脱落酸抗体的抗独特型抗体的制备与鉴定

用ABA多克隆抗体(Ab_1)以金黄色葡萄球菌菌体(SPA)作为载体,免疫家兔,制备的抗独特型抗体(Ab_2)初步纯化后用ELISA试验鉴定其特异性的结果表明,该抗独特型抗体具有良好的特异性,能阻断ABA抗体对ABA的结合反应,并与ABA结合蛋白结合,暗示其有模拟抗原的作用。 Jerne的免疫网络学说认为,特异性抗体(Ab_1)可变区中的独特型决定簇(Id)可诱导抗独特型抗体(Ab_2)的产生,Ab_2中的一部分可以模拟抗原的作用。Sege和Peterson提出,     

B淋巴细胞恶性肿瘤独特型-抗独特型研究现状

<正>根据Jerne的网络学说,免疫球蛋白(Ig)的可变区可诱导抗独特型抗体的产生。抗Id抗体能与相应抗原结合调整免疫系统,保持其内环境的相对稳定性。近年来实验证明,不仅Ig分子,B细胞的抗原受体有Id,而且T细胞抗原受体和T细胞分泌的辅助和抑制因子也有Id,他们均有抗原特异性Id和交叉反应Id。这些Id的表达均受基因调控。     

记忆性T细胞的形成、维持和功能

免疫记忆是指机体在对某一抗原产生特异性识别及应答的同时,记住该抗原,当再次遭遇同一抗原时,能发生快速和强烈的免疫应答。树突状细胞吞噬病原微生物后,通过主要组织相容性复合体分子提呈抗原短肽段,与T细胞相互作用。在T细胞抗原受体信号和共刺激信号的协同作用下,抗原特异性T细胞增殖,收缩,小部分细胞作为记忆细胞长期存活。免疫记忆T细胞在表型特征和功能上都存在多样性。深入研究机体记忆性T细胞的特征,不仅能指导新型疫苗的设计,而且可望帮助治疗疾病。     

人绒毛膜促性腺激素抗独特型抗体在小鼠中的免疫反应

我室制备了人绒毛膜促性腺激素(hCG)的抗独特型抗体,它们与hCG有相似的抗体和受体结合位点,因而认为它们可能具有hCG内镜像结构。如果这些抗独特型抗体也具有与hCG类似的免疫原性,可望利用它们来配合或代替hCG制备更好的免疫避孕疫苗。我们用一种hCG抗独特型抗体(Anti-BAH_1)免疫小鼠可得到抗hCG抗体,这些抗体占所产生的Anti-Anti-BAH_1抗体的1—2％,最高滴度可达1:2万左右。这个滴度可保持2个月左右,以后逐步下降,在停止免疫半年后抗体滴度降到最高滴度的15.6％。用Anti-BAH_1与hCG同时免疫,对hCG的免疫反应有一定抑制作用,但先用Anti-BAH_1免疫对随后的hCG免疫反应有一定增强作用。表明利用抗独特型抗体可能调控对hCG的免疫反应。这种调控作用与所采用的免疫方式及抗原剂量有关。     

抗独特型抗体Ab2β的制备及其应用

抗独特型抗体Ab2β由于含有抗原内影像结构而表现出抗原的部分生物活性。由于Ab2β具有模拟抗原的功能,使其在蛋白质、受体及疫苗等研究领域中的应用越来越广泛。文中简述了抗独特型抗体Ab2β的制备和应用及其应用所存在的问题,并讨论了Ab2β抗原内影像功能的结构基础,旨在展望其应用前景。     

免疫网络学说及其在医学中的应用进展

本文综述了免疫网络学说的基本要点,说明对自身独特型免疫产生抗独特型是体内的正常现象。然而一旦免疫网络的平衡失调就可能导致自身免疫病的发生,着重介绍了独特型网络和受体病的关系,阐明抗受体抗体就是抗独特型抗体的观点。并联系了抗独特型在医学的上应用,主要是有可能代替病毒、肿瘤抗原作为疫苗,并有可能用于淋巴瘤的治疗。     

抗独特型抗体研究的新进展

独特型是存在于抗体分子某些部位上的一种特殊基因。该基因具有抗原性,能在自体或异体内诱导出针对该基因的特异性抗体——抗独特型抗体。近年大量的动物实验证明,抗独特型抗体可以作为新一代免疫制剂,用以弥补现有疫苗的不足。同时,它还可用于癌症和自身免疫性疾病的治疗。     

肺炎支原体抗独特型卵黄抗体的制备与鉴定

目的制备肺炎支原体(M.pneumonia)抗独特型卵黄抗体(vitelline Ab2),鉴定其生物学特性,探讨其作为动物疫苗的潜在应用价值。方法首先制备兔、小鼠抗肺炎支原体抗体(Ab1),筛选出对肺炎支原体有免疫中和性的兔抗体和小鼠抗体,再用兔抗体免疫产蛋鸡,筛选并收集有高效价抗独特型卵黄抗体的鸡蛋,分离蛋黄,破碎蛋黄组织,用蒸馏水稀释和酸化提取抗独特型卵黄抗体。用冷酒精沉淀法纯化抗独特型卵黄抗体。用ELISA检测肺炎支原体抗独特型卵黄抗体(Ab2)的效价、质量浓度和特异性。用竞争抑制试验和动物免疫检测卵黄Ab2β。结果兔抗肺炎支原体抗体的效价为1×10~(-6),Ab1的效价为1×10~(-4)～1×10~(-5);以上抗体均只和肺炎支原体发生免疫反应,不和解脲支原体发生免疫反应;它们和肺炎支原体混合后能中和肺炎支原体的活性,使其不能在条件培养基生长。Ab2效价为1×10~(-5),质量浓度为8 mg/mL。该抗独特型卵黄抗体只和Ab1发生免疫反应,不和小鼠抗解脲支原体抗体发生免疫反应。该Ab2和Ab1结合能被肺炎支原体竞争抑制,且Ab2能诱导小鼠产生肺炎支原体抗体(Ab3),该Ab3能和肺炎支原体发生免疫反应。结论成功制备了特异性强、效价高的β型Ab2,具有作为动物肺炎支原体疫苗的潜在应用价值。     

阿尔茨海默病重组4Aβ15-TF亚单位疫苗的免疫原性研究

目的:研究重组嵌合抗原4Aβ15-TF的免疫原性,评估其作为亚单位疫苗的可行性。方法:设计合成了重组融合蛋白4Aβ15-TF的基因序列,插入原核表达载体p TIG-Trx中,用大肠杆菌表达并纯化重组嵌合抗原4Aβ15-TF,与铝佐剂配制成亚单位疫苗免疫C57BL/6小鼠以研究其免疫原性。结果:重组嵌合抗原4Aβ15-TF免疫小鼠后刺激其产生了抗β淀粉样蛋白(Aβ)42的特异性抗体,抗体滴度4次免疫后达到较高水平,抗体亚型主要为IgG1型,并且伴随着少量的IgG2b,T淋巴细胞增殖实验证明免疫后产生了针对辅助性T细胞表位的T细胞免疫反应,不产生针对Aβ42的T细胞免疫反应。结论:大肠杆菌表达的重组嵌合抗原4Aβ15-TF具有良好的免疫原性,能够刺激产生高滴度的抗Aβ42抗体,并且产生的免疫反应主要为Th2型,无Aβ42特异的T淋巴细胞增殖反应。提示它可作为候选疫苗用于预防或免疫治疗阿尔茨海默病。     

布鲁氏菌抗独特型抗体的研究

在建立布鲁氏菌单克隆抗体细胞株的基础上,筛选具有保护作用的单抗A7免疫家免制备抗独特型抗体(简称二抗)。经阻断试验和竞争抑制试验证实,该二抗具有抗原“内影象”。将其提纯后配制成甘油佐剂苗免疫豚鼠和小白鼠．检测结果表明：免疫豚鼠和小白鼠产生了布鲁氏菌凝集抗体;免疫小鼠的循环T ANAE-细胞百分数明显高于对照组;免疫豚鼠在免疫后4个月时强毒菌株攻击有79．2％获得保护。因此认为,该二抗不仅具有抗原的。内影象”结构,而且具有良好的免疫原性,可供作疫苗用。     

Induction of Plasmodium falciparum-specific CD4+ T cells and memory B cells in Gabonese children vaccinated with RTS,S/AS01(E) and RTS,S/AS02(D)

The recombinant circumsporozoite protein (CS) based vaccine, RTS,S, confers protection against Plasmodium falciparum infection in controlled challenge trials and in field studies. The RTS,S recombinant antigen has been formulated with two adjuvant systems, AS01 and AS02, which have both been shown to induce strong specific antibody responses and CD4 T cell responses in adults. As infants and young children are particularly susceptible to malaria infection and constitute the main target population for a malaria vaccine, we have evaluated the induction of adaptive immune responses in young children living in malaria endemic regions following vaccination with RTS,S/AS01(E) and RTS,S/AS02(D). Our data show that a CS-specific memory B cell response is induced one month after the second and third vaccine dose and that CS-specific antibodies and memory B cells persist up to 12 months after the last vaccine injection. Both formulations also induced low but significant amounts of CS-specific IL-2(+) CD4(+) T cells one month after the second and third vaccine dose, upon short-term in vitro stimulation of whole blood cells with peptides covering the entire CS derived sequence in RTS,S. These results provide evidence that both RTS,S/AS01(E) and RTS,S/AS02(D) induced adaptive immune responses including antibodies, circulating memory B cells and CD4(+) T cells directed against P. falciparum CS protein. TRIAL REGISTRATION: ClinicalTrials.gov NCT00307021.     

Cellular immune response to an engineered cell-based tumor vaccine at the vaccination site

The engineered expression of the immune co-stimulatory molecules CD80 and CD137L on the surface of a neuroblastoma cell line converts this tumor into a cell-based cancer vaccine. The mechanism by which this vaccine activates the immune system was investigated by capturing and analyzing immune cells responding to the vaccine cell line embedded in a collagen matrix and injected subcutaneously. The vaccine induced a significant increase in the number of activated CD62L(-) CCR7(-) CD49b(+) CD8 effector memory T cells captured in the matrix. Importantly, vaccine responsive cells could be detected in the vaccine matrix within a matter of days as demonstrated by IFN-gamma production. The substitution of unmodified tumor cells for the vaccine during serial vaccination resulted in a significant decrease in activated T cells present in the matrix, indicating that immune responses at the vaccine site are a dynamic process that must be propagated by continued co-stimulation.     

Clinical trials of antitumor vaccination with an autologous tumor cell vaccine modified by virus infection: improvement of patient survival based on improved antitumor immune memory

For active specific immunotherapy of cancer patients, we designed the autologous virus–modified tumor cell vaccine ATV-NDV. The rationale of this vaccine is to link multiple tumor-associated antigens (TAAs) from individual patient-derived tumor cells with multiple danger signals (DS) derived from virus infection (dsRNA, HN, IFN-). This allows activation of multiple innate immune responses (monocytes, dendritic cells, and NK cells) as well as adaptive immune responses (CD4 and CD8 memory T cells). Preexisting antitumor memory T cells from cancer patients could be activated by antitumor vaccination with ATV-NDV as seen by augmentation of antitumor memory delayed-type hypersensitivity (DTH) responses. In a variety of phase II vaccination studies, an optimal formulation of this vaccine could improve long-term survival beyond what is seen in conventional standard therapies. A new concept is presented which proposes that a certain threshold of antitumor immune memory plays an important role (1) in the control of residual tumor cells which remain after most therapies and (2) for long-term survival of treated cancer patients. This immune memory is T-cell based and most likely maintained by persisting TAAs from residual dormant tumor cells. Such immune memory was prominent in the bone marrow in animal tumor models as well as in cancer patients. Immunization with a tumor vaccine in which individual TAAs are combined with DS from virus infection appears to have a positive effect on antitumor immune memory and on patient survival.     

Maternal antibody blocks humoral but not T cell responses to BVDV.

Bovine viral diarrhoea virus (BVDV) contributes significantly to health-related economic losses in the beef and dairy industry. Antibodies of maternal origin can be protective against BVDV infection, however, calves with low titres of maternal antibody or that do not receive colostrum may be at risk for acute BVDV infection. Interference by high titres of maternal antibodies prevents the development of an antibody response following vaccination with either a killed or attenuated BVDV vaccine. However, the T cell mediated immune response to BVDV may be generated in the absence of a detectable serum neutralizing antibody response. Two trials were conducted to evaluate the potential to elicit T cell mediated immune responses to BVDV in calves with circulating maternal antibody to BVDV. In the first trial, calves with high levels of circulating maternal antibody to BVDV 1 and BVDV 2 were experimentally infected with BVDV 2 (strain 1373) at two to five weeks of age. The T-cell mediated immune responses of the experimentally infected calves and non-infected calves were monitored monthly until circulating maternal antibody was no longer detectable in either treatment group. Calves experimentally infected with BVDV developed BVDV specific CD4(+), CD8(+), and delta T cell responses while high levels of maternal antibody were circulating. A second challenge with BVDV 2 (strain 1373) was performed in the experimentally infected and control calves once maternal antibody could no longer be detected. Previous exposure to BVDV in the presence of maternal antibody protected calves from clinical signs of acute BVDV infection compared to the control calves. In the second trial, three groups of calves with circulating maternal antibody to BVDV were given either a modified live vaccine (MLV) containing BVDV 1 and BVDV 2, a killed vaccine containing BVDV 1 and BVDV 2, or no vaccine, at seven weeks of age. Serum neutralizing antibody levels and antigen specific T cell responses were monitored for 14 weeks following vaccination. Calves vaccinated with MLV BVDV developed BVDV 1 and BVDV 2 specific CD4(+)T cell responses, and BVDV 2 specific gammadelta T cell responses, in the presence of maternal antibody. Vaccination with killed BVDV did not result in the generation of measurable antigen specific T cell immune responses. In this trial, a second vaccination was performed at 14 weeks to determine whether an anamnestic antibody response could be generated when calves were vaccinated in the presence of maternal antibody. Calves vaccinated with either a MLV or killed BVDV vaccine while they had maternal antibody developed an anamnestic antibody response to BVDV 2 upon subsequent vaccination. The results of these trials indicate that vaccinating young calves against BVD while maternal antibody is present may generate BVDV specific memory T and B cells. The data also demonstrated that seronegative calves with memory T and B cells specific for BVDV may be immune to challenge with virulent BVDV.     

结核分枝杆菌蛋白亚单位疫苗与疫苗诱导的T细胞免疫记忆研究进展

牛分枝杆菌减毒活疫苗--卡介苗(bacillus Calmette-Guérin,BCG)对预防严重的儿童结核病有效,但其免疫保护效率随儿童年龄增长而降低。BCG不能提供终身免疫保护可能与其诱导的记忆性T细胞主要是寿命较短的效应记忆性T细胞有关。新型结核分枝杆菌蛋白亚单位疫苗将有效的抗原有机组合起来,在适宜的疫苗佐剂辅助下诱导Th1型免疫应答。动物实验表明,增加抗原谱可有效提高亚单位疫苗的保护效率。更重要的是,亚单位疫苗在体内持续时间较短,可诱导寿命较长的中央记忆性T细胞,提供比BCG更持久的免疫保护力。记忆性T细胞的分化受抗原特性与剂量、细胞因子、转录因子及雷帕霉素等的调控。对亚单位疫苗及其诱导的免疫记忆进行研究将对新型结核分枝杆菌疫苗的设计与评价产生积极影响。     

Memory T cells protect against Plasmodium vivax infection

Immunity induced by Plasmodium vivax infection leads to memory T cell recruitment activated during "relapse" or "re-infection". This study aims to characterise memory T cells in patients with acute or convalescent P. vivax infection. Lymphocytes were collected from patients infected by P. vivax, immune controls and naive controls. The proportion of immature memory T cells, expressing CD45RO(+)CD27(+), and mature cells lacking CD27 was assessed. A statistically significant increase in the median percentage of memory T cell subsets expressing CD4(+) was observed in material from patients with an acute infection compared with that from either naive or immune controls. The high percentage of memory T cells in infected patients was maintained until 60 days post treatment. The immune controls living in a malaria endemic area had a somewhat increased proportion of memory T cell subsets expressing CD8(+). An approximately three-fold increase of these cell types was shown in patients with an acute infection and the level persisted until 60 days post treatment. Phenotypic characterisation of the peripheral lymphocytes during acute infection revealed that a large fraction of the lymphocytes carried the gammadelta phenotypes suggesting a role for these cells in the early response against P. vivax. Very low levels of P. vivax specific antibody were found. This might suggest that cell-mediated immunity may play a greater role in the development of naturally acquired protection against P. vivax infection than humoral immunity. Our results provide further insight into the mechanism of cell-mediated immunity to P. vivax infection that could be important for the future development of a successful vaccine and anti-malarial drug designation.     

Divergent Primary Immune Responses Induced by Human Immunodeficiency Virus-1 gp120 and Hepatitis B Surface Antigen Determine Antibody Recall Responses

The development of a vaccine based on human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) that elicits potent protective antibodies against infection has been challenging. Recently, we compared the antibody production patterns of HIV-1 Env gp120 and hepatitis B virus surface antigen (HBsAg) to provide insights into how we may improve the protective efficacy of Env-based immunogens. Our previous study showed that HIV Env and HBsAg display different mechanisms of antibody elicitation and that T cells facilitate the responses to repeated immunizations. Here, to elucidate the detailed roles of primary immunization in immune memory response formation and antibody production, we immunized C57BL/6 mice with each antigen and evaluated the development of T follicular helper (Tfh) cells, germinal centers, and the memory responses involved in prime and boost immunizations. We found that after prime immunization, compared with HBsAg, gp120 induced higher frequencies of Tfh cells and programmed death (PD)-1⁺ T cells, greater major histocompatibility complex II expression on B cells, comparable activated B cells, but weaker germinal center (GC) reactions and memory B cell responses in the draining lymph nodes, accompanied by slower antibody recall responses and poor immune memory responses. The above results suggested that more PD-1⁺ T cells arising in primary immunization may serve as major contributors to the slow antibody recall response elicited by HIV-1 Env.     

Therapeutic vaccination with simian immunodeficiency virus (SIV)-DNA + IL-12 or IL-15 induces distinct CD8 memory subsets in SIV-infected macaques

DNA vaccination is an invaluable approach for immune therapy in that it lacks vector interference and thus permits repeated vaccination boosts. However, by themselves, DNA-based vaccines are typically poor inducers of Ag-specific immunity in humans and non-human primates. Cytokines, such as IL-12 and IL-15, have been shown to be potent adjuvants for the induction and maintenance of cellular immune responses, in particular during HIV infection. In this study, we examined the ability of therapeutic vaccination with SIV-DNA+IL-12 or IL-15 as molecular adjuvants to improve DNA vaccine potency and to enhance memory immune responses in SIV-infected macaques. Our results demonstrate that incorporating IL-12 into the vaccine induces SIV-specific CD8 effector memory T cell (T(EM)) functional responses and enhances the capacity of IFN-gamma-producing CD8 T(EM) cells to produce TNF. Lower levels of PD-1 were expressed on T cells acquiring dual function upon vaccination as compared with mono-functional CD8 T(EM) cells. Finally, a boost with SIV-DNA+IL-15 triggered most T cell memory subsets in macaques primed with either DNA-SIV or placebo but only CD8 T(EM) in macaques primed with SIV-DNA+IL-12. These results indicate that plasmid IL-12 and IL-15 cytokines represent a significant addition to enhance the ability of therapeutic DNA vaccines to induce better immunity.     

MHC Class I-Presented T Cell Epitopes Identified by Immunoproteomics Analysis Are Targets for a Cross Reactive Influenza-Specific T Cell Response

Influenza virus infection and the resulting complications are a significant global public health problem. Improving humoral immunity to influenza is the target of current conventional influenza vaccines, however, these are generally not cross-protective. On the contrary, cell-mediated immunity generated by primary influenza infection provides substantial protection against serologically distinct viruses due to recognition of cross-reactive T cell epitopes, often from internal viral proteins conserved between viral subtypes. Efforts are underway to develop a universal flu vaccine that would stimulate both the humoral and cellular immune responses leading to long-lived memory. Such a universal vaccine should target conserved influenza virus antibody and T cell epitopes that do not vary from strain to strain. In the last decade, immunoproteomics, or the direct identification of HLA class I presented epitopes, has emerged as an alternative to the motif prediction method for the identification of T cell epitopes. In this study, we used this method to uncover several cross-specific MHC class I specific T cell epitopes naturally presented by influenza A-infected cells. These conserved T cell epitopes, when combined with a cross-reactive antibody epitope from the ectodomain of influenza M2, generate cross-strain specific cell mediated and humoral immunity. Overall, we have demonstrated that conserved epitope-specific CTLs could recognize multiple influenza strain infected target cells and, when combined with a universal antibody epitope, could generate virus specific humoral and T cell responses, a step toward a universal vaccine concept. These epitopes also have potential as new tools to characterize T cell immunity in influenza infection, and may serve as part of a universal vaccine candidate complementary to current vaccines.     

Modeling AIDS vaccines: the cellular level.

This paper discusses current strategies for the development of AIDS vaccines which allow immunization to disturb the natural course of HIV at different detailed stages of its life cycle. Mathematical models describing the main biological phenomena (i.e. virus and vaccine induced T4 cell growth; virus and vaccine induced activation of latently infected T4 cells; incremental changes in immune response as infection progresses; antibody dependent enhancement and neutralization of infection) and allowing for different vaccination strategies serve as a background for computer simulations. The mathematical models reproduce updated information on the behavior of immune cells, antibody concentrations and free viruses. The results point to some controversial outcomes of an AIDS vaccine such as an early increase in virus concentration among vaccinated when compared to nonvaccinated individuals.