ISCOM 型白血病瘤苗联合1-甲基色氨酸免疫治疗荷瘤小鼠疗效观察

目的：探讨免疫刺激复合物（ISCOM ）型白血病肿瘤疫苗（简称瘤苗）联合1-甲基色氨酸对荷瘤小鼠的治疗作用。方法皂苷溶液中加入脂肪酶蛋白（1 mg／mL ）7℃反应12 h ,加入80μL 脂类混合物溶液和5 mL 皂苷溶液（1 mg／mL ）制备ISCOM 型白血病瘤苗。 C57BL／6小鼠分为模型组、ISCOM 型白血病瘤苗组、1-甲基色氨酸组和联用组（ISCOM 型白血病瘤苗＋1-甲基色氨酸）,小鼠注射 FBL-3细胞建立白血病荷瘤小鼠模型,模型组给予等量生理盐水,其余各组接受对应药物治疗4周后,记录体质量,NK 细胞、Mφ细胞和细胞毒 T 淋巴细胞（CTL）细胞杀伤活性、血清 IL-10和 IL-12表达水平。结果联用组瘤质量低于1-甲基色氨酸组和 ISCOM 型白血病瘤苗组[（0．64±0．26）g vs ．（2．49±0．91）g ,P＜0．01;（0．64±0．26）g vs ．（1．28±0．73） g ,P＜0．05）];联用组 M φ细胞杀伤活性显著高于1-甲基色氨酸组[（55．69±13．69）％ vs ．（69．47±14．79）％,P＜0．01）];联用组NK 细胞杀伤活性显著高于1-甲基色氨酸组[（38．41±8．27）％ vs ．（67．22±12．74）％,P＜0．01];联用组 CTL 细胞杀伤活性高于1-甲基色氨酸组和 ISCOM 型白血病瘤苗组[（43．77±8．89）％ vs ．（69．68±11．44）％,P ＜0．01;（58．87±9．45）％ vs ．（69．68±11．44）％,P＜0．05）];联用组 IL-10均显著低于1-甲基色氨酸组、ISCOM 型白血病瘤苗组[（76．2±6．82）pg／L vs ．（98．3±13．4） pg／L ,P＜0．01;（76．2±6．82）pg／L vs ．（202．3±44．5）pg／L ,P＜0．01）];联用组 IL-12高于1-甲基色氨酸组、ISCOM 型白血病瘤苗组[（381．2±47．3）pg／L vs ．（332．1±30．2）pg／L ,P ＜0．05;（381．2±47．3）pg／L vs ．（291．2±17．3）pg ／L ,P＜0．01）。结论ISCOM 白血病瘤苗联合1-甲基色氨酸具有较佳的抗瘤活性,其机制可能是通过介导 IL-10和 IL-12的表达。     

创伤弧菌ISCOM疫苗的免疫学效应研究

目的探讨创伤弧菌ISCOM疫苗的免疫学效应。方法制备创伤弧菌ISCOM疫苗,通过注射、浸泡与灌胃接种鳗鲡进行安检试验,显示创伤弧菌ISCOM疫苗安全、可靠;注射途径室内免疫欧洲鳗,通过菌体凝集方法和ELISA方法测定血清免疫应答规律,表明两者趋势基本一致,免疫组的血清抗体水平明显高于对照组;攻毒试验表明相对免疫保护率达100%;田间试验口服免疫日本鳗后的攻毒试验证明相对免疫保护率近80%。结果创伤弧菌ISCOM疫苗安全,且免疫鳗鲡能产生强大的免疫保护力。结论创伤弧菌ISCOM疫苗有效且实用。     

重组日本血吸虫脂肪酸结合蛋白在不同佐剂条件下的免疫效果观察

目的观察重组日本血吸虫脂肪酸结合蛋白在几种佐剂条件下的免疫预防效果。方法用E.coli表达日本血吸虫脂肪酸结合蛋白基因,制备日本血吸虫脂肪酸结合蛋白与GST的重组融合蛋白(rSj14/GST),分别以福氏完全佐剂(FCA)/福氏不完全佐剂(FIA)、卡介苗(BCG)和免疫刺激复合物(ISCOM)作为佐剂免疫昆明系小鼠,比较攻击感染后的减虫效果。结果以BCG为佐剂皮内免疫和以ISCOM为佐剂皮下免疫分别诱导了34.3%和36.0%的减虫率;而以FCA/FIA为佐剂进行免疫,虽然诱导了较高的抗体反应,但几乎没有产生明显的减虫效果(8.5%)。结论BCG和ISCOM均是rSj14/GST的适宜佐剂。     

Immunogenicity in rabbits and monkeys of influenza ISCOMs conjugated with repeated sequences of the Plasmodium falciparum antigen Pf155/RESA

Rabbits and monkeys were immunized with two fusion proteins, ZZ-M3 and ZZ-M5, coupled to pre-formed influenza virus membrane glycoprotein ISCOMs. The fusion proteins comprise two IgG-binding domains from staphylococcal protein A (ZZ) and repeated amino acid sequences from the C-terminal (M3) or central (M5) repeat regions of the Plasmodium falciparum antigen Pf155/RESA. The induced antibody responses were of long duration, could be efficiently boosted and were comparable to those obtained with Freund's Adjuvant. The produced antibodies reacted with M3, M5, protein A and the influenza glycoprotein, recognized Pf155/RESA and inhibited merozoite invasion in vitro. These results suggest that coupling of immunogens to pre-formed ISCOMs may be a basis for construction of multivalent subunit vaccines.     

Serum IgG titres,but not avidity,correlates with neutralizing antibody response after H5N1 vaccination

Background

Influenza H5N1 virus constitutes a pandemic threat and development of effective H5N1 vaccines is a global priority. Anti-influenza antibodies directed towards the haemagglutinin (HA) define a correlate of protection. Both antibody concentration and avidity may be important for virus neutralization and resolving influenza disease.

Methods

We conducted a phase I clinical trial of a virosomal H5N1 vaccine adjuvanted with the immunostimulating complex Matrix M™. Sixty adults were intramuscularly immunized with two vaccine doses (21 days apart) of 30 μg HA alone or 1.5, 7.5 or 30 μg HA adjuvanted with Matrix M™. Serum H5 HA1-specific antibodies and virus neutralization were determined at days 0, 21, 42, 180 and 360 and long-term memory B cells at day 360 post-vaccination. The binding of the HA specific antibodies was measured by avidity NaSCN-elution ELISA and surface plasmon resonance (SPR).

Results

The H5 HA1-specific IgG response peaked after the second dose (day 42), was dominated by IgG1 and IgG3 and was highest in the adjuvanted vaccine groups. IgG titres correlated significantly with virus neutralization at all time points (Spearman r ≥ 0.66, p < 0.0001). By elution ELISA, serum antibody avidity was highest at days 180 and 360 post vaccination and did not correlate with virus neutralization. Long-lasting H5 HA1-specific memory B cells produced high IgG antibody avidity similar to serum IgG.

Conclusions

Maturation of serum antibody avidity continued up to day 360 after influenza H5N1 vaccination. Virus neutralization correlated with serum H5 HA1-specific IgG antibody concentrations and not antibody avidity.     

Matrix-M adjuvanted virosomal H5N1 vaccine confers protection against lethal viral challenge in a murine model

Please cite this paper as: Pedersen et al. (2011) Matrix‐M adjuvanted virosomal H5N1 vaccine confers protection against lethal viral challenge in a murine model. Influenza and Other Respiratory Viruses 5(6), 426–437. Background A candidate pandemic influenza H5N1 vaccine should provide rapid and long‐lasting immunity against antigenically drifted viruses. As H5N1 viruses are poorly immunogenic, this may require a combination of immune potentiating strategies. An attractive approach is combining the intrinsic immunogenicity of virosomes with another promising adjuvant to further boost the immune response. As regulatory authorities have not yet approved a surrogate correlate of protection for H5N1 vaccines, it is important to test the protective efficacy of candidate H5N1 vaccines in a viral challenge study. Objectives This study investigated in a murine model the protective efficacy of Matrix‐M adjuvanted virosomal influenza H5N1 vaccine against highly pathogenic lethal viral challenge. Methods Mice were vaccinated intranasally (IN) or intramuscularly (IM) with 7·5 μg and 30 μg HA of inactivated A/Vietnam/1194/2004 (H5N1) (NIBRG‐14) virosomal adjuvanted vaccine formulated with or without 10 μg of Matrix‐M adjuvant and challenged IN with the highly pathogenic A/Vietnam/1194/2004 (H5N1) virus. Results and conclusions IM vaccination provided protection irrespective of dose and the presence of Matrix‐M adjuvant, whilst the IN vaccine required adjuvant to protect against the challenge. The Matrix‐M adjuvanted vaccine induced a strong and cross‐reactive serum antibody response indicative of seroprotection after both IM and IN administration. In addition, the IM vaccine induced the highest frequencies of influenza specific CD4+ and CD8+ T‐cells. The results confirm a high potential of Matrix‐M adjuvanted virosomal vaccines and support the progress of this vaccine into a phase 1 clinical trial.     

Vaccination of harbour seals (Phoca vitulina) against phocid distemper with two different inactivated canine distemper virus (CDV) vaccines

Two inactivated canine distemper virus (CDV) vaccines—an adjuvanted whole inactivated virus and a subunit ISCOM preparation—were tested for their ability to induce protective immunity in harbour seals (Phoca vitulina) against phocid distemper, a disease that recently killed > 17 000 harbour seals in the North and Baltic seas, and was shown to be caused by infection with a newly discovered morbillivirus, which is antigenically closely related to CDV. Four CDV seronegative harbour seals were vaccinated three times with the whole-virus vaccine, two with the ISCOM subunit vaccine and two were sham-vaccinated with an antigen-free preparation. Ten days after the last vaccination, when all six vaccinated animals had developed CDV neutralizing antibody titres ranging from 300 to 3000, all eight animals were challenged by the oculonasal and the peritoneal routes, with an organ suspension from dead seals. None of the six vaccinated animals developed clinical signs. The two sham-vaccinated seals died on days 14 and 18, respectively, after having shown a body temperature rise, respiratory symptoms and weight loss. In organs from both dead animals morbillivirus antigen was demonstrated with an enzyme-linked immunosorbent assay and an immunofluorescence assay. One of these two animals had developed a low titre of CDV-specific antibodies just before death. These data clearly indicate that seals can be protected from fatal challenge with the phocid distemper virus (PDV), by vaccination with certain inactivated CDV vaccines. They also reconfirm that infection with PDV should be considered the primary cause of the recent epizootic in seals.     

抗原与免疫刺激复合物结合方法研究

近年来,一些利用通用表达系统表达抗原,并将其耦联于佐剂系统的研究屡有报道.本文介绍了应用基因融合技术实现重组抗原与免疫刺激复合物的联合,并对一系列研究结果进行了阐述.     

Efficacy of a trans-sialidase-ISCOMATRIX subunit vaccine candidate to protect against experimental Chagas disease

Recombinant protein vaccines are safe but elicit low immunological responses. The new generation of adjuvants is currently reversing this situation. Here, a new antigen–adjuvant combination for protection against experimental Chagas disease was assessed. The antigen used in the formulation was a glycosylated mutant inactive trans-sialidase (mTS) that was previously proven to be highly protective against Trypanosoma cruzi infection; here, we show that it can be produced in large quantities and high quality using Pichia pastoris. The adjuvant used in the formulation was ISCOMATRIX (IMX), which was found to be effective and safe in human clinical trials of vaccines designed to control other intracellular infections. Fifteen days after the third immunization, mice immunized with mTS-IMX showed a TS-specific IgG response with titers >10⁶ and high avidity, an increased IgG₂a/IgG1 ratio, significant delayed-type hypersensitivity (DTH) reactivity, a balanced production of IFN-γ and IL-10 by splenocytes and a strong IFN-γ secretion by CD8⁺ T lymphocytes. When these mice where challenged with 1000 trypomastigotes of T. cruzi, all mTS-IMX immunized mice survived, whereas mice immunized with mTS alone, IMX or PBS exhibited high mortality. Remarkably, during acute infection, when the parasitemia is highest in this infection model (day 21), mTS-IMX immunized mice had ∼50 times less parasitemia than non-immunized mice. At this moment and also in the chronic phase, 100 days after infection, tissue presented ∼4.5 times lower parasite load and associated inflammatory infiltrate and lesions. These results indicate that protection against Chagas disease can be achieved by a protein antigen–adjuvant mTS formulation that is compatible with human medicine. Therefore, the current formulation is a highly promising T. cruzi vaccine candidate to be tested in clinical trials.     

Induction of Cell Death by Saponin and Antigen Delivery

PURPOSE: Saponin is the major component in the formation of immune stimulating complex (ISCOM), a potent adjuvant able to induce both humoral and cellular immune reactions. The immunogenicity induced by saponin, however, has been unclear. The objective of this study was to investigate the apoptotic and necrotic effects induced by saponin in ELA mouse lymphoma cells, expected to be a possible mechanism of the cytotoxic T-lymphocyte (CTL) effect elicited by the ISCOM. METHODS: EL4 cells were treated with saponin, and viability of the cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase release assays. Fluorescence microscopy was used to detect the morphological changes by staining saponin-treated cells with Hoechst 33342. Extent of apoptosis and necrosis was determined by Annexin V-FITC/propidium iodide staining, followed by flow cytometric analysis. Dendritic cells were cultured with either saponin-protein complexes or saponin-treated cells and analyzed by flow cytometry. RESULTS: Treatment of EL4 cells with saponin resulted in concentration-dependent cytotoxicity and the appearance of the hypodiploid DNA peak. Cells treated with saponin showed highly condensed chromatin when stained with fluorescent DNA-binding dye Hoechst 33342. Analysis of EL4 cells by flow cytometry after Annexin V/propidium iodide staining demonstrated that saponin induced both apoptosis and necrosis. Pretreatment of EL4 cells with zVAD-fmk, a broad-range caspase inhibitor, did not prevent cell death induced by saponin, indicating the non-caspase-dependent cell death. Dendritic cells were shown to phagocytose both the antigen-saponin complexes and the saponin-induced dead cells. CONCLUSIONS: Results obtained in this study demonstrated that saponin induced both apoptosis and necrosis in ELA cells. These events are critical for antigen processing and presentation.