妊娠相关血浆蛋白-A单克隆抗体的制备和初步鉴定

目的制备娠相关血浆蛋白-A（PAPP-A）单克隆抗体（McAb）。方法利用PAPP-A抗原免疫Balb／c小鼠，应用杂交瘤技术将免疫小鼠的脾细胞与小鼠骨髓瘤细胞（SP2／0）融合，间接ELISA方法对细胞培养上清检测、筛选，建立分泌PAPP—A单克隆抗体的杂交瘤细胞株，扩人培养后，Balb／c小鼠腹腔注射杂交瘤细胞株，产生腹水后，对腹水进行收集、纯化、签定．结果筛选出稳定分泌PAPP—AMcAb的杂交瘤细胞株，Western—blot分析证实McAb与PAPP—A有较高的特异性及敏感性。结论本实验成功制备了抗PAPP—A特异性的McAb，可用于PAPP—A免疫检测方法的建立。     

合成纳米铝佐剂及其对乙型肝炎、狂犬病毒辅佐效应的研究

目的 通过自制纳米铝佐剂,研究其对乙型肝炎病毒和狂犬病毒的体液免疫应答。方法 在25℃条件下,采用微乳液法制备纳米铝佐剂。与常规铝佐剂比较,经皮下注射豚鼠和Balb／c小鼠后,于不同的时间测定血清中特异性酥;抗体的效价。结果 透射电镜（TEM）和差式量热扫描（DSC）,可知产物为平均粒径约为72．62nm,近球形的A1（OH）3结晶颗粒。纳米铝佐剂辅佐的HBsAg,在免疫Balb／c小鼠后第1周和第2周的血清抗体滴度明显高于常规铝佐剂组（P〈0．01;P〈0．05）;纳米铝佐剂辅佐的狂犬疫苗,其特异性IgG抗体效价高于常规铝佐剂组,并且在免疫后的第7天,抗体就呈现出阳性（P〈0．05）。结论 纳米铝佐剂在诱导HBsAg和Rabies疫苗体液免疫应答的早期优于目前的常规铝佐剂,能够快速地激活和提高Balb／c小鼠和豚鼠的免疫应答和应答水平。     

HCV多表位基因重组BCG的筛选及对其诱导的免疫应答研究

目的将丙型肝炎病毒（HCV）多表位基因的穿梭质粒pDE22-CtEm电转化BCG，筛选重组BCG（rBCG），免疫BALB／c小鼠，研究其诱导的免疫应答。方法培养并制备BCG感受态，将重组穿梭质粒pDE22-CtEm电转化BCG，筛选rBCG。rBCG免疫小鼠，同时进行基因免疫，测定血清中特异性抗体，分离小鼠脾淋巴细胞，体外测定淋巴细胞刺激指数、IFN-γ和进行CTL杀伤实验，观察rBCG在小鼠体内诱导的体液和细胞免疫应答。结果筛选出HCV多表位基因rBCG，免疫小鼠后在小鼠体内诱导出特异性的体液和细胞免疫应答，免疫应答水平均高于重组的基因免疫。结论构建的HCV多表位抗原rBCG活疫苗优于基因疫苗。     

树突状细胞疫苗联合Imiquimod对小鼠乳腺肿瘤的治疗作用

目的观察局部应用TLR7激动剂Imiquimod对树突状细胞(dendritic cell,DC)疫苗治疗小鼠肿瘤的影响,寻找增强DC肿瘤疫苗疗效的佐剂。方法培养乳腺肿瘤细胞株EMT-6,反复冻融法制备肿瘤相关抗原,小鼠乳腺区注射EMT-6制备荷瘤动物模型。用含重组小鼠GM-CSF和IL-4的培养液扩增培养Balb/c小鼠来源的BM-DC,负载肿瘤相关抗原(Ag-DC)后进行肿瘤治疗实验。荷瘤小鼠分别采用Imiquimod局部涂抹、Ag-DC皮内注射、Imiquimod联合Ag-DC进行治疗,检测不同处理方法小鼠的肿瘤生长情况。采用上述方案免疫Balb/c小鼠后细胞增殖抑制实验检测小鼠脾脏淋巴细胞对EMT-6细胞的杀伤效应。流式细胞术检测Imiquimod处理局部皮肤对BM-DC向局部引流淋巴结(DLN)迁移的影响。结果 Imiquimod联合Ag-DC治疗荷瘤小鼠可明显抑制肿瘤生长,与单纯Imiquimod、Ag-DC治疗组及NS处理对照组比较差异具有显著性。Imiquimod联合Ag-DC免疫小鼠后脾脏淋巴细胞杀伤肿瘤细胞能力较其它组明显增强。局部涂抹Imiquimod后注射BM-DC,24 h后DLN内BM-DC数量较对照组明显增多。结论 TLR7激动剂Imiquimod可增强BM-DC疫苗诱导的免疫应答,提高肿瘤治疗效果。其机制可能与Imiquimod诱导DLN BM-DC细胞数量增多有关。     

犬腺病毒DNA疫苗的免疫实验研究

目的研究犬腺病毒DNA疫苗pVAX1-CpG-Loop刺激机体产生免疫应答的效果。方法采用2种不同的免疫途径和免疫方案免疫Balb/c小鼠;免疫后每周断尾采血,分离血清测定血清IgG抗体效价;采用MTT和CCK-8方法检测免疫小鼠的T淋巴细胞增殖活性,EIA试剂盒测定IFN-γ的浓度。结果所有接种DNA疫苗的小鼠均产生了针对抗原病毒的特异性IgG抗体。细胞学试验提示构建的犬腺病毒DNA疫苗也可诱导小鼠产生细胞性免疫应答,重组质粒-蛋白联合的免疫方案在刺激机体细胞免疫应答方面优于单一重组质粒。结论以上结果提示犬腺病毒DNA疫苗pVAX1-CpG-Loop既能诱导小鼠产生特异性的体液免疫应答,也诱导小鼠产生了细胞免疫应答,对于机体具有一定的免疫保护效果。     

呼吸道合胞病毒样颗粒疫苗制备及免疫效果研究

目的利用昆虫表达系统表达以流感病毒基质蛋白M1为骨架制备的嵌合呼吸道合胞病毒(RSV)融合蛋白F和表面糖蛋白G蛋白的呼吸道合胞病毒样颗粒(RSV-F/G VLPs)疫苗候选株,并滴鼻免疫Balb/c小鼠,评价其免疫原性与免疫保护性。方法通过基因重组技术制备以流感基质蛋白M1为骨架,并嵌合RSV F/G蛋白的RSV-F/G VLPs,经超滤浓缩、蔗糖密度梯度离心纯化VLP,滴鼻免疫Balb/c小鼠,检测血清抗体IgG、IgG1、IgG2a,黏膜sIgA效价以及细胞因子IL-4、INF-γ等,评价候选疫苗的免疫原性;二免后2周RSV A2株攻毒,通过检测小鼠体质量变化,肺病毒载量及肺病理切片来评价候选疫苗的免疫保护性。结果成功制备了RSV-F VLPs、RSV-G VLPs疫苗抗原,动物实验结果证实,候选疫苗株RSV-F/G VLPs可刺激机体产生特异性Th1型细胞免疫及黏膜免疫;攻毒实验结果表明候选疫苗株RSV-F/G VLPs针对RSV A2株的攻击可以产生一定的保护效果。结论成功制备了RSV-F VLPs、RSV-G VLPs候选疫苗抗原,并通过动物实验证明RSV-F/G VLPs具有良好的免疫原性和免疫保护性,为发展新型RSV疫苗提供实验依据。     

不同佐剂与鼠疫F1-V融合重组蛋白抗原滴鼻免疫效果的研究

目的 研究不同佐剂与鼠疫F1-V融合重组蛋白抗原滴鼻免疫Balb/c小鼠,观察机体产生体液免疫和局部粘膜免疫反应的效果,为发展黏膜疫苗提供理论基础.方法 鼠疫F1-V融合重组蛋白抗原按比例分别与PorB(2类外膜蛋白)重组蛋白、蛋白体佐剂制备黏膜疫苗,滴鼻免疫Balb/c小鼠3次,取尾静脉血,采用ELISA检测血清IgG及抗体亚型分类,并检测鼻咽、肺、小肠及阴道灌洗液sIsA;采用FAC检测脾淋巴细胞表型的变化.结果 PorB重组蛋白佐剂疫苗组和蛋白体佐剂疫苗组较无佐剂组体液免疫抗体水平高、蛋白体佐剂疫苗组好于PorB重组蛋白佐剂疫苗组,但无显著性差异.结论 PorB重组蛋白佐剂疫苗和蛋白体佐剂疫苗均能诱导较强的系统免疫和黏膜免疫应答,且PorB重组蛋白佐剂疫苗免疫效果可与蛋白体佐剂疫苗相媲美,可进一步论证是否可用PorB重组蛋白佐剂替代蛋白体佐剂,这为鼠疫粘膜疫苗的研制奠定了基础.     

鼠疫菌重组质粒pcDNATE/F1-V的构建及其免疫效果的研究

目的 获得含有鼠疫F1和V抗原编码基因的重组质粒pcDNATE／E1-V,并测定其诱导特异性免疫应答的能力。方法PCR扩增鼠疫菌F1和V编码基因,分别与pGEM-T连接测序,构建pcDNATE／F1-V融合重组质粒,转染COS-7细胞,用Western blot方法鉴定目的蛋白的表达,重组质粒pcDNATE／E1-V加集落刺激因子(GM-CSF)免疫Balb／c小鼠,观察免疫效果。结果pcDNATE／F11-V在COS-7细胞中表达,免疫鼠体内产生特异性抗体,抗体亚型分析、细胞因子等指标的测定结果表明所构建DNA疫苗以诱发Th1型免疫为主。结论成功构建重组真核表达质粒pcDNATE／F1-V,其具有诱导特异性细胞免疫和体液免疫应答的能力,为鼠疫菌新型疫苗研制奠定了基础。     

新型免疫佐剂在淋巴细胞杂交瘤技术中的应用

目的：观察新型免疫佐剂ImmunEasy^TM(Cp GODN)的免疫调节作用，并与弗氏佐剂相比较，探讨其在单克隆抗体制备中的应用前景。方法：将小鼠用新型免疫佐剂ImmunEasy^TM或弗氏佐剂混合原核表达的重组APRIL抗原，分别以常规免疫和少量抗原免疫方案免疫Balb／c小鼠，用间接ELISA法检测不同时相小鼠免疫血清抗APRIL抗体的总效价及各类和亚类的效价。建立一种能在单个细胞水平反映小鼠B细胞分泌特异性抗体亚类的改良ELISPOT方法，并对两种佐剂免疫组中配对的小鼠进行检测。常规方法制备杂交瘤，以间接ELISA法筛选阳性杂交瘤，比较不同佐剂免疫小鼠所获得的杂交瘤上清液的类及其亚类频率。结果：与弗氏佐剂相比，ImmunEasy^TM在单克隆抗体制备过程中可明显减少抗原用量，缩短免疫周期，提高免疫血清效价，并增加IgG2a、IgM及IgA抗体的比例。结论：在细胞融合制备鼠源性mAb中，应用ImmunEasy^TM，可减少免疫原用量，提高效率，还可优先获得某些类及其亚类的mAb。     

基于枯草芽孢杆菌系统制备的EV71VP1重组抗原诱导小鼠免疫应答的研究

目的观察基于枯草芽孢杆菌系统制备的EV7lVPl重组抗原诱导BALB／c小鼠产生的免疫应答反应。方法通过建立BALB／c小鼠动物模型,分别将前期构建的基于枯草芽孢杆菌系统制备的EV71重组抗原（rVPl）、灭活EV71病毒免疫组（EV71）和空白对照组（PBS）,经鼻腔接种6～8周龄BALB／c小鼠,ELISA方法检测免疫后不同时间产生的特异性IgG、IgA以及IgGl和IgG2a水平。结果EV71重组抗原可以有效诱导小鼠产生高水平的体液免疫和明显的黏膜免疫应答,且能够诱发均衡的Th1、Th2免疫调节。结论肠道病毒71型重组VPl抗原可诱发小鼠产生明显的特异性体液免疫和黏膜免疫应答。     

Comparative safety and efficacy against Bacillus anthracis of protective antigen and live vaccines in mice

The efficacy and mechanisms of protection of two live vaccines and of a protective antigen (PA) vaccine against Bacillus anthracis were studied in inbred mice. Mice that differed in their natural resistance to killing by Sterne, a non-encapsulated, toxigenic vaccine strain of B. anthracis, were used. Vaccination with live Sterne spores protected Sterne-resistant mice against challenge with the virulent Vollum 1B (V1B) strain of B. anthracis, but only at doses of Sterne greater than or equal to 0.1 50% lethal dose. The live B. subtilis recombinant strain PA2, which produces the PA component of anthrax toxin, fully protected (CBA/J) or partially protected (BALB/cJ) Sterne-resistant mice against V1B. Neither immunization with the cell-free PA vaccine nor passive administration of anti-PA antiserum protected Sterne-resistant mice against V1B. Sterne-susceptible A/J mice were not protected against V1B by either live vaccine or by the PA vaccine. However, immunization with strain PA2 induced anti-PA antibody and protected A/J mice against Sterne. A/J mice passively treated with antitoxin antibodies also survived Sterne, and survivors were then partially protected against V1B. Thus, immunity to Sterne correlated with an effective anti-PA response. Immunity to fully virulent V1B also required PA but may involve mechanisms in addition to humoral immunity.     

Immunization against anthrax with Bacillus anthracis protective antigen combined with adjuvants.

The protective efficacy of immunization against anthrax with Bacillus anthracis protective antigen (PA) combined with different adjuvants was tested in Hartley guinea pigs and CBA/J and A/J mice. Adjuvant components derived from microbial products that were tested included threonyl-muramyl dipeptide (threonyl-MDP); monophosphoryl lipid A (MPL); trehalose dimycolate (TDM); and the delipidated, deproteinized, cell wall skeleton (CWS) from either Mycobacterium phlei or the BCG strain of Mycobacterium bovis. Non-microbially derived adjuvants tested included aluminum hydroxide and the lipid amine CP-20,961. In guinea pigs, all adjuvants and adjuvant mixtures enhanced antibody titers to PA as well as survival after a parenteral challenge of virulent B. anthracis Ames spores. In contrast, PA alone or combined with either aluminum hydroxide or CP-20,961 failed to protect mice. Vaccines containing PA combined with threonyl-MDP or MPL-TDM-CWS protected a majority of female CBA/J mice. Statistical analysis of survival data in the guinea pigs indicated that PA-MPL-CWS and PA-MPL-TDM-CWS were more efficacious than the currently licensed human anthrax vaccine.     

Immunization against anthrax with aromatic compound-dependent (Aro-) mutants of Bacillus anthracis and with recombinant strains of Bacillus subtilis that produce anthrax protective antigen.

The safety and efficacy of five prototype, live anthrax vaccines were studied in Hartley guinea pigs and CBA/J and A/J mice. Two of the strains, Bacillus anthracis FD111 and FD112, are Aro- mutants derived by Tn916 mutagenesis of B. anthracis UM23-1. Bacillus subtilis PA1 and PA2 contain a recombinant plasmid, pPA101 or pPA102, respectively, that carries the gene from B. anthracis encoding synthesis of protective antigen (PA). The final strain, B. subtilis PA7, was isolated in this study from B. subtilis DB104 transformed with pPA101. All five strains were less virulent in guinea pigs and A/J and CBA/J mice than the toxinogenic, nonencapsulated B. anthracis veterinary vaccine Sterne strain. A/J and CBA/J inbred mice represent strains that are innately susceptible and resistant, respectively, to the Sterne strain. These differences in susceptibility are due to differences in ability to produce complement component 5. In guinea pigs, immunization with PA1 or PA2 vegetative cells or PA7 spores protected greater than or equal to 95% from an intramuscular spore challenge with the virulent, "vaccine-resistant" B. anthracis Ames strain. Strain PA2 vegetative cells and strain PA7 spores were as effective as the Sterne strain in Sterne-resistant CBA/J mice, protecting 70% of the mice from Ames strain spore challenge. Immunization with FD111 or FD112 vegetative cells fully protected guinea pigs from challenge. Immunization with FD111 cells protected up to 100% of CBA/J mice and up to 70% of A/J mice.     

Protection of mice against challenge with Bacillus anthracis STI spores after DNA vaccination

Immune responses against the protective antigen (PA) of Bacillus anthracis are known to confer immunity against anthrax. We evaluated the efficacy of genetic vaccination with plasmid vectors encoding PA, in protecting mice from a lethal challenge with B. anthracis STI spores. BALB/c and A/J mice were immunized via gene gun inoculation, using eukaryotic expression vectors with different cellular targeting signals for the encoded antigen. The vector pSecTag PA83, encoding the full-length PA protein, has a signal sequence for secretion of the expressed protein. The plasmids pCMV/ER PA83 and pCMV/ER PA63, encoding the full-length and the physiologically active form of PA, respectively, target and retain the expressed antigen in the endoplasmic reticulum of transfected cells. All three plasmids induced PA-specific humoral immune responses, predominantly IgG1 antibodies, in mice. Spleen cells collected from plasmid-vaccinated BALB/c mice produced PA-specific interleukin-4, interleukin-5, and interferon-gamma in vitro. Vaccination with either pSecTag PA83 or pCMV/ER PA83 showed significant protection of A/J mice against infection with B. anthracis STI spores.     

Experimental cutaneous Bacillus anthracis infections in hairless HRS/J mice

Previous studies of experimental Bacillus anthracis cutaneous infections in mice have implicated hair follicles as a likely entry site. Hairless HRS/J mice were used to investigate this possibility because of their non-functional hair follicles that lack penetrating hair shafts. These mice also have diminished macrophage function, increased susceptibility to Listeria, and enhanced neutrophil responses. HRS/J and Balb/c mice were found to be resistant to epicutaneous inoculation with Bacillus anthracis (Sterne) spores onto abraded skin when compared with DBA/2 mice or leucopenic C57BL/6 mice. The HRS/J mice also resisted spore injections that bypassed hair follicles. Haired HRS/J heterozygote mice demonstrated similar reduced susceptibility to B. anthracis spores. Hairless HRS/J mice that were made leucopenic did become susceptible to the epicutaneous spore inoculations. Histologically, the hairless and haired HRS/J mice showed markedly reduced numbers of organisms in hair follicles and the interfollicular dermis when compared even with the resistant Balb/c mice; inflammatory cell infiltrates in the superficial dermis were increased in the HRS/J mice compared with more sensitive strains. Therefore, resistance in the HRS/J mice was apparent at the initial site of epicutaneous inoculation and seemed related to an accumulation of dermal neutrophils rather than to a lack of functional hair follicles.     

Engineered recombinant ovomucoid third domain can desensitize Balb/c mice of egg allergy

The purpose of this study was to determine the in vivo desensitization efficacy of a hypoallergenic variant of egg white ovomucoid third domain (DIII) in Balb/c mice model. We mapped the immunodominant B-cell epitopes of ovomucoid in Balb/c mice. A hypoallergenic ovomucoid third domain (GMFA) mutant isoform having ablated allergenicity against egg allergic patient's sera was used to desensitize DIII-sensitized Balb/c mice by intraperitoneal injections. Ovomucoid DIII generated high levels of plasma histamine and specific immunoglobulin (Ig)E levels, and increased Th2 type cytokine (IL-4). On the other hand, the allergic response of mice desensitized with the GMFA was found to be significantly inhibited and abrogated by prevention of anaphylaxis reactions, low histamine levels and increased Th1-type cytokine (INF-gamma). It was found that significantly higher levels of IL-10 and IL-12 were secreted in the desensitized group. Desensitization with the GMFA antigen also suppressed synthesis of DIII specific-IgE levels and enhanced specific IgG2a and IgG levels compared with the group treated with the DIII antigen. The present results indicated that hyposensitization with the GMFA can desensitize or down-regulate the allergic response in Balb/c mice and this hypoallergenic variant of ovomucoid DIII can shift an ongoing allergen-specific Th2 response towards a Th1 skewed response.     

The capsule of Bacillus anthracis behaves as a thymus-independent type 2 antigen

Bacillus anthracis elaborates a homopolymeric capsule composed of gamma-D-glutamic acid residues. Mice were immunized with formalin-fixed encapsulated B. anthracis bacilli, and the serum antibody response to a gamma-D-glutamyl capsular epitope was measured. Antiglutamyl antibodies were elicited in athymic BALB/c Nu/Nu, BALB/c Nu/+, and CBA/J mice but not in CBA/N xid mice. These response patterns define the capsule of B. anthracis as a thymus-independent type 2 antigen.     

Novel murine tumour models depend on strain and route of inoculation

This study describes variations in tumour growth patterns which occur when changes in the routes of inoculation and mouse strain are used to introduce tumours into established murine model systems that are known to vary in location and aggression. Intraperitoneal, subcutaneous, intravenous and hydrodynamic inoculations of B16F10 cells were compared among CD‐1, C57BL/6 and Balb/c mice. Most surprisingly, allogeneic tumour growth in Balb/c mice after intravenous and hydrodynamic inoculation of B16F10 cells was faster than tumour growth in the syngeneic C57BL/6 mice. These and other variations in the tumour growth patterns described here can help provide the researcher with more experimental control when planning to use the optimal tumour model for any particular study.     

The Effects of Interleukins 4 and 5 on the Differentiation of B Cells from (NZB × NZW)F1 Mice

We describe here that IL-4 and IL-5 together can induce the production of high amounts of IgG1 polyclonal antibodies by B cells from old (NZB x NZW)F1 mice even in the absence of LPS. The effect was less marked in young mice from the same strain or in normal Balb/c mice. The cells sensitive to the treatment with the interleukins were the large B cells. Old mice had higher proportions of such cells than young mice or normal Balb/c mice. Synthesis of anti-DNA antibodies of the IgM class was induced. Although IL-4 plus IL-5 induced a strong polyclonal IgG1 production, there were no IgG1 anti-DNA antibodies.     

Hyperactivity of donor B cells after neonatal induction of lymphoid chimerism in mice.

Balb/c mice made chimaeric by neonatal injection of semi-allogeneic (A/J x Balb/c)F1 hybrid spleen cells develop anti-DNA and rheumatoid factor-like antibodies in the context of hypergammaglobulinaemia with marked elevation of IgG1 and IgE serum levels. Chimaeric mice also display increased levels of antibodies to different haptens and to tobacco mosaic virus (TMV). The allotypic marker of the A/J strain is present on anti-DNA and anti-hapten antibodies. In addition, spleen cells of chimaeric mice spontaneously produce high levels of IgG1 and anti-DNA antibodies in vitro and this hyperactivity is abolished after lysis of donor lymphocytes. These findings indicate that polyclonal activation of donor B cells plays an important role in this model of autoimmunity.