Vaccination of the Leishmania major susceptible BALB/c mouse. I. The precise selection of peptide determinant influences CD4+ T cell subset expression

BALB/c mice are susceptible to cutaneous lelshmanlasls uponinfection with Leishmania major while C57BL/6 are not. Thereis a major promastigote surface protease (PSP or gp63) whichis available in both native and recomblnant forms, and for whichthe primary amlno acid sequence is known. Immunization withPSP has been shown to offer some protection against challengewith the live organism. Therefore, we attempted to develop apeptide vaccine with PSP peptldes. In the first experiments,recall prollferatlve responses to PSP were measured using aset of 15mer peptldes spanning the entire PSP molecule whichallowed designation of major determinant regions in BALB/c,C57BL/6, and CBA mice. Several of these determinants were promiscuousand shared almost the identical core amlno acid residues inthe different strains. Immunization with major determinant peptldeswas recalled vigorously with L. major soluble antigen as wellas with PSP. The response to peptide was almost entirely T_h1as measured by a localized ELISA assay for single-cell productionof IFN-. A similar assay for IL-5, which overcomes problemsof sensitivity and inhibition by lymphoklnes produced by T_h1cells, Indicates very little production of T_h1 cells even byBALB/c. It was found that if a major responsive peak was examinedby recall with overlapping peptldes, the highest, central peptidegave a mainly Th1 response while the boundary, less efficientpeptldes gave more of a T_h2 response. Possible reasons for thiswere discussed. These results point to the importance of selectingthe exactly appropriate peptide in considering a vacclnogenthat might protect susceptible individuals. Even the choiceof a somewhat immunogenlc peptide within the determinant envelopemight actually exacerbate infection by steering the responsein a T_h2 direction.     

巢蛋白和阶段特异性胚胎抗原-1在大鼠2型星形胶质细胞中的表达

目的 观察1型和2型星形胶质细胞(T1A、T2A)是否表达神经干细胞的标志物、是否具有神经干细胞的特性.方法 取新生大鼠脑皮质,体外培养纯化的O-2A祖细胞、T1A和T2A,应用激光共焦双重免疫荧光标记技术检测巢蛋白和阶段特异性胚胎抗原-1(SSEA-1)的表达;观察O-2A祖细胞、 T1A和T2A在碱性成纤维生长因子(bFGF)和表皮生长因子(EGF)的培养液中生长方式的改变.结果 巢蛋白在O-2A祖细胞和T2A中表达,T1A不表达;SSEA-1仅在T2A中表达.在干细胞培养基中培养10d,T2A形成能增殖和连续传代的细胞球,细胞球巢蛋白标记阳性,贴壁后分化细胞具有神经元、星形胶质细胞和少突胶质细胞样形态;但相同培养条件下的O-2A祖细胞和T1A生长方式无改变.结论 巢蛋白和SSEA-1在两型星形胶质细胞中的表达存在差异,T2A具有神经干细胞的某些生物学特性.     

DAF与CD3协同刺激人外周血T细胞活化的实验研究

目的：探讨人促衰变加速因子（decay-accelerating factor,DAF)作为共刺激分子参与T细胞活化的作用机制。方法：观察3株针对DAF不同SCR的单抗单独使用或者与抗人CD3单抗联合使用时，对人外周血T细胞增殖、IL－2分泌以及胞浆Ca^2 水平的影响。结果：所用3株抗人DAF单抗不能活化T细胞，而抗人DAF单抗与抗人CD3单抗可以协同刺激T细胞增殖，促进IL－2分泌以及提高胞浆Ca^2 水平。结论：抗人DAF单抗与抗人CD3单抗可协同刺激人外周血T细胞活化。     

Thymic sarcomatoid carcinoma with skeletal muscle differentiation: report of two cases, one with cytogenetic analysis

AIMS: Malignant thymic tumour histologically resembling a soft tissue sarcoma is extremely rare and defined as sarcomatoid carcinoma in the recent World Health Organization (WHO) classification. We report two such cases in which the tumour cells showed a prominent rhabdomyoblastic differentiation and analyse whether these tumours retain an epithelial nature at least in part. METHODS AND RESULTS: One tumour occurred in a 51-year-old man (Case 1) and the other in a 40-year-old woman (Case 2). Microscopically, both tumours consisted essentially of two types of tumour cells: spindle and large round cells, with no apparent epithelial components. Osteosarcomatous small foci were also found in Case 2. Immunohistochemically, desmin and muscle-specific actin were positive in the majority of both types of tumour cells, whereas myogenin was predominant in the spindle cells and myoglobin in the large round cells. Some of both types of cells expressed cytokeratin with co-expression of myoglobin in the large round cells, but with no myogenin in the spindle cells. Some cytokeratin-positive spindle cells were also negative for desmin. Ultrastructural examination of a recurrent tumour in Case 2 revealed some epithelial features among the spindle cells. Cytogenetic study of the same tumour showed a complex abnormality including der(16)t(1;16)(q12;q12.1), an identical pattern previously reported in a case of thymic squamous cell carcinoma. CONCLUSIONS: The findings support the definition in the WHO classification of sarcomatoid carcinoma that includes purely sarcomatous tumour as in the present cases. Occurrence of this type of tumour may indicate a relationship between thymic epithelial cells and myoid cells and/or a potential for divergent differentiation in thymic epithelial tumours.     

Shared amino acid sequences in the NDβN and Nα regions of the T cell receptors of tumor-infiltrating lymphocytes within malignant glioma

The purpose of this study was to assess the V-(D)-J junctional region of the T cell receptor (TCR), the CDR3 region, which is responsible for glioma-specific antigen contact in αβ TCR-mediated recognition. We sequenced the TCR α and β chians of Vα7, and Vβ13.1 cDNA derived from tumor-infiltrating lymphocytes (TIL) of 12 glioma patients and also the corresponding clones from the patients' peripheral blood lymphocytes (PBL). A shared Vβ13.1 DJ sequence of the CDR3 region, NDβN, was demonstrated in 49 of 66 Vβ13.1⁺ clones (74.2 %) from the glioma TIL, whereas only 4 of 33 clones (12.1 %) were observed in the Vβ13.1⁺ clones from the PBL (p < 0.001). A common VDJ sequence, FCASS (Vβ13.1)-YRLPWGTSDS (NDβN)-GELFF(Jβ2.2), was observed not only in the gliomas from each patient, but also among all the patients with a preference for Vβ13.1. In contrast, the amino acid sequences of the Vβ13.1⁺ PBL clones were diverse and random. Next, we sequenced subclones from other Vβ subfamilies randomly selected to compare their VDJ region rearrangements (Vβ3 and Vβ5.1). In contrast to Vβ13.1, the amino acid sequences of these junctional regions were completely different in these subclones. The V-J junctional region of the α chain is dominated by a few clones in some patients, and no shared amino acid sequences were detected in the TCR Vα junctional region. However, in the Nα region of the Vα7-bearing TIL clones, arginine was used in 27 of 44 clones (61.4%) compared to only 3 of 12 clones from the PBL (p < 0.05). These results are consistent with the hypothesis that a clonal expansion/accumulation of glioma lineage-specific T cells occurred in vivo at the tumor site and that these T cells may be recognizing glioma-specific antigens.     

免疫耐受机制研究进展

免疫耐受是机体免疫系统在接触某种抗原后所产生的对该抗原特异性免疫无应答状态,是免疫应答的一种特殊形式,免疫应答的复杂性决定了免疫耐受诱导的复杂性和困难性.随着免疫学的发展,人们对免疫耐受产生机制有了较多的认识.本文对免疫耐受与细胞凋亡、调节性T细胞及树突状细胞的研究进展进行综述.     

Vesicular monoamine transporter 2 as a marker of gastric enterochromaffin-like cell tumors

The vesicular monoamine transporter 2 (VMAT2) facilitates the ATP-dependent accumulation of biogenic amine inside the secretory granules of endocrine cells and neurons and was demonstrated in the histamine-producing enterochromaffin-like (ECL) cells of the stomach. In the present investigation, VMAT2 immunohistochemistry was tested in 85 endocrine tumors, of which 60 were well differentiated gastrointestinal and pancreatic growths, 5 poorly differentiated (neuro)endocrine carcinomas (PDEC) and 1 mixed PDEC/ECL cell carcinoma of the stomach, 12 pheochromocytomas/paragangliomas, 3 adrenocortical lesions, 2 parathyroid and 2 lung neuroendocrine tumors. Extensive and intense VMAT2 immunoreactivity was observed in 16 of 16 gastric ECL cell tumors, 6 of 6 adrenal pheochromocytomas, 2 of 2 chromaffin paragangliomas and in 3 of the 4 carotid body paragangliomas investigated. Rare VMAT2-positive cells were observed in 12 of 21 intestinal enterochromaffin (EC) cell tumors, in 9 of 11 pancreatic neuroendocrine tumors, and in the mixed PDEC/ ECL cell carcinoma of the stomach (differentiated cells only). No VMAT2 immunoreactivity was observed in five gastrin, four somatostatin and three enteroglucagon/peptideYY tumors of the gastrointestinal tract, in six gastric PDECs, in three adrenocortical growths, and two parathyroid and two lung neuroendocrine tumors. These data support VMAT2 immunohistochemistry as being a useful tool for the diagnosis of gastric ECL cell tumors, separating them from all other endocrine tumors arising in the gastroduodenal area i.e., gastrin, somatostatin, EC cell and PDEC tumors, all of which proved essentially negative. Received: 28 June 1999 / Accepted: 20 October 1999     

雪旺氏细胞内NGF含量的定量测定方法研究

目的：建立一套测定单个细胞内蛋白含量的新方法。方法：纯化培养乳鼠雪旺氏细胞，施加实验因素，通过间接免疫荧光法标记细胞内ＮＧＦ蛋白，而后用流式细胞仪（适用于细胞悬液样品）或粘附细胞仪（适用于粘附细胞样品）进行测定。结果：流式细胞仪及粘附细胞仪均可得到每一实验组的精确测定结果，并能进行统计分析，提供统计图表和各种数据。结论：应用流式细胞仪或粘附细胞仪可对单个雪旺氏细胞内的ＮＧＦ含量进行定量研究