两种免疫调节剂增强弓形虫W2b2a表位疫苗的小鼠保护作用

目的:探讨匹多莫德、沙利度胺增强弓形虫W2b2a表位疫苗刺激机体产生免疫应答和保护免疫的效果。方法:将匹多莫德、沙利度胺分别与弓形虫W2b2a表位疫苗混合肌注免疫小鼠,检测其细胞免疫和体液免疫,并观察其受到弓形虫攻击感染后的生存时间。结果:pc DNA3-W2b2a加匹多莫德组、pc DNA3-W2b2a加弗氏佐剂组、pc DNA3-W2b2a加沙利度胺组小鼠血清IFN-γ水平显著高于pc DNA3-W2b2a组(P0.05);pc DNA3-W2b2a加匹多莫德组、pc DNA3-W2b2a加弗氏佐剂组Ig G抗体水平、CD4+/CD8+比值、T细胞增殖活性显著高于pc DNA3-W2b2a组和pc DNA3-W2b2a加沙利度胺组(P0.05);小鼠攻击试验表明,免疫组小鼠存活时间明显长于对照组(P0.05)。结论:匹多莫德、沙利度胺可增强弓形虫W2b2a表位疫苗免疫小鼠的保护作用。     

匹多莫德增强弓形虫新基因wx2b4a表位疫苗免疫小鼠的保护研究

目的 探讨匹多莫德增强弓形虫新基因wx2b4a表位疫苗刺激机体产生免疫应答和保护免疫的效果.方法 将昆明小鼠分成4组,分别用pcDNA3-W2b4a质粒、pcDNA3-W2b4a+匹多莫德、pcDNA3及生理盐水肌注3次.ELISA法检测血清IgG抗体水平,取脾细胞用流式细胞仪检测T淋巴细胞亚群,末次免疫后第4周,小鼠经腹腔注射弓形虫速殖子500个,观察小鼠生存时间.结果 pcDNA3-W2b4a+匹多莫德组、pcDNA3-W2b4a组小鼠血清IgG抗体水平显著高于pcDNA3组和生理盐水对照组(P＜0.05);各免疫组小鼠CD4+、CD8+T淋巴细胞数量显著高于对照组(P＜0.05);pcDNA3-W2b4a+匹多莫德组CD4+T细胞数量、CD4+/CD8+比值高于pcDNA3-W2b4a组(P＜0.05).小鼠攻击试验表明,pcDNA3-W2b4a+匹多莫德组小鼠存活时间明显长于对照组和pcDNA3-W2b4a组(P＜0.05).结论 匹多莫德可增强弓形虫新基因wx2b4a表位疫苗诱导小鼠产生抗弓形虫感染保护性免疫.     

IL-2联合不可分型流感嗜血杆菌P6重组蛋白对小鼠免疫功能的影响

目的观察IL-2联合不可分型流感嗜血杆菌重组P6蛋白免疫小鼠的免疫效果,探讨IL-2的佐剂效应。方法将50只Balb/c小鼠随机分为5组:P6重组蛋白组、P6重组蛋白+IL-2组、IL-2组、P6重组蛋白+弗氏佐剂组及PBS对照组,分别于第0、14、28天经腹腔进行3次免疫,末次免疫后14 d,取小鼠血、脾标本,ELISA法检测血清中抗体IgG水平,并分析其脾淋巴细胞IL-4、IL-10、IL-2和IFN-γ的产生水平。CCK-8法检测各组脾淋巴细胞增殖活性。结果 P6重组蛋白联合IL-2组通过腹腔免疫刺激小鼠产生的血清IgG水平,高于PBS对照组、P6重组蛋白组及IL-2组(P0.05)。P6重组蛋白联合IL-2组小鼠特异性脾淋巴细胞刺激指数及其所产生的IFN-γ、IL-2水平均高于PBS对照组、P6重组蛋白组及IL-2组(P0.05),而IL-4、IL-10水平各组无差异。各项检测中P6重组蛋白联合IL-2组与P6重组蛋白联合弗氏佐剂组无显著性差异(P0.05)。结论 IL-2联合P6重组蛋白诱导小鼠的免疫应答优于P6重组蛋白单独免疫,IL-2可以作为不可分型流感嗜血杆菌P6重组蛋白的佐剂。     

免疫途径和佐剂对CVB3VP1蛋白免疫效果的影响

目的:观察不同免疫途径和佐剂类型对柯萨奇病毒B组3型(Coxsackievirus group B type 3,CVB3)衣壳蛋白VP1免疫效果的影响.方法:将原核表达质粒pET-his/VP1转入E.coli BL21 (DE3) pLysS中,用异丙基-1-硫代-β呋喃半乳糖苷(IPTG)诱导CVB3VP1蛋白的表达并进行纯化.首先采用不同的免疫途径(皮下,腹腔,肌肉)用VP1蛋白免疫小鼠,每组12只.然后另取小鼠分为PBS组和不同佐剂组(氢氧化铝、弗氏佐剂、Montanide ISA720),每组18只,采用肌肉注射途径免疫.每次每只小鼠注射50μg,共免疫3次,间隔3周.用ELISA和微量中和试验检测血清特异性IgG抗体和中和抗体.用CCK-8法检测淋巴细胞增殖活性和CTL杀伤活性.用致死量的CVB3攻击后,检测血中病毒的滴度并观察小鼠的存活状况.结果:在大肠杆菌中成功表达CVB3VP1蛋白.三种免疫途径比较,肌肉注射组血清中和抗体和特异性IgG抗体的水平明显高于其他组(P＜0.01).采用肌肉注射免疫时,弗氏佐剂组Montanide ISA 720佐剂组的体液免疫和细胞免疫应答的水平明显高于氢氧化铝组(P＜0.05);但血中病毒的滴度低于氢氧化铝组(P＜0.05).弗氏佐剂组小鼠的生存率好于氢氧化铝组(P＜0.05).结论:采用肌肉注射途径,并联合弗氏佐剂或Montanide ISA 720佐剂可以使CVB3VP1免疫获得较好的免疫效果.     

铝佐剂对HBoV1 VP2 VLPs 诱导小鼠免疫应答的影响

目的:探讨铝佐剂对HBoV1 VP2 VLPs诱导小鼠免疫应答的影响。方法:BABL/c小鼠随机分为VLPs实验组、明矾佐剂实验组、PBS对照组和明矾佐剂对照组。实验组小鼠分别采用HBoV1 VP2 VLPs和HBoV1 VP2 VLPs加明矾佐剂肌肉注射免疫,对照组小鼠同期注射等量明矾佐剂或PBS缓冲液;实验8周后ELISA检测两实验组特异性Ig G抗体效价和活性,ELIspot检测两实验组特异性细胞免疫反应强度,从细胞免疫和体液免疫强度探讨铝佐剂对HBoV1 VP2 VLPs诱导小鼠免疫应答的影响。结果:明矾佐剂降低HBoV1 VP2 VLPs诱导细胞免疫反应强度(P0.001),增强HBoV1 VP2 VLPs诱导的血清Ig G效价(P0.01)和Ig G活性(P0.05)。结论:明矾佐剂使HBoV1 VP2 VLPs诱导的体液免疫反应增强而细胞免疫反应减弱。HBoV1 VP2 VLPs作为预防性疫苗使用时应添加明矾佐剂,作为治疗性疫苗使用时应不加明矾佐剂。     

重组弓形虫棒状体蛋白5诱导小鼠的免疫应答及其抗弓形虫感染的保护作用

为探讨重组弓形虫棒状体蛋白5诱导的免疫应答及其免疫保护效应,本研究克隆表达了弓形虫棒状体蛋白5,并分析其诱导的细胞免疫、体液免疫应答和抗弓形虫感染的保护作用。采用PCR方法从刚地弓形虫cDNA中扩增出ROP5基因片段,将该基因片段克隆至pET-28a原核表达载体表达,用重组ROP5蛋白免疫BALB／c小鼠,ELISA检测免疫后小鼠抗体和细胞因子的变化。以强毒型RH株弓形虫攻击感染免疫小鼠,统计小鼠不同时间存活率,评价重组蛋白产生的免疫保护性。结果表明ROP5重组蛋白疫苗免疫BALB／c小鼠诱导机体产生高水平的IgG、IgG1、IgG2a抗体和IFN—y、IL-2及IL-10细胞因子。与PBS及佐剂对照组相比,重组蛋白免疫组小鼠的存活时间明显延长。本实验证实了ROP5重组蛋白免疫BALB／c小鼠能够诱导其产生高水平的体液免疫和细胞免疫应答,以及一定的抗弓形虫感染保护作用。     

匹多莫德干预治疗儿童传染性单核细胞增多症

目的探讨传染性单核细胞增多症(IM)细胞免疫调节剂匹多莫德干预治疗的有效性。方法将62例IM患儿随机分为两组,各31例,对照组急性期予以阿昔洛韦抗病毒及对症等常规治疗;干预组在常规治疗的基础上加用细胞免疫调节剂匹多莫德,疗程2周。观察两组临床指标的恢复情况,分别检测治疗前后T细胞亚群的变化。结果干预组临床症状及体征较对照组消失快(P0.05);干预组平均住院天数较对照组明显缩短(P0.05),差异有显著性,对照组患儿治疗前后CD3、CD4、CD8 T细胞及CD4/CD8比值差异无显著性(P0.05);干预组患儿治疗后CD3、CD8 T细胞比例降低,CD4T细胞比例及CD4/CD8比值明显升高(P0.05)差异有显著性。结论 IM患儿存在T细胞免疫功能紊乱,在性期治疗中加用细胞免疫调节剂匹多莫德能缩短IM的病程,促进T细胞免疫功能的尽快恢复。     

不同佐剂对随机组合多表位恶性疟疾疫苗M. RCAg-1的免疫原性及体外抑虫率影响的研究

目的 研究弗氏佐剂及3种人用佐剂[Al(OH)3、Montanide ISA720、Montanide ISA51]对重组多表位蛋白M.RCAg-1(malaria random constructed antigen-1)在BALB/c小鼠及新西兰大白兔体内产生免疫效果的影响.方法 以弗氏佐剂、Al( OH)3佐剂、Montanide ISA720以及MontanideISA51佐剂分别与M.RCAg-1蛋白进行配伍,分别免疫BALB/c小鼠及新西兰白兔;采用ELISA法检测M.RCAg-1蛋白及其所组成各个表位特异的血清IgG含量;间接荧光免疫试验分析不同配伍组免疫血清对天然疟原虫抗原的识别;酶联免疫斑点试验(ELISPOT)检测特异性鼠T淋巴细胞的活化;另借助生物传感器评价抗原与不同佐剂配伍组血清的亲和力,并用体外生长抑制试验(GIA)对恶性疟原虫的体外生长的影响进行评价.结果 不同佐剂可诱发不同水平的抗体滴度,Montanide ISA51佐剂配伍组的效果与弗氏佐剂组最为接近,并可使蛋白包含的11个表位肽能都较好诱发出特异性抗体,可有效激发以IFN-γ为主的细胞免疫应答,而且Montanide ISA51佐剂组免疫产生的抗体和M.RCAg-1蛋白质的亲和力高于其他两种佐剂;而Montanide ISA720佐剂和Al(OH)3佐剂免疫组不能诱发小鼠产生显著的IFN-γ反应(P＞0.05).Montanide ISA51配伍蛋白质免疫产生的IgG在浓度为2mg/ml时对3D7和Dd2的抑制率分别为60%和100%,Al(OH)3佐剂组免疫兔血清IgG体外抑虫率较低(10%左右),而Montanide ISA720佐剂免疫组血清不能有效抑制疟原虫生长.结论 通过比较3种人用佐剂和弗氏佐剂对BALB/c小鼠和新西兰兔的免疫辅助效能显示,Montanide ISA51佐剂能很好的辅助M.RCAg-1蛋白疫苗诱发动物体内的体液免疫和细胞免疫应答,可做为疫苗的候选佐剂之一.     

BALB/C小鼠对不同佐剂SARS灭活疫苗的早期免疫反应

目的：研究含不同佐剂的SARS灭活疫苗免疫小鼠后，小鼠的早期细胞免疫和体液免疫反应。方法：灭活的SAPS冠状病毒F69株分别与弗氏佐剂、氢氧化铝、CpG佐剂配伍，制备灭活疫苗。接种6周龄SPF’级BALB／C小鼠。定时采血，分析小鼠外周血中CD4^ 、CD8^ T细胞亚群动态变化，同时测定鼠血清中特异性IgG抗体及抗体的病毒中和活性。结果：由3种佐剂制备的SARS灭活疫苗免疫小鼠后，CD4^ 、CD8^ T细胞百分比升高或无明显改变，CD4／CD8比值无显著性改变。其中，弗氏佐剂疫苗免疫小鼠的CD4^ T细胞百分比升高较明显，且在一段时间内，维持在一个较高的水平；铝佐剂疫苗免疫小鼠后，未观察到明显T细胞亚群改变；而CoG佐剂疫苗免疫小鼠的CD8^ T细胞百分比改变较其它佐剂疫苗改变更明显。与此相异的是，3种疫苗均可诱导小鼠产生较高滴度特异性IgG抗体，并且所产生的抗体具有中和活性。在初免后第34天，3种佐剂组的IgG抗体滴度分别为1：12800、1：3200和1：1600，中和效价分别为1：2560、1：960和1：320。结论：SARS灭活疫苗接种小鼠后，可诱导较强的体液免疫反应，同时轻度上调CD4^ 、CD8^ T细胞活性，程度因佐剂而异。     

匹多莫德对预防幼年特发性关节炎患儿感染及对其免疫功能的影响

幼年特发性关节炎(JIA)患儿存在免疫紊乱,易发生各种感染。本文探讨了口服匹多莫德对预防JIA患儿感染及对其免疫功能的影响。选取JIA患儿共60例作为研究对象,按治疗方案分为一般治疗组(n=30)和匹多莫德组(n=30)。匹多莫德组在治疗原发病的基础上加用匹多莫德口服。观察治疗前后12个月内JIA患儿感染情况,包括感染次数、病程、部位,外周血T淋巴细胞亚群变化(CD3+,CD4+,CD8+,CD4+/CD8+等),IgG、IgM、IgA、C3和C4水平,NK细胞(CD16+56+)数量及功能变化以及匹多莫德口服液的副作用。另取30例正常儿童作为治疗前的健康对照组。比较匹多莫德组和一般治疗组治疗前后的感染情况以及外周血免疫功能变化。结果显示,接受匹多莫德治疗的患儿控制感染的总有效率(90%)较一般治疗组(36.7%)明显增高(P0.01)。两组治疗后12个月相比,匹多莫德组CD3+、CD4+、CD4+/CD8+,IgG、IgM、IgA,自然杀伤细胞活性、C3均明显高于一般治疗组,CD8+则明显低于一般治疗组(P0.05)。提示匹多莫德能够促进JIA患儿免疫异常的恢复,有效预防感染发生。     

Enhanced protection against viral infection by co-administration of plasmid DNA coding for viral antigen and cytokines in mice.

BACKGROUND: DNA vaccines have been shown to induce protective immunity against viral infections in different animal models. We have recently demonstrated that DNA vaccine induced protective immunity against influenza A virus and La Crosse virus (LACV) is primarily mediated by humoral immune response. OBJECTIVE: The goal of this study was to investigate whether administration of DNA coding for cytokines such as interleukin 12 (IL-12) and granulocyte-macrophage colony-stimulating factor (GM-CSF) could increase the protective immune response induced by vaccination with DNA coding for viral antigens. STUDY DESIGN: For the influenza A virus or LACV model, C57BL/6 or interferon-alpha/beta receptor (IFNAR-1)-deficient mice, respectively, were vaccinated once or twice with 100 micrograms of DNA encoding viral antigens. At the same time plasmid DNAs (100 micrograms) coding either for mouse GM-CSF or mouse IL-12 were administered. The mice were subsequently challenged with a lethal dose of influenza A virus or LACV and monitored for clinical symptoms (weight loss) and survival. RESULTS: To achieve a high degree of protection (70% survival) two injections of DNA encoding the influenza A virus surface protein hemagglutinin (HA) were required. Intriguingly, administration of DNA coding for IL-12 alone also led to a pronounced protective effect against virus challenge. Co-administration of DNAs encoding IL-12 and HA significantly increased the protective immunity against influenza A virus, while IL-12 expression did not improve protection upon vaccination with DNA coding for the internal nucleocapsid protein N of LACV. Co-injection of DNA coding for mouse GM-CSF and HA also showed an adjuvant effect. CONCLUSIONS: The data clearly indicate that co-administration of DNA encoding cytokines such as IL-12 and GM-CSF with DNA coding for viral antigens has adjuvant effects on the protective immune response against different viral pathogens.     

A GRA1 DNA vaccine primes cytolytic CD8(+) T cells to control acute Toxoplasma gondii infection

Protective immunity against Toxoplasma gondii is known to be mediated mainly by T lymphocytes and gamma interferon (IFN-gamma). The contribution of CD4(+) and CD8(+) T-lymphocyte subsets to protective immune responses against T. gondii infection, triggered by a GRA1 (p24) DNA vaccine, was assessed in this study. In vitro T-cell depletion experiments indicated that both CD4(+) and CD8(+) T-cell subsets produced IFN-gamma upon restimulation with a T. gondii lysate. In addition, the GRA1 DNA vaccine elicited CD8(+) T cells that were shown to have cytolytic activity against parasite-infected target cells and a GRA1-transfected cell line. C3H mice immunized with the GRA1 DNA vaccine showed 75 to 100% protection, while 0 to 25% of the mice immunized with the empty control vector survived challenge with T. gondii cysts. In vivo T-cell depletion experiments indicated that CD8(+) T cells were essential for the survival of GRA1-vaccinated C3H mice during the acute phase of T. gondii infection, while depletion of CD4(+) T cells led to an increase in brain cyst burden during the chronic phase of infection.     

<Emphasis Type="Italic">Toxoplasma gondii</Emphasis>: expression and characterization of a recombinant protein containing SAG1 and GRA2 in <Emphasis Type="Italic">Pichia pastoris</Emphasis>

Toxoplasma gondii is an obligate intracellular protozoan which infects most species of warm-blooded animals and causes toxoplasmosis. Previous immunological and immunization studies have demonstrated the potential role of T. gondii antigens SAG1 and GRA2 as a vaccine candidate. In the present study, we have cloned, expressed, and purified a recombinant protein SAG1–GRA2 in Pichia pastoris. Results showed that P. pastoris was a robust system producing a large amount of highly purified and biological activity protein. BALB/c mice immunized with SAG1–GRA2 elicited stronger humoral and cellular responses in comparison to control groups. This immunization resulted in an enhanced Th1 immune response as measured by IgG2a antibody production and increased splenocyte IFN-γ production, whereas no IL-4 was detected. After a lethal challenge with the highly virulent T. gondii RH strain, a prolonged survival time in SAG1–GRA2-immunized mice was observed in comparison to control groups. Our data demonstrate that SAG1–GRA2 triggered a protective response against toxoplasmosis. Therefore, SAG1–GRA2 protein might be a good candidate for the further development of a multiantigenic vaccine.     

DNA vaccination with genes encoding Toxoplasma gondii antigens GRA1, GRA7, and ROP2 induces partially protective immunity against lethal challenge in mice

C57BL/6, C3H, and BALB/c mice were vaccinated with plasmids encoding Toxoplasma gondii antigens GRA1, GRA7, and ROP2, previously described as strong inducers of immunity. Seroconversion for the relevant antigen was obtained in the majority of the animals. T. gondii lysate stimulated specific T-cell proliferation and secretion of gamma interferon (IFN-gamma) in spleen cell cultures from vaccinated BALB/c and C3H mice but not in those from control mice. Although not proliferating, stimulated splenocytes from DNA-vaccinated C57BL/6 mice also produced IFN-gamma. No interleukin-4 was detected in the supernatants of lysate-stimulated splenocytes from DNA-vaccinated mice in any of the mouse strains evaluated. As in infected animals, a high ratio of specific immunoglobulin G2a (IgG2a) to IgG1 antibodies was found in DNA-vaccinated C3H mice, suggesting that a Th1-type response had been induced. For BALB/c mice, the isotype ratio of the antibody response to DNA vaccination was less polarized. The protective potential of DNA vaccination was demonstrated in C3H mice. C3H mice vaccinated with plasmid encoding GRA1, GRA7, or ROP2 were partially protected against a lethal oral challenge with cysts of two different T. gondii strains: survival rates increased from 10% in controls to at least 70% after vaccination in one case and from 50% to at least 90% in the other. In vaccinated C3H mice challenged with a nonlethal T. gondii dose, the number of brain cysts was significantly lower than in controls. DNA vaccination did not protect BALB/c or C57BL/6 mice. Our results demonstrate for the first time in an animal model a partially protective effect of DNA vaccination against T. gondii.     

Evaluation of the adjuvant effect of pidotimod on the immune protection induced by UV-attenuated Toxoplasma gondii in mouse models

The current anti-Toxoplasma gondii drugs have many shortcomings and effective vaccines against T. gondii may contribute to the control of this pathogen. Pidotimod is a synthetic substance capable of stimulating both cellular and humoral immunity. To investigate the possible adjuvant effect of pidotimod on the immune response to T. gondii in Kunming mice induced by ultraviolet-attenuated T. gondii (UV-T.g), in this study, mice were immunized intraperitoneal (i.p.) with UV-T.g or UV-T.g co-administered with pidotimod (UV-T.g?+?PT). After infection or challenge by i.p. injection of 10² RH tachyzoites, the animal survival rate, parasite burden in peritoneal lavage fluids, liver histopathology, the level of serum anti-toxoplasma IgG antibody, and the mRNA expressions of IL-2, IFN-γ, and TNF-α from spleen analyzed using real-time PCR, were compared among different groups. The results showed that, compared with infected controls, infected mice treated with pidotimod had significantly increased survival rate and extended survival time, decreased parasite burden, improved liver histopathology, increased level of anti-toxoplasma IgG antibody, and increased mRNA expressions of Th1-type cytokine (IL-2, IFN-γ, and TNF-α) (P?<?0.01), while mice vaccinated with UV-T.g and then challenged had even significantly increased survival rate and extended survival time, decreased parasite burden, improved liver histopathology, and increased mRNA expressions of Th1-type cytokines (IL-2, IFN-γ, and TNF-α) (P?<?0.01); furthermore, vaccinated mice co-administered with pidotimod had even more lower parasite burden, milder liver histopathology, and higher levels of Th1-type cytokine and anti-toxoplasma IgG antibody (P?<?0.01). Our data demonstrated that pidotimod in vivo could promote strong and specific humoral and cellular immune response to T. gondii challenge infection when co-administered with UV-attenuated T. gondii. It suggests that pidotimod may have the potential to be used as an effective vaccine adjuvant.     

Response of irradiated mice to live-virus (TC-83) immunization.

Studies were conducted to determine the effects of sublethal, acute, total-body irradiation (600 R) on the immune response of mice to a replicating antigen. Irradiation was performed at varying times (0 to 21 days) prior to immunization with attenuated Venezuelan equine encephalomyelitis virus, TC-83. Development of protective immunity was studied by inoculating subgroups of irradiated mice with virulent Venezuelan equine encephalomyelitis virus on days 1 through 28 after immunization. Irradiation failed to affect the overt clinical response of mice inoculated with the attenuated strain, but antibody responses and the onset of protective immunity was delayed, particularly in mice irradiated 2 h to 3 days prior to vaccination. Immunity afforded by TC-83 developed more rapidly as the interval between irradiation and vaccination increased: when this interval was 14 or more days, the temporal course of immune response in irradiated mice was similar to that of nonirradiated vaccines. Persistence of TC-83 viremia was greatly prolonged in irradiated mice through the irradiation recovery period and probably provided the antigenic stimulus responsible for delayed development of effective immunity.     

Protection against Plasmodium chabaudi malaria induced by immunization with apical membrane antigen 1 and merozoite surface protein 1 in the absence of gamma interferon or interleukin-4

Strategies to optimize formulations of multisubunit malaria vaccines require a basic knowledge of underlying protective immune mechanisms induced by each vaccine component. In the present study, we evaluated the contribution of antibody-mediated and cell-mediated immune mechanisms to the protection induced by immunization with two blood-stage malaria vaccine candidate antigens, apical membrane antigen 1 (AMA-1) and merozoite surface protein 1 (MSP-1). Immunologically intact or selected immunologic knockout mice were immunized with purified recombinant Plasmodium chabaudi AMA-1 (PcAMA-1) and/or the 42-kDa C-terminal processing fragment of P. chabaudi MSP-1 (MSP-1(42)). The efficacy of immunization in each animal model was measured as protection against blood-stage P. chabaudi malaria. Immunization of B-cell-deficient JH(-/-) mice indicated that PcAMA-1 vaccine-induced immunity is largely antibody dependent. In contrast, JH(-/-) mice immunized with PcMSP-1(42) were partially protected against P. chabaudi malaria, indicating a role for protective antibody-dependent and antibody-independent mechanisms of immunity. The involvement of gammadelta T cells in vaccine-induced PcAMA-1 and/or PcMSP-1(42) protection was minor. Analysis of the isotypic profile of antigen-specific antibodies induced by immunization of immunologically intact mice revealed a dominant IgG1 response. However, neither interleukin-4 and the production of IgG1 antibodies nor gamma interferon and the production of IgG2a/c antibodies were essential for PcAMA-1 and/or PcMSP-1(42) vaccine-induced protection. Therefore, for protective antibody-mediated immunity, vaccine adjuvants and delivery systems for AMA-1- and MSP-1-based vaccines can be selected for their ability to maximize responses irrespective of IgG isotype or any Th1 versus Th2 bias in the CD4(+)-T-cell response.     

Protective immunity induced in Aotus monkeys by a recombinant SERA protein of Plasmodium falciparum: adjuvant effects on induction of protective immunity.

We report the results of vaccination trial 2 of Panamanian Aotus monkeys with a recombinant blood-stage antigen, SERA 1, of the malaria parasite Plasmodium falciparum. Monkeys were immunized with SERA 1, a 262-amino-acid fragment (amino acids 24 to 285) of the 989-amino-acid SERA protein produced by the Honduras 1 strain of the parasite. Immunization mixtures contained 100 micrograms of recombinant SERA 1 protein per dose mixed with one of five different adjuvants. The protein mixed with either Freund's adjuvant or MF75.2 adjuvant stimulated protective immunity. When other P. falciparum antigens were included in the SERA 1-Freund's adjuvant mixture, no protective immunity was observed, although high anti-SERA 1 antibody titers were produced. Three other adjuvants mixed with SERA 1 failed to induce a protective immune response. These results, their relationship to those reported previously in the first vaccination trial (trial 1), and their relationships to the quantitative measurement of anti-SERA 1 antibodies in enzyme-linked immunosorbent assays provided insights into the induction of a protective immune response in vaccinated monkeys.     

嗜肺军团菌免疫原蛋白核酸疫苗诱导的小鼠免疫应答及其保护力

目的:研究嗜肺军团菌免疫原蛋白核酸疫苗诱导的小鼠免疫原性以及对LP感染小鼠的保护能力。方法:用嗜肺军团菌免疫原蛋白基因真核表达重组质粒pcDNA3.1-ip作为DNA疫苗免疫BALB/c小鼠,检测免疫小鼠体内抗原特异性抗体水平、脾淋巴细胞增殖活性、IFNγ-产生水平和CTL特异杀伤活性等指标,以评价疫苗的免疫原性。真核表达重组质粒pcDNA3.1-ipDNA疫苗重复免疫BALB/c小鼠2次,末次免疫2周后,用10倍LD50剂量攻击小鼠,计数小鼠的存活数及小鼠肺中的细菌数,观察感染鼠的肺部病理变化。结果:pcDNA3.1-ip免疫小鼠后诱导产生了特异的体液免疫应答和细胞免疫应答,免疫组的免疫原性和免疫保护性均高于对照组pcDNA3.1( )组(P<0.01)。结论:免疫原蛋白基因可作为嗜肺军团菌核酸疫苗的侯选基因。