Costimulatory Molecule B7-H1 on the Immune Escape of Bladder Cancer and Its Clinical Significance

B7-H1, a recently described member of the B7 family of costimulatory molecules, is thought to be involved in tumor immune escape by inducing T-cell apoptosis. In order to investigate the relationship between B7-H1 and immune escape of bladder cancer, B7-H1 expression in 50 cases of bladder cancer was detected by using immunohistochemical method. Survival curves were con- structed using the Kaplan-Meier method and independent prognostic factors were evaluated using the Cox regression model. Our results showed that the positive rate of B7-H1 immunostaining in normal bladder tissue and bladder cancer was 0 and 72% respectively. The expression of B7-H1 was strongly associated with the pathological grade, clinical stage and recurrence （P〈0.05）. The survival rate was significantly lower in patients with B7-H1 positive group than in those with B7-H1 negative group and multi-variable analysis revealed that B7-H1 could be regarded as an independent factor in evaluating the prognosis of bladder cancer. It is concluded that the expression of B7-H1 is strongly associated with neoplastic progression and prognosis of bladder cancer. The manipulation of B7-H1 may become a beneficial target for immunotherapy in human bladder cancer.

B7.1 MOLECULE EXPRESSION ON TUMOR CELLS IN HUMAN CANCEROUS TISSUSES

The data from in vitro and animal experiment study has showed that costimulaory molecule B7 1 plays an important role in antitumor immunity In the present study, B7 1 expression was observed in 130 samples from a veriety of human malignancies by using immunocytochemistry, in situ hybridization and RT PCR combined with dot hybridization and B7 1 specific Mab and probe The results demonstrated B7 1 expression on tumor cells in 76 cases at both protein and mRNA level Forty two specimens were stained with B7 1 HLA ABC and HLA DR Mab and 26 showed that the three antibodies used all were positive Together with the achievement in tumor antigen study, the present findings imply that in most tumors (if not all) the tumor cells have all the requisite element to elicit anti tumor rejection response, the heterogeneous mechanism for tumor escape from immunosurvillance should be emphasized

穿梭质粒pCEPmB_7的构建及其对小鼠宫颈癌U_(14)细胞体内生长的影

目的：构建可用于肿瘤基因治疗研究的基因表达载体ｐＣＥＰｍＢ７，并研究该质粒转染小鼠宫颈癌Ｕ１４细胞后的体内致瘤性变化。方法：（１）用限制性核酸内切酶ＨｉｎｄⅢ和ＸｈｏⅠ分别对质粒ｐＣＥＰ４和ｐＬＸＳＮｍＢ７进行双酶切，分别回收１０．４ｋｂ的线性ｐＣＥＰ４ＤＮＡ片断和０．９ｋｂ的ｍＢ７ｃＤＮＡ片断，将上述两片断混合，在Ｔ４－ＤＮＡ连接酶的作用下连接，连接液转化受体菌ＴＧ－１，琼脂糖凝胶电泳鉴定连接是否正确；（２）用电穿孔法将ｐＣＥＰｍＢ７转染Ｕ１４细胞，转染后的细胞经ＨｙｇｒｏｍｙｃｉｎＢ（２００μｇ／ｍｌ）选择培养２周后得到选择阳性混合克隆细胞Ｕ１４／ｐＣＥＰｍＢ７，用流式细胞仪检测Ｕ１４／ｐＣＥＰｍＢ７细胞中Ｂ７表达阳性细胞的百分率；（３）将Ｕ１４和Ｕ１４／ｐＣＥＰｍＢ７细胞分别以不同的剂量皮下接种昆明鼠，找出两种细胞的最小成瘤剂量（ｍｉｎｉｍａｌｔｕｍｏｒｉｇｅｎｉｃｄｏｓｅｓ，ＭｉＴＤ）。结果：（１）连接后的新质粒经双酶切和单酶切后，琼脂糖凝胶电泳鉴定连接正确，该质粒即为ｐＣＥＰｍＢ７；（２）流式细胞仪检测结果显示，Ｕ１４细胞的Ｂ７表达阳性率为５．２４％，Ｕ１４／ｐＣＥＰｍＢ７细胞的Ｂ７表达阳性率为４?

B7-1和新型隐球菌DHA1基因嵌合重组质粒的构建

目的 构建包含新型隐球菌细胞免疫主要相关基因———迟发超敏反应抗原基因 (delayed -typehypersen tivityantigen 1,DHA1)与小鼠共刺激分子B 7-1的嵌合重组质粒。方法 设计合成两对寡核苷酸引物 ,用PCR法分别从pUCmB 7-1TM和新型隐球菌重组质粒pcDNA3 -DHA1中特异扩增出编码B 7-1和DHA1的基因片段 ( 92 1bp和 984bp) ,分别用HindⅢ ,EcoRⅠ ,XbaⅠ酶切后 ,逐个定向连接到质粒pcDNA3中 ,转化宿主菌DH -5α ,分别用上述内切酶酶切及DNA测序鉴定重组质粒。结果 酶切鉴定示所切下的片段大小均与预计相符 ,测序结果与文献报道序列及预计结果一致 ,证实符合表达框架。结论 该研究成功构建了新型隐球菌嵌合重组质粒pcDNA3 -B 7-1-DHA1。

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.

B7-H4 Expression and Increased Death Risk of Cancer Patients： A Meta-Analysis

OBJECTIVE The relationship between higher levels of B7-H4 expression and death risk of cancer patients remains to be clarified. In the current study, information from an ordinary scale and those from several outcome scales were combined to make a single estimate. PubMed databases were searched for survival studies on the hazard ratios （HR） of malignant tumors associated with higher B7-H4 expression from 1999 to 2010. METHODS The fixed effect model was used to estimate the combined HRs of six studies. Sensitivity analysis was performed to assess the stability. Publication bias was also estimated. Six studies that meet the inclusion criteria were identified; these studies reported the associations between the higher B7-H4 expression and death risk of cancer patients. RESULTS A 42% increase in death risk was observed in patients with higher B7-H4 expression （HR = 1.42; 95% confidence interval： 1.16-1.72）. Sensitivity analyses found the results robust. The analysis shows that higher levels of B7-H4 expression are associated with the death risk of patients suffering from various cancers. CONCLUSION B7-H4 may be a negative regulatory molecule for antitumor immune responses and a molecular target for tumor immunotherapy.

B7-H3:Another Molecule Marker for Mo-DCs?

Using a newly generated monoclonal antibody （2E6） against human B7-H3, we explored the expression of the molecule on dendritic cells derived from monocytes （Mo-DCs）. Its expression was examined by means of immunostaining and flow cytometric （FCM） analysis. The results showed that B7-H3 was expressed in the course of Mo-DC maturation induced with interleukin 4 （IL-4） and granulocyte/macrophage colony-stimulating factor （GM-CSF）. The expression could be detected at all the stages of Mo-DC differentiation, and remained at a quite stable level. Interestingly, B7-H3 was not expressed by T cells and B cells, even these cells were activated respectively by PHA or PWM. A weak expression could be detected on resting monocytes. These data showed that constitutive expression of B7-H3 at a high level was found on imDCs and mDCs derived from monocytes. Due to no expression on T cells and B cells, we speculate that B7-H3 might be another valuable molecule marker for Mo-DCs.

PD-L1 is increased in the spinal cord and infiltrating lymphocytes in experimental allergic encephalomyelitis

Experimental allergic encephalomyelitis is a mouse model of human multiple sclerosis with similar pathology and pathogenesis. Thl cells play an important role in the pathogenesis of experimental allergic encephalomyelitis. This study determined the potential effect of programmed cell death 1 ligand 1 in the pathogenesis of experimental allergic encephalomyelitis induced by injecting myelin oligodendrocyte glycoprotein, complete Freund＇s adjuvant and Bordetella pertussis toxin into C57BL/6J mice. Experimental allergic encephalomyelitis mice developed disease and showed in- flammatory changes in the central nervous system by hematoxylin-eosin staining of spinal cord pathological sections, demyelination by Luxol fast-blue staining and clinical manifestations. The expression of programmed cell death 1 ligand 1 in mice was detected by immunohistochemistry, flow cytometry and western blot anatysis. The expression of programmed cell death 1 ligand 1 in the spinal cord and splenocytes of mice was significantly increased compared with normal mice. Our findings suggest the involvement of programmed cell death 1 ligand 1 in the pathogenesis of ex- perimental allergic encephalomyelitis and suggest this should be studied in multiple sclerosis.

A dimeric structure of PD-L1: functional units or evolutionary relics?

PD-L1 is a member of the B7 protein family,most of whose members so far were identified as dimers in a solution and crystalline state,either complexed or uncomplexed with their ligand(s).The binding of PD-L1 with its receptor PD-1(CD279)delivers an inhibitory signal regulating the T cell function.Simultaneously with the Garboczi group,we successfully solved another structure of human PD-L1(hPD-L1).Our protein crystallized in the space group of C222_(1) with two hPD-L1 molecules per asymmetric unit.After comparison of reported B7 structures,we have found some intrinsic factors involved in the interaction of these two molecules.Based on these results,we tend to believe this uncomplexed hPD-L1 structure demonstrated its potential dimeric state in solution,althougt it could just be an evolutionary relic,too weak to be detected under present technology,or still a functional unit deserved our attentions.