兔抗人CXCR3-B分子N端多肽多克隆抗体的制备与初步应用

目的:获得兔抗人CXCR3-B分子N端第1~19、第17~35及第33~51个氨基酸多肽的多克隆抗体,并对多克隆抗体进行初步鉴定和应用。方法:应用Fmoc法化学合成CXCR3-B分子N端第1~19、第17~35及第33~51个氨基酸多肽,经C18的RP-HPLC纯化后,通过高碘酸钠法将纯化的CXCR3-B分子的多肽与KLH交联;皮下注射抗原免疫日本大耳白兔,加强免疫得到抗血清,应用蛋白G纯化获得多克隆抗体。对纯化的抗体进行ELISA、免疫印迹、免疫组化等初步鉴定和应用。结果:分别化学合成CXCR3-B分子N端第1~19、第17~35及第33~51个氨基酸多肽,纯化后多肽纯度分别为98%、88.54%及80%,达到免疫用抗原标准。多肽与KLH交联,用于免疫动物。经纯化后的抗体效价分别为1∶32000(0.1mg/L),1∶4000(3mg/L)和1∶1000(10mg/L)。3种多肽的抗体可特异识别胎心组织中相对分子质量(Mr)约为50的CXCR3-B分子,相应抗原定位于3种多肽的抗体可特异识别胎心组织中的血管内皮细胞。结论:所制备的多克隆抗体可应用于ELISA、免疫印迹和免疫组化等实验,为确定CXCR3-B分子的组织及细胞分布和定位、寻找CXCR3-B相互作用的分子提供了有力的工具。目的:获得兔抗人CXCR3-B分子N端第1~19、第17~35及第33~51个氨基酸多肽的多克隆抗体,并对多克隆抗体进行初步鉴定和应用。方法:应用Fmoc法化学合成CXCR3-B分子N端第1~19、第17~35及第33~51个氨基酸多肽,经C18的RP-HPLC纯化后,通过高碘酸钠法将纯化的CXCR3-B分子的多肽与KLH交联;皮下注射抗原免疫日本大耳白兔,加强免疫得到抗血清,应用蛋白G纯化获得多克隆抗体。对纯化的抗体进行ELISA、免疫印迹、免疫组化等初步鉴定和应用。结果:分别化学合成CXCR3-B分子N端第1~19、第17~35及第33~51个氨基酸多肽,纯化后多肽纯度分别为98%、88.54%及80%,达到免疫用抗原标准。多肽与KLH交联,用于免疫动物。经纯化后的抗体效价分别为1∶32000(0.1mg/L),1∶4000(3mg/L)和1∶1000(10mg/L)。3种多肽的抗体可特异识别胎心组织中相对分子质量(Mr)约为50的CXCR3-B分子,相应抗原定位于3种多肽的抗体可特异识别胎心组织中的血管内皮细胞。结论:所制备的多克隆抗体可应用于ELISA、免疫印迹和免疫组化等实验,为确定CXCR3-B分子的组织及细胞分布和定位、寻找CXCR3-B相互作用的分子提供了有力的工具。     

小鼠抗人C5aR短肽（9—30）单克隆抗体制备及鉴定

目的获得有生物功能的小鼠抗人 C5 a R短肽单克隆抗体。方法对 C5 a受体 (CD88)二级结构和 B细胞表位进行分析研究 ,采用 Fmoc方案固相合成 C5 a R N-端第 9～ 30位氨基酸残基的 2 2 -肽 ,以此为抗原免疫 Balb/ c小鼠。结果建立了 1株小鼠抗人 C5 a R短肽杂交瘤细胞系 E3,其平均染色体数目为 10 2条 ,所分泌抗体为 Ig G1,κ型 ,腹水抗体效价为 1×10 - 4 ～ 1× 10 - 6 ,可识别 U 937、人脐静脉内皮细胞 (VEC)和 PMN等表达 C5 a R细胞。 E3单抗的亲和常数 Ka=2 .5× 10 5 ,其结合表位为 C5 a R第 15～ 2 1位氨基酸基序 D1 5 DKDTL2 0 D。结论 B细胞表位多肽具有免疫原性 ,可制作单克隆抗体 ,为 C5 a-C5 a R相互作用的研究以及 AL I、ARDS等 C5 a相关疾病的研究提供实验材料。     

抗菌抗内毒素多肽小鼠体内拮抗内毒素作用的研究

目的：观察抗菌抗内毒素多肽对内毒素(LPS)攻击小鼠死亡的保护作用。方法：以一个LD50的LPS(20mg/kg)静脉注射攻击小鼠,分别于LPS攻击后20S内静脉注射不同剂量的抗菌抗内毒素多肽;于LPS攻击前及攻击后不同时间内分别静脉注射5mg/kg和10mg／kg的抗菌抗内毒素多肽,以观察抗菌抗内毒素肽对LPS攻击所致小鼠死亡的保护作用、抗菌抗内毒素肽对LPS攻击小鼠死亡保护作用的时效关系及抗菌抗内毒素肽对LPS攻击小鼠死亡的预防作用。     

天花粉毒蛋白免疫毒素对黑色素瘤细胞的体外抑制

用单链致核糖体失活蛋白天花粉蛋白(TCS)和抗人黑色素瘤单抗(Ng76)构建了免疫毒素(Ng76—TCS),它对体外培养的人黑色素瘤细胞M21具有强烈的抑制活性,IC_(50)为5.6×10~(-10)mol/L,其毒性比游离的TCS 和Ng76的混合物高2000倍,比TCS 与正常小鼠免疫球蛋白的复合物(NIgG—TCS)高160倍,而它对非靶细胞HeLa 的IC_(50)为7.0×10~(-?)mol/L,毒性较靶细胞低125倍。结果表明,免疫毒素TCS—Ng76对体外培养的黑色素瘤细胞有很强的选择性杀伤作用.     

华游蛇PLIγ模拟肽的设计与活性验证

目的设计华游蛇血清PLIγ模拟肽并研究其对PLA2抑制作用。方法用RT-PCR方法克隆华游蛇PLIγ基因并测序进行序列比对。基于华游蛇PLIγ序列设计一个长度为19个氨基酸的多肽。利用Auto dock分子对接分析该19肽与sPLA2相互作用,运用琼脂糖平板法验证其对sPLA2的抑制效果,并通过小鼠实验进一步检测其抗sPLA2出血毒性。利用LPS诱导小鼠Raw264.7细胞炎性反应,检测细胞花生四烯酸含量以评价19肽对细胞sPLA2酶活性抑制作用。结果设计得到的华游蛇PLIγ模拟肽序列为PGLPLSYPNGGGGSVAFRS。该19肽较好地抑制蛇毒PLA2酶活性和出血毒性,并可以显著减少LPS诱导Raw264.7炎性细胞中花生四烯酸含量,IC50为86.3μmol/L。结论本文设计的华游蛇PLIγ模拟肽,具备了天然PLIγ的活性,具有抗细胞炎性反应和蛇毒出血毒作用。     

神经内分泌多肽7B2与T淋巴细胞间的关系

本文证实神经内分泌多肽7B2(150个氨基酸)当其浓度在300～500pg/ml 可抑制12份猪胸腺细胞或10份人外周血分离的淋巴细胞的活性T 细胞花环值。人工合成的氨基酸序列为23—39 7B2多肽片段也具有同样的抑制作用,但氨基酸序列为117—128 7B2多肽片段和氨基酸序列为141—150多肽片段无此作用;人和猪胸腺细胞经与兔抗7B2多肽片段(23—39)抗体温育,然后再以FITC 标记羊抗兔IgG(第二抗体)作用,采用免疫荧光显微镜和流式细胞仪分析,可观察到50%以上的胸腺细胞表面存在着光亮的荧光斑点。此种荧光染色可因0.5%胰蛋白酶预先处理细胞而消失,但可抵抗45C5分钟处理,提示此种荧光斑点是由于7B2与胸腺细胞表面蛋白质相互作用所致。     

β_2糖蛋白1多肽抗体的制备与应用

目的利用人工合成β2糖蛋白1(β2GP1)多肽制备针对人源、鼠源β2GP1的多克隆抗体,并鉴定抗体的特异性及致病性。方法应用Fmoc法化学合成β2GP1 N端第35~51位氨基酸的多肽,将合成后的多肽与钥孔血蓝蛋白(KLH)偶联,免疫新西兰大白兔制备抗血清,蛋白G纯化得到抗β2GP1多肽抗体,利用ELISA和Western blot法鉴定其效价和特异性。体外实验使用抗β2GP1多肽抗体/β2GP1复合物刺激C3H/He N小鼠腹腔巨噬细胞一定时间,收集细胞总RNA和总蛋白,实时定量PCR、Western blot法分别检测细胞组织因子(TF)mRNA和蛋白表达;Western blot法检测细胞p38、磷酸化p38、核因子κB p65(NF-κB p65)及磷酸化NF-κB p65表达情况;体内实验采用C3H/He N小鼠腹腔注射抗β2GP1多肽抗体建立实验性抗磷脂综合征(EAPS)模型,检测小鼠外周血抗β2GP1抗体滴度及部分凝血活酶时间(APTT)。结果化学合成β2GP1多肽的纯度为94%,达到免疫用抗原标准。偶联KLH后免疫新西兰大白兔,其抗血清效价大于1∶32 000。Western blot结果显示抗β2GP1多肽抗体可特异性识别人源和鼠源β2GP1条带,双抗夹心ELISA检测表明该多肽抗体可与β2GP1隐蔽表位特异性结合。体外实验显示抗β2GP1多肽抗体/β2GP1复合物能够增强小鼠腹腔巨噬细胞p38、NF-κB p65磷酸化,诱导细胞TF mRNA及蛋白表达。体内实验成功建立EAPS小鼠模型,小鼠外周血抗β2GP1抗体滴度大于1∶3200,APTT明显缩短。结论所制备的抗β2GP1多肽抗体可识别人源和鼠源β2GP1分子,能与β2GP1隐蔽抗原特异性结合且具有致病效应。     

人LAK细胞抗菌多肽基因重组及其结构与功能的研究

目的和方法 :本研究采用一系列微量肽分离纯化技术及微量抗菌活性检测方法 ,从人LAK细胞中分离纯化获得一个对大肠杆菌和绿脓杆菌具有抗菌作用的活性分子 ,所测得的N -端 10个氨基酸序列为脯氨酸 (Pro ,P)、赖氨酸 (Lys,K)、精氨酸(Arg ,R)、赖氨酸 (Lys ,K)、丙氨酸 (Ala ,A)、天冬氨酸 (Asp ,D)、甘氨酸 (Gly ,G)、谷氨酸 (GluE)、丙氨酸 (Ala ,A)、赖氨酸 (Lys ,K)。应用RACE -PCR技术扩增其cDNA ,获得一个全长编码序列 ,mRNA数据库的检索显示HLP - 3P2 1与HMG - 17分子相同 ,但国内外尚无HMG - 17抗菌功能的报道。为…     

RGD多肽(224)、蛇毒和17β-雌二醇对破骨样细胞骨吸收活性的影响

目的　探讨RGD多肽 (2 2 4 )和ED 71对骨吸收的作用。　方法　将RGD多肽 (2 2 4 )、蛇毒提取物(Ech)和 17β 雌二醇 (E2 )分别加入破骨样细胞 (OLC)与象牙骨片共培养体系中。　结果　 10 - 7mol LRGD、Ech及E2均有不同程度使骨吸收陷窝数目减少 ,面积缩小和空洞减少的作用。　结论　RGD 多肽 (2 2 4 )Ech和E2 能不同程度抑制OLC骨吸收活性。     

研究C5a反义肽的理论价值和实际意义

存在于蛋白质中某些相邻片段的微小表面之间的疏水作用力可以稳定天然蛋白质的构象 ,它也是小肽与蛋白质特异性结合过程中的主要驱动力。在正义DNA链上编码亲水性氨基酸残基的密码子 ,其同一阅读框内所对应的反义DNA链上大多会编码疏水性氨基酸 ,反之亦然。Mekler Biro Blalock模型 (MBB)认为正义 反义肽的相互作用是根据Kyte&Doolittle的疏水 亲水复合指数的疏水性反互补机制 (hydrophobicanticomplementarity)而实现的。在离体和在体实验中 ,都存在有正义 反义多肽发生相互作用的现象 ,如 :一氧化氮合成酶 (nitricoxidesynthase ,NOS)的钙调蛋白结构域的反义肽 ,0 .0 1～ 1 .0mmol L的浓度就能够抑制结构型和诱导型NOS ,其IC(50 )值分别为 98mmol L和 56mmol L ;内皮素受体 (endothelinreceptor ,ETR A)一个片段的反义肽ETR P1 f可抑制内皮素诱导的颈动脉和股动脉血管收缩 ,1 .0 μmol LETR P f反义肽将明显抑制ET 1的功能活性。 0 .2 5μmol L的人C5a反义肽可以保护小鼠免受rh C5a的攻击 ,单独使用rh C5a会使小鼠发生中毒反应 ,血细胞减少     

Virulence of Listeria spp.: course of infection in resistant and susceptible mice

The virulence of representative strains of the five species of Listeria monocytogenes sensu lato was compared in C57BL/6 and BALB/c mice in terms of LD50 values and of bacterial growth kinetics and histological changes in mouse livers. L. monocytogenes sensu stricto and L. ivanovii showed relatively low LD50 values and much bacterial growth for 2-3 days before viable counts declined. Histological changes in L. ivanovii infection resembled those caused by L. monocytogenes, with early development of neutrophil-rich micro-abscesses and hepatocyte necrosis followed by macrophage infiltration and formation of granulomas. By contrast, L. innocua, L. welshimeri and L. seeligeri were almost entirely avirulent as shown by high LD50 values, early elimination of viable bacteria and no evidence of growth. Histological changes consisted only of slight, transient infiltration of the liver with neutrophils. Both groups of bacteria were seen infrequently in Kupffer cells early in infection, but only the highly virulent species appeared to replicate. LD50 values for L. monocytogenes and L. ivanovii were (10-20)-fold greater, and for the less virulent bacteria at least two-fold greater, in C57BL/6 than in BALB/c mice. This difference in host susceptibility was not reflected in detectable histological differences between the two mouse strains.     

Biological activity of chemically synthesized core sugar linked lipid A analog, heptose-(alpha 1----5)-2-keto-3-deoxyoctonic acid-(alpha 2----6)-2,3-diacyloxyacylglucosamine-4-phosphate.

The mitogenicity, lethal toxicity and antitumor activity against Meth A fibrosarcoma and the induction of tumor necrosis factor (TNF) of chemically synthesized compounds designated as A-103, 2,3-diacyloxyacylglucosamine-4-phosphate (GlcN-4-P), and A-503), heptose-(alpha 1----5)-2-keto-3-deoxyoctonic acid (KDO)-linked GlcN-4-P (A-103), were determined. Compound A-103 induced significant incorporation of [3H]thymidine of C57BL/6 mice at 25-100 micrograms/ml, and A-503 showed the highest incorporation of [3H]thymidine at 100 micrograms/ml. The mitogenicity of A-503 exhibited a lower activity than of A-103. Compound A-503 showed no lethality at high doses of 25 and 50 micrograms/mouse in C57BL/6 mice loaded with D-galactosamine, whereas A-103 caused the death of one of three mice at a dose of 50 micrograms/mouse. Although, the two compounds with or without muramyl dipeptide showed weak antitumor activity against Meth A fibrosarcoma in BALB/c mice, but there were no remarkable differences between the compounds on antitumor activity. Peritoneal macrophages, stimulated with A-103 or A-503 caused no production of TNF which induces L929 cell lysis in vitro. These findings indicate that the addition of heptose and KDO to GlcN-4-P seems not to affect mitogenic activity, lethal toxicity, antitumor activity and TNF-production of the GlcN-4-P compound (A-103).     

Characterization of oral Yersinia enterocolitica infection in three different strains of inbred mice

Several studies have highlighted differences in the resistances of various mouse strains to intravenous (i.v.) infection with Yersinia enterocolitica. In particular, differences in resistance and immunological response between BALB/c and C57BL/6 mouse strains have been determined. Following i.v infection, C57BL/6 mice are more resistant to Y. enterocolitica than are BALB/c mice. However, because Y. enterocolitica is typically a food-borne pathogen, the oral route of infection more accurately reflects the natural route of infection. Therefore, it was of interest to ascertain if the differences in resistance between mouse strains observed for an i.v. infection can be recapitulated following an oral infection. C57BL/6j, BALB/cj, and 129X1/Svj mouse strains presented no differences in 50% lethal dose (LD(50)) following oral infection with Y. enterocolitica. Subsequent analysis of cytokine levels, bacterial colonization and immune cell populations following oral infection confirmed characteristics previously described following i.v. Y. enterocolitica infection. All tissues analyzed from each mouse strain demonstrated a polarized Th1 cytokine profile and inflammatory cell influx throughout a 7-day course of infection. This immune response was present in all tissues and increased as bacterial colonization progressed. The lack of a differing LD(50) phenotype and common trends in immunological response among the three mouse strains tested suggests that oral infection is a useful model for studying the host response to Y. enterocolitica infection.     

谷氨酸诱导新生小鼠皮层神经细胞损伤体外模型的建立

目的:本实验建立谷氨酸(Glu)诱导神经细胞的损伤模型,观察Glu对神经细胞的兴奋毒性作用,探索Glu诱导神经细胞损伤模型的最佳浓度,为进一步研究Glu与神经系统疾病之间的关系奠定基础。方法:原代培养新生小鼠皮层神经细胞,鉴定成功后,采用不同浓度的Glu诱导神经细胞损伤,酶标仪测定乳酸脱氢酶(LDH)漏出率,用流式细胞仪检测细胞凋亡率和死亡率,以获得Glu诱导神经细胞损伤模型的最佳浓度。结果:成功培养新生小鼠皮层神经细胞,Glu诱导神经细胞损伤呈浓度依赖性。实验中Glu浓度=100μmol/L,细胞凋亡率(%)为44.34±6.19而细胞死亡率仅为4.6±0.90说明在Glu浓度=100μmol/L诱导神经细胞,能得到较大的凋亡率和较小的死亡率。结论:成功建立Glu诱导的神经细胞损伤模型,验证Glu=100μmol/L为诱导神经凋亡的最佳浓度。     

Increase in Serum Concentration of FAS Ligand as a Possible Mechanism for Antithyroid Cytotoxicity during Autoimmune Thyroid Diseases

We studied the effect of combination treatment with T-activin and vitamin E on acute toxicity and antitumor activity of cyclophosphamide in mice. Combined administration of these preparations 1.37-fold increased the maximum permissible dose of cyclophosphamide without affecting its LD(50)and delayed mouse death from cyclophosphamide toxicity. Most mice died only 3 days after combination treatment with the test preparations and cyclophosphamide in doses of LD(16)-LD(84). The second peak of death from hematologic toxicity of cyclophosphamide was absent under these conditions. T-activin and vitamin E did not abolish the antitumor effect of cyclophosphamide on mice with subcutaneously implanted P-388 lympholeukemia. Tumor growth was suppressed by 100%.     

Yersinia enterocolitica infection in resistant and susceptible strains of mice.

We investigated natural resistance in mice to Yersinia enterocolitica, an enteric bacterial pathogen of humans, with a view to determine host genetic factors that are important in resistance. Most mouse strains studied (C3H/HeN, BALB/c, BALB.B, DBA/2, A, Swiss, and SWR) were highly susceptible to infection (50% lethal dose [LD50], 2 X 10(2) to 6 X 10(2) Y. enterocolitica administered intravenously [i.v.]). In contrast, C57BL/6 mice were highly resistant (LD50, 2 X 10(5) Y. enterocolitica administered i.v.). Resistance to i.v. Yersinia infection did not appear to be related to the Ity locus (which codes for resistance to Salmonella typhimurium and other pathogens) because Ityr mice (C3H/HeN, DBA/2, A, and SWR) were more susceptible to Y. enterocolitica than were Itys (C57BL/6) mice. In addition, because BALB.B mice (congenic to C57BL/6 mice at the H-2 locus) were susceptible, resistance was probably not H-2 linked. BALB/c X C57BL/6 F1 mice were intermediate in their resistance to Y. enterocolitica infection (LD50, 3 X 10(4) organisms administered i.v.), suggesting that resistance to Y. enterocolitica depends on a gene dosage affect or a resistance gene(s) interaction between susceptible and resistant parents. Further studies with C57BL/6 and BALB/c mice as prototype resistant and susceptible strains were undertaken. A time course study of Y. enterocolitica growth in various organs following i.v. infection revealed no strain difference in bacterial growth during the first 48 h of infection. Thereafter, however, C57BL/6 mice were capable of restricting Y. enterocolitica growth in all tissues (liver, lung, spleen, kidneys), whereas extensive bacterial proliferation occurred in BALB/c mice tissues. BALB/c mice were also more susceptible to oral Y. enterocolitica infection than were C57BL/6 mice, demonstrating increased mortality and greater numbers of bacteria in the Peyer's patches. Finally, whereas thymus-bearing C57BL/6 X BALB/c F1 mice were resistant to infection, athymic (nude) C57BL/6 X BALB/c F1 mice were susceptible. These studies provide a model to investigate natural immunity to enteric pathogens at mucosal surfaces, as well as provide the basis for clarifying the role of host genotype in Y. enterocolitica resistance.     

单克隆抗体亲和层析纯化绿脓杆菌外毒素A

本文用间接ELISA法测定了本室研制的4株绿脓杆菌外毒素A单克隆抗体的相对亲和力。结果表明,它们的相对亲和力可排列为23B9>14F10>24B5>23C12。选用23B9制备免疫吸附柱,用于亲和层析纯化绿脓杆菌外毒素A。洗脱液用pH11.5,0.05 mol的二乙胺溶液,回收率为上柱样品的72.4％。所获纯化毒素对BALB/c小鼠的LD50为137ng,在SDS聚丙烯酰胺凝胶电冰中为一条带,保持有良好的毒性及免疫学活性。     

Enantioselective hydrolysis of dipeptide amino acid esters by di- and tripeptide-type L-histidine derivatives in a bilayer vesicular system

The enantioselective hydrolysis of dipeptide-type amino acid esters (Z-(L )-Ala-(L or D )-Ala-PNP ( 5a ), Z-(L )-Ala-(L or D )-Leu-PNP ( 5b ), and Z-(L )-Ala-(L or D )-Phe-PNP ( 5c )) by di- or tri-peptide nucleophiles (Z-(L )-Leu-(L )-His ( 2a ), Z-(L )-Phe-(L )-His ( 2b ), and Z-(L )-Leu-(L )-His ( 3 )) in the bilayer vesicular aggregates of didodecyldimethylammonium bromide ( 6 ) resulted in the enantiomer rate ratio of LL /LD = 1, 1 to 18, the value of which was considerably higher than that (L /D = 1,0 to 4,6) in the hydrolysis of Z-(L or D )-Ala-PNP ( 4a ), Z-(L or D )-Leu-PNP ( 4b ), and Z-(L or D )-Phe-PNP ( 4c ) by the identical vesicular system and that (L /D = 0,7 to 3,1) in the hydrolysis of the dipeptide substrates 5a – c by Z-(L )-His ( 1 ) and 6 . The high enantioselectivity (LL /LD = 18) in the hydrolysis of 5c by the system of 2a and 6 was enhanced to be LL /LD = 36 by lowering the temperature from 25 to 10°C.     

Endogenous dipeptide cycloprolylglycine shows selective anxiolytic activity in animals with manifest fear reaction

Experiments on two mouse strains with opposite reactions to emotional stress showed selectivity of the anxiolytic effect of endogenous dipeptide cycloprolylglycine. In the open field test cycloprolylglycine (0.01-0.10 mg/kg intraperitoneally) dose-dependently (1.8-2.1-fold) increased motor activity of BALB/c mice with manifest fear reaction and had no effect on C57Bl/6 mice with active behavior. The content of endogenous cycloprolylglycine in mouse brain correlated with the type of emotional stress reaction: its content in the brain of C57Bl/6 mice 1.5 times surpassed that in BALB/c mice. It is concluded that cycloprolylglycine is involved in the endogenous regulation of fear reaction.