含CpG寡聚脱氧核苷酸对肿瘤抗原肽P815AB的免疫佐剂效应研究

目的 以肿瘤抗原Ｐ８１５ＡＢ抗原肽为模式抗原,研究ＣｐＧ寡聚脱氧核苷酸（ＣｐＧ ＯＤＮ）对该肿瘤抗原表位肽的免疫佐剂效应。方法 用［＾３Ｈ］－ＴｄＲ掺入法研究ＣｐＧ ＯＤＮ体外刺激小鼠脾细胞增殖效应,用ＥＬＩＳＰＯＴ和［＾３Ｈ］－ＴｄＲ释放法检测不同构成形式的疫苗在体诱发特异性ＣＴＬ应答的效应。结果 ＯＤＮ１８２６在体外可刺激小鼠脾细胞显著增殖,经４次免疫,在“肽＋ＯＤＮ１８２６＋ＩＦＡ”组中,４     

MART-1 HLA-A2限制性CTL表位的预测

目的 预测黑色素瘤分化抗原ＭＡＲＴ－１的ＨＬＡ－Ａ２限制性细胞毒性Ｔ淋巴细胞（ＣＴＬ）表位。方法 采用超基序与量化基序多项式方案相结合的办法,对目的抗原ＭＡＲＴ－１的ＨＬＡ－Ａ２限制性ＣＴＬ表位进行预测。结果 预测出了６个九肽表位。结论 两种方法预测结果的一致性较好,所预测出的６个ＭＡＲＴ－１的ＨＬＡ－Ａ２限制性ＣＴＬ表位经后续实验筛选,鉴定后,可望用于新型ＭＡＲＴ－１肿瘤治疗性多肽疫苗的设计研究     

蛋白糖基化与细胞毒性T淋巴细胞应答

糖基化是已知的蛋白最重要的翻译后修饰。已知的蛋白糖基化有多种类型 ,其中最常见的是发生在天冬酰胺 (Ａｓ ｐａｒａｇｉｎｅ ,Ａｓｎ)的Ｎ 糖基化 (Ｎ ｌｉｎｋｅｄｇｌｙｃｏｓｙｌａｔｉｏｎ)和发生在丝氨酸 (Ｓｅｒｉｎｅ ,Ｓｅｒ)和苏氨酸 (Ｔｈｒｅｏｎｉｎｅ ,Ｔｈｒ)的Ｏ 糖基化 (Ｏ ｌｉｎｋｅｄｇｌｙｃｏｓｙｌａｔｉｏｎ)。糖蛋白中糖基的结构大小不一 ,少者仅一个单糖 ,稍复杂的寡糖链可由 12～ 15个单糖残基衍生物组成 ,甚至可多达 2 0～ 30个单糖残基。糖链的结构类型与其在肽链上共价连接的氨基酸种类有关。蛋白 (肽 )糖…     

Novel phenotype associated with in vivo activated CTL precursors

A previously undefined phenotype of CD8(+) cells that appears to represent in vivo activated CTL precursors (CTLP*) has been identified in the spleens of C57Bl/6 mice responding to a P815 tumor allograft. This population was first evident by the transient expression of very high levels of CD28 and CD44 on day 5 of the allograft response and reached maximal levels on days 7 and 8 before declining on day 9. A transient increase in CD69 expression was also observed on these cells on day 5. In contrast, CTL effectors (CTLE), identified by their CD8(+)CD44(hi)CD62LloCD45RBlo phenotype, were not appreciably detected in the spleen until day 8 and reached maximal levels on day 10. Further characterization of CTLP* on day 7 revealed that they represented blasting cells by increased light scatter and also expressed very high levels of CD54 but not CD122, CD152, or CD154. In addition, the cells had already up-regulated CD49d, asialo GM1, CD11a, and CD95L, and down-regulated their expression of CD62L. A small percentage of these cells also expressed CD25. Day 7 CTLP* sorted on the basis of their CD44(xhi) and CD54(xhi) phenotype did not exhibit cytolytic activity in a standard chromium release assay but became cytotoxic when they were cultured in the presence of exogenous murine IL-2 for 5 days. Granzyme B activity, however, was detected in CTLP* on day 7 at levels equivalent to CTLE on day 10. In order to establish a potential precursor relationship between CTLP* and CTLE, mice were treated with various doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a chemical that has been shown to dose-dependently suppress the in vivo generation of CTLE to P815 tumor cells by altering an early stage of CTLP activation. Results indicated that CTLP* were suppressed by TCDD on day 7 to the same degree that CTLE were suppressed on day 10. Importantly, for controls and for all doses of TCDD, there were approximately 12.5 CTLE on day 10 for every CTLP* detected on day 7. These results suggested that TCDD acted identically across all doses to inhibit the early stages of activation of CTLP but did not affect the final stages of differentiation and expansion to CTLE. This interpretation supports the previous observation that TCDD exposure had to occur within the first 3 days of the allograft response in order to induce suppression of CTLE activity. Taken together, these results support the conclusion that in vivo activated CTLP can be identified by their unique expression of very high levels of CD44, CD28, and/or CD54 prior to their full maturation and clonal expansion to functional CTLE.     

Induction of carbohydrate‐specific antibodies in HLA‐DR transgenic mice by a synthetic glycopeptide: a potential anti cancer vaccine for human use

Abstract: Over the last few years, anticancer immunotherapy has emerged as a new exciting area for controlling tumors. In particular, vaccination using synthetic tumor‐associated antigens (TAA), such as carbohydrate antigens hold promise for generating a specific antitumor response by targeting the immune system to cancer cells. However, development of synthetic vaccines for human use is hampered by the extreme polymorphism of human leukocyte‐associated antigens (HLA). In order to stimulate a T‐cell dependent anticarbohydrate response, and to bypass the HLA polymorphism of the human population, we designed and synthesized a glycopeptide vaccine containing a cluster of a carbohydrate TAA B‐cell epitope (Tn antigen: α‐GalNAc‐Ser) covalently linked to peptides corresponding to the Pan DR ‘universal’ T‐helper epitope (PADRE) and to a cytotoxic T lymphocyte (CTL) epitope from the carcinoembryonic antigen (CEA). The immunogenicity of the construct was evaluated in outbred mice as well as in HLA transgenic mice (HLA‐DR1, and HLA‐DR4). A strong T‐cell dependent antibody response specific for the Tn antigen was elicited in both outbred and HLA transgenic mice. The antibodies induced by the glycopeptide construct efficiently recognized a human tumor cell line underlying the biological relevance of the response. The rational design and synthesis of the glycopeptide construct presented herein, together with its efficacy to induce antibodies specific for native tumor carbohydrate antigens, demonstrate the potential of a such synthetic molecule as an anticancer vaccine candidate for human use.     

重组人纽表位肽12生物学活性测定方法的研究

目的：建立适用于重组人纽表位肽12体外质量控制的生物学活性测定方法，用于该制品的生物学活性评价。方法：采用小鼠，比较不同品系、给药浓度、给药周期等条件下应用ELISA方法检测出的小鼠相应抗体水平，确定最佳实验条件，以建立相应的体外活性测定方法。结果：FVB／N转neu基因小鼠(TgN MMTVneu202 Mul，Jackson Lab．，USA)对重组人纽表位肽12的反应存在量——效关系，并确定了最佳测定条件和给药剂量，用抗体阳转百分率作为评价指标，样品测定重复性较好，CV％值为6．7％(H=4)，结果可靠。结论：已建立的FVB／N转neu基因小鼠测定重组人纽表位肽12生物学活性的方法可用于重组人纽表位肽12生物学活性的常规评价。     

用噬菌体肽库筛选SARS病原体的模拟抗原表位

目的筛选SARS病原体的模拟抗原表位。方法以混合SARS患者恢复期血清Ig作为筛选分子，从噬菌体肽库中筛选出能与患者血清Ig结合的模拟抗原表位，并研究其抗原特性。结果得到2个能与SARS患者恢复期血清Ig特异性结合的阳性克隆；DNA测序结果显示这2个模拟抗原表位与SARS抗原无同源性。结论用噬菌体肽库成功筛选得到SARS的模拟表位，为开展用SARS模拟抗原表位探索SARS的防治研究创造了条件。     

旋毛虫53kDa ES抗原蛋白二级结构及B细胞表位预测

目的　分析旋毛虫 5 3kDaES抗原蛋白二级结构及B细胞表位。方法　应用生物信息分析软件DNASTAR和Anthep ro5 .0 ,按照Kyte -Doolittle氨基酸亲水性标准对旋毛虫 5 3kDaES抗原的亲水性基序、二级结构及B细胞表位进行分析预测。结果　在旋毛虫 5 3kDaES抗原蛋白中 ,第 1 9- 2 5、4 0 - 5 1、6 1 - 6 7、99- 1 0 5、1 1 1 - 1 1 9、1 2 6 - 1 34、1 37- 1 5 2、1 79- 1 85、1 91 - 2 0 0、2 1 9- 2 38、2 6 1 - 2 6 7、2 81 - 2 95、31 2 - 32 3、331 - 343、36 7- 372、2 90 - 393位氨基酸残基具有较强的抗原性 ,第 1 9- 2 5、4 0 - 5 1、6 1 -6 7、99- 1 0 5、1 1 1 - 1 1 9、1 2 6 - 1 34、1 37- 1 5 2、1 79- 1 85、1 91 - 2 0 0、2 1 9- 2 38、2 6 1 - 2 6 7、2 81 - 2 95、31 2 - 32 3、331 - 343、36 7- 372、390- 393位氨基酸残基可能是B细胞的表位。结论　对旋毛虫 5 3kDaES抗原蛋白和B细胞表位的分析为研制旋毛虫病新的诊断抗原奠定了基础