Functional expression of CD95/Fas Antigen and Bcl-2 on Cord blood Hematopoietic Progenitor Cells

The cell surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34 + cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF+FL could up regulate the expression of CD95 in vitro culture and tumor necrosis factor α (TNF α) and interon γ (IFN γ) further increased the CD95 expression induced by positive cytokines. The functional status of CD95 mediated apoptosis were analyzed by incubation of CD34 +CB cells in the presence of anti CD95 monoclonal antibodies (McAbs). The effects of anti CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU C assays. A decrease of viable cells, CFU C and LTIC numbers were observed in the presence of anti CD95 McAbs and TNF α or IFN γ. However, growth factor deprivation or the early acting cytokine such as SCF and FL cross linking to CD95 caused low apoptosis of CD34 + cells. The correlation of increased intracytoplasmic levels of bcl 2 and the presence of CD95 on fresh CB CD34 + cells suggested that bcl 2 might be involved in protecting against CD95 mediated apoptosis of CB CD34 + cells.

Cinnamon extract suppresses experimental colitis through modulation of antigen-presenting cells

AIM:To investigate the anti-inflammatory effects of cinnamon extract and elucidate its mechanisms for targeting the function of antigen presenting cells.METHODS:Cinnamon extract was used to treat murine macrophage cell line(Raw 264.7),mouse primary antigen-presenting cells(APCs,MHCII+) and CD11c+dendritic cells to analyze the effects of cinnamon extract on APC function.The mechanisms of action of cinnamon extract on APCs were investigated by analyzing cytokine production,and expression of MHC antigens and co-stimulatory molecules by quantitative real-time PCR and flow cytometry.In addition,the effect of cinnamon extract on antigen presentation capacity and APC-dependent T-cell differentiation were analyzed by [H3]-thymidine incorporation and cytokine analysis,respectively.To confirm the anti-inflammatory effects of cinnamon extract in vivo,cinnamon or PBS was orally administered to mice for 20 d followed by induction of experimental colitis with 2,4,6 trinitrobenzenesulfonic acid.The protective effects of cinnamon extract against experimental colitis were measured by checking clinical symptoms,histological analysis and cytokine expression prof iles in inflamed tissue.RESULTS:Treatment with cinnamon extract inhibited maturation of MHCII+ APCs or CD11c+ dendritic cells(DCs) by suppressing expression of co-stimulatory molecules(B7.1,B7.2,ICOS-L),MHCII and cyclooxygenase(COX)-2.Cinnamon extract induced regulatory DCs(rDCs) that produce low levels of pro-inflammatory cytokines [interleukin(IL)-1β,IL-6,IL-12,interferon(IFN)-γ and tumor necrosis factor(TNF)-α] while expressing high levels of immunoregulatory cytokines(IL-10 and transforming growth factor-β).In addition,rDCs generated by cinnamon extract inhibited APC-dependent T-cell proliferation,and converted CD4+ T cells into IL-10high CD4+ T cells.Furthermore,oral administration of cinnamon extract inhibited development and progression of intestinal colitis by inhibiting expression of COX-2 and pro-inflammatory cytokines(IL-1β,IFN-γ and TNF-α),while enhancing IL-10 levels.CONCLUSION:Our study suggests the potential of cinnamon extract as an anti-inflammatory agent by targeting the generation of regulatory APCs and IL-10+ regulatory T cells.

Activation of killer cells with soluble gastric cancer antigen combined with anti-CD3 McAb

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅｈａｖｅｂｅｅｎｍａｎｙｒｅｐｏｒｔｓｏｎｃａｎｃｅｒｔｈｅｒａｐｙｗｉｔｈｌｙｍｐｈｏｋｉｎｅａｃｔｉｖａｔｅｄｋｉｌｅｒ（ＬＡＫ）ｃｅｌｓａｎｄｉｎｔｅｒｌｅｕｋｉｎ２（ＩＬ２），ｂｕｔｔｈｅｐｒｏｌｉｆｅ...

The human leucocyte differentiation antigens (HLDA) workshops: the evolv-ing role of antibodies in research, diagnosis and therapy

The 8^th International Workshop on Human Leucocyte Differentiation Antigens （chaired by HZ and managed by BS） was run over a 4-year period and culminated in a conference in December 2004. Here we review the achievements of the HLDA Workshops and provide links to information on CD molecules and antibodies against them, including the 93 new CDs assigned in the 8^th Workshop. We consider what remains to be achieved （including an estimate of the number of leucocyte surface molecules still to be discovered）, and how the field can best move forward.

Impact of PRRSV on activation and viability of antigen presenting cells

Porcine reproductive and respiratory syndrome(PRRS) is one of the most important diseases of swine industry. The causal agent, PRRS-virus(PRRSV), is able to evade the host immune response and survive in the organism causing transient infections. Despite all scientific efforts, there are still some gaps in the knowledge of the pathogenesis of this disease. Antigen presenting cells(APCs), as initiators of the immune response, are located in the first line of defense against microorganisms, and are responsible for antigen recognition, processing and presentation. Dendritic cells(DCs) are the main type of APC involved in antigen presentation and they are susceptible to PRRSV infection. Thus, PRRSV replication in DCs may trigger off different mechanisms to impair the onset of a host effective immune response against the virus. On the one side, PRRSV may impair the basic functions of DCs by regulating the expression of major histocompatibility complex class Ⅱ and CD80/86. Other strategy followed by the virus is the induction of cell death of APCs by apoptosis, necrosis or both of them. The impairment and/or cell death ofAPCs could lead to a failure in the onset of an efficient immune response, as long as cells could not properly activate T cells. Future aspects to take into account are also discussed in this review.

Key role of human leukocyte antigen in modulating human immunodeficiency virus progression: An overview of the possible applications

Host and viral factors deeply influence the human immunodeficiency virus(HIV) disease progression. Among them human leukocyte antigen(HLA) locus plays a key role at different levels. In fact, genes of the HLA locus have shown the peculiar capability to modulate both innate and adaptive immune responses. In particular, HLA class Ⅰmolecules are recognized by CD8+ T-cells and natural killers(NK) cells towards the interaction with T cell receptor(TCR) and Killer Immunoglobulin Receptor(KIR) 3DL1 respectively. Polymorphisms within the different HLA alleles generate structural changes in HLA classⅠpeptide-binding pockets. Amino acid changes in the peptide-binding pocket lead to the presentation of a different set of peptides to T and NK cells. This review summarizes the role of HLA in HIV progression toward acquired immunodeficiency disease syndrome and its receptors. Recently, many studies have been focused on determining the HLA binding-peptides. The novel use of immune-informatics tools, from the prediction of the HLA-bound peptides to the modification of the HLAreceptor complexes, is considered. A better knowledge of HLA peptide presentation and recognition are allowing new strategies for immune response manipulation to be applied against HIV virus.

Studies on mechanism of Sialy Lewis-X antigen in liver metastases of human colorectal carcinoma

INTRODUCTIONSialyl Lewis-X antigen ,correlated with carcinoma, is a group of carbohydrate antigen containing oligosaccharide expressed of embryonic tisue and glycoproteins on cell surface of embryonic tissue[1].The SLeX antigen located on cell surface is synthesized principally by two enzymes ,al ,3fucosyltransfrease and a2, 3sialyctransferase.In adults ,SLeX antigen is expressed principally on the surfaces of granulocytic cells and some tumor cells .

The Secondary Structure of Heated Whey Protein andIts Hydrolysates Antigenicity

Fourier transform infrared spectroscopy(FTIR) and circular dichroism(CD) were used to investigate the conformational changes of heated whey protein(WP) and the corresponding changes in the hydrolysates immunoreactivity were determined by competitive enzyme-linked immunosorbent assay(ELISA).Results showed that the contents of α-helix and β-sheet of WP did not decrease much under mild heating conditions and the antigenicity was relatively high;when the heating intensity increased(70 ℃ for 25 min or 75 ℃ for 20 min),the content of α-helix and β-sheet decreased to the minimum,so was the antigenicity;However,when the WP was heated at even higher temperature and for a longer time,the β-sheet associated with protein aggregation begun to increase and the antigenicity increased correspondingly.It was concluded that the conformations of heated WP and the antigenicity of its hydrolysates are related and the optimum structure for decreasing the hydrolysates antigeniity is the least content of α-helix and β-sheet.Establishing the relationship between the WP secondary structure and WP hydrolysates antigenicity is significant to supply the reference for antigenicity reduction by enzymolysis.

Detection of microbial antigenic components of circulating immune complexes in HIV patients:Involvement in CD4^+ T lymphocyte count depletion

Objective:To investigate the prevalence of microbial antigenic components of circulating immune complexes amongst grades of CD4 T lymphocyte counts in HIV sero positive and seronegative participants.Methods:Polyethelene glycol(PEG-600) and buffering methods of precipitation and dissociation of immune complexes was used to generate immune solution from sera of 100 HIV sero-positive and 100 HIV sero-negative participants.These were categorized into 3 grades based on CD4 count:】 500 cell/mm,200-499 cell/mm3 and 【200 cell/mm3.The immune solutions were assayed using membrane based immunoassay and antibody titration, along side its unprocessed serum for detection of various microbial antigens and or antibodies. CD4 T cell counts were estimated using Patec Cyflow SL-3 Germany.Results:Antigenic component of immune complexes of various infectious agents was detected in 99 and 70 HIV seropositive and HIV sero-negative participants,respectively.In group A,there were 10 HIV positive participants,including 4(40.0%) had circulating immune complexes(CICs) due to Salmonella species only:1(10.0%) due to Salmonella-Plasmodium falciparum(P.falciparum),SalmonellaP. falciparum-HCV and P.falciparum antigens,respectively.In group B,45(45.4%) HIV seropositive participants with CICs had CD4 T lymphocyte count between 200-499 cells/mm^3.Out of these,20(44.4%) had CICs due to Salmonella species only:9(20%) due to Salmonella-P. falciparum.In group C,there were 44(44.4%) HIV sero-positive participants,including 3(6.8%) due to Salmonella species only:24(54.4%) due to Salmonella-P.falciparum:2(4.5%) due to P. falciparum only.Conclusions:In HIV sero-positive participants,presence of heterogeneity of Salmonella species-P.falciparum antigens was highly incriminated in CD4 count depletion but not homogeneity of malaria parasites antigens.Malaria parasites antigens only were incriminated in CD4^+ count depletion amongst HIV sero-negative participants.Before taking any decision on the management of HIV-1-positive individuals,their malaria and Salmonella paratyphi status should be assessed,but not malaria status alone.

EXPRESSION CLONING OF A PROTECTIVE LEISHMANIA ANTIGEN

Parasite-specific CD8+ T cells have been shown to transfer protection against nLeishmania major in susceptible BALB/c mice.An epitope-tagged expression library was used to identify the antigen recognized by a protective CD8+ T cells clone. The expression library allowed recombinant proteins made in bacteria to be captured by macrophages for presentation to T cells restricted to major histompatibility complex class n. A conserved 36-kilodalton member of the tryptophanaspartic acid repeat family of proteins was identified that was expressed in both stages of the parasite life cycle. A 24-kilodalton portion of this antigen protected susceptible mice when administered as a vaccine with interleukin-12before injection.

Rejection of Experimental Hodgkins Lymphoma by T-Cells Engineered with a CD19 Chimeric Antigen Receptor

T cells engineered to express chimeric antigen receptors (CARs) combining an external antibody binding domain with the CD3ζ T cell receptor (TCR) signaling domain for triggering cell activation are being used for immunotherapeutic targeting of tumor cells in a non-HLA restricted manner. In this study we transduced T cells with a CD19-CAR construct containing a truncated CD34 gene (tCD34) marker and used these to target the B cell antigen CD19 on the surface of a Hodgkin’s lymphoma (HL) cell line (L591) both in vitro and in vivo. Levels of tCD34 expression in transduced peripheral blood mononuclear cells (PBMCs) ranged from 6% - 20% and this was increased to 82% after selection for transduced tCD34+ cells. In vitro cytotoxicity testing on a CD19+ HL cell line (L591) showed specific cell lysis initiated by the CD19-CAR transduced PBMCs. Importantly, CD19-CAR T cells prevented the growth of L591 HL tumor cells when co-injected subcutaneously (sc) in 6/6 severe combined immunodeficient (SCID) mice. There was no evidence of anti-tumor activity when CD19-CAR T cells were infused intravenously (iv) at the same time as L591 HL tumor cells were injected sc. However, 3/6 SCID mice showed tumor rejection within 83 days after iv infusion of CD19-CAR T cells 3 - 9 days after establishment of L591 HL tumors, while all control animals succumbed to tumors within 60 days. Interestingly, immuno-histochemical analysis of L591 HL tumors demonstrated that CD19-CAR T cells were detected not earlier than 11 days after infusion within the tumor mass. These results suggest that CD19 is a potentially attractive target for the immunotherapy of HL.

Regulatory T cells suppress autoreactive CD4^+ T cell response to bladder epithelial antigen

AIM： To investigate the role of regulatory T （Treg） cells in CD4^＋ T cell-mediated bladder autoimmune infammation. METHODS： Urothelium-ovalbumin （URO-OVA）/OT-II mice, a double transgenic line that expresses the membrane form of the model antigen （Ag） OVA as a self-Ag on the urothelium and the OVA-specific CD4^＋ T cell receptor specifc for the I-Ab/OVA323-339 epitope in the periphery, were developed to provide an autoimmune environment for investigation of the role of Treg cells in bladder autoimmune infammation. To facilitate Treg cell analysis, we further developed URO-OVA^GFP-Foxp3/OT-II mice, a derived line of URO-OVA/OT-II mice that express the green fuorescent protein （GFP）-forkhead box protein P3 （Foxp3） fusion protein. RESULTS： URO-OVA/OT-II mice failed to develop bladder infammation despite the presence of autoreactive CD4^＋ T cells. By monitoring GFP-positive cells, bladder infltration of CD4^＋ Treg cells was observed in URO-OVA^GFP-Foxp3/OT-II mice. The infiltrating Treg cells were functionally active and expressed Treg cell effector molecule as well as marker mRNAs including transforming growth factor-β, interleukin （IL）-10, fibrinogen-like protein 2, and glucocorticoid-induced tumor necrosis factor receptor （GITR）. Studies further revealed that Treg cells from URO-OVA^GFP-Foxp3/OT-II mice were suppressive and inhibited autoreactive CD4^＋ T cell proliferation and interferon （IFN）-g production in response to OVA Ag stimulation. Depletion of GITR-positive cells led to spontaneous development of bladder infammation and expression of inflammatory factor mRNAs for IFN-γ, IL-6, tumor necrosis factor-α and nerve growth factor in URO-OVA^GFP-Foxp3/OT-II mice. CONCLUSION： Treg cells specifc for bladder epithelial Ag play an important role in immunological homeostasis and the control of CD4^＋ T cell-mediated bladder autoimmune infammation.

Correlation of CD95 and soluble CD95 expression with acute rejection status of liver transplantation

AIM: To analyze the expression levels of soluble form of CD95, CD95 ligand (sCD95 and SCD95L, respectively) in plasma and CD95 expression on CD3+cells in liver-transplanted recipients with acute rejection (AR). METHODS: Peripheral blood mohonuclear cells (PBMCs) were isolated from 30 clinically liver transplanted recipients. CD95 expression on CD3+ cells was quantitatively measured by two-color fluorescence activated cell sorter (FACS) analysis. Lymphocyte surface phenotypes of CD4, CD8, CD16 and CD56 were determined by flow cytometry. Plasma levels of sCD95 and SCD95L were detected by Enzyme Linked-Immuno-Sorbent Assay (ELISA). The results were compared with that from normal healthy volunteers (n=15 individuals). RESULTS: FACS analysis showed that CD95 expression on CD3+ T cells was significantly increased in liver transplanted recipients with AR compared to that in stable recipients without rejection and infection or healthy individuals who did not undergo transplantation (18 676.93±11 588.34/molecule, 6 848.20±1 712.96/molecule, 6 418.01±2 001.95/molecule, respectively, P<0.01). Whereas no significant difference was seen between liver-transplanted stable recipients and healthy individuals. Furthermore, no significant differences were detected between each group with CD4/CD8 ratio or the percentage of CD16+56+cells. Plasma levels of sCD95 were significantly higher in transplanted recipients with AR compared to that in stable recipients or healthy individuals (391.88±196.00, 201.37±30.30, 148.83±58.25 pg/mL, respectively, P<0.01). In contrast, the plasma levels of sCD95L in liver-transplanted recipients were not significantly different from that in healthy individuals. CONCLUSION: The present results indicate that the increased CD95 expression on CD3+cells and the increased levels of sCD95 in plasma may modify the immunological situation of the recipients after transplantation or represent the ongoing graft rejection.

Reciprocal expression of TRAIL and CD95L in Th1 and Th2 cells: role of apoptosis in T helper subset differentiation

Upon activation, naive T-helper cells can differentiate into two major distinct subsets, T helper 1 (Th1) and T helper 2 (Th2), as defined by their effector functions and cytokine secretion patterns. Cytokine milieu and costimulatory molecules have been shown to play an essential role in determining T helper differentiation. However, it is still unclear how the effects of signals of co-stimulatory molecules and cytokines are exerted during T helper differentiation. We show evidence suggesting that while cytokine signals initiate differentiation program, the selective action of death effectors determines the endpoint balance of differenti-

DNA origami nanodevice with spatial regulation of CD95 signaling for rheumatoid arthritis treatment

Recently,a work jointly studied by Ling Li and coworkers1 was published in Nature Materials,describing a reconfigurable DNA origami nanodevice designed to regulate CD95 death-inducing signaling of immune cells.The researchers utilized the DNA origami nanodevice to establish selective local immune tolerance and demonstrated its ability to alleviate rheumatoid arthritis(RA)in the inflamed synovial tissue of mice without causing any obvious side effects(Fig.1).This approach presents a novel idea for the development of drug interventions involving ligandreceptor interactions.

HIV感染对记忆型和处女型CD4^+T细胞上CD95的影响

目的 :了解 CD95在 HIV感染者记忆型和处女型 CD4 + T细胞表面的表达情况 ,探讨 Fas/ CD95在 HIV感染中的作用。方法 :采用流式细胞检测仪 (FACS)对 HIV感染者外周血 CD4 + T细胞表面 CD95、CD4 5 RA、CD4 5 RO的表达进行分析 ,用 EL ISA检测血清中 Fas水平。结果 :HIV感染后 ,血清 Fas水平随疾病的进展而逐渐升高 ,同时伴有处女型 T细胞表面 CD95表达增高以及记忆型 T细胞 CD95表达逐渐下降。结论 :Fas参与了 HIV的感染过程。研究 Fas和 CD95、CD4 5 RA、CD4 5 RO之间的关系 ,可以加深对 HIV致病机制的认识 ,并可了解疾病的进展情况和指导治疗。

老年人外周血淋巴细胞的凋亡及CD28和CD95的表达

目的通过对健康老年人与健康成年人外周血淋巴细胞的凋亡率及CD28和CD95表达水平的比较性研究,观察衰老对淋巴细胞凋亡的影响,以及CD28和CD95与淋巴细胞凋亡的关系。方法将实验对象分为2组:成年组(25～59岁)与老年组(60～90岁)各20例,采用免疫荧光标记流式细胞术检测外周血淋巴细胞CD28和CD95的水平;Annexin-V-FITC/PI双染色流式细胞术测定地塞米松诱导的淋巴细胞凋亡。结果老年组:淋巴细胞凋亡率〔(14.90±4.12)%〕显著高于成年组〔(8.12±3.12)%〕;CD28+CD95-〔(8.80±4.86)%〕及CD28+〔(36.31±10.38)%〕均明显低于成年组〔(23.09±3.48)%、(52.29±4.90)%〕,而CD28-CD95+〔(53.23±8.28)%〕、CD95+〔(80.25±7.19)%〕及CD28-〔(63.69±10.38)%〕明显高于成年组〔(33.58±4.72)%、(63.18±4.12)%、(47.71±4.90)%〕;CD28+CD95+在两组间差异无统计学意义。淋巴细胞凋亡率与CD28(CD28+)呈负相关,与CD95(CD95+)呈正相关。结论老年人淋巴细胞凋亡率上升;CD28+表达下降,CD28-、CD95+表达上升;淋巴细胞的凋亡率与CD28+、CD95+有相关性。提示老化导致老年人淋巴细胞凋亡增加,CD28和CD95的变化与淋巴细胞凋亡密切相关。

慢性HBV感染者CD8^+T细胞CD95、CD38、HLA-DR表达的变化和意义

目的检测慢性HBV感染者外周血CD8^+T细胞CD95、CD38、HLA-DR表达水平,探索HBV感染过程中CD8^+T细胞活化与耗竭的相关性。方法收集未经抗病毒治疗的HBV感染者76例及健康对照者14例外周血,根据外周血HBV DNA水平分为高病毒载量组与低病毒载量组;使用流式细胞术检测HBV感染者CD8^+T细胞CD95、CD38、HLA-DR的表达以及共表达水平,同时进行相关性分析。结果与健康对照组比较,慢性HBV感染者CD8^+T细胞CD95、HLA-DR的表达、CD38和HLA-DR的共表达水平显著升高(P<0.01);CD8^+T细胞CD95与HLA-DR表达呈正相关(P<0.05)。结论慢性HBV感染过程中CD95的表达可能对外周血CD8^+T细胞的耗竭过程发挥重要作用,而HLA-DR的表达升高和CD38+HLA-DR+CD8^+T细胞频率的升高提示CD8^+T细胞仍然维持着一定的效应潜能。

肝细胞癌患者外周血CD95和OX40L的表达

目的:研究肝细胞癌(HCC)患者外周血CD95和OX40L mRNA的表达情况,并探讨其临床意义。方法:将研究对象的淋巴细胞与相应荧光标记的单克隆抗体反应,经洗涤、固定后,应用双色流式细胞术分析T淋巴细胞表面CD95+CD3+的表达量。采用荧光定量逆转录聚合酶链反应(FQ-RT-PCR)方法检测外周血单个核细胞共刺激分子OX40L mRNA的表达水平。结果:HCC患者外周血CD95+CD3+的表达水平明显高于健康对照组,差异有统计学意义([34±20)%vs(20±7)%,t=2.960,P<0.01];HCC患者外周血单个核细胞OX40L mRNA表达水平明显低于健康对照组,差异有统计学意义(0.46±0.36vs0.86±0.70,t=2.302,P<0.05)。结论:HCC患者外周血CD95及OX40L分子的异常表达在HCC的发生中起重要作用。

NADH对L02细胞Bcl-2、Bax、P53、CD95及CD95L表达的影响

目的 研究抗氧化剂NADH对体外培养的正常人肝细胞系L0 2缺血再灌注损伤的保护作用及可能的机制。方法 实验分组 :将培养的L0 2细胞分为 :缺血再灌注损伤组 (I R) ,缺血再灌注损伤 +NADH(I R +NADH)及对照组 (未经处理的L0 2细胞 )。用流式细胞仪观察细胞处理后6、12、18及 2 4h细胞的凋亡率及 12h时 ,Bcl 2、Bax、P5 3、CD95及CD95L的表达 ,并以透射电镜观察细胞凋亡的超微结构。结果 NADH可明显抑制缺血再灌注损伤细胞的凋亡 ,并能上调Bcl 2表达 ,下调Bax、P5 3、CD95及CD95L的表达 ,与I R组相比较差异显著 (P <0 .0 5 )。透射电镜下可见典型的凋亡细胞的特征。结论 NADH对缺血再灌注损伤诱导的L0 2肝细胞有明显地保护作用。其作用机制可能与通过调节Bcl 2、Bax、P5 3。