为进一步丰富鱼类MHC class Ⅱ基因的研究,同时也为进一步探讨低磷饲料中添加维生素D3对鱼类免疫功能可能的影响,实验利用RACE(Rapid-amplification of c DNA ends)即c DNA末端快速扩增技术,成功克隆出黄颡鱼(Pelteobagrus fulvidraco)...为进一步丰富鱼类MHC class Ⅱ基因的研究,同时也为进一步探讨低磷饲料中添加维生素D3对鱼类免疫功能可能的影响,实验利用RACE(Rapid-amplification of c DNA ends)即c DNA末端快速扩增技术,成功克隆出黄颡鱼(Pelteobagrus fulvidraco)主要组织相容性复合体(Major histocompatibility complex,MHC)class Ⅱ抗原基因,全长1074 bp,其中ORF(Open reading frame)708 bp,编码236个氨基酸,5′UTR(5′端非翻译区)78 bp,3′UTR(3′端非翻译区)259 bp。进行氨基酸序列比对分析得到:黄颡鱼MHC class Ⅱ基因ORF氨基酸序列与长吻逘(Leiocassis longirostris)的氨基酸序列相似度最高为69.5%,与锦鲤(Cyprinus carpio)的氨基酸序列相似度最低为50.4%。利用q PCR对黄颡鱼MHC class Ⅱ基因进行组织表达分析,结果表明MHC class Ⅱ在小肠、肝脏、鳃中表达较高;在肌肉、鳍条中表达较低;而在肾、脾脏、脑、头肾中表达量极低(几乎检测不到)。在低磷饲料中添加维生素D3显著诱导了该基因的上调表达。研究结果展示了黄颡鱼MHC class Ⅱ抗原基因的分子结构、组织表达以及维生素D3的作用,在降低磷排放的同时,为今后黄颡鱼免疫抗病及分子选育等方向的深入研究及免疫型饲料的使用奠定了基础。展开更多
[ Objective] To prepare the monoclonal antibody against chicken major histocompatibility complex class II molecules （MHC II）. [ Method ] The prokaryotic expression of the gene fragments of exons 2 -6 encoding alpha ...[ Objective] To prepare the monoclonal antibody against chicken major histocompatibility complex class II molecules （MHC II）. [ Method ] The prokaryotic expression of the gene fragments of exons 2 -6 encoding alpha chain of MHC II and exons 3 -6 encoding beta chain of MHC II were performed based on its protein sequences. After BALB/c mice were immunized with the purified fusion proteins, the mouse spleen cells were fused with mouse myeloma cells SP2/0. Then the positive hybridoma cells were screened and detected by indirect enzyme-linked immunosorbent assay （ELISA）. [ Result] One hybridoma cell strain secreting monoclonal antibody against alpha chain and two strains secreting monoclonal antibody against beta chain were obtained. These three hybridoma cell strains were named as MHC II alpha-4, MHC II betas-2 and MCH II betas-31, respectively. Their titers of ascites in indirect ELISA were 1 ： 256 000, 1 ： 256 000 and 1 ： 1 280 000, respectively. These antibodies could specifically recog- nize MHC II alpha chain or beta chain in western blotting. [ Conclusion] Three obtained hybridoma stains can stably produce the monoclonal antibody against chicken MHC class II molecules.展开更多
In daily life,we are frequently attacked by infection organisms such as bacteria and viruses. Major Histocompatibility (MHC) molecules have an essential role in T-cell activation and initiating an adaptive immune resp...In daily life,we are frequently attacked by infection organisms such as bacteria and viruses. Major Histocompatibility (MHC) molecules have an essential role in T-cell activation and initiating an adaptive immune response. Development of methods for prediction of MHC-Peptide binding is important in vaccine design and immunotherapy. In this study, we try to predict the binding between peptides and MHC class II. Support vector machine (SVM) and Multi-Layer Percep-tron (MLP) are used for classification. These classifiers based on pseudo amino acid compositions of data that we ex-tracted from PseAAC server, classify the data. Since, the dataset, used in this work, is imbalanced, we apply a pre-processing step to over-sample the minority class and come over this problem. The results show that using the concept of pseudo amino acid composition and applying over-sampling method, increases the performance of predictor. Fur-thermore, the results demonstrate that using the concept of PseAAC and SVM is a successful method for the prediction of MHC class II molecules.展开更多
评估IFN-γ调控型启动子(CIITA-pIV)驱动的MHC II类分子反式激活因子突变体(MHC class II transactivator mu-tant,CIITAm)重组腺病毒Ad-pIV-CIITAm对小鼠实验性自身免疫性甲状腺炎(experimental autoimmune thyroiditis,EAT)的治疗效果...评估IFN-γ调控型启动子(CIITA-pIV)驱动的MHC II类分子反式激活因子突变体(MHC class II transactivator mu-tant,CIITAm)重组腺病毒Ad-pIV-CIITAm对小鼠实验性自身免疫性甲状腺炎(experimental autoimmune thyroiditis,EAT)的治疗效果,并探讨其可能的作用机制。34只健康雌性CBA/J小鼠随机分成CIITAm治疗组(n=9)、GFP对照组(n=9)、EAT模型组(n=8)和正常对照组(n=8)共四组。正常对照组不做特殊处理,其余三组均以猪甲状腺球蛋白(porcinethyroglobulin,pTg)+弗氏佐剂(complete or incomplete Freund adjuvant,CFA/IFA)建立EAT小鼠模型,并分别静脉注射重组腺病毒Ad-pIV-CIITAm、Ad-GFP及等体积生理盐水。首次免疫后第29天处死小鼠,进行H-E染色观察甲状腺病理形态;免疫组织化学染色测定甲状腺MHC II类分子表达;分析pTg刺激下脾脏淋巴细胞的增殖及其上清液中IFN-γ的分泌水平;ELISA法检测血浆中抗-pTg自身抗体滴度;流式细胞术分析外周血和脾脏淋巴细胞中T细胞亚群。结果:H-E染色结果表明,CIITAm治疗组甲状腺淋巴细胞浸润指数(0.5±0.5)低于GFP对照组(1.5±0.2)和EAT模型组(1.4±0.4,P<0.01)。免疫组化结果显示,GFP对照组和EAT模型组甲状腺组织有弥漫性MHC II类分子表达,而CIITAm治疗组未见明显表达,正常对照组表达呈阴性。80μg/ml pTg刺激下,CIITAm治疗组小鼠淋巴细胞刺激指数(SI)明显低于GFP对照组或EAT模型组(P<0.01);培养上清各组IFN-γ分泌水平结果类似(P<0.01)。CIITAm治疗组血浆抗-pTg自身抗体滴度显著低于GFP对照组或EAT模型组(P<0.05);CIITAm治疗组外周血和脾脏CD4+T细胞百分率亦显著低于GFP对照组或EAT模型组(P<0.05)。重组腺病毒Ad-pIV-CIITAm能抑制EAT小鼠甲状腺组织MHC II类分子表达,抑制自身反应性T细胞增殖,减轻甲状腺炎性细胞浸润,降低自身抗体滴度,对EAT有一定的治疗作用。展开更多
The major histocompatibility complex(MHC) genes play pivotal roles in the immune system of vertebrates against antigens.They are also significant indicators of genetic structure,and are vital to species-level populati...The major histocompatibility complex(MHC) genes play pivotal roles in the immune system of vertebrates against antigens.They are also significant indicators of genetic structure,and are vital to species-level population viability analyses and disease risk assessments.In this study,two DRA and two DQA sequences were isolated from Hainan Eld's deer(Cervus eldi hainanus) using rapid amplification of cDNA ends(RACE) and single-strand conformation polymorphism-heteroduplex(SSCP-HD) analysis.Nucleotide sequence analysis revealed large differences between the two DQA sequences,especially in their exon 2 regions,but only minimal differences between the variants of the DRA gene.Comparison of the predicted amino acid sequences of the Ceel-MHC class Ⅱ A variants with those from six other species revealed that these molecules share high homology among ruminants.A phylogenetic tree of four class Ⅱ A sequences from Hainan Eld's deer and the other species placed the newly identified DQA and DRA genes on two distinct branches(100%-supportively),and further divided the two DQA sequences into 98%-supportive DQA1 and 99%-supportive DQA2 clusters,respectively.Therefore,this study identified monomorphic Ceel-DQA1 and Ceel-DQA2 genes,and one dimorphic Ceel-DRA gene from Hainan Eld's deer.展开更多
The currently accepted model for superantigen (SAg) induced T cell activation suggests that SAg, without being processed, cross link both MHC class II, from Antigen Presenting Cells (APC), and V-β , from T-cell recep...The currently accepted model for superantigen (SAg) induced T cell activation suggests that SAg, without being processed, cross link both MHC class II, from Antigen Presenting Cells (APC), and V-β , from T-cell receptor (TCR), initi-ating nonspecific T-cell activation. This T-cell proliferation induces a massive cytokine release associated with several human diseases. It is thought that murine CD4+ T cells do not express MHC class-II molecules. However, we discov-ered that a subtype of mouse na?ve CD4+ T cells expresses MHC class II on their cell surface and that these CD4+ T cells can perform the role of both APC and T cells, able to present Staphy-lococcal enterotoxin A (SEA) to itself or neigh- boring CD4+ T cells via MHC class II, thus in-ducing massive CD4+ T cell proliferation. Treat- ment with neutralizing anti MHC class II anti-body inhibits this CD4+ T cell proliferation re-sponse. The fact that murine CD4+ T cells ex-press MHC class II offers new insight about SAg activity. Based on our findings, we propose re-vising and extending previous models for SAg induced T cell activation, altering previous models of MHC class II restriction of T cell re-sponses to SEA as well as the requirement for SAg processing.展开更多
Rheumatoid arthritis (RA) is associated with an HLA-DRB1-coded sequence motif called “shared epitope” (SE). To explore potential mechanisms of RA susceptibility, we analyze in vitro effect of peptides bearing differ...Rheumatoid arthritis (RA) is associated with an HLA-DRB1-coded sequence motif called “shared epitope” (SE). To explore potential mechanisms of RA susceptibility, we analyze in vitro effect of peptides bearing different HLA-DR4 sequences on human peripheral blood-derived cells. Three 15-mer peptides were used: 65-79*0401 (HLA-DRB1*04:01- coded sequence SE motif, QKRAA);65-79*0402 (HLA-DRB1*04:02-coded sequence SE-negative motif, DERAA);65-79*0403 (HLA-DRB1*04:03-coded sequence SE-negative motif, QRRAE). We found that CD4 TH17 cells are regulated by peptide treatment with gender bias. In male-derived T cells, all peptide treatments significantly reduced TH17 cell differentiation in vitro when compared to no peptide treatment, and to female samples. TH17 differentiation in samples not treated with peptides, either in the presence or absence of TH17-polarizing cytokines, was higher in males than in females;however, in unfractionated PBMC after treatment with TH17 polarizing cytokines, IL-17A-positive cells were more abundant in females than in males. In addition, SE-positive females showed a significantly higher percentage of IL-17A-positive cells compared to SE-negative females. In conclusion, donor’s SE status and gender may both influence TH17 immune polarization.展开更多
The in silico prediction of peptide binding affinities to MHC proteins is a very important first step in the process of epi-tope-based vaccine design and development. Five MHC class II binding prediction servers were ...The in silico prediction of peptide binding affinities to MHC proteins is a very important first step in the process of epi-tope-based vaccine design and development. Five MHC class II binding prediction servers were combined in different ways and the resulting performance of these combinations was evaluated using a test set, which consisted of 4540 known HLA-DRB1 binders. The five servers were: NetMHCIIpan, NetMHCII, ProPred, RANKPEP, and EpiTOP. The top 5% of the ranked predictions from each server were combined using union and intersection operators. The outputs were evaluated in terms of sensitivity and positive predictive value (PPV). The union operator showed high sensitivity (65-79%) and low PPVs (6-8%), while intersection outputs had low sensitivities (4-41%) yet significantly higher PPVs (14-31%). Thus there is a defining trade-off between sensitivity and PPV for each combination. The union of outputs from different servers brings more “noise” than “signal” to the resulting set of predicted binders. Conversely, selecting only commonly predicted binders increases the probability that an identified binder is a true binder.展开更多
文摘为进一步丰富鱼类MHC class Ⅱ基因的研究,同时也为进一步探讨低磷饲料中添加维生素D3对鱼类免疫功能可能的影响,实验利用RACE(Rapid-amplification of c DNA ends)即c DNA末端快速扩增技术,成功克隆出黄颡鱼(Pelteobagrus fulvidraco)主要组织相容性复合体(Major histocompatibility complex,MHC)class Ⅱ抗原基因,全长1074 bp,其中ORF(Open reading frame)708 bp,编码236个氨基酸,5′UTR(5′端非翻译区)78 bp,3′UTR(3′端非翻译区)259 bp。进行氨基酸序列比对分析得到:黄颡鱼MHC class Ⅱ基因ORF氨基酸序列与长吻逘(Leiocassis longirostris)的氨基酸序列相似度最高为69.5%,与锦鲤(Cyprinus carpio)的氨基酸序列相似度最低为50.4%。利用q PCR对黄颡鱼MHC class Ⅱ基因进行组织表达分析,结果表明MHC class Ⅱ在小肠、肝脏、鳃中表达较高;在肌肉、鳍条中表达较低;而在肾、脾脏、脑、头肾中表达量极低(几乎检测不到)。在低磷饲料中添加维生素D3显著诱导了该基因的上调表达。研究结果展示了黄颡鱼MHC class Ⅱ抗原基因的分子结构、组织表达以及维生素D3的作用,在降低磷排放的同时,为今后黄颡鱼免疫抗病及分子选育等方向的深入研究及免疫型饲料的使用奠定了基础。
基金supported by the National Natural Science Foundation (30671537)
文摘[ Objective] To prepare the monoclonal antibody against chicken major histocompatibility complex class II molecules （MHC II）. [ Method ] The prokaryotic expression of the gene fragments of exons 2 -6 encoding alpha chain of MHC II and exons 3 -6 encoding beta chain of MHC II were performed based on its protein sequences. After BALB/c mice were immunized with the purified fusion proteins, the mouse spleen cells were fused with mouse myeloma cells SP2/0. Then the positive hybridoma cells were screened and detected by indirect enzyme-linked immunosorbent assay （ELISA）. [ Result] One hybridoma cell strain secreting monoclonal antibody against alpha chain and two strains secreting monoclonal antibody against beta chain were obtained. These three hybridoma cell strains were named as MHC II alpha-4, MHC II betas-2 and MCH II betas-31, respectively. Their titers of ascites in indirect ELISA were 1 ： 256 000, 1 ： 256 000 and 1 ： 1 280 000, respectively. These antibodies could specifically recog- nize MHC II alpha chain or beta chain in western blotting. [ Conclusion] Three obtained hybridoma stains can stably produce the monoclonal antibody against chicken MHC class II molecules.
文摘In daily life,we are frequently attacked by infection organisms such as bacteria and viruses. Major Histocompatibility (MHC) molecules have an essential role in T-cell activation and initiating an adaptive immune response. Development of methods for prediction of MHC-Peptide binding is important in vaccine design and immunotherapy. In this study, we try to predict the binding between peptides and MHC class II. Support vector machine (SVM) and Multi-Layer Percep-tron (MLP) are used for classification. These classifiers based on pseudo amino acid compositions of data that we ex-tracted from PseAAC server, classify the data. Since, the dataset, used in this work, is imbalanced, we apply a pre-processing step to over-sample the minority class and come over this problem. The results show that using the concept of pseudo amino acid composition and applying over-sampling method, increases the performance of predictor. Fur-thermore, the results demonstrate that using the concept of PseAAC and SVM is a successful method for the prediction of MHC class II molecules.
基金supported by the National Natural Science Foundation of China (30970426)a special grant from the State Forestry Administration of Chinathe Fundamental Research Funds for the Central Universities of China
文摘The major histocompatibility complex(MHC) genes play pivotal roles in the immune system of vertebrates against antigens.They are also significant indicators of genetic structure,and are vital to species-level population viability analyses and disease risk assessments.In this study,two DRA and two DQA sequences were isolated from Hainan Eld's deer(Cervus eldi hainanus) using rapid amplification of cDNA ends(RACE) and single-strand conformation polymorphism-heteroduplex(SSCP-HD) analysis.Nucleotide sequence analysis revealed large differences between the two DQA sequences,especially in their exon 2 regions,but only minimal differences between the variants of the DRA gene.Comparison of the predicted amino acid sequences of the Ceel-MHC class Ⅱ A variants with those from six other species revealed that these molecules share high homology among ruminants.A phylogenetic tree of four class Ⅱ A sequences from Hainan Eld's deer and the other species placed the newly identified DQA and DRA genes on two distinct branches(100%-supportively),and further divided the two DQA sequences into 98%-supportive DQA1 and 99%-supportive DQA2 clusters,respectively.Therefore,this study identified monomorphic Ceel-DQA1 and Ceel-DQA2 genes,and one dimorphic Ceel-DRA gene from Hainan Eld's deer.
文摘The currently accepted model for superantigen (SAg) induced T cell activation suggests that SAg, without being processed, cross link both MHC class II, from Antigen Presenting Cells (APC), and V-β , from T-cell receptor (TCR), initi-ating nonspecific T-cell activation. This T-cell proliferation induces a massive cytokine release associated with several human diseases. It is thought that murine CD4+ T cells do not express MHC class-II molecules. However, we discov-ered that a subtype of mouse na?ve CD4+ T cells expresses MHC class II on their cell surface and that these CD4+ T cells can perform the role of both APC and T cells, able to present Staphy-lococcal enterotoxin A (SEA) to itself or neigh- boring CD4+ T cells via MHC class II, thus in-ducing massive CD4+ T cell proliferation. Treat- ment with neutralizing anti MHC class II anti-body inhibits this CD4+ T cell proliferation re-sponse. The fact that murine CD4+ T cells ex-press MHC class II offers new insight about SAg activity. Based on our findings, we propose re-vising and extending previous models for SAg induced T cell activation, altering previous models of MHC class II restriction of T cell re-sponses to SEA as well as the requirement for SAg processing.
文摘Rheumatoid arthritis (RA) is associated with an HLA-DRB1-coded sequence motif called “shared epitope” (SE). To explore potential mechanisms of RA susceptibility, we analyze in vitro effect of peptides bearing different HLA-DR4 sequences on human peripheral blood-derived cells. Three 15-mer peptides were used: 65-79*0401 (HLA-DRB1*04:01- coded sequence SE motif, QKRAA);65-79*0402 (HLA-DRB1*04:02-coded sequence SE-negative motif, DERAA);65-79*0403 (HLA-DRB1*04:03-coded sequence SE-negative motif, QRRAE). We found that CD4 TH17 cells are regulated by peptide treatment with gender bias. In male-derived T cells, all peptide treatments significantly reduced TH17 cell differentiation in vitro when compared to no peptide treatment, and to female samples. TH17 differentiation in samples not treated with peptides, either in the presence or absence of TH17-polarizing cytokines, was higher in males than in females;however, in unfractionated PBMC after treatment with TH17 polarizing cytokines, IL-17A-positive cells were more abundant in females than in males. In addition, SE-positive females showed a significantly higher percentage of IL-17A-positive cells compared to SE-negative females. In conclusion, donor’s SE status and gender may both influence TH17 immune polarization.
文摘The in silico prediction of peptide binding affinities to MHC proteins is a very important first step in the process of epi-tope-based vaccine design and development. Five MHC class II binding prediction servers were combined in different ways and the resulting performance of these combinations was evaluated using a test set, which consisted of 4540 known HLA-DRB1 binders. The five servers were: NetMHCIIpan, NetMHCII, ProPred, RANKPEP, and EpiTOP. The top 5% of the ranked predictions from each server were combined using union and intersection operators. The outputs were evaluated in terms of sensitivity and positive predictive value (PPV). The union operator showed high sensitivity (65-79%) and low PPVs (6-8%), while intersection outputs had low sensitivities (4-41%) yet significantly higher PPVs (14-31%). Thus there is a defining trade-off between sensitivity and PPV for each combination. The union of outputs from different servers brings more “noise” than “signal” to the resulting set of predicted binders. Conversely, selecting only commonly predicted binders increases the probability that an identified binder is a true binder.
