B7／CD28和ICAM—1／LFA—1共刺激信号对T及B细胞功？…

目的 研究共刺激途径Ｂ７／ＣＤ２８和ＩＣＡＭ－１／ＬＦＡ－１对Ｔ细胞活化以及Ｂ细胞效应的作用。方法 在体外建立ＡＰＣ：Ｔ：Ｂ细胞反应系统,用Ｂ７－１单抗和ＩＣＡＭ－１单抗分别阻断Ｂ７／ＣＤ２８和ＩＣＡＭ－１／ＬＦＡ－１共刺激途径,利用＾３Ｈ－ＴｄＲ法检测Ｔ细胞增殖,ＥＬＩＳＡ法测定Ｂ细胞分泌的杭体,用ＲＴ－ＰＣＲ法检测细胞因子基因的表达。结果 Ｂ７－１单抗和ＩＣＡＭ－１单坑均可抑制Ｔ细胞增殖及ＩＬ     

T细胞耐受的诱导及其机理研究

目的　阐明抗原特异性 Ｔ 细胞无能的诱导条件、无能细胞的特性及其耐受的机理。方法　抗 Ｂ７１ 单抗与 Ｃｓ Ａ 联用诱导抗原特异性 Ｔ 细胞无能, 通过３ Ｈ Ｔｄ Ｒ 掺入法测定 Ｔ 细胞增殖和 Ｍ Ｌ Ｒ, 利用 Ｒ Ｔ Ｐ Ｃ Ｒ 检测细胞因子基因表达。结果　耐受 Ｔ 细胞与异体淋巴细胞比例为０ ．０１∶１时, 可显著抑制 Ｍ Ｌ Ｒ, 转染 Ｂ７１ 分子的 Ｍ Ｄ Ａ４５３ 和３ Ａ Ｏ 能协同刺激 Ｃ Ｄ３ 诱导的 Ｔ 细胞增殖,不表达 Ｂ７ 分子的 Ｍ Ｄ Ａ４５３ 和３ Ａ Ｏ 无此作用。 Ｐ Ｈ Ａ、 Ｃ Ｄ３ 单抗、 Ｐ Ｍ Ａ＋ Ａ２３１８７ 可以逆转本试验所用诱导方法所致的 Ｔ 细胞的耐受状态。无能 Ｔ 细胞 Ｉ Ｌ２ 和 Ｉ Ｆ Ｎγｍ Ｒ Ｎ Ａ 不表达, 而 Ｉ Ｌ４ 和 Ｉ Ｌ１０ ｍ Ｒ Ｎ Ａ可表达。无能 Ｔ 细胞活化后, Ｉ Ｌ２ 和 Ｉ Ｆ Ｎγｍ Ｒ Ｎ Ａ 能够表达。结论　抗原特异性 Ｔ 细胞耐受是可以人为诱导的, 无能 Ｔ 细胞细胞因子基因格局向 Ｔ Ｈ２ 细胞偏离。     

共刺激对T细胞功能和细胞因子格局的作用

利用Ｂ７－１单抗和环孢素Ａ处理ＡＰＣ：Ｔ细胞反应系统,探讨了Ｂ７／ＣＤ２８芡刺激对Ｔ细胞增殖及细胞因子产生的影响,并用ＲＴ－ＰＣＲ方法分析了细胞因子基因格局的改变。结果表明Ｂ７－１单抗可抑制特异性抗原诱导的Ｔ细胞增殖和ＩＬ－２的产生,Ｂ７－１单抗瑟ＣｓＡ联用可阻断Ｔ细胞增殖和ＩＬ－２产生。Ｂ７－１单抗绎ＩＬ－４的产生未显示明显的影响,而Ｂ７－１单抗与ＣｓＡ联用ＩＬ－４仍可检测到。     

LFA-1/ICAM-1单抗对ConA诱导脾淋巴细胞增殖及分泌细胞因子的影响

通过研究ＬＦＡ－１／ＩＣＡＭ－１单抗对ＣｏｎＡ诱导的脾淋巴细胞活化增殖及其分泌细胞因子的影响　，探　讨了ＬＦＡ－１／ＩＣＡＭ－１分子在Ｔ细胞活化过程中所起的共刺激作用。结果表明，单独应用ＬＦＡ－１α链单抗（Ｍ１７／４．４．１１．９）或ＩＣＡＭ－１单抗（ＹＮ１／１．７．４）均不能引起脾淋巴细胞的增殖，但在加入ＣｏｎＡ诱导脾淋巴细胞增殖反应的最初８小时内加入ＬＦＡ－１单抗可以剂量依赖性地抑制ＣｏｎＡ诱导的脾淋巴细胞增殖反应及脾淋巴细胞分泌ＩＬ－２、ＩＰＮ－γ，而加入ＩＣＡＭ－１单抗却无此效应。说明ＬＰＡ－１在ＣｏｎＡ诱导的Ｔ细胞活化过程中起着重要的共刺激作用，ＬＰＡ－１通过与除ＩＣＡＭ－１以外的其它配体分子（如ＩＣＡＭ－３）相互识别，提供Ｔ细胞活化所必需的共刺激信号。     

LFA—1／ICAM—1单抗对ConA诱导脾淋巴细胞增殖及分…

通过研究ＬＦＡ－１／ＩＣＡＭ－１单抗对Ｃｏｎ Ａ诱导的脾淋巴细胞活化增殖及其分泌细胞因子的影响，探讨了ＬＦＡ－１／ＩＣＡＭ－１分子在Ｔ细胞活化过程中所起的共刺激作用。结果表明，单独应用ＬＦＡ－１α链单抗（Ｍ１７／４．４．１１．９）或ＩＣＡＭ－１单抗（ＹＮ１／１．７．４）均不能引起脾淋巴细胞的增殖，但在加入ＣｏｎＡ诱导脾淋巴细胞增殖反应的最初８小时内加入ＬＦＡ－１单抗可以剂量依赖性地抑制ＣｏｎＡ诱导     

rhIL-1ra 对儿童自身免疫性甲状腺病IFNγ/IL-4水平失衡的影响

在免疫反应的初始阶段,巨噬细胞递呈抗原后产生的ＩＬ１,可作为炎症反应的启动因子,作用于静止Ｔ细胞膜上的ＩＬ１受体ＩＬ１ｒ,使之活化分泌ＩＦＮγ和ＩＬ２等细胞因子,参与Ｔ细胞的免疫应答〔１〕。在自身免疫性甲状腺病ａｕｔｏｉｍｍｕｎｅｔｈｙｒｏｉｄｄｉｓｅａｓｅＡＩＴＤ的甲状腺局部存在大量ＩＬ１基因的表达及产物,在ＡＩＴＤ发病中具有重要的作用〔２〕。ＡＩＴＤ包括慢性淋巴细胞甲状腺炎ＣＬＴ和Ｇｒａｖｅｓ病ＧＤ。我们前期的研究证实,ＡＩＴＤ患儿体内存在Ｔｈ１／Ｔｈ２型细胞因子的失衡,以Ｔｈ１…     

LFA-1/ICAM-1在柯萨奇B组病毒播散感染中的作用初探

目的观察ＣｏｘＢ３感染大鼠单个核细胞，诱导细胞表面ＬＦＡ－１表达的变化，以及ＬＦＡ－１／ＩＣＡＭ－１在ＣｏｘＢ３从单个核细胞向心肌细胞播散感染中的作用。方法制备和培养大鼠心肌细胞和大鼠外周血单个核细胞，并进行病毒感染；制备和纯化分泌抗大鼠ＬＦＡ－１（ＣＤ１１ａ）和抗大鼠ＩＣＡＭ－１（ＣＤ５４）的单克隆抗体；在Ｗｉｓｈ细胞上进行病毒感染性滴定，并观察细胞病变；流式细胞仪分析各组单个核细胞ＬＦＡ－１的表达情况；观察抗－ＬＦＡ－１和抗－ＩＣＡＭ－１单克隆抗体在ＣｏｘＢ３复制和播散感染中的作用。结果ＣｏｘＢ３感染大鼠外周血单个核细胞１８～２４小时可以诱导细胞膜ＬＦＡ－１表达增多，同时释放感染性病毒颗粒感染正常大鼠心肌细胞；加入抗－ＬＦＡ－１或抗－ＩＣＡＭ－１的单克隆抗体均可不同程度地抑制病毒向心肌细胞播散感染，并显著降低培养上清液中病毒滴度。结论ＣｏｘＢ３感染增加白细胞表面ＬＦＡ－１表达可能是病毒病理作用的重要步骤     

转染B7—1基因至鼻咽癌细胞株及其诱导的细胞免疫应答

通过包装细胞把逆转录病毒载体ｐＬＸＳＮ／Ｂ７－１导入鼻咽癌细胞株ＣＮＥ１，利用ＲＴ－ＰＣＲ及ＦＡＣｓ等技术证实Ｂ７－１的表达情况，同时检测了ＣＮＥ１细胞表面ＭＨＣＩ抗原。在此基础之上，观察了表达Ｂ７－１的ＣＮＥ１细胞（ＣＮＥ１／Ｂ７－１）对健康个体ＰＢＬ（外周血淋巴细胞）的增殖及细胞因子分泌的影响，结果表明：ＣＮＥ１／Ｂ７－１可以促进ＰＢＬ的增殖及细胞因子的分泌，且增高水平的细胞因子主要是ＩＬ－２和ＩＦＮ－γ。提示：ＣＮＥ１／Β７－１诱导的免疫应答以细胞免疫为主。     

巨噬细胞型骨髓基质细胞对肿瘤抗原提呈的体外实验研究

目的　探讨骨髓基质细胞对肿瘤抗原的提呈功能。方法　小鼠骨髓贴壁细胞经 Ｇ Ｍ Ｃ Ｓ Ｆ 诱导,形成以成熟巨噬细胞为主的基质细胞,用小鼠红白血病细胞 Ｆ Ｂ Ｌ３ 肿瘤抗原刺激,然后再与 Ｆ Ｂ Ｌ３ 肿瘤抗原致敏的 Ｔ 淋巴细胞混合培养。结果　骨髓基质细胞经 Ｆ Ｂ Ｌ３ 肿瘤抗原刺激后, Ｔ Ｎ Ｆα和 Ｉ Ｌ１β的分泌水平明显升高,经抗原预激的骨髓基质细胞能特异性地刺激同种抗原致敏的 Ｔ 淋巴细胞增殖和分泌高水平的 Ｉ Ｌ２ 。单抗阻断试验发现, Ｍ Ｈ ＣⅡ类分子和 Ｂ７２ 分子的联合阻断能有效地抑制致敏 Ｔ 淋巴细胞分泌 Ｉ Ｌ２ 。结论　本实验证实骨髓基质细胞具有抗原提呈功能, Ｍ Ｈ ＣⅡ类分子和 Ｂ７２ 分子在其抗原提呈中发挥了重要作用。     

B7-1分子诱导体外抗肝癌免疫反应

目的：了解Ｂ７分子在体外抗肝癌免疫中的作用。方法：健康人外周血单个核细胞（ＰＢＭＣ）与ＨｅｐＧ２／ｈＢ７－１，ＨｅｐＧ２／ｎｅｏ及亲代ＨｅｐＧ２瘤苗混合培养（ＭＬＴＣ），检测淋巴细胞活化增殖能力，淋巴细胞ＨＬＡ－Ｉ类抗原的表达，培养上清ＩＦＮ－γ水平，ＴＮＦ活性及ＬＡＫ，ＣＴＬ细胞活性。结果：ＨｅｐＧ２／ｈＢ７－１瘤苗促淋巴细胞增殖最高达１４．６倍，明显高于ＨｅｐＧ２／ｎｅｏ和ＨｅｐＧ２瘤苗的作用     

Expression and function of the murine CD95/FasR/APO-1 receptor in relation to B cell ontogeny

Mice defective in Fas-mediated apoptosis (lpr phenotype) have an intrinsic B cell abnormality that predisposes them to autoantibody production. To investigate potential roles for the Fas receptor (FasR) in B cell tolerance, FasR expression and function were evaluated at different stages of B cell development. FasR expression was very low or absent on pro- and pre-B cells, but was detected in early B cell lines and was up-regulated following IFN-γ-induced maturation of the pre-B cell line 70-Z. Whereas FasR expression was very low in resting mature sIgM⁺ B cells, expression was markedly increased following mitogen activation and was also elevated in two mature sIgG⁺ lymphoma lines. FasR expression correlated strongly with the ability of B cells to undergo Fas-mediated apoptosis. In addition, although Fas did not appear to play a direct role in apoptosis mediated by cross-linking of sIg with anti-IgM, anti-FasR and sublethal concentrations of anti-Ig were additive in the induction of apoptosis in the early B cell line WEHI 231. These findings suggest that the Fas pathway is not involved in the elimination of pro- and pre-B cells, but are compatible with an ancillary role for FasR in the elimination of early B cells and elimination of mature B cells following activation.     

B7-H1/PD-1共刺激途径对慢性乙型肝炎患者HBV特异性T淋巴细胞功能的影响

目的研究B7-H1／PD-1共刺激信号途径对慢性乙型肝炎（chronic hepatitis B，CHB）患者HBV特异性T淋巴细胞免疫功能的影响。方法流式细胞术检测CHB患者和健康人外周血髓样树突细胞（myeloid dendritic cells，mDC）上B7-H1及T淋巴细胞上PD-1的表达水平，并分析患者B7-H1和PD-1的表达水平与ALT水平的相关性；体外培养CHB患者单核细胞来源的树突细胞（monocyte-derived cells，MoDC），HBcAg负载后用“细胞因子鸡尾酒”（TNF-α、IL-6、IL-1β和PGE2）促成熟。MoDC和自体T淋巴细胞混合培养，并对B7-H1／PD-1途径进行阻断处理，^3H-TdR掺入法检测HBV特异性T淋巴细胞增殖的能力；ELISA法检测混合淋巴细胞培养上清中细胞因子的浓度；ELISPOT法检测分泌IFN-γ的T淋巴细胞频数。结果B7-H1及受体PD-1在CHB患者外周血mDC和T淋巴细胞上的表达水平明显升高，且B7-H1和PD-1的表达水平与患者的ALT水平呈明显的正相关；阻断B7-H1／PD-1共刺激途径，不但能够促进HBV特异性T淋巴细胞的增殖和Ⅰ型细胞因子分泌，同时可以提高分泌IFN-γ的抗原特异性T淋巴细胞的频数。结论CHB患者B7-H1和PD-1表达水平的升高，降低了HBV特异性T淋巴细胞免疫功能。     

B7-H1/PD-1共刺激途径与病毒感染

B7-H1及其受体PD-1是共刺激分子B7-CD28家族的重要成员.B7-H1在淋巴组织及外周非淋巴组织广泛诱导性表达,PD-1则主要表达在活化的T细胞、B细胞及髓系细胞表面.B7-H1/PD-1共刺激途径主要作用是负性调节T、B细胞的免疫反应,参与维持外周组织的免疫耐受.病毒感染可以上调B7-H1及PD-1的表达,抑制病毒特异性T细胞的免疫功能,B7-H1/PD-1途径是病毒逃避免疫监视,引发慢性感染的重要通路,因而阻断B7-H1/PD-1共刺激途径能够恢复病毒特异性T细胞的功能,清除病毒感染,这对于病毒感染的免疫治疗,尤其是病毒慢性感染的免疫治疗具有重要意义.     

Activation and Function of the Rap1 Gtpase in B Lymphocytes

Rap1 is a monomeric GTPase that is closely related to Ras. In this review, we summarize our recent work showing that the B cell antigen receptor (BCR), as well as chemokine receptors, activate Rapl via a pathway that involves phospholipase C-dependent production of diacylglycerol (DAG). The possible identities of the DAG-regulated guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) that regulate the activation of Rap1 by the BCR and chemokine receptors will be discussed. Although initially thought to be an antagonist of Ras-mediated signaling, Rap1 does not appear to modulate the ability of the BCR to activate downstream targets of Ras. Instead, activation of Rap1 promotes B cell adhesion as well as B cell migration toward chemokines. Thus, Rap1 may play a key role in a number of processes that are essential for B cell development and activation.     

Interleukin-1B (IL-1B) and interleukin-1 receptor antagonist (IL-1RN) gene polymorphisms are not associated with tubal pathology and Chlamydia trachomatis-related tubal factor subfertility

BACKGROUND: Chlamydia trachomatis infections have been associated with tubal pathology. However, not all C.trachomatis-infected women actually develop tubal pathology. Recently, host genetic factors such as the interleukin-1 gene cluster have been linked to inflammatory and infectious diseases. METHODS: Dutch Caucasian women were investigated for (i) the role of interleukin-1B (IL-1B) and interleukin-1 receptor antagonist (IL-1RN) gene polymorphisms in tubal pathology (group 1); and (ii) the presence of these gene polymorphisms in C.trachomatis IgG-positive women with and without tubal pathology (group 2). Group 1 consisted of women with (n = 40) or without (n = 95) tubal pathology, respectively, and group 2 of C.trachomatis IgG-positive women of whom 28 had tubal pathology at laparoscopy and 47 did not. IL-1B-511 and IL-1B+3954 gene polymorphisms were assessed by PCR-restriction fragment length polymorphism (RFLP), and the variable number of tandem repeats (VNTR) of the IL-1RN gene were assessed by a PCR-based assay. RESULTS: Neither IL-1B-511, IL-1B+3954 nor IL-1RN genotypes, allele or carrier frequencies showed significant association with tubal pathology or C.trachomatis post-infection-based tubal pathology. CONCLUSIONS: The data obtained suggest that specific IL-1 gene polymorphisms are not associated with the tubal pathology risk or to the development of C.trachomatis-based post-infectious severe sequelae.     

Reciprocal generation of Th1/Th17 and T(reg) cells by B1 and B2 B cells

Regulatory T (T(reg)) cells are indispensable for maintaining peripheral tolerance, whereas T helper (Th)1 and Th17 cells induce inflammation and tissue destruction. Using Foxp3-GFP knock-in mice, we report a novel regulatory role for B cell subsets in influencing the differentiation of T(reg) versus Th1/Th17 cells. Peritoneal B1 cells strongly promoted T cell proliferation and cytokine secretion when presenting nominal or allogeneic antigens, as compared to conventional follicular B (B2) cells. However, peritoneal B1 cells largely failed to convert naive Foxp3(-)CD4(+) T cells into Foxp3(+) T(reg) cells in the presence of TGF-beta and IL-2, in marked contrast to conventional B2 cells, which excelled in T(reg) conversion. Interestingly, under the same T(reg) conversion conditions, peritoneal B1 cells preferentially promoted Th1 and Th17 cell differentiation. Blockade of CD86 but not CD80 costimulation markedly enhanced T(reg) cell induction by B1 cells. Thus, B cell antigen presentation function is inversely correlated with de novo T(reg) cell induction for these B cell subsets. Our findings suggest that B1 and B2 cell subsets play distinct roles in immune regulation by promoting reciprocal differentiation of T cell lineages.     

B7H1在胰腺癌panc-1细胞的表达及其功能研究

目的:探讨胰腺癌细胞株panc-1中B7同源物1(B7H1)的表达及其对T细胞增殖活化的调节作用。方法:分别应用RT-PCR和流式细胞术检测B7H1在γ-干扰素(IFN-γ)处理或B7H1小干扰RNA(siRNA)转染前后panc-1细胞中的表达。采用植物血凝素(PHA)刺激人外周血T细胞体外增殖,加入IFN-γ处理或B7H1-siRNA转染前后panc-1细胞混合培养72 h,四甲基偶氮唑盐(MTT)比色法检测T细胞的增殖,用酶联免疫吸附法(ELISA)检测共培养上清中的IFN-γ、白细胞介素-2(IL-2)和白细胞介素-10(IL-10)的分泌。结果:panc-1细胞组成性表达B7H1。IFN-γ处理可以显著上调B7H1表达,抑制共培养T细胞的增殖和IFN-γ、IL-2分泌,但是促进IL-10的分泌。相反,应用B7H1-siRNA阻断B7H1表达后则显著促进T细胞增殖和IFN-γ、IL-2的分泌,但下调IL-10的分泌。结论:B7H1分子在体外通过抑制T细胞增殖和Th1类细胞因子分泌来下调T细胞功能。应用siRNA技术阻断B7H1有望成为治疗胰腺癌的新途径。