血型A抗原模拟多肽与抗A抗体的分子对接

目的：从分子结构水平研究血型A抗原及其模拟多肽（肽P1 QIWYERTLPFTF,肽P2EYWYCGMNRTGC）与血型A抗体的相互作用。方法：利用Chimera软件构建血型A抗原模拟多肽（P1,P2）的三维结构;将天然血型A抗原及其模拟多肽通过Autodock软件与血型A抗体Fv段（PDB：1jv5）对接。结果：天然血型A抗原和多肽P1、P2都能与1jv5分子中一个由疏水性氨基酸组成的凹槽对接,且对接部位重叠。天然A抗原和P1可以与1jv5形成2个氢键,且天然抗原和模拟多肽都能够与1jv5中的多个氨基酸相合作用。结论：通过生物信息学计算软件成功模拟了血型A抗原及其模拟多肽与抗体1jv5的相互作用情况。此2个模拟多肽是从功能上对天然A抗原进行模拟的。     

模拟抗原表位基因测定及合成多肽的血吸虫病诊断价值的研究

目的测定能用于血吸虫病诊断及疗效考核的噬菌体展示肽基因序列,研究合成多肽抗原的血吸虫病诊断价值.方法扩增目的噬菌体,制备和纯化噬菌体DNA,对目的噬菌体中外源性肽的基因序列进行测定和演绎氨基酸序列分析.根据血清反应强度和演绎氨基酸序列选择2个噬菌体的展示肽段进行人工多肽合成.以合成的多肽为抗原,建立血吸虫病诊断方法,检测急、慢性血吸虫病人血清,观察方法的敏感性及特异性;同时检测治疗前及治愈后的血吸虫病人血清,观察该合成抗原的血吸虫病疗效考核价值.结果测定了14个噬菌体展示外源肽的基因序列,序列分析表明,其中有6个噬茵体的外源肽基因序列完全相同,其余8个噬菌体展示肽的基因序列不相同.分析演绎氨基酸序列,发现1个噬菌体展示肽中的3个连续的氨基酸(GVK)残基与血吸虫23 kDa分子氨基酸残基相同.合成多肽抗原检测急、慢性血吸虫病人血清,敏感性分别为92.3%和91.1%,与华支睾吸虫病人血清的交叉反应率为7.5%,检测健康人血清,特异性为95.5%.检测治愈后0.5年的同一病人血清,阴转率为55.3%,治愈后1年的病人血清中IgG抗体的阴转率为63.2%.结论 9个具有血吸虫病诊断价值的噬菌体展示表位的基因序列被确定,并证明了合成多肽抗原有较好的血吸虫病诊断及疗效考核价值.     

日本血吸虫模拟虫卵抗原表位的筛选和鉴定

目的　通过噬菌体肽文库技术探索可用于诊断日本血吸虫病的模拟虫卵抗原。　方法　用日本血吸虫虫卵单克隆抗体 6 B12作“诱饵”,采用生物淘金法从噬菌体 15 -肽文库中经过 3轮筛选 ,有效地富集与 6 B12有亲和力的噬菌体肽克隆。随后采用 EL ISA、竞争 EL ISA、Western blotting等检测方法 ,从 4 0 0个单克隆化的噬菌体株中得到 13株与 6 B12有特异性、高亲和力反应的噬菌体克隆。　结果　对噬菌体所携带的外源 DNA片段序列测序结果表明 ,13株噬菌体所携带的外源多肽序列完全相同。该噬菌体多肽抗原包被酶标板经 EL ISA方法对血吸虫病患者及健康人血清Ig G抗体检测结果表明 ,两者有显著性差异。　结论　噬菌体多肽模拟抗原有可能替代天然抗原用于血吸虫病诊断     

丙型肝炎病毒非结构蛋白NS3抗原模拟表位的筛选和鉴定

目的 筛选丙型肝炎病毒(HCV)非结构蛋白NS3(HCV NS3)特异性噬菌体模拟表位，为抗—HCV的疫苗研究探索新途径。方法 以抗—HCV NS3的单克隆抗体作为固相筛选分子，对人工合成的噬菌体随机七肽库进行3轮“吸附—洗脱—扩增”的筛选过程，随机挑取60个克隆，经噬菌体酶联免疫吸附法(ELISA)鉴定并进行交叉反应实验以及竞争抑制性结合实验，最后对所选克隆进行DNA序列分析，以确定HCV NS3抗原的模拟表位。结果 经噬菌体富集后，从随机筛选的60个克隆中得到13个阳性克隆，确定氨基酸序列SRNTxKL为HCV NS3的模拟表位。结论 用噬菌体七肽库成功筛选得到HCV NS3的模拟表位。     

丙型肝炎病毒非结构蛋白NS5抗原模拟表位的筛选和鉴定

目的 筛选丙型肝炎病毒非结构蛋白NS5（HCV NS5）特异性噬菌体模拟表位，为抗HCV的疫苗研究探索新途径。方法 以抗－HCV NS5的单克隆抗体作为固相筛选分子，对人工合成的噬菌体随机七肽库进行5轮“吸附－洗脱－扩增”的筛选过程，随机挑取30个克隆，经噬菌体酶联免疫吸附法（ELISA）鉴定并进行交叉反应实验以及竞争抑制性结合实验，最后对所选克隆进行DNA序列分析，以确定HCV NS5抗原的模拟表位。结果 经噬菌体富集后，从随机筛选的30个克隆中得12上阳性克隆，确定氨基酸序列QIRPTRQ为HCV NS5的模拟表位。结论 用噬菌体七肽库成功筛选得到HCV NS5的模拟表位，为用HCV模拟表位探索HCV感染的研究创造了条件。     

妊娠相关血浆蛋白A重组抗原表位分析及抗体制备

目的探讨妊娠相关血浆蛋白A(PAPP-A)的抗原表位及抗PAPP-A抗体制备方法。方法把PAPP-A的CDS序列翻译成氨基酸序列,利用互联网分析蛋白的疏水性和信号肽区段,利用DNAstar软件分析二级结构、表面可及性、亲水性、抗原指数以及柔韧性,综合分析抗原表位。通过分子生物学技术制备重组PAPP-A,进而免疫新西兰家兔制备抗PAPP-A抗体。结果 PAPP-A抗原性较强,抗原优势表位位于23～94、1 110～1 131氨基酸区段;PAPP-A重组蛋白以及抗PAPP-A抗体制备成功。结论本研究方法建立了PAPP-A的高灵敏免疫检测体系,能进一步提高PAPP-A的临床应用价值。     

用噬菌体展示随机7肽库筛选血型A抗原模拟肽

目的:通过血型A单克隆抗体从噬菌体展示随机7肽库中筛选血型A抗原的模拟多肽。方法:通过对噬菌体随机7肽库进行3轮亲和筛选,从第三轮筛选后获得的洗脱物中挑选多个噬菌体克隆,采用ELISA方法鉴定阳性克隆,测序并推导噬菌体展示短肽的氨基酸序列,化学合成短肽、红细胞凝集抑制试验鉴定短肽模拟A抗原的能力。结果:三轮筛选后特异性噬菌体被富集了200多倍,对ELISA鉴定信号较强的16个噬菌体克隆DNA测序并推导氨基酸序列的结果显示两个克隆展示相同的序列FSYLPSH。化学合成肽能抑制A型红细胞与抗A的凝集作用。结论:肽FSYLPSH具有模拟血型A抗原表位的作用,具有代替天然血型A抗原在临床中应用的潜能。     

EPEC粘附相关蛋白融合表达载体的构建及表达

目的构建与EPEC粘附相关蛋白IntiminC300、EspA、BfpA融合表达载体,并进行表达。方法用PCR方法从EPEC染色体中调取intiminC300、espA、bfpA基因,用基因重组的方法把3个基因片段用2个(Gly4Ser)3连接肽串联克隆到载体pQE30的多克隆区,转化宿主菌M15,用IPTG诱导表达,用SDS-PAGE和Western blot检测表达的融合蛋白。结果酶切和测序表明成功构建了融合表达载体,SDS-PAGE检测表达蛋白的分子质量单位分别为36、43和76kd,与理论值相符,Western blot显示表达的融合蛋白均能被抗His标签抗体识别。结论本研究成功构建了EPEC粘附相关融合蛋白表达载体,并表达目的蛋白,为进一步研究融合蛋白的免疫原性奠定了基础。     

再障引起A型血型抗原减弱1例

正确的ABO血型鉴定,是临床安全输血的关键。临床上某些疾病如再障、实体瘤、白血病等可以造成ABO抗原减弱或缺乏,影响血型的准确鉴定。现将1例再障患者血型抗原减弱的病例报告如下。1资料与方法1.1资料患者,女,72岁,无近期输血史,在本院住院治疗,诊断为再生障碍性贫血。因病情需要申请输血,在ABO血型鉴定时发现正反定型不符。故进一步检查鉴定其血型。1.2血型血清学检查1.2.1试剂与方法抗-A、抗-B(长春博德);抗-AB、抗-H,抗人球蛋白试剂(上海生物技术有限公司);ABO试剂细胞本室自制;筛选细胞(上海血液中心)。1.2.2 ABO血型鉴定正反…     

Suppressed expression of blood group B antigen and blood group galactosyltransferase in a preleukemic subject

The B antigen activity was severely diminished in a patient's RBCs at the preleukemic stage prior to chemo- or radiotherapy. The amount of H sites of the patient's RBC membranes was found to be comparable to that of O RBC membranes. The activity of alpha (1----2) fucosyltransferase (H enzyme) was not severely decreased in the patient's plasma and bone marrow. However, the activity of alpha (1----3) galactosyltransferase (B enzyme), which converts H substance to B substance, was drastically reduced in the patient's bone marrow. Thus, the diminished B antigen in the patient's RBCs was caused mainly by the blockage of conversion of the H substance to B substance. It is suggested that the viral oncogene linked to the ABO locus at q34 of chromosome No. 9 would occasionally suppress the expression of blood group A and B enzymes and A and B antigens.     

Immunodiffusion studies of blood group A antigen

Abstract. Stromata of blood group A₁ erythrocytes fragmented by ultrasound were studied by means of double diffusion in gel. In many instances the reactions with immune anti-A sera were composed of two lines. Evidence was presented that group A₁ secretor saliva contains all the A antigenic specificities present on the stromata. On the other hand, group A₁ secretor serum appeared to be antigenically poorer than stromata. The reaction line with group A₁ stromata was stronger than with group A₂ stromata. Some evidence for a qualitative antigenic difference between the group A₁ and A₂ stromata was also obtained. Phaseolus limensis lectin produced a reaction line with group A₁ stromata. Data were presented in support of the existence of two populations of stromal particles, one combining with this lectin and anti-A serum and the other with the antiserum only. The first population of particles could be eliminated from the stromal suspension without influencing the reactivity of the sedond population.     

A gene,y, modifying the blood group antigen A

Evidence is given for the existence in man of a locus Yy. The very rare genotype yy modifies the development of the A antigen in the red cells and, to a very much less extent, in the saliva; the B and H antigens are not affected. The Yy locus is not closely linked to the ABO locus.

Résumé

Les études sérologiques et génétiques présentées dans ce travail font penser qu'il existe chez l'homme une paire de gènes Yy ; le rare genotype yy influencerait la puissance du facteur A dans les érythrocytes, beaucoup moins dans la salive, tandis que les facteurs B et H ne sont pas affectés. Il n'y a point de conjugaison étroite entre le locus Yy et le locus ABO.

Zusammenfassung

Auf Grund der vorliegenden genetischen und serologischen Untersuchungen ist anzunehmen, daß beim Menschen ein Genpaar Yy vorkommt, wobei der sehr seltene Genotypus yy die phänotypische Ausprägung des Blutgruppenantigens A in den Erythrozyten beeinflußt. Die Ausscheidung von Blutgruppensubstanz A im Speichel wird kaum beeinflußt. Der Genotypus yy hat keinen Einfluß auf die phänotypische Ausprägung der Antigene B und H. Der Genlokus Yy zeigt keine enge Koppelung mit dem Genlokus ABO.     

Prognostic influence of loss of blood group A antigen expression in pathologic stage I non-small-cell lung cancer

Introduction

In the scientific literature, contradictory results has been published on the prognostic value of the loss of expression of blood group antigen A (BAA) in lung cancer. The objective of our study was to analyze this fact in our surgical series.

Patients and methods

In a multicenter study, 402 non-small-cell lung cancer (NSCLC) patients were included. All were classified as stage-I according to the last 2009-TNM classification. We analyzed the prognostic influence of the loss of expression of BAA in the 209 patients expressing blood group A or AB.

Results

The 5-year cumulative survival was 73% for patients expressing BAA vs 53% for patients with loss of expression (P=.03). When patients were grouped into stages IA and IB, statistical significance was only observed in stage I-A (P=.038). When we analyzed the survival according to histologic type, those patients with adenocarcinoma and loss of expression of BAA had a lower survival rate that was statistically very significant (P=.003). The multivariate analysis showed that age, gender and expression of BAA were independent prognostic factors.

Conclusions

The loss of expression of blood group antigen A has a negative prognostic impact in stage I NSCLC, especially in patients with adenocarcinoma.     

Detection of blood group A antigen expression in human colon cancer using monoclonal antibodies with different specificities

Blood group antigen expression in human colon cancer was studied by means of two monoclonal antibodies of broad anti-A (HE-14) and anti-type 3 and type 4 chain-based A and H (HE-10) specificity. These antigens were proved to reappear in tumors of the distal colon, the HE-10 antibody reacting more frequently (9 out of 12 samples) than HE-14 (5 out of 12 samples) and frequently with supranuclear staining of the cytoplasm probably in those places of the Golgi apparatus where carbohydrate antigens are synthesized. This staining pattern is characteristic of HE-10 in normal colonic mucosa as well. With HE-14, staining was often absent in less differentiated tumors, while HE-10 did react in such tumors. In this connection, the possible expression of type 3 and type 4 chain H antigens in the tumor tissue is discussed. In some cases, these two antibodies gave different staining patterns in parallel sections from the same tissue sample, primarily at the cellular level. Three out of 12 cases showed blood group antigen expression in the mucosa of the distal colon adjacent to the tumor only when HE-10 antibody was used.     

A and B blood group antigen expression on mixed colony cells and erythroid precursors: relevance for human allogeneic bone marrow transplantation

Using anti-A and anti-B blood group monoclonal antibodies and fluorescent activated cell sorting of human bone marrow, A (or B) blood group antigen was shown to be on 5.2 ± 5.9 (meanfSD) % of CFU-GEMM and 12 ± 5 ± 19.6% of the erythroid burst forming cells (designated BFU-GEMM) as defined by the mixed colony assay, and 49.5±20% of the BFU-E and 83.5±9.9% of the CFU-E as defined by the erythroid colony assay. This antigen expression on the BFU-GEMM is consistent with the concept that erythroid bursts stimulated by leucocyte conditioned medium are less mature, and are closer in development to the pluripotent stem cell than the BFU-E. These results help to explain the delayed erythropoiesis, and perhaps impaired engraftment of all cell lineages, that may occur in some recipients of ABO incompatible bone marrow transplants, with persistent and high anti-A titres.