B7-H1 expression is associated with expansion of regulatory T cells in colorectal carcinoma

AIM： To investigate the expression of B7-H1 in human colorectal carcinoma （CRC） to define its regulating ef- fects on T cells in tumor microenvironment.

Anti-gastric cancer active immunity induced by FasL/B7-1 gene-modified tumor cells

AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL+/B7-1+SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P＜0.01). SGC- 7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC 7901 cells (z = 2.06-44.30, P＜0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1±2.4% vs30.5±2.3%,P＜0.05).CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.

Synergetic anticancer effect of combined quercetin and recombinant adenoviral vector expressing human wild-type p53,GM-CSF and B7-1 genes on hepatocellular carcinoma cells in vitro

AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cell lines in vitro.METHODS: The sensitivity of HCC cells to anticancer agentswas evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of cells infectedwith BB-102 was determined by trypan blue exclusion. Theexpression levels of human wild-type p53, GM-CSF and B7-1genes were determined by Western blot, enzyme-linkedimmunosorbent assay (ELISA) and flow cytometric analysis,respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyltransferase (TdT) assay or DNA ladder electrophoresis.RESULTS: Quercetin was found to suppress proliferation ofhuman HCC cell lines BEL-7402, HUH-7 and HLE, with peaksuppression at 50 μmol/L quercetin. BB-102 infection wasalso found to significantly suppress proliferation of HCC celllines. The apoptosis of BB-102-infected HCC cells was greaterin HLE and HUH-7 cells than in BEL-7402 cells. Quercetin didnot affect the expression of the three exogenous genes inBB-102-infected HCC cells (P＞0.05), but it was found to furtherdecrease proliferation and promote apoptosis of BB-102-infected HCC cells.CONCLUSION: BB-102 and quercetin synergeticallysuppress HCC cell proliferation and induce HCC cell apoptosis,suggesting a possible use as a combined anti-cancer agent.

ANTITUMOR IMMUNITY AND VACCINE EFFECT INDUCED BY IL-12 SYNERGIZES B7-1 GENE TRANSFECTED CELLS

Objective: To study the synergic effects of IL-12 and B7-1 transfectant on antitumor immunity in vivo. Methods: The retrovirus vector encoding mIL-12 and mB7-1 gene was tranfected into EL-4 thymic lymphoma cells respectively.The cells were used as tumor vaccine and the therapeutic effect was observed. Results: In contrast to the miceimmunized with EL-4/Wt or EL-4/Neo groups, thetumorigenicity of EL-4/IL-12 transfectant was decreased(P<0.001). The EL-4/IL-12 and EL-4/B7-1 cells irradiatedwith 60Co showed significant systematic protective effectsagainst the rechallenge of EL-4/Wt. 60Co irradiatedEL-4/IL-12 cells delayed the occurrence of tumor andprolonged the survival period of tumor bearing mice.Combination of the vaccines of EL-4/IL-12 and EL-4/B7-1 resulted in the enhanced therapeutic effect compared witheach single transfectant group (P<0.001). Conclusion: The results showed that IL-12 transduced cells could enhancethe antitumor immunity of host as cancer vaccine.Combination of the EL-4/IL-12 and EL-4/B7-1 transfectant could improve immunity of host and is a prospect cancervaccine.

Expression of the B7 - related molecule B7 - H1 by glioma cells: a potential mechanism of immune paralysis

Human glioblastoma is a highly lethal tumor that is known for its immune inhibitory capabilities.B7-homologue l(B7-H 1),a recently identified homologue of B7.1/2(CD80/86),has been described to exert costimulatoryand immune regulatory functions.We investigated the expression and the functional activity of B7-H 1 in humanglioma cells in vitro and in vivo.Although lacking B7.1/2(CD80/86),all 12 glioma cel1 1ines constitutivelyexpressed B7-H1 mRNA and protein.Exposure to IFN-gamma strongly enhanced B7-H 1 expression.Im-

Expression and significance of B7-H1 in peripheral blood dendritic cells from patients with bladder cancer

Objective： The aim of this study was to study the expression and the clinical significance of B7-H1 on dendritic cells （DCs） in peripheral blood from patients with bladder cancer. Methods： Peripheral blood mononuclear cell were disparted from 30 bladder cancer patients and 7 healthy controls by density gradient centfifugation and then co-cultured. The expres- sion of B7-H1 on DCs were analyzed by flow cytometry. Results： Expression of BT-H1 on DCs in bladder cancer was higher than healthy controls （P 〈 0.01）. And the expression were strongly associated with the pathological grade and clinical stage of bladder cancer （P 〈 0,05）. Conclusion： The up-regulation of B7-H1 on DCs was strongly associated with neoplastic progres-sion of bladder cancer. B7-H1/programmed death （PD）-1 signal pathway may also play an important role in immune escape of bladder cancer during initial phase of T cell immune response.

GM-CSF GENE OR B7-1 GENE MODIFIED MURINE EL-4 CELLS VACCINE

Objective: To study the vaccine potency of gene-modified tumor cells. Methods: The EL-4 lymphoma was transduced with recombinant retrovirus containing the murine GM-CSF gene or B7-1 gene. The effect of gene transduction on antitumor immunity was investigated. Results: Flow cytometry analysis showed that expression of their surface marker between wild-type EL-4 cells and gene transduced tumor cells was the same except for CD80 positive in B7-1 gene transduced cells. GM-CSF gene or B7-1 gene transduced EL-4 cells resulted in remarkable loss of tumorigenicity in syngenetic mice. The systemic protective immunity was induced against the challenge with EL-4/wt cells. Therapeutic vaccine with EL-4/GM-CSF or EL/7-1 cells could retard the growth of established early-stage EL-4/wt tumor significantly, but not retard the growth of late-stage EL-4/wt tumor. Irradiated GM-CSF gene transduced EL-4 cells showed strong vaccine effect against EL-4 cell challenge, but irradiated B7-1 gene transduced EL-4 cells showed weak vaccine effect. Remarkable cooperative antitumor effect against EL-4 cell challenge was observed when both irradiated EL-4/GM-CSF and EL-4/B7-1 were inoculated together. Conclusion: GM-CSF gene or B7-1 gene transduced BL-4 cells can be used as a good tumor vaccine. The combination of the two kinds of vaccine may have potential application value in human cancer treatment.

Expression of co-stimulatory molecules B7-2 and PD-L1 on peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

Objective： To explore the roles of the expression of the co-stimulatory molecule, B7-2, and the co-inhibitory molecule, PD-L1, on peripheral blood mononuclear cells in the mechanism of immunotolerance in chronic hepatitis B virus infection. Methods： Thirty HBV infected patients in the immunoreactive phase and 20 patients in the immunotolerant phase were enrolled in the study, while 20 healthy volunteers were used as controls. RT- PCR and real-time PCR methods were used to detect the expression levels of B7-2 and PD-L1 mRNA in peripheral blood mononuclear cells in chronic HBV infected patients. Results： The B7-2 expression in irnrnunoreactive and immunotolerant patients was significantly lower than that in the controls （P all 〈 0.01 ）; B7-2 expression in immunoreactive patients was significantly lower than in immunotolerant patients （P 〈 0.01）. PD-L1 expression in irnmunoreactive patients and immunotolerant patients was significantly higher than that in normal controls （P all 〈 0.01）. The PD-L1/BT-2 ratios in immunoreactive and immunotolerant patients were significantly higher than that of the healthy controls （P all 〈 0.01）; the PD-L1/ B7-2 ratio was significantly higher in the immunoreactive patients than in the immunotolerant patients （P 〈 0.01）. Conclusion： In chronic HBV infection, changes in the expression of co-stimulatory and co-inhibitory molecules imply a protective adjustment against the patient＇ s immune response that may result in increased immunotolerance and persistent HBV infection.

抗奥合剂通过p38 MAPK/NF-κB信号通路和ACE2/Ang1-7/Mas轴缓解急性肺损伤研究

目的探讨抗奥合剂(KAHJ)治疗小鼠急性肺损伤(ALI)的作用及机制,为其可能作为缓解新型冠状病毒(COVID-19)感染后症状的药物提供依据。方法采用网络药理学方法预测KAHJ治疗ALI的主要活性成分、潜在靶点和相关信号通路。将C57BL/6J小鼠随机分为对照组、LPS组和LPS+KAHJ组。LPS+KAHJ组小鼠灌胃KAHJ(4.76 g·kg^(-1)·d^(-1),8.8 mL·kg^(-1)·d^(-1)),其余组小鼠灌胃生理盐水(8.8 mL·kg^(-1)·d^(-1))。14 d后,腹腔注射LPS(5 mg·kg^(-1))诱导ALI模型。收集小鼠血清和肺组织,通过组织病理学观察肺组织的病理变化。采用Western blot、qPCR、ELISA和IHC等方法评估KAHJ对ALI的改善作用。结果通过网络药理学筛选出疾病和药物共同的70个核心靶基因,并显示与多个信号通路密切相关,如MAPK、NF-κB、Apoptosis、COVID-19和肾素-血管紧张素系统(Ras)信号通路等。此外,通过实验验证发现KAHJ能改善小鼠ALI后的炎症和细胞凋亡,减少肺损伤和肺水肿,抑制肺纤维化。同时,KAHJ的作用机制与p38 MAPK和NF-κB的磷酸化以及ACE2/Ang1-7/Mas轴的调控也有着密切关系。结论KAHJ可能通过抑制p38 MAPK/NF-κB信号通路和调控ACE2/Ang1-7/Mas轴缓解ALI,为缓解COVID-19感染后症状提供了补充和替代药物。

基于B7-1/2/CD28/CTLA-4通路探讨扶正祛毒汤干预急性髓系白血病完全缓解患者CD34~+细胞诱导成树突细胞激发T细胞的影响

目的探讨扶正祛毒汤治疗急性髓系白血病完全缓解的可能作用机制。方法12只新西兰大白兔随机分为正常组以及扶正祛毒汤低、中、高剂量组,每组3只。扶正祛毒汤低、中、高剂量组兔分别给予扶正祛毒汤浓缩煎剂5、10、20g/(kg·d)灌胃3d,正常组兔给予等体积蒸馏水灌胃,末次灌胃后心脏取血获得正常血清和扶正祛毒汤低、中、高剂量血清。将急性髓系白血病完全缓解患者骨髓稀释后分离提纯CD34~+细胞,将扩增后的CD34^(+)细胞分为空白组、细胞因子组、正常血清组和扶正祛毒汤低、中、高剂量血清组。除空白组外,其余各组均添加细胞因子诱导9d成为树突细胞。流式细胞术(FCM)检测各组树突细胞表面抗原分子CD83、CD1a、HLA-DR的表达,以及共刺激分子B7-1、B7-2的表达。诱导成熟后的树突细胞分别激发自体和异体T细胞,免疫印迹试验(WB)和RT-qPCR法检测T细胞中特异性表面糖蛋白CD28(CD28)和细胞毒性T淋巴细胞相关蛋白4(CTLA-4)蛋白和mRNA的表达。MTT比色法检测激发后的T细胞在不同效靶比时对人髓系白血病细胞株K562的杀伤作用。结果与空白组相比较,细胞因子组、正常血清组和扶正祛毒汤低、中、高剂量血清组树突细胞表面抗原分子CD83、CD1a、HLA-DR的表达明显升高(P<0.05),共刺激分子B7-1、B7-2的表达明显升高(P<0.05);与细胞因子组和正常血清组相比较,扶正祛毒汤低、中、高剂量血清组树突细胞表面抗原分子CD83、CD1a、HLA-DR的表达明显升高(P<0.05),共刺激分子B7-1、B7-2的表达明显升高(P<0.05)。与空白组、细胞因子组和正常血清组相比较,扶正祛毒汤低、中、高剂量血清组CD28蛋白及mRNA表达均明显增加(P<0.05),CTLA-4蛋白及mRNA表达均明显降低(P<0.05),T细胞对K562细胞的杀伤率明显增加(P<0.05),且杀伤作用随效靶比的增加而增强,但正常人T细胞与患者T细胞对K562细胞的杀伤作用无明显差异(P>0.05)。结论扶正祛毒汤治疗急性髓系白血病完全缓解的机制可能与该方能够有效促进急性髓系白血病完全缓解患者骨髓CD34^(+)细胞源树突细胞的成熟,从而抑制共刺激分子B7-1、B7-2与CTLA-4结合,且促进B7-1、B7-2与CD28结合,调控B7-1/2/CD28/CTLA-4信号通路有关。

Prevention of hepatocellular carcinoma in mice by IL-2 and B7-1 genes co-transfected liver cancer cell vaccines

AIM: To study the immunoprotective effect of liver cancer vaccine with co-transfected IL-2 and B7-1 genes on hepatocarcinogenesis in mice.METHODS: The murine liver cancer cell line Hepal-6 was transfected with IL-2 and/or B7-1 gene via recombinant adenoviral vectors and the liver cancer vaccines were prepared. C57BL/6 mice were immunized with these vaccines and challenged with the parental Hepal-6 cells afterwards.The immunoprotection was investigated and the reactive T cell line was assayed.RESULTS: The immunoprotection of the tumor vaccine was demonstrated. The effect of IL-2 and B7-1 genes cotransfected Hepal-6 liver cancer vaccine (Hep6-IL2/B7vaccine) on the onset of tumor formation was the strongest.When attacked with wild Hepal-6 cells, the median survival period of the mice immunized with Hep6-IL2/B7 vaccine was the longest (68 days, χ2=7.70-11.69, P＜0.05) and the implanted tumor was the smallest (z =3.20-44.10, P＜0.05).The effect of single IL-2 or B7-1 gene-transfected vaccine was next to the IL2/B7 gene co-transfected group, and the mean survival periods were 59 and 54 days, respectively.The mean survival periods of wild or enhanced green fluorescence protein gene modified vaccine immunized group were 51 and 48 days, respectively. The mice in control group all died within 38 days and the implanted tumor was the largest (z=3.20-40.21, P＜0.05). The cellular immunofunction test and cytotoxicity study showed that the natural killer (NK) cell, lymphokine activated killer (LAK) cell and cytotoxic T lymphocyte (CTL) activities were significantly increased in mice immunized with the Hep6-IL2/B7 vaccine, (29.5±2.5%,65.0±2.9%, 83.1±1.5% respectively, compared with other groups, P＜0.05).CONCLUSION: The Hep6-IL2/B7 liver cancer vaccines can induce the mice to produce activated and specific CTL against the parental tumor cells, and demonstrate stronger effect on the hepatocarcinogenesis than single gene modified or the regular tumor vaccine. Therefore, the vaccines may become a novel potential therapy for recurrence and metastasis of HCC.

Construction of Eukaryotic Expression Vector Containing B7-1/GFP Gene and Its Expression in Osteosarcoma Cell Line

Objective： To construct eukaryotic expression vector containing B7-1/GFP geneand study its expression in osteosarcoma cell line LM8. Methods： By using gene cloning technique, eukaxyotic expression vector pEGFP-C1 was used to construct the murine B7-1 recombinant plasmid （pEGFP-C1/B7）. Recombinant plasmid was transfected into LM8 cells with liposome and was confirmed by restriction endonuclease digestion and DNA sequencing. The expression of the fusion protein was detected using fluorescence microscope and Western blot analysis. Results： The recombinant eukaryotic expression plasmid pEGFP-C1/B7 was successfully constructed, which was confirmed by DNA sequencing, RT-PGR and restriction enzymes analysis. The green fluorescent protein could be detected in the transfected LM8 with fluorescence microscope. The expected B7-1 and green fluorescent protein （GFP） fusion protein was detected by RT-PCR and Western blot. Conclusion： The eukaryotic expression vector containing B7-1/GFP gene was constructed successfully, and it could be expressed in LM8 after transfection.

鼠抗人B7-1分子功能性单克隆抗体的制备及生物学特性

目的 :制备鼠抗人B7 1分子的功能性单克隆抗体 ,研究其对高表达相应配基分子细胞的生物学效应。方法 :用两株转人B7 1基因细胞株XG7 B7和L B7分别作为免疫原及检测细胞株 ,利用B淋巴细胞杂交瘤技术制备单克隆抗体。以快速定性试纸分析法鉴定单抗所属的小鼠IgG亚类 ,采用竞争抑制及间接免疫荧光法分析单抗的特异性和亲和力 ,以高表达B7 1分子的恶性淋巴瘤细胞Raji和Daudi为靶细胞 ,分析单抗对其生长的影响。以人多发性骨髓瘤细胞转入B7 1基因细胞株XG1 B7为刺激细胞 ,以人外周血单个核细胞 (PBLs)为反应细胞 ,用MTT法分析单抗的中和活性。结果 :成功地获得了 1株鼠抗人B7 1的功能性单克隆抗体 (克隆 4E5 ) ,属于小鼠IgG1亚类 ,经流式细胞仪分析 ,4E5与PBLs、体外人工诱导的树突状细胞(DCs)、Raji和Daudi的阳性结合率分别为 10 2 %、95 1%、92 7%及 89 2 % ;能完全阻断标准抗人B7 1单抗与相应抗原的结合。同时还发现 ,单抗 4E5能显著地抑制恶性淋巴瘤细胞Raji和Daudi的生长繁殖 ,并能阻断B7分子介导的协同刺激信号的传导。结论 :单克隆抗体 4E5是一株抗人B7 1分子的功能性单抗 ,具有重要的研究和应用价值。

IL-12协同B7-1增强实验小鼠的抗肿瘤免疫

目的：我们应用逆转录病毒构建了ＩＬ－１２，Ｒ７－１和ＧＭ－ＣＳＦ表达载体，以研究基因修饰的肿瘤细胞的癌疫苗作用。方法：将３种表达载体分别转染ＥＭ胸腺瘤细胞并研究了该基因导入细胞的抗肿瘤免疫效果。结果：当接种了ＥＬ－４／ＩＬ－１２细胞后，在Ｃ５７ＢＬ／６同系鼠中其基因导入细胞的肿瘤原性比较ＥＬ－４和ＥＬ－４／Ｎｅｏ组明显减少（Ｐ＜０．０１）。在ＥＬ－４／ＩＬ－１２被排斥后，体内试验中诱发了实验动物抗 ＥＬ－４／Ｗｔ的系统性、保护性免疫，５１Ｃｒ释放测定中，获得一个较强的抗ＥＬ－４／Ｗｔ和一个较弱的抗同系Ｌｅｗｉｓ肿瘤细胞的ＣＴＬ活性，体内淋巴细胞消除分析的结果提示减少的肿瘤原性主要依赖于ＣＤ４＋，ＣＤ８＋和ＮＫ细胞。用ＥＬ－４／ＩＬ－１２细胞进行疫苗治疗比较用ＥＬ－４／Ｎｅｏ细胞能有效地延缓已建立的ＥＬ－４／Ｗｔ肿瘤的生长（Ｐ＜０．００５），ＥＬ－４／ＩＬ－１２和ＥＬ－４／Ｂ７－１联合比用单一的转基因细胞增强了治疗效果（Ｐ＜０．００５）。结论：提示应用ＩＬ－１２进行血液肿瘤的治疗是有效的，ＩＬ－１２和Ｂ７－１联合使用在未来人类癌症的治疗中亦可有一定的应用前景。

SEA和B7-1基因真核共表达载体的构建及在B16细胞的表达

目的构建葡萄球菌肠毒素A(SEA)和小鼠B71基因真核共表达载体。方法采用PCR和RTPCR方法分别克隆了带B71跨膜区的SEA(SEAB7tm)和小鼠B71基因,中间通过内部核糖体进入位点(Internalribosomeentrysite,IRES)序列的连接克隆至真核表达载体pcDNA3.1+。利用阳离子脂质体将重组质粒转染B16细胞,间接免疫荧光法检测B71和SEA分子在B16细胞膜表面的表达情况。结果测序结果与Genebank中公布的SEA、小鼠B71cDNA序列相符,双标记间接免疫荧光检测结果表明B71、SEA同时在转染的B16细胞膜上表达。结论成功构建了SEA和小鼠B71真核共表达载体,为进一步研究SEA和B71联合应用抗肿瘤免疫治疗及其免疫机理奠定了基础。

川芎嗪对活动期狼疮性肾炎外周血单个核细胞B7-1和B7-2mRNA表达的影响

目的 :探讨川芎嗪对活动期狼疮肾炎 (LN)外周血单个核细胞 (PBMC)的B7- 1(CD80 )和B7- 2 (CD86 )mRNA表达的影响 ,为临床使用川芎嗪治疗LN提供理论依据。方法 :取活动期LN患者PBMC培养 ,分别以川芎嗪、地塞米松和川芎嗪 +地塞米松进行处理 ,以PBS对照 ,采用半定量反转录PCR的方法 ,检测PBMC的B7- 1和B7- 2mR NA表达。结果 :与对照组相比 ,川芎嗪组和地塞米松组均能明显抑制B7- 2mRNA表达 (P <0 .0 5 ) ,而川芎嗪 +地塞米松组对B7- 2mRNA表达的抑制更加明显 (P <0 .0 1)。各组对B7- 1mRNA表达均无显著影响 (P >0 .0 5 )。结论 :川芎嗪能下调活动期LN外周血单个核细胞B7- 2mRNA表达 ,合并使用地塞米松能更好地抑制B7- 2mRNA表达。

miR-129-5p通过HMGB1调控乳腺癌MCF-7细胞对紫杉醇的敏感性

目的:探讨miR-129-5p通过调控高迁移率族蛋白B1基因(high mobility group box 1,HMGB1)影响乳腺癌MCF-7细胞对紫杉醇(paclitaxel,PTX)的敏感性。方法:采用脂质体转染技术将miR-129-5p mimics、HMGB1小干扰RNA(si-HMGB1)分别转染入MCF-7细胞,用PTX刺激培养细胞后,用实时荧光定量PCR检测转染后MCF-7细胞miR-129-5p和HMGB1 m RNA的表达,Western blotting检测转染后MCF-7细胞HMGB1蛋白的表达,CCK-8增殖实验检测转染后PTX对MCF-7细胞增殖的影响,流式细胞术检测转染后对PTX诱导MCF-7细胞凋亡的影响。结果:转染miR-129-5p mimics后,MCF-7细胞中miR-129-5p的表达水平明显高于阴性对照组细胞(P<0.01);过表达miR-129-5p后可明显增强PTX抑制MCF-7细胞的增殖和诱导细胞凋亡的能力(均P<0.05),并显著抑制HMGB1 m RNA和蛋白的表达(均P<0.05)。转染si-HMGB1后,显著降低MCF-7细胞HMGB1 m RNA和蛋白的表达(均P<0.05);干扰HMGB1表达进一步促进PTX抑制MCF-7细胞的增殖并诱导细胞凋亡(均P<0.05)。结论:miR-129-5p通过下调HMGB1的表达增强乳腺癌MCF-7细胞对PTX的敏感性。

共刺激分子4-1BBL和B7-1在人脑胶质瘤细胞中的表达

背景与目的:4-1BBL和B7-1为诱导和维持T细胞活化提供了重要的共刺激信号,目前被认为是提高抗肿瘤免疫的治疗靶点。本研究探讨4-BBL和B7-1在7株胶质瘤细胞系表面的表达情况。方法:用流式细胞仪检测7株胶质瘤细胞株表面的共刺激分子4-1BBL和B7-1的表达,同时用MTT法分析胶质瘤细胞系对抗癌药物长春新碱(VCR)敏感性,并分析4-1BBL的表达与耐药性的相关性。结果:发现在所检测的胶质瘤细胞表面有不同程度的表达4-1BBL,但均不表达B7-1。其中T98G和MGR1细胞表面的4-1BBL表达>30%,对VCR不敏感,UW28、SKMG1、MGR2、SF767、SKMG4细胞表面的4-1BBL表达<10%,对VCR敏感。结论:本研究所检测的胶质瘤细胞均不表达共刺激分子B7-1,但有不同程度的表达4-1BBL,并且4-1BBL高表达的胶质瘤细胞对长春新碱敏感性差。

分子佐剂C3d上调Raji细胞协同刺激分子B7-1和B7-2的表达(简报)

我们在以往研究中，引入选择性增强体液免疫效应的新型分子佐剂C3d，成功构建了重组避孕疫苗hCGβ-C3d3，通过免疫Th2型优势的BALB／c小鼠和Th1型优势的C57BL／6小鼠．显示分子佐剂C3d在不同品系小鼠均使免疫效应从Th1型细胞免疫向Th2型体液免疫偏倚。

B7-1与B7-2对调节人IL-2基因的转录因子NF-κB和AP-1的相同作用

为了解B7共刺激对细胞因子 ,特别是对IL 2mRNA及转录因子NF κB和AP 1的影响 ,探讨B7介导的IL 2调节的分子机制 ,在异基因混合淋巴细胞反应 (MLR)体系中分别或联合加入抗B7 1、抗B7 2单克隆抗体和CTLA 4Ig以阻断B7/CD2 8信号传导 ,通过竞争性PCR定量检测其对IL 2和IL 4mRNA的影响 ,并初步测定IFN γmRNA的改变 ,同时用转染MHCⅡ类分子及联合转染等量B7 1或B7 2的NIH3T3转基因细胞tDR7,tDR7/B7 1和tDR7/B7 2刺激CD2 8+ T细胞 ,通过DNA 蛋白结合实验观察B7对IL 2转录因子NF κB和AP 1的影响。结果表明 :抗B7 2单抗和CTLA 4Ig可明显抑制B7介导的IL 2和IL 4mRNA合成 ,而抗B7 1单抗仅有轻度抑制作用 ,2种或 3种抗体联合应用时抑制作用相加。MLR 1 - 6小时 ,单独tDR7即可诱导NF κB的表达 ,联合转染B7早期对其结合活力无明显影响 ,6小时后tDR7诱导作用减弱 ,B7却可显著延长tDR7的诱导作用至 72小时。tDR7早期同样可诱导AP 1的表达 ,联合转染B7分子在 2 4小时内对其有一定的抑制作用 ,而在反应后期可延长tDR7对AP 1的上调作用 ,B7 1与B7 2间作用未见明显不同。结论 :B7通过减少IL 2mRNA降解和影响基因转录而上调IL 2分泌 ,并可同时影响多种细胞因子分泌 ;在转录水平B7 1与B7 2作用未见明显不同 。