慢性乙肝患者树突状细胞抗原递呈功能状态的初步研究

目的:研究慢性乙肝患者树突状细胞(DC)抗原递呈功能的改变。方法:从慢乙肝患者和健康人外周血分离单个核细胞,诱导培养出DC,显微镜下观察DC形态并计数,流式细胞仪检测DC表面协同刺激分子(CD80,CD86),MTT法检测DC刺激同种异体淋巴细胞增殖的能力,ELISA法测定培养上清液中IL-12、r-IFN水平。结果:慢乙肝患者外周血单个核细胞诱导培养所获得的DC数量及表面协同刺激分子(CD80,CD86)表达水平、刺激同种异体淋巴细胞增殖能力和细胞因子产生水平均明显低于健康者(P<0.05)。结论:慢乙肝患者DC的数量及抗原递呈、免疫刺激功能状态均处于低下水平。     

慢性乙型肝炎患者外周血来源树突状细胞的功能状态

通过比较细胞因子诱导的外周血来源的慢性乙型肝炎患者树突状细胞 (DC )和正常人DC在免疫分子表达和免疫功能等方面的差别 ,探讨慢性乙型肝炎患者DC所处的功能状态。以细胞计数、间接荧光表型分析、MTT法测定DC对同种异体淋巴细胞的刺激作用、ELISA法测定DC分泌IL 1 2、IL 6等方法进行研究。实验结果表明 :慢性乙型肝炎患者相同数量的前体细胞经诱导分化形成的DC数量明显减少 ;在培养的 3、 6、 9d,与同期正常人相比 ,慢性乙型肝炎患者的DC表达CD1、CD83、CD80和HLA DR分子水平均较低 ,而CD1 4分子表达水平较高 ;刺激同种异体淋巴细胞增殖能力也低于同期正常人 ;在培养的第 6天DC分泌的上清液中 ,慢性乙型肝炎患者DC分泌的IL 1 2水平低于正常人 ,而分泌的IL 6水平高于正常人。结果提示 ,慢性乙肝患者外周血来源的DC免疫功能处于抑制状态 ,细胞因子表达异常。     

乙型肝炎病毒感染者树突状细胞(DC)亚群的变化及意义

目的　分析乙型肝炎病毒 (HBV)感染引起的慢性肝炎和肝炎肝硬变患者体内树突状细胞 (DC)亚群 (包括MDC和PDC)的数量和功能变化。方法　采用流式细胞分析技术检测 12例急性乙型肝炎、4 3例慢性乙型肝炎、15例肝炎肝硬变患者及 2 2例健康人体内MDC和PDC细胞的比例和数量 ;体外培养患者及健康人外周血DC1并检测其表型和刺激混合淋巴细胞反应 (MLR)的能力 ,评价MDC的功能 ;用 1型单纯疱疹病毒 (HSV 1)刺激外周血单个核细胞 (PBMCs)并与PBMCs共培养 ,通过检测PBMCs产生的α 干扰素水平评估PDC的功能。结果　慢性乙型肝炎患者的DC1表面CD80、CD86的表达水平低于健康人 ;健康人外周血MDC的比例为 0 .4 5 %± 0 .14 % ,绝对数为 (11.3± 6 .3)× 10 6个 L ,两者在肝炎肝硬变患者下降 ;而健康人外周血PDC的比例为 0 .36 %± 0 .15 % ,绝对数为 (8.9±4 .2 )× 10 6 个 L ,两者在慢性肝炎和肝炎肝硬变患者均下降 ;慢性肝炎和肝硬变患者PDC分泌的α 干扰素量也低于健康人。结论　乙肝病毒感染慢性化后 ,患者体内两种DC均出现数量和功能异常 ,这种异常可能是导致HBV感染的慢性化和疾病进程的原因之一     

肺炎支原体荚膜多糖抑制树突状细胞吞噬和膜分子表达

目的:了解肺炎支原体(Mp)荚膜多糖(CPS)通过结合树突状细胞特异性细胞间黏附分子-3-结合非整合素分子(DC-SIGN)对树突状细胞吞噬功能及细胞表面膜分子表达的影响。方法:复苏培养Mp 菌株,抽提和纯化CPS。培养人外周血单个核细胞来源的DC,吉姆萨染色观察和流式细胞术(FCM)鉴定;用CPS 刺激DC,FCM 检测DC 对FITC-多聚糖的吞噬指数、DC 表面特异标志CD83、HLA-DR 抗原以及协同刺激分子CD80 和CD86 的表达。结果:培养7 d 的DC 有典型的树突状结构,并高表达CD11c 分子。经CPS 刺激后,DC 内FITC-多聚糖的平均荧光强度较对照PBS 处理组显著增加(P<0.05),DC 表面膜分子CD83、HLA-DR、CD80 和CD86 较对照组显著减少(P<0.05)。用CPS 刺激被DC-SING 受体封闭的DC,发现DC 内FITC-多聚糖吞噬指数和四种膜表面分子的表达与对照组差异均无显著性(P>0.05)。结论:Mp CPS 可促进DC 的吞噬功能和减少细胞膜分子CD83、HLA-DR、CD80 和CD86 的表达。     

HBsAg体外冲击的慢性乙肝患者树突状细胞的生物学特性及其对HBV特异性CTL的诱导作用

目的 :研究HBsAg冲击的慢性乙肝患者单核细胞来源的树突状细胞 (DCs)的功能状况及体外对HBV特异性CTL的诱导作用 ,初步探讨诱导特异性抗HBV细胞免疫的途径。方法 :分离慢性乙肝患者外周血单核细胞 ,以GM CSF +IL 4 +TNF α培养诱导DCs,加入HBsAg冲击以诱导HBV特异性DCs。采用FCM测定细胞表面免疫分子CD1a、CD83、CD86、CD80、CD4 0以及HLA DR的表达水平 ,ELISA法检测培养上清中细胞因子IL 6、IL 12的分泌含量 ,MTT法测定DC刺激同种异体淋巴细胞增殖的能力 ,LDH法检测DC诱导的患者外周血T细胞对HepG2 2 2 15 (转染HBVDNA)、HepG2肝癌细胞株及K5 6 2白血病细胞株的细胞毒作用。结果 :HBsAg冲击的DC其表达CD1a、CD83、CD86、CD80、CD4 0、HLA DR表面分子明显高于对照组 (P <0 0 1,P <0 0 5 ) ,分泌IL 12的水平也高于对照组 (P <0 0 1) ,而分泌IL 6的水平则较对照组显著降低(P <0 0 1) ;HBsAg冲击的DC刺激同种异体淋巴细胞增殖的能力明显增强 (P <0 0 5 ) ,并可有效地诱导自体CTL对转HBV基因的HepG2 2 2 15细胞高效特异性杀伤作用 (P <0 0 1)。结论 :慢性乙型肝炎患者单核细胞来源的DCs经HBsAg抗原冲击后 ,生物学活性增强 ,并且能有效地诱导对HBV特异性反应的CTL。     

慢性乙型肝炎患者外周血来源的树突状细胞功能的研究

目的:研究慢性乙型肝炎患者外周血来源的树突状细胞(Dendritic cells, DCs)与慢性乙型肝炎的病程发展以及不同抗病毒治疗的关系.方法:采集71例慢性乙肝患者外周静脉血,抗凝,分离外周血单个核细胞(PBMCs).进行体外诱导培养,使之发育成DC,流式细胞仪检测其表面共刺激分子的表达.其中57例HBV-DNA阳性患者,分别采用拉米夫定或α-干扰素治疗,1个疗程后,再次检测DC表面分子的表达,并分析、比较治疗前后的表达水平.结果:与正常对照比较,慢性肝炎和慢性病毒携带者DC上CD1a(13.97±5.22和11.28±5.70 vs 27.25±4.32)%以及CD86(57.27±12.57和32.94±11.37 vs 82.12±13.54)%的表达,均明显降低(P＜0.05或0.01).比较血清HBV-DNA载量与DC表面分子的表达,发现DNA阴性组DC上CD1a、CD40、CD80和CD86的表达均比DNA阳性组高,但只有CD86的表达量有明显差别(P＜0.05).此外,57例抗病毒治疗后,拉米夫定治疗组CD40的表达(66.40±7.85 vs 43.48±7.93)%明显高于治疗前水平;而α-干扰素治疗组,CD40的表达(78.71±6.31)%高于治疗前水平外,CD86的表达(87.47±16.07 vs 44.18±10.07)%也明显高于治疗前水平(P＜0.05).结论:慢性乙型肝炎病毒感染与DC功能缺陷密切相关,血清中HBV-DNA载量越高,DC功能的缺陷越明显.拉米夫定和α-干扰素抗病毒治疗均能使患者外周血来源的DC表面的共刺激分子有不同程度的升高,促使DC成熟和功能的恢复.     

恩替卡韦联合细胞因子诱导的杀伤细胞序贯治疗慢性乙型肝炎患者树突状细胞相关功能观察

观察恩替卡韦联合细胞因子诱导的杀伤细胞(cytokine-induced kill cells,CIK)序贯治疗慢性乙型肝炎患者DC功能变化,为指导CIK联合核苷(类)药物抗病毒治疗提供理论依据。以15例接受恩替卡韦联合CIK序贯治疗的慢性乙型肝炎患者为观察对象,单独接受CIK治疗患者为对照,分别在治疗前、HBVDNA500IU/ml及CIK治疗2周后流式细胞技术测定DC表面共刺激分子CD1a、CD80、CD83及HLA-DR表达水平,同时淋巴细胞增殖实验评估DC细胞功能。结果显示15例恩替卡韦联合CIK序贯治疗患者同治疗前相比在接受恩替卡韦治疗并达到HBVDNA500IU/ml时仅有HLA-DR表达水平高于治疗前,其它共刺激分子标志物及淋巴细胞增殖能力没有显著变化。CIK序贯治疗后DC共刺激分子标志物和HLA-DR水平明显升高,并且淋巴细胞增殖能力也明显升高。单独CIK治疗患者同治疗前比较DC表面分子标志物水平及淋巴细胞增殖能力均无变化,同联合治疗组相比DC标志物水平和淋巴细胞增殖能力均低于联合治疗组。以上结果提示恩替卡韦联合CIK序贯治疗明显提高慢性乙型肝炎患者DC共刺激分子及HLA-DR表达,并诱导免疫细胞应答功能,恩替卡韦联合CIK序贯治疗可能通过增强DC相关功能提高慢性乙肝患者的抗病毒疗效。     

CD40分子在树突状细胞中的信号转导通路

树突状细胞 (DC )作为体内功能最强的抗原提呈细胞 (APC ) ,是启动机体免疫应答的中心环节[1] 。未成熟DC定居在外周组织 ,具有极强的捕获抗原能力 ,通过多种方式捕获入侵的病原体、损伤或恶变的组织后迁移至淋巴结 ,将加工过的抗原以MHC 抗原肽的形式提呈给T细胞启动机体免疫应答。在此过程中 ,DC逐渐发育成熟 ,伴随着膜表面黏附分子表达的变化以及MHCII类分子和共刺激分子如CD4 0、OX4 0L、CD80、CD86表达的上调。然而 ,DC抗原提呈功能的完全成熟需要T细胞提供的共刺激信号 ,其中CD4 0相关的信号通路在此过程中发挥了重要作用     

外周血单核细胞诱导的CD123＋髓系树突状细胞的特性研究

目的:探讨体外髓系培养体系中外周血单核细胞来源的CD123+髓系树突状细胞(mDC)的生物学特性.方法:分离健康人外周血单核细胞,用重组的粒/单核细胞集落刺激因子(GM-CSF)和白细胞介素4(IL-4)将其诱导为树突状细胞(DC).用流式细胞术(FCM)检测DC表面共刺激分子、 CD304 、 CD123和CD11C的表达,并用间接免疫磁珠法将其中CD123+DC加以分离纯化; 激光共聚焦显微镜、扫描电镜观察CD123+DC形态; ELISA法检测CD123+DC的IL-12 分泌量; 葡聚糖吞噬试验和3H-TdR渗入法分别检测CD123+DC的吞噬功能和对同种异体T细胞的刺激能力.结果:外周血单核细胞经GM-CSF和IL-4诱导7 d后,细胞表面高度表达CD86和CD11C,中等量表达CD1a和CD123,低表达CD83,丧失CD14的表达,其中,CD123和CD11C均匀分布于DC表面.免疫磁珠纯化后的CD123+DC呈现典型的不成熟DC形态,除细胞体积较小外,其表面突起类似于CD123-DC.CD123+DC仅微量分泌IL-12,其吞噬能力强于CD123-DC(P<0.05),但抗原刺激功能低于后者(P<0.05).结论:GM-CSF和IL-4培养体系中的CD123+DC可能是DC分化发育过程中更早期的未成熟mDC,具有独特的生物学特性.     

孕早期干预CD80/CD86协同刺激信号对自然流产模型免疫活性细胞协同刺激分子表达的影响

目的 :探讨孕早期干预协同刺激信号对自然流产模型孕鼠免疫活性细胞MHC Ⅱ类抗原和协同刺激分子的调控作用。方法 :建立自然流产模型组CBA×DBA 2和协同刺激信号干预组CBA×DBA 2 (CBA小鼠在孕 4天腹腔注射CD80及CD86mAb各 0 1mg)。分别于孕第 14天计数两组的胚胎吸收率 ,于孕第 9天采用流式细胞技术分析孕鼠脾细胞MHC Ⅱ类抗原与协同刺激分子CD80 (B7 1)、CD86 (B7 2 )、CD2 8和CD15 2 (CTLA 4 )的表达。结果 :孕早期干预协同刺激信号后 ,孕第 14天的胚胎吸收率显著下降 (P <0 0 5 ) ;孕第 9天免疫活性细胞CD80、CD86和CD2 8的表达显著下降 (P <0 0 1) ;CTLA 4的表达则显著升高 (P <0 0 5 ) ;而MHC Ⅱ类抗原的表达无显著改变 (P >0 0 5 )。结论 :孕早期体内干预协同刺激信号使免疫活性细胞协同刺激分子CD80、CD86、CD2 8表达下调和CTLA 4表达上调 ,及母胎界面Th2型免疫偏离 ,从而诱导系统性母 胎免疫耐受     

重组人可溶性CD40配体对树突状细胞体外分化、成熟及功能的影响

用Ficoll密度离心及贴壁法获得外周血单个核细胞 (PBMC ) ,PBMC经细胞因子组合诱导分化成树突状细胞 (DC ) :GM CSF (10 0ng/ml)与IL 4 (5 0ng/ml)诱导 5d后 ,分别加入TNF α (10ng/ml)或rhsCD4 0L (2 μg/ml)继续培养 4d ;倒置显微镜下观察DC形态 ,免疫荧光标记和流式细胞术分析DC表型 (CD1a、CD80、CD83、HLA DR、CD14、CD16、CD19)及摄取FITC Dextran抗原的能力 ;3 H TdR掺入法检测DC刺激自体混合淋巴细胞体外增殖反应 (MLR )能力 ;ELISA法分析DC培养上清中IL 12的水平 ;Trans well细胞趋化实验检测DC对自体外周T淋巴细胞的趋化能力。发现经rhsCD4 0L刺激的DC表面分子 (CD1a、CD80、CD83、HLA DR )的表达水平高于经典的细胞因子组合组 (GM CSF +IL 4 +TNF α ) ,同时rhsCD4 0L刺激后的DC摄取FITC Dextran的能力下降而刺激自体MLR和分泌IL 12的能力明显提高 ;而且rhsCD4 0L诱导的DC表面趋化因子受体CXCR4的表达水平及对自体外周T淋巴细胞的趋化能力均强于TNF α或FL激发的DC。rhsCD4 0L在体外不仅具有显著的诱导DC分化 ,促进DC成熟的功能 ,而且经rhsCD4 0L作用的DC能更有效地激发T淋巴细胞     

Distinct effects of CD86-mediated costimulation on resting versus activated human CD4+ T cells

CD80 and CD86 are important in the initiation of T cell immunity. Although their costimulatory function has long been appreciated, it remains unclear whether the biological significance of the two B7 isoforms resides in their different patterns and kinetics of expression or whether differences exist in their function. We have addressed this issue using HLA‐DR1 transfectants co‐expressing CD80, CD86, or both molecules as stimulators for naïve, memory, and activated human CD4⁺ T cells. Both CD80 and CD86 efficiently costimulated alloresponses by unseparated peripheral blood CD4⁺ T cells; however, CD86 was substantially inferior in costimulating alloresponses by separated memory T cells, and completely incompetent in costimulating three human T cell clones. Furthermore, CD80/CD86 double transfectants stimulated lower responses by the clones than cells expressing CD80 alone. That CD86 was actively inhibitory rather than merely neutral was evidenced by the increase in response to the double CD80/CD86 APC when anti‐CD86 antibody was added. Furthermore, addition of anti‐CTLA‐4 Fab to cultures of HLA‐DR1 transfectants co‐expressing CD86, fully restored the proliferative response. These results indicate that CD80 and CD86 mediate distinct signals in previously activated T cells, and demonstrate that CTLA‐4 ligation may dominate the outcome of CD86‐mediated costimulation of activated CD4⁺ T cells.     

HLA class I molecule expression is up-regulated during maturation of dendritic cells, protecting them from natural killer cell-mediated lysis

It has been widely demonstrated that natural killer (NK) cells are able to discriminate between normal and abnormal cells on the basis of the interaction of their NKRs with the MHC molecules expressed on the target cells. Recent studies showed that also normal dendritic cells are susceptible to NK cell-mediated lysis. In this work, the potential relationships between the expression of different surface molecules on both immature and mature DC and susceptibility to lysis have been investigated. The reduced density of HLA class I on the surface of immature DC resulted in the only permissive signal to NK cell mediated killing. On the contrary, the remarkable increase in HLA class I molecules detected during DC maturation was strictly related to the resistance to NK cell. Contemporary, no clear evidences of a role for other surface molecules modulated during DC maturation (CD80, CD83, CD86 and CD40), were obtained.     

Human dendritic cells activate T lymphocytes via a CD40: CD40 ligand-dependent pathway

The CD40: CD40 ligand (CD40L) interaction provides T lymphocyte-mediated help for B lymphocyte and monocyte function but has also been shown to serve as a co-stimulus for T lymphocyte activation. In this report, we studied the regulation of CD40 expression and its functional relevance for the human dendritic cell (DC) stimulation of T lymphocytes. Only a small subpopulation of directly isolated blood DC expressed CD40. However, CD40 was rapidly up-regulated by culture, and its expression was further enhanced by interleukin (IL)-1α, IL-1β, IL-3, tumor necrosis factor-α and granulocyte/macrophage-colony-stimulating factor. Expression of CD40L on DC was not detected. The proliferation of T lymphocytes in an allogeneic mixed leukocyte reaction, stimulated by blood DC or epidermal Langerhans cells, was significantly reduced in the presence of the CD40 immunoglobulin (CD40Ig) fusion protein or CD40L monoclonal antibodies. Cross-linking of CD40 on directly isolated DC with mouse CD40L trimer (mCD40LT) markedly augmented CD80 and CD86 up-regulation. Nevertheless, the same cross-linking mCD40LT inhibited DC stimulated T lymphocyte proliferation. When CD40Ig was added simultaneously with CTLA-4Ig, only minimal and variable additional inhibition of DC-stimulated allogeneic T lymphocyte proliferation and IL-2 secretion was observed, compared to each fusion protein alone. These results suggest that both CD80/CD86-dependent and -independent components of DC-T lymphocyte CD40: CD40L co-stimulation exist and further emphasize that the majority of blood DC have to differentiate or be activated to express co-stimulatory molecules.     

Human CD1a molecule expressed on monocytes plays an accessory role in the superantigen-induced activation of T lymphocytes

The CD1 molecules exhibit characteristics of the MHC class I and class II molecules. They are expressed on cortical thymocytes and, similarly to MHC class II molecules, on antigen-presenting cells. In the present study, we investigated the role of the CD1 molecules in the T-cell response to bacterial superantigens. Indeed, we have observed that CD1 molecules could be detected on the CD14-positive population of some healthy donors (14% of donors tested). The CD1 expression on monocytes is correlated with an activation state of the donors as demonstrated by the increased expression of the CD25, CD38, CD45R0, and MHC class II molecules on their lymphocytes. On these donors, CD1a mAbs induced a clear inhibition (65%) of lymphocyte proliferation induced by either staphylococcal enterotoxin A or toxic shock syndrome toxin-1, whereas this proliferation was constantly unaffected by the addition of mAbs directed against CD1b or CD1c. Moreover, an intracellular calcium flux was induced in monocytes following CD1a engagement, and this calcium flux was partially inhibited by preincubation of these cells with the superantigen. These results attribute to the CD1a molecule expressed by monocytes a role in the transduction of signal(s) involved in superantigen-induced activation.     

Induction of dendritic cell costimulator molecule expression is suppressed by T cells in the absence of antigen-specific signalling: role of cluster formation, CD40 and HLA-class II for dendritic cell activation.

Full activation of T lymphocytes by dendritic cells (DC) during antigen presentation is known to require the interaction of several inducible receptor-ligand pairs. We have postulated that the reciprocal activation of DC by T lymphocytes is also important. Potential signalling molecules that might increase the stimulatory capacity of DC during antigen presentation to T lymphocytes were tested using an in vitro model. Fresh human blood DC were cocultured with CD4+ and CD8+ allogeneic or with autologous T lymphocytes plus Staphylococcus superantigen A (SEA). Surprisingly, costimulator expression on DC cocultured with T lymphocytes was reduced in comparison to DC cultured alone. However, the minority (10-30%) of DC clustering with T lymphocytes showed antigen-specific up-regulation of the CD40, CD80 and CD86 costimulator molecules, whereas the non-clustered DC (70-90%) had less up-regulation than control DC cultured alone and did not respond to antigen-specific triggering. Monoclonal antibodies (mAb) to CD40 ligand (CD40L) and human leucocyte antigen (HLA)-DR, but not lymphocyte function-associated antigen-1 (LFA-1), LFA-3 or HLA-class I, significantly inhibited the T-lymphocyte induction of DC costimulator expression. Since HLA-class II, but not HLA-class I mAb, inhibited allogeneic T-lymphocyte-mediated activation of DC, CD4 T lymphocytes appear to be the main subset activating DC in the mixed lymphocyte reaction. Cross-linking of CD40, but not HLA-class II, up-regulated DC or B-cell costimulator expression. Although direct class II signalling does not appear to play a role in DC activation, antigen-specific T-cell recognition contributes via other mechanisms to regulate DC activation.     

CD40‐activated B cells can be generated in high number and purity in cancer patients: analysis of immunogenicity and homing potential

Cellular adjuvants such as dendritic cells (DC) are in the focus of tumour immunotherapy. In DC‐vaccine trials, induction of tumour antigen‐specific immunity is observed frequently and well‐documented clinical responses have been reported. However, the overall response rate is less than 3%, therefore alternative strategies are being investigated. CD40‐activated B cells (CD40‐B) have been characterized previously as an interesting alternative because they present antigen efficiently and can be expanded by several logs from small amounts of peripheral blood. To determine the central technical challenges of cell‐based vaccines we performed a single‐patient analysis of 502 patients from DC‐based tumour vaccine trials and identified at least three factors contributing to their limited efficiency: (1) lack of cell numbers; (2) lack of documented purity thus high contamination of bystander cells; and (3) lack of quality control and thus heterogeneous or unknown expression of important surface molecules such as major histocompatibility complex (MHC) and chemokine receptors. Based on these findings we re‐evaluated the CD40‐B approach in cancer patients. Here, we show that proliferation of B cells from cancer patients is equivalent to that observed in healthy donors. Purity is always > 90% after 2 weeks and remains stable for several weeks. They have comparable antigen‐presenting capability determined phenotypically and by allogeneic mixed lymphocyte reaction. Expression of CCR7 and CD62L was detected in all samples and B cells migrated towards the relevant homing chemokines. Taken together, CD40‐B cells from cancer patients can be expanded in virtually unlimited numbers at high purity and full function concerning antigen‐presentation and migratory properties.     

CD40分子在树突状细胞抗人多发性骨髓瘤免疫应答中的作用及其机理

目的为研究CD40分子在人树突状细胞(DC)抗多发性骨髓瘤(MM)中的作用及其机制。方法采用CD40配体(CD40L)转基因细胞及抗CD40的激发型单克隆抗体在体外激发DC,并通过DC细胞计数、形态学和细胞表型分析、IL-12定量检测、DC对MM抗原的摄取及混合淋巴细胞反应等手段对其进行研究。结果CD40分子配基化可促进DC的体外增殖和分化,使DC增加分泌IL-12,并下调DC摄取抗原的能力,促进DC的成熟,同时赋予DC激发自体CD8+细胞增殖的作用,使后者对MM细胞产生特异性的杀伤作用。结论CD40分子激发不仅有利于DC的增殖、分化和增强激发T细胞增殖,而且Th细胞表达的CD40L是DC获得直接激发抗MM抗原特异性CD8+T细胞的关键分子。     

激动型CD40单克隆抗体体外抑制结肠癌细胞增殖的实验研究

目的 探讨激动型CD40单克隆抗体在体外对结肠癌细胞增殖的抑制作用.方法 树突状细胞(DCs)经结肠癌冻融抗原致敏后予以不同条件激活,分为激动型CD40单克隆抗体组、阴性对照组及肿瘤坏死因子-α(TNF-α)阳性对照组,诱导培养至第7天,用流式细胞仪检测各组DCs表面分化相关抗原CD80、CD83、CD86和HLA-DR的表达,酶联免疫吸附测定法检测DCs培养液上清中白细胞介素-12(IL-12)的质量浓度,噻唑蓝比色法检测DCs体外刺激T淋巴细胞增殖的能力,进而检测DCs所诱导的肿瘤特异性细胞毒性T淋巴细胞(CTL)对人结肠癌细胞HCT116的杀伤作用.结果 与阴性对照组相比,激动型CD40单克隆抗体组活化的DCs表面抗原CD80、CD83、CD86和HLA-DR的表达率均显著升高(均P＜0.05),DCs上清中IL-12的质量浓度亦显著升高((716.80±53.43) pg/ml比(405.51±12.17) pg/ml,P＜0.05),活化的DCs具有更强的刺激T淋巴细胞增殖的能力(刺激指数2.006 2±0.438 3比1.365 0±0.209 8,P＜0.05),活化的DCs所诱导的CTL对HCT116细胞具有更强的杀伤作用(抑制率(66.08±0.41)％比(46.60±1.10)％,P＜0.05);而与TNF-α阳性对照组相比,其差异均无统计学意义(均P＞0.05).结论 激动型CD40单克隆抗体在体外可促进DCs的活化与成熟,进而诱导肿瘤特异性CTL的产生,从而抑制人结肠癌细胞HCT116的增殖.