日本血吸虫副肌球蛋白T细胞表位的预测和鉴定

目的鉴定日本血吸虫副肌球蛋白的T细胞表位。方法用SYFPEITHI软件预测日本血吸虫(中国大陆株)副肌球蛋白的T细胞表位，候选表位分别命名为P20、P21、P22、P23、P24。设计并合成候选表位的编码核苷酸，定向克隆入融合表达载体pET-32c( )，经酶切及测序鉴定出重组克隆。阳性克隆经IPTG诱导表达，表达产物以Ni^2 -NTA柱亲和层析及透析纯化。纯化后的硫氧还蛋白(Trx)融合蛋白体外刺激C3H／HeJ及C57BL／6小鼠腹股沟淋巴结或脾脏单个核细胞，^3H-TdR掺入法检测其增殖。结果候选表位中P20、P21、P22、P23能有效刺激C3H鼠致敏淋巴细胞细胞增殖，P20、P22能刺激C57鼠致敏淋巴细胞增殖。结论P20和P22可能是日本血吸虫副肌球蛋白的通用性T细胞表位。     

日本血吸虫大陆株副肌球蛋白部分基因克隆

目的 :克隆日本血吸虫大陆株副肌球蛋白部分基因。方法 :用 PCR方法根据已发表日本血吸虫菲律宾株副肌球蛋白基因部分核苷酸序列扩增大陆株副肌球蛋白基因。结果 :获得一日本血吸虫大陆株 72 0 bp基因克隆。结论 :经核苷酸序列分析证实 ,本克隆基因与菲律宾株基因核苷酸同源性为 99.0 3%。     

DNA immunization for the production of monoclonal antibodies to Blo t 11, a paramyosin homolog from Blomia tropicalis

BACKGROUND: Blo t 11 is a high molecular weight allergen from Blomia tropicalis with significant immunoglobulin (Ig)E binding frequency. Native and recombinant Blo t 11 are susceptible to degradation and the isolation and expression of the allergen is problematic thus obtaining sufficient amounts of purified Blo t 11 for antibody production is limiting. DNA-based immunization is an attractive alternative strategy that bypasses antigen purification for antibody production. OBJECTIVES: To use a DNA-based immunization protocol for the production and characterization of Blo t 11 monoclonal antibodies (mAbs). METHODS: The 2625 bp cDNA coding for Blo t 11 was cloned into a mammalian expression vector and immunized intramuscularly with electroporation into mice. Monoclonal antibodies to Blo t 11 were generated using a methylcellulose-based hybridoma cloning kit. These mAbs were utilized for native Blo t 11 isolation and the development of sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: Six mAbs recognizing the native and recombinant Blo t 11 were generated and characterized. Native Blo t 11 was affinity purified from Bt extract and its identity was confirmed by matrix assisted laser desorption/ionization - time of flight mass spectrometry. The native Blo t 11 showed IgE reactivity with 67% of mite allergic sera. A two-site ELISA developed showed a detection limit of 100 pg/ml of Blo t 11. CONCLUSION: A DNA-based immunization protocol was successfully used to generate Blo t 11 mAbs with a spectrum of distinct epitopes located throughout the whole molecule, and they are useful for immunoaffinity purification and immunoassays.     

Peptide mapping of immunoglobulin E and immunoglobulin G immunodominant epitopes of an allergenic Blomia tropicalis paramyosin, Blo t 11

BACKGROUND: The identification of immunodominant peptides containing the IgE and IgG epitopes on allergen molecules is an important step in understanding the interaction of the allergen with the immune system and, thus, essential for the development of effective immunotherapeutic and diagnostic reagents. The present study aimed to map the IgE and IgG immunodominant peptides of Blomia tropicalis (Bt) allergen Blo t 11, a high molecular weight allergen homologous to paramyosin, exhibiting important allergenic activity. METHODS: Eleven overlapping fragments of Blo t 11 cDNA gene were expressed as glutathione s-transferase (GST) fusion peptides, which were affinity-purified using the glutathione-Sepharose column. Human IgE and IgG immunodominant peptides were determined by dot blot immunoassay using crude Bt extract-positive sera from asthmatic patients. Evaluation of allergenicity, specific hIgG subclass analysis, and cross- and self-inhibition studies were determined by enzyme-linked immunosorbent assay. RESULTS: Blo t 11 contains multiple IgE and IgG immunodominant peptides scattered throughout the molecule. The dominant IgE and IgG peptides were mapped at amino acid positions 336-557 and 698-875, respectively. An immunodominant peptide (fD) registered a higher percentage of IgE and IgG reactivity compared to the rFL-Blo t 11. Significant serum levels of Blo t 11- and fD-specific IgG1, IgG2 and IgG4, but not IgG3 were detected in the Bt extract-positive sera tested. Cross-inhibition study revealed the rFL-Blo t 11 was significantly inhibited by fD. CONCLUSION: The IgE and IgG immunodominant peptides of Blo t 11 have been mapped. Our data suggest that utilization of Blo t 11 fragment(s) or chimeric fusion fragments containing IgE and IgG epitopes could be a better alternative in the development of diagnostic and therapeutic reagents for mite allergy.     

抗旋毛虫副肌球蛋白单克隆抗体的制备与鉴定

目的利用杂交瘤技术制备分泌抗重组旋毛虫副肌球蛋白N端抗原（rTsP3）的单克隆抗体（McAb）并进行鉴定。方法以rTsP3免疫BALB/c小鼠,取其脾细胞与小鼠骨髓瘤SP2/0细胞融合,筛选分泌高滴度McAb杂交瘤细胞株,制备腹水并进行纯化,采用间接ELISA法测定培养细胞上清液及腹水中的McAb滴度、相对亲和力及抗体亚类,Western blot法鉴定抗体对抗原识别的特异性。结果获得了2株稳定分泌抗旋毛虫rTsP3的McAb杂交瘤细胞株,分泌的McAb分别为IgG2b亚类κ型和IgG1亚类κ型,亲和力常数分别为8.98×108mol/L和9.7×10^8mol/L,Western blot显示2株单抗均能识别旋毛虫成虫匀浆蛋白、rTsP3及重组副肌球蛋白（rTsPmy）。结论成功制备了抗旋毛虫rTsP3单克隆抗体,该单抗能识别旋毛虫副肌球蛋白抗原。     

日本血吸虫副肌球蛋白全基因核酸疫苗在小鼠诱生的保护性免疫力

目的： 研究日本血吸虫大陆株副肌球蛋白全基因核酸疫苗免疫Ｃ５７ ＢＬ／６ 及ＢＡＬＢ／ｃ 小鼠诱生的保护性免疫力。方法： 将构建的日本血吸虫大陆株副肌球蛋白全基因核酸疫苗 （ｐＣＭＶ－ＳｊＣ９７） 经后腿胫前肌免疫Ｃ５７ＢＬ／６及ＢＡＬＢ／ｃ小鼠, 共免疫３ 次, 每次间隔３ ｗ ｋ。末次免疫后３ ｗ ｋ 以血吸虫尾蚴攻击感染, ６ ｗｋ 后计数成虫负荷及肝、脾、肠组织虫卵数。设不含ＳｊＣ９７ 编码基因的空载体质粒免疫组为对照组。结果： ｐＣＭＶ－ＳｊＣ９７ 免疫Ｃ５７ ＢＬ／６ 小鼠主要诱生ＩｇＧ２ａ 和ＩｇＧ２ｂ 亚类, 而免疫ＢＡＬＢ／ｃ小鼠除诱生ＩｇＧ２ａ 和ＩｇＧ２ｂ 亚类外, 还诱生ＩｇＧ１。ｐＣＭＶ－ＳｊＣ９７ 免疫Ｃ５７ＢＬ／６ 小鼠诱生较明显的减虫率 （３５．５％ ～４１．１％ ） 和减卵率 （肝、脾及肠组织减卵率分别为４４．５％ ～５９．６％ 、５６．７％ ～８２．４％ 及５７．９％ ）, 而对ＢＡＬＢ／ｃ小鼠未诱生保护性。结论： ｐＣＭＶ－ＳｊＣ９７ 核酸疫苗能对Ｃ５７ＢＬ／６ 小鼠诱生较明显保护性免疫力, 而对ＢＡＬＢ／ｃ 小鼠未诱生免疫保护力     

重组日本血吸虫副肌球蛋白免疫小鼠血清特异性抗体的检测

目的探讨重组日本血吸虫副肌球蛋白(rSj97)免疫小鼠产生抗感染保护力的机制.方法用ELISA法对每次免疫前、攻击感染前的免疫小鼠血清中特异性抗体的动态及滴度进行检测.结果第1次免疫后即产生了特异性抗体,第2次加强免疫后抗体水平进一步上升,攻击感染前达最高.攻击感染前的血清抗体滴度测定结果显示,平均抗体滴度达151200.结论rSj97免疫小鼠可引起明显的体液免疫应答.     

日本血吸虫复合表位DNA疫苗免疫保护作用的研究

目的研究日本血吸虫复合表位DNA疫苗诱导BALB/c小鼠抗血吸虫感染的免疫保护作用。方法将40只雌性BALB/c小鼠随机分为4组:pcDNA3.1组(对照组),每鼠经两侧股四头肌注射100μg pcDNA3.1质粒DNA,每侧50μg;TPI组,每鼠肌注100μg pcDNA3.1-TPI质粒DNA;TP组,每鼠肌注100μg pcDNA3.1-T-linker-P质粒DNA;PT组,每鼠肌注100μg pcDNA3.1-P-linker-T质粒DNA。每隔2周加强免疫1次,剂量和方法相同,共免疫3次。末次免疫后4周每鼠经腹部皮肤攻击感染(45±1)条日本血吸虫尾蚴,45d后剖杀,计数成虫及肝脏虫卵数。首次免疫前2 d及感染前2 d尾静脉采血,间接ELISA检测特异IgG及IgG1I、gG2a水平。末次免疫后3周,每组取2只小鼠制备脾细胞,双抗体夹心法检测脾细胞经ConA和rSjCTPI刺激后培养上清中的IL-2I、L-4和IFN-γ水平。结果TP组和PT组小鼠减虫率分别为34.76%和36.14%,显著高于TPI组(P<0.05)和对照组(P<0.01);减卵率分别为51.20%和50.79%,与TPI及对照组比较差异有显著性(P<0.05)。TP组和PT组小鼠血清特异性IgG水平均升高(P<0.05),IgG2a/IgG1的比值分别为4.23和4.34。脾细胞经ConA和rSjCTPI刺激后,IL-2水平TP组和PT组较对照组均升高。结论复合表位DNA疫苗能诱导小鼠产生抗血吸虫感染的免疫保护力,效果优于rSjCTPI疫苗。     

Vaccination of calves with yeast‐ and bacterial‐expressed paramyosin from the bovine lungworm Dictyocaulus viviparus

Previously, vaccination of cattle with Escherichia coli‐expressed bovine lungworm paramyosin (EcPMY) adjuvanted with Quil A resulted in considerable reduction in worm burden and larvae shedding (Strube et al., 2015). To further evaluate the protective potential of PMY, cattle vaccination trials were performed using either E. coli‐ (EcPMY) or Pichia pastoris‐expressed PMY (PpPMY) with different adjuvants (Matrix‐Q^? or Quil A). Combinations EcPMY+Matrix‐Q^? (trial 1), PpPMY+Matrix‐Q^? (trial 2) and PpPMY+Quil A (trial 3) were tested against challenge infections with 2000 Dictyocaulus viviparus larvae. Even though GM worm burden and larvae shedding was lower in almost all vaccinated groups, there were high variations between individuals hampering significant differences. However, in all vaccinated groups, lungworms were significantly shorter compared with those in controls. In vitro stimulation of peripheral blood mononuclear cells (PBMC) with recombinant (r)PMY revealed no significant proliferation following vaccinations or challenge infection. All vaccinated cattle showed a significant rise in specific antibodies, particularly IgG and its subclass IgG1, and detected the native lungworm PMY in immunoblots starting 2 weeks after the first vaccination. The use of a different rPMY‐adjuvant combination or combined vaccination with additional recombinant antigens might be a promising future approach towards a new vaccine against lungworms in cattle.     

Comparative allergenicity studies of native and recombinant Blomia tropicalis Paramyosin (Blo t 11)

BACKGROUND: The complementary DNA (cDNA) encoding for Blo t 11, a 102 kD allergen from Blomia tropicalis (Bt) was isolated, expressed and characterized previously. This study aimed to isolate the native Blo t 11 allergen and compare its allergenicity with the recombinant forms. METHODS: Native Blo t 11 (nBlo t 11) was isolated from crude Bt extract by immuno-affinity chromatography, analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot, and verified by MALDI-TOF MS. Recombinant full-length Blo t 11 (rFL-Blo t 11) and its immunodominant peptide (fD) were expressed as glutathione S-transferase (GST)-fusion proteins in Escherichia coli. Immunoglobulin E (IgE) reactivity of the Blo t 11 allergens were determined by enzyme-linked immunosorbent assay (ELISA) and skin prick test. The inhibition capacity of the nBlo t 11 against fD and vice versa was determined by absorption studies. RESULTS: Affinity purified nBlo t 11 was susceptible to degradation with the major degraded product resolved at approximately 66 kD. The nBlo t 11 was confirmed by immunoblot analysis and MALDI-TOF MS that generated 13 peptides with complete identity to the deduced amino acid sequence of Blo t 11. Comparative in vitro and in vivo allergenicity tests and the cross inhibition studies between the native and recombinant Blo t 11 showed that recombinant fD, but not the rFL-Blo t 11, has comparable IgE reactivity with the native counterpart. CONCLUSIONS: This comparative study confirmed that the recombinant peptide fD contains the main immunodominant region of Blo t 11. This recombinant peptide, instead of the full-length protein, is a good candidate for diagnostic and therapeutics development for mite allergy.