、NFAT5对T2DM合并OP患者骨折的预测价值,多因素logistic回归分析T2DM合并OP患者骨折的影响因素。结果:OP组血清miR-9-5p水平高于T2DM组,NFAT5水平低于T2DM组(均P<0.05)。与无骨折组相比,骨折组患者糖尿病病程、FPG、HOMA-IR、β-CTX、miR-9-5p水平均升高,而PINP、NFAT5水平均降低(均P<0.05)。骨折患者血清miR-9-5p与NFAT5水平呈负相关(r=−0.716,P<0.05);miR-9-5p水平与FPG、HOMA-IR、β-CTX均呈正相关,与PINP呈负相关(均P<0.05),而血清NFAT5水平与FPG、HOMA-IR、β-CTX均呈负相关,与PINP呈正相关(均P<0.05)。血清miR-9-5p、NFAT5单一预测T2DM合并OP患者骨折风险的曲线下面积(area under curve,AUC)分别为0.878和0.868,联合预测的AUC为0.933。β-CTX、miR-9-5p为T2DM合并OP患者骨折的危险因素,PINP、NFAT5为T2DM合并OP患者骨折的保护因素(均P<0.05)。结论:T2DM合并OP患者血清miR-9-5p表达水平升高,NFAT5表达水平降低,两者与骨折发生均有一定关系,miR-9-5p联合NFAT5对骨折预测价值更高。

类风湿关节炎患者血清脂肪因子趋化素与疾病活动度和Th17/Treg的关系

目的探究类风湿关节炎(RA)患者血清脂肪因子趋化素水平与疾病活动度和辅助性T细胞17/调节性T细胞(Th17/Treg)比值的相关性。方法纳入RA患者180例为观察组,根据DAS28评分将观察组分为高活动组、中活动组和低活动组,每组60例;另选取同期体检的健康者180例作为对照组。采用酶联免疫吸附试验(ELISA)法检测血清趋化素、白细胞介素(IL)-9、IL-10、IL-17水平;流式细胞术检测Th17/Treg比例;分析RA患者血清趋化素水平与DAS28评分,Th17、Treg细胞百分比及Th17/Treg比值的相关性。结果观察组血清趋化素水平高于对照组(P<0.05)。RA患者血清趋化素水平与DAS28评分呈正相关;高、中、低活动组血清趋化素水平和DAS28评分依次降低;观察组Th17细胞百分比、Th17/Treg比值、IL-17、IL-9水平高于对照组,Treg细胞百分比、IL-10水平低于对照组(P<0.05)。RA患者血清趋化素水平与Th17细胞百分比、Th17/Treg比值呈正相关,与Treg细胞百分比呈负相关(P<0.05)。结论RA患者的血清趋化素水平升高,与疾病活动度和Th17/Treg比值具有密切关系。