目的构建经MHCⅡ通路的屋尘螨1类变应原Der p 1的T细胞表位肽疫苗重组载体。方法分别合成TAT、Ih C和含编码Der p 1的3段T细胞表位的融合核苷酸序列,用特异性引物PCR扩增相应的基因片段,分别用相应的双酶切后,用T4 DNA连接酶连接形成TAT...目的构建经MHCⅡ通路的屋尘螨1类变应原Der p 1的T细胞表位肽疫苗重组载体。方法分别合成TAT、Ih C和含编码Der p 1的3段T细胞表位的融合核苷酸序列,用特异性引物PCR扩增相应的基因片段,分别用相应的双酶切后,用T4 DNA连接酶连接形成TAT-Ih C-Der p 1-3T融合基因,并插入至原核表达载体p ET-28a(+)中,构建重组原核表达载体p ET-28a(+)-TATIh C-Der p 1-3T,Bam HⅠ和XhoⅠ进行双酶切和测序鉴定。重组载体转化大肠杆菌E.coli BL21(DE3)菌株,IPTG诱导后,经SDS-PAGE电泳分析和Western blot验证,纯化TAT-Ih C-Der p 1-3T蛋白后进行Ig E结合试验。结果双酶切和测序结果表明,成功构建了p ET-28a-TAT-Ih C-Der p 1-3T重组原核表达载体;SDS-PAGE电泳分析显示TAT-Ih C-Der p 1-3T可诱导表达;Western blot检测表明该融合蛋白纯化成功;Ig E结合试验表明TAT-Ih C-Der p 1-3T结合屋尘螨过敏病人血清Ig E的能力强于Der p 1变应原(P<0.001)。结论成功构建了可表达经MHC通路的编码Der p 1的3段T细胞表位的重组p ET-28a-TAT-Ih C-Der p 1-3T载体,纯化的TAT-Ih C-Der p 1-3T具有较强的Ig E结合能力,从而为后续经MHC通路的特异性免疫治疗奠定基础。展开更多
目的鉴定1型登革病毒感染病人血清中1型登革病毒非结构蛋白1(nonstructural Protein 1 of Dengue virus type 1,DENV-1 NS1)B细胞线性表位。方法以重组DENV-1 NS1为抗原,免疫印迹法筛选NS1阳性病人血清。一组重叠DENV-1 NS1的重叠多肽...目的鉴定1型登革病毒感染病人血清中1型登革病毒非结构蛋白1(nonstructural Protein 1 of Dengue virus type 1,DENV-1 NS1)B细胞线性表位。方法以重组DENV-1 NS1为抗原,免疫印迹法筛选NS1阳性病人血清。一组重叠DENV-1 NS1的重叠多肽同这些NS1阳性血清反应鉴定NS1蛋白线性B细胞表位。采用梯度稀释的1-4型重组DENVNS1竞争抑制阳性多肽同病人血清反应鉴定其反应特异性和交叉反应性。结果12份DENV-1核酸阳性病人中筛选得到5份抗DENV-1 NS1阳性病人血清。重叠多肽法、竞争抑制法和生物信息学方法筛选出3条阳性NS1多肽(氨基酸残基序列第1-15,131-145,271-285),其中aa1-15在已报道的DENV-1分离株高度保守,提示这个区域可能存在DENV-1血清型特异性表位。aa131-145和aa271-285对应的蛋白序列比对分析表明以上区域中的133-FI/LIDGP-138和271-GKLEL/M/IDF-277在已报道的4种血清型DENV分离株中高度保守,提示这2个区域存在4种血清型DENV共同表位。结论发现3个NS1上B细胞线性表位,其中aa131-145和aa271-285为首次报道,结果有助于疫苗和诊断试剂的研发。展开更多
Background:Coeliac disease(CD)is due to an inappropriate T cell mediated response to specific gluten peptides.Measured by interferon γ(IFN-γ)ELISPOT,about half of the gliadin specific T cells induced with in vivo wh...Background:Coeliac disease(CD)is due to an inappropriate T cell mediated response to specific gluten peptides.Measured by interferon γ(IFN-γ)ELISPOT,about half of the gliadin specific T cells induced with in vivo wheat gluten exposure in HLA-DQ2+CD are specific for an α/β-gliadin peptide(p57-73 QE65;QLQPFPQPELPYPQ-PQS)that includes two overlapping T cell epitopes(PFPQPELPY and PQPELPYPQ).Aim:To define minimally substituted variants of p57-73 QE65 universally devoid of IFN-γstimulatory capacity but capable of antagonising IFN-γsecretion from polyclonal T cells specific for p57-73 QE65.Methods:Peripheral blood mononuclear cells collected from 75 HLA-DQ2+CD patients after in vivo gluten challenge were used in overnight ELISPOT assays to screen 218 single or double substituted variants of p57-73 QE65 for cytokine stimulatory and antagonist activity.Results:The region p60-71(PFPQPELPYPQP)and especially p64-67(PELP)was sensitive to substitution.Twelve substitutions in p64-67 stimulated no IFN-γELISPOT response.Among 131 partial agonists identified,45 produced statistically significant inhibition of IFN-γELISPOT responses when cocultured in fivefold excess with p57-73 QE65(n = 10).Four substituted variants of p57-73 QE65 were inactive by IFN-γELISPOT but consistently antagonised IFN-γELISPOT responses to p57-73 QE65,and also retained interleukin 10 stimulatory capacity similar to p57-73 QE65.Conclusions:Altered peptide ligands of p57-73 QE65,identified using polyclonal T cells from multiple HLA-DQ2+CDdonors,have properties in vitro that suggest that a single substitution to certain α/β-gliadins could abolish their capacity to stimulate IFN-γfrom CD4 T cells and also have anti-inflammatory or protective effects in HLA-DQ2+CD.展开更多
Background: Identification of critical autoantigenic T-cell epitopes is key to developing antigen-based therapies for autoimmune diseases, including psoriasis. Our previous work demonstrated that 3 peptides on keratin...Background: Identification of critical autoantigenic T-cell epitopes is key to developing antigen-based therapies for autoimmune diseases, including psoriasis. Our previous work demonstrated that 3 peptides on keratin 17 are able to stimulate peripheral blood lymphocytes of HLA-DRB1 07-positive patients with psoriasis and to serve as immunodominant T cell epitopes. Objective: We sought to determine antagonistic altered peptide ligands to psoriatic T cells with a down-modulatory effect in inhibiting keratinocyte proliferation. Methods: Psoriatic altered peptide ligands were generated by single alanine residue substitutions at a critical T-cell receptor contact residue position. Antagonistic altered peptide ligands were identified by suppression screening of psoriatic T-cell activation and keratinocyte proliferation. Results: Altered peptide ligands 119R and 355L can inhibit psoriatic T-cell activation more effectively than other altered peptide ligands, especially 355L, with inhibition of T-cell proliferation and the secretion of interferon gamma and interleukin 2 in parallel with the upregulation of interleukins 4 and 10 as well as transforming growth factor-β . In coincubation assay, altered peptide ligands 119R and 355L can down-regulate the function of psoriatic T cells more effectively than wild-type epitopes solely, but less effectively than altered peptide ligands solely. In prepulse assay altered peptide ligand 119R can down-regulate the activation of psoriatic T cells more effectively than in coincubation but less effectively as compared with altered peptide ligand 119R only. Altered peptide ligand 355L was also shown to have a similar presentation. T-cell culture supernatants (1:100) from the concentrations (10 μ g · mL-1 and 100 μ g · mL-1 with 119R, 100 μ g · mL-1 with 355L) were more effective than the other ratios in inhibiting keratinocyte proliferation. Limitations: This study had a relatively small sample size (52 patients and 48 healthy controls). Conclusion: Our findings show that the altered peptide ligands 119R (VAALEEANTELEVKI) and 355L (ENRYCVQASQIQGLI) are capable of inhibiting proliferative responses of psoriatic T cells and keratinocyte proliferation in vitro, at least, with enhanced helper T cell type 2 polarization. Thus, to our knowledge, this article is the first report of the demonstration of therapeutic activity of altered peptide ligands derived from keratin 17.展开更多
文摘目的构建经MHCⅡ通路的屋尘螨1类变应原Der p 1的T细胞表位肽疫苗重组载体。方法分别合成TAT、Ih C和含编码Der p 1的3段T细胞表位的融合核苷酸序列,用特异性引物PCR扩增相应的基因片段,分别用相应的双酶切后,用T4 DNA连接酶连接形成TAT-Ih C-Der p 1-3T融合基因,并插入至原核表达载体p ET-28a(+)中,构建重组原核表达载体p ET-28a(+)-TATIh C-Der p 1-3T,Bam HⅠ和XhoⅠ进行双酶切和测序鉴定。重组载体转化大肠杆菌E.coli BL21(DE3)菌株,IPTG诱导后,经SDS-PAGE电泳分析和Western blot验证,纯化TAT-Ih C-Der p 1-3T蛋白后进行Ig E结合试验。结果双酶切和测序结果表明,成功构建了p ET-28a-TAT-Ih C-Der p 1-3T重组原核表达载体;SDS-PAGE电泳分析显示TAT-Ih C-Der p 1-3T可诱导表达;Western blot检测表明该融合蛋白纯化成功;Ig E结合试验表明TAT-Ih C-Der p 1-3T结合屋尘螨过敏病人血清Ig E的能力强于Der p 1变应原(P<0.001)。结论成功构建了可表达经MHC通路的编码Der p 1的3段T细胞表位的重组p ET-28a-TAT-Ih C-Der p 1-3T载体,纯化的TAT-Ih C-Der p 1-3T具有较强的Ig E结合能力,从而为后续经MHC通路的特异性免疫治疗奠定基础。
文摘目的鉴定1型登革病毒感染病人血清中1型登革病毒非结构蛋白1(nonstructural Protein 1 of Dengue virus type 1,DENV-1 NS1)B细胞线性表位。方法以重组DENV-1 NS1为抗原,免疫印迹法筛选NS1阳性病人血清。一组重叠DENV-1 NS1的重叠多肽同这些NS1阳性血清反应鉴定NS1蛋白线性B细胞表位。采用梯度稀释的1-4型重组DENVNS1竞争抑制阳性多肽同病人血清反应鉴定其反应特异性和交叉反应性。结果12份DENV-1核酸阳性病人中筛选得到5份抗DENV-1 NS1阳性病人血清。重叠多肽法、竞争抑制法和生物信息学方法筛选出3条阳性NS1多肽(氨基酸残基序列第1-15,131-145,271-285),其中aa1-15在已报道的DENV-1分离株高度保守,提示这个区域可能存在DENV-1血清型特异性表位。aa131-145和aa271-285对应的蛋白序列比对分析表明以上区域中的133-FI/LIDGP-138和271-GKLEL/M/IDF-277在已报道的4种血清型DENV分离株中高度保守,提示这2个区域存在4种血清型DENV共同表位。结论发现3个NS1上B细胞线性表位,其中aa131-145和aa271-285为首次报道,结果有助于疫苗和诊断试剂的研发。
文摘Background:Coeliac disease(CD)is due to an inappropriate T cell mediated response to specific gluten peptides.Measured by interferon γ(IFN-γ)ELISPOT,about half of the gliadin specific T cells induced with in vivo wheat gluten exposure in HLA-DQ2+CD are specific for an α/β-gliadin peptide(p57-73 QE65;QLQPFPQPELPYPQ-PQS)that includes two overlapping T cell epitopes(PFPQPELPY and PQPELPYPQ).Aim:To define minimally substituted variants of p57-73 QE65 universally devoid of IFN-γstimulatory capacity but capable of antagonising IFN-γsecretion from polyclonal T cells specific for p57-73 QE65.Methods:Peripheral blood mononuclear cells collected from 75 HLA-DQ2+CD patients after in vivo gluten challenge were used in overnight ELISPOT assays to screen 218 single or double substituted variants of p57-73 QE65 for cytokine stimulatory and antagonist activity.Results:The region p60-71(PFPQPELPYPQP)and especially p64-67(PELP)was sensitive to substitution.Twelve substitutions in p64-67 stimulated no IFN-γELISPOT response.Among 131 partial agonists identified,45 produced statistically significant inhibition of IFN-γELISPOT responses when cocultured in fivefold excess with p57-73 QE65(n = 10).Four substituted variants of p57-73 QE65 were inactive by IFN-γELISPOT but consistently antagonised IFN-γELISPOT responses to p57-73 QE65,and also retained interleukin 10 stimulatory capacity similar to p57-73 QE65.Conclusions:Altered peptide ligands of p57-73 QE65,identified using polyclonal T cells from multiple HLA-DQ2+CDdonors,have properties in vitro that suggest that a single substitution to certain α/β-gliadins could abolish their capacity to stimulate IFN-γfrom CD4 T cells and also have anti-inflammatory or protective effects in HLA-DQ2+CD.
文摘Background: Identification of critical autoantigenic T-cell epitopes is key to developing antigen-based therapies for autoimmune diseases, including psoriasis. Our previous work demonstrated that 3 peptides on keratin 17 are able to stimulate peripheral blood lymphocytes of HLA-DRB1 07-positive patients with psoriasis and to serve as immunodominant T cell epitopes. Objective: We sought to determine antagonistic altered peptide ligands to psoriatic T cells with a down-modulatory effect in inhibiting keratinocyte proliferation. Methods: Psoriatic altered peptide ligands were generated by single alanine residue substitutions at a critical T-cell receptor contact residue position. Antagonistic altered peptide ligands were identified by suppression screening of psoriatic T-cell activation and keratinocyte proliferation. Results: Altered peptide ligands 119R and 355L can inhibit psoriatic T-cell activation more effectively than other altered peptide ligands, especially 355L, with inhibition of T-cell proliferation and the secretion of interferon gamma and interleukin 2 in parallel with the upregulation of interleukins 4 and 10 as well as transforming growth factor-β . In coincubation assay, altered peptide ligands 119R and 355L can down-regulate the function of psoriatic T cells more effectively than wild-type epitopes solely, but less effectively than altered peptide ligands solely. In prepulse assay altered peptide ligand 119R can down-regulate the activation of psoriatic T cells more effectively than in coincubation but less effectively as compared with altered peptide ligand 119R only. Altered peptide ligand 355L was also shown to have a similar presentation. T-cell culture supernatants (1:100) from the concentrations (10 μ g · mL-1 and 100 μ g · mL-1 with 119R, 100 μ g · mL-1 with 355L) were more effective than the other ratios in inhibiting keratinocyte proliferation. Limitations: This study had a relatively small sample size (52 patients and 48 healthy controls). Conclusion: Our findings show that the altered peptide ligands 119R (VAALEEANTELEVKI) and 355L (ENRYCVQASQIQGLI) are capable of inhibiting proliferative responses of psoriatic T cells and keratinocyte proliferation in vitro, at least, with enhanced helper T cell type 2 polarization. Thus, to our knowledge, this article is the first report of the demonstration of therapeutic activity of altered peptide ligands derived from keratin 17.
