抗B型葡萄球菌肠毒素高亲和力单链抗体的制备

目的 构建针对B型葡萄球菌肠毒素(SEB)的特异性单链抗体(scFv),并进行纯化和鉴定.方法 设计抗SEB高亲和力单克隆抗体(mAb) FMU-SEB-No.2重链和轻链可变区基因片段VH和VL的引物,利用RT-PCR技术,从本室制备的抗SEBmAb FMU-SEB-No.2杂交瘤细胞株中扩增出VH和VL基因片段;然后通过在轻链引物上设计linker序列,重叠引物延伸法(SOE)将VH和VL基因拼接成scFv基因片段,并将其克隆入原核表达载体PGEX4T-1中;转化E.coli BL21(DE3)感受态细胞,IPTG诱导表达,融合蛋白经谷胱甘肽亲和层吸柱纯化.采用SDS-PAGE,Western blot,ELISA等方法对其表达水平和特异性进行分析.结果 成功从1株抗SEB mAb FMU-SEB-No.2杂交瘤细胞株中扩增出VH和VL可变区基因,并通过linker序列将其拼接成scFv片段,大小约750 bp,编码250个氨基酸.PCR、酶切鉴定和测序结果表明表达载体构建成功.转化E.coli BL21(DE3),经IPTG诱导后,以可溶形式表达相对分子质量(Mr)约54 000的融合蛋白.经谷胱甘肽亲和层析法纯化融合蛋白,可获得纯度达90％以上的scFv,ELISA和Western blot法检测结果表明,可溶性scFv与抗原SEB有较强的结合活性.结论 成功构建并表达出抗SEB的特异性单链抗体.     

抗SEB单克隆抗体可变区基因克隆及单链抗体的基因构建和表达

目的 从分泌抗SEB的单克隆抗体(FMU-SEB-No.1)杂交瘤细胞中,克隆出FMU-SEB-No.1重链和轻链可变区(VH和VL)基因,构建FMU-SEB-No.1单链抗体(scFv)的原核表达载体,并进行scFv基因的蛋白表达.方法 从FMU-SEB-No.1杂交瘤细胞中提取总RNA,采用RT-PCR扩增出VH和VL基因;通过在引物上设计linker序列,拼接VH和VL为完整FMU-SEB-No.1的scFv基因(FMU-SEB-scFv).将测序正确的scFv基因克隆入PGEX4T-1载体,转化入E.coli BL21(DE3)进行蛋白表达.通过SDS-PAGE,Western blot法分析其表达水平和特异性,酶联免疫吸附试验(ELISA)鉴定其抗原结合活性.结果 测序结果显示,本实验成功克隆出FMU-SEB-No.1重链及轻链可变区基因,并成功构建FMU-SEB-scFv基因,所得的基因全长为750 bp,编码250个氨基酸.SDS-PAGE和Western blot分析表明,PGEX4T1-FMU-SEB-scFv在E.coli BL21(DE3)可表达为Mr约54 000的可溶型scFv/GST融合蛋白.间接ELISA检测结果表明,可溶型scFv/GST融合蛋白与SEB具有较高的抗原结合活性.结论 制备并鉴定了针对SEB的基因工程抗体,为开发出针对SEB的治疗性抗体奠定了实验基础.     

抗重组人bFGF单克隆抗体可变区基因克隆及单链抗体的构建和表达

目的：从分泌抗重组人碱性成纤维细胞生长因子（bFGF）单克隆抗体（mAb）杂交瘤细胞株B2F3中克隆抗体可变区（V）基因，构建bFGF单链抗体（scFv），并进行可溶性表达。方法：从分泌bFGF mAb杂交瘤细胞株B2F3提取总RNA，用RT-PCR方法扩增抗体重链可变区基因（VH）和轻链的可变区基因（VL）；再通过重叠延伸拼接（SOE）PCR方法，在VH和VL基因之间引入linker（Gly4Ser）3，构建bFGF scFv。将测序正确的scFv基因克隆到表达载体pCANTAB 5E中，选择非抑制型菌株E.coli HB2151进行可溶性表达；经SDS—PAGE检测抗体表达水平，ELISA鉴定其抗原结合活性。结果：测序分析结果显示，VH基因序列全长375碱基对，编码125个氨基酸，VL基因序列全长399碱基对，编码133个氨基酸，二者均符合小鼠免疫球蛋白可变区基因特征，含有4个框架区（FR）、3个抗原互补决定区（CDR）及抗体特征性的2个半胱氨酸残基；构建的scFv全长789碱基对，编码263个氨基酸，连接结构为VH-linker-VL。SDS-PAGE分析表明scFv基因在大肠杆菌为可溶性表达，表达产物主要位于周质腔中，表达产物的Mr为27000，与理论预期值相符；间接ELISA检测结果显示原核表达的scFv具有与bFGF特异性结合的活性。结论：成功地克隆bFGF mAb可变区基因，并构建表达bFGF scFv，为下一步研究bFGF抗体人源化改造奠定实验基础。     

封闭N-cadherin解整合素金属蛋白酶水解位点的单链抗体的制备及鉴定

目的 制备封闭神经型钙黏素(N-cadherin)解整合素金属蛋白酶水解位点(ADAM)的单链抗体(scFv),并进行鉴定.方法 首先利用RT-PCR技术从分泌抗N-cadherin的ADAM水解位点单克隆抗体(mAb)细胞株中扩增出重链(VH)和轻链(VL)可变区基因片段,然后通过重叠延伸PCR法(SOE-PCR),构建成scFv基因片段.再将其克隆入原核表达载体pET-28a中,在大肠杆菌中诱导表达,通过镍柱纯化和复性后,用SDS-PAGE、ELISA和Western blot法等测定重组蛋白的生物学活性.结果 PCR、酶切和测序表明scFv片段长744 bp,编码248个氨基酸.scFv基因表达载体转化E.coli BL21(DE3),经IPTG诱导表达出相对分子质量(Mr)约29 000的目的蛋白,主要为包涵体形式,经变性,纯化和复性后,获得纯度达90％以上的scFv蛋白,ELISA和Western blot法检测表明可溶性scFv可以与N-cadherin的ADAM水解位点序列多抗原短肽和全长N-cadherin结合.结论 成功构建并表达封闭N-cadherin的ADAM加工位点单链抗体.     

抗HEV中和抗体13D8的单链抗体的构建及表达

目的 :降低HEV中和性单抗 (mAb) 13D8的鼠源性 ,表达其单链抗体 (scFv)。方法 :从分泌 13D8鼠mAb的杂交瘤细胞中 ,通过RT PCR克隆mAb的VL、VH 基因 ,并进一步组装成VH linker VL 型的scFv片段。将scFv片段克隆到pTO T7载体中 ,在大肠杆菌中进行表达。用ELISA、Westernblot检测scFv的活性。结果 :SDS PAGE表明 ,13D8的scFv在E .coli中得到高效表达 ,表达量达菌体总蛋白的 2 6 .8%左右 ,表达产物主要以包涵体的形式存在。间接ELISA和Westernblot检测表明 ,表达的 13D8的scFv能与HEVOFR2区中一段重组蛋白(NE2 )特异结合。竞争ELISA表明 ,scFv与原鼠mAb识别的为同一表位。结论 :成功地表达出具有免疫学活性的 13D8的scFv。     

抗人整合素αυβ3单链抗体的构建和表达

目的：利用基因工程抗体技术构建抗人整合素αυβ3单链抗体(scFv)。方法：从分泌抗人整合素αυβ3单抗(mAb)的杂交瘤细胞E10总RNA中，用RT-PCR扩增VH和VL基因，对其核苷酸序列分析后，通过PCR在VH和VL基因间插入柔性连接子(Gly4Ser)3 组装成scFv基因，并克隆至原核表达载体pTIG—TRX中。以重组子转化大肠杆菌B121(DE3)诱导目的基因表达。结果：转化菌可表达相对分子质量(Mr)为31000的scFv。Western blot证实，具有His6标签蛋白的表达。经低剂量的IPTG诱导和较低温度培养，scFv获得了可溶性形式表达。表达产物经Ni—NTA琼脂糖层析纯化后纯度达91％以上。ELISA鉴定证实，scFv具有良好的抗原结合活性。结论：成功地构建并表达抗人整合素αυβ3的scFv，为进一步临床研究奠定了基础。     

抗人乙酰胆碱受体scFv-人血清白蛋白融合蛋白的构建及在大肠杆菌中的表达

目的:制备抗人乙酰胆碱受体单链抗体637(scFv637)与人血清白蛋白(HSA)的融合蛋白,提高scFv637的稳定性。方法:用PCR扩增人HSA基因,并克隆到含有抗人乙酰胆碱受体scFv637基因的载体pHEN2中构建重组载体pHEN2-scFv637-HSA。以重组载体转化E.coliHB2151,表达产物用斑点杂交试验检测,并以SDS-PAGE和Westernblot鉴定其融合蛋白的相对分子质量(Mr)。结果:琼脂糖凝胶电泳显示,扩增的人HSA基因和融合基因的大小分别为1770bp和7054bp。构建的scFv637-HSA经测序证实核苷酸序列正确,并且正确克隆至载体的开放读码框架内。表达产物仅存在于pHEN2-scFv637-HSA转化的E.coliHB2151外周质裂解液中。表达的融合蛋白的Mr约为95900。结论:在E.coli中成功地表达scFv637-HSA融合蛋白,为进一步对其进行功能研究和应用奠定了基础。     

抗重组志贺样毒素ⅡA亚单位单链抗体的构建及表达

目的 构建重组志贺样毒素ⅡA亚单位（SLT2A）单链抗体基因（scFv），并在大肠杆菌中进行分泌表达。方法 通过连接肽（Gly4Ser），将已成功扩增的抗SLT2A单克隆抗体（mAb）5F3的VL和Va连接成scFv基因VH-Linker-VL并在Va基因5′端和VL基因3′端引入Sfi Ⅰ和Not Ⅰ的酶切位点，克隆至经改造的分泌性表达载体pCANTAB6His中，转化Ecoli HB2151，IPTG诱导表达。表达产物经亲和层析纯化后，SDS-PAGE和Westem blot分析鉴定。结果 经限制性酶切鉴定及DNA测序分析证实，基因构建正确。SDS-PAGE和Westem blot分析表明scFv基因在大肠杆菌中得到表达，表达产物的相对分子质量为27000，与理论预期值相符，且可与相应抗原特异结合。结论 成功地实现了抗SLT2A scFv基因的原核分泌表达，为探讨0157菌感染的机制及防治研究奠定了基础。     

抗人乙酰胆碱受体单链抗体1956#在大肠杆菌中的可溶性表达

目的: 重组表达抗人乙酰胆碱受体(AChR)单链抗体(scFv)1956#, 提高scFv1956#的可溶性表达量.方法: 用PCR扩增含抗人AChR scFv1956#的载体pHEN1中的scFv1956#结构基因, 并将其插入到原核表达载体pET44a( ).用重新构建的载体转化E.coli BL21(DE3)pLysS, IPTG诱导表达.用SDS-PAGE来比较更换载体及不同温度和时间对可溶性表达量的影响, 并通过Western blot进行鉴定.结果: PCR产物大小为785 bp, 与预计相符; 所构建质粒经测序证实scFv1956# 核苷酸序列正确, 并正确插入载体pET44a( ).诱导后得到的可溶性表达量优于原载体pHEN1.结论: 载体pET44a( )表达的端融蛋白NusA可以帮助scFv1956# 的正确折叠, 从而获得大量可溶性表达.低温长时间诱导有助于提高可溶性表达的量.     

抗阿尔茨海默病Aβ人源单链抗体基因的筛选和表达

目的 从人源噬菌体单链抗体库中筛选与阿尔茨海默病发病中起关键作用的β淀粉样多肽(Aβ)1-42特异性结合的单链可变区抗体(scFv)基因,利用原核生物大肠杆菌进行可溶性表达,以获得抗AB1-42人源抗体.方法 利用噬菌体展示技术对人源噬菌体单链抗体库进行多轮富集,以Aβ1-42为抗原经酶联免疫吸附(ELISA)检测,筛选与Aβ1-42特异性结合的阳性噬菌体克隆,再用阳性噬菌体感染E.coli HB2151进行可溶性表达,经SDS-PAGE、Western blot及ELISA法检测scFv单抗的可溶性表达水平及抗原结合活性.并对阳性scFv抗体基因进行基因测序鉴定.结果 获得了7个特异性的抗Aβ1-42 scFv阳性噬菌体克隆,其中4个克隆ELISA检测吸光度值(A值)高于阴性对照5倍以上;其中1株(A 10)获得可溶性单链抗体的成功表达,表达产物主要位于菌体中,ELISA效价显示在全菌蛋白中A值高于对照5倍以上.其相对分子质量约为33 000.DNA测序表明所获抗体的可变区基因属于scFv抗体基因,推导得到的氨基酸序列具有典型的抗体可变区结构.结论 用人源噬菌体单链抗体库筛选出抗Aβ1-42的人源抗体单链可变区基因,并成功表达了具有抗原结合活性的可溶性单链抗体,为进一步研究阿尔茨海默病的发病机制和治疗奠定了基础.     

Rates of oxygen consumption and of anaerobic glycolysis in renal cortex and medulla of adult and new-born rats and guinea-pigs

1. Rates of oxygen uptake and of anaerobic glycolysis were estimated in slices from the renal cortex and medulla (a) of adult rats and guinea-pigs, (b) of new-born (1-, 5- and 21-day-old) rats and of guinea-pigs of 1, 12, 21, 24 and 120 hr age.2. In the adult rat, Q(O2) values for the cortex were 12.55 +/- 0.20 (22) and for the medulla: 8.56 +/- 0.17 (22) mul./hr.mg dry weight, while in the new-born rat (24 hr old) they were 10.99 +/- 0.46 (12) and 9.33 +/- 0.18 (9) mul./hr.mg dry weight respectively.3. Values for Q(CO2) (N2) (anaerobic glycolysis) in the 14 hr old new-born rat were in the renal cortex 9.65 +/- 0.35 (5) and in the medulla 7.39 +/- 0.43 (5) mul./hr.mg dry weight; while in the adult they were 2.25 +/- 0.08 (16) and 5.76 +/- 0.14 (16) mul./hr.mg dry weight, respectively.4. In the adult guinea-pig values for Q(CO2) (N2) were of the same order as in the adult rat, though the rate of O(2) uptake was for the cortex 8.12 +/- 0.22 (12) and for the medulla 5.02 +/- 0.23 (11) mul./hr.mg dry weight.5. Though the Q(O2) values in the renal cortex and medulla were smaller in the 1 hr old new-born guinea-pig, they were already increasing in the 12 hr old neonate.6. The results are discussed in the light of enzyme changes occurring during the process of maturation of the nephron as indicated by histochemical observations.     

Modes of reinforcement and gender and culture of experimenter and subject: effects of "alien" and external reinforcement for Japanese and American men and women

In this study, we examined external and "alien" reinforcement (ER and AR. respectively) as a factor in social learning, and studied the combined effects of culture and reinforcement mode. A female (Experiment 1) and a male (Experiment 2) experimenters conducted experimental sessions. Both men and women, who grew up in the same culture as the experimenter, participated and performed the experimental task. A three-way interaction effect of experimenter gender, culture, and reinforcement mode was found on task performance. And the effect was more pronounced for a Japanese experimenter. A female and a male experimenters conducted Experiments 3 and 4, respectively; however participants this time were men and women who grew up in different cultures than the experimenter. Results indicated that the pattern of the subject gender and reinforcement mode interaction effect, when the experimenter was Japanese with American subjects, was exactly opposite to that when the experimenter was American. These experiments showed that AR was as effective for social learning as ER, and that the cultural backgrounds of experimenter and subject influenced AR and ER effectiveness.     

Timing and intensity of early fevers and the development of allergies and asthma

BACKGROUND: Early childhood fevers appear to protect against later allergies and asthma. What is not known is the time in which fevers exert this effect and whether the degree of temperature increase is important. OBJECTIVE: We sought to examine the relationship between the time and degree of early fevers and later allergies and asthma. METHODS: Eight hundred thirty-five children from southeast Michigan were enrolled at birth. Clinic records from their first 2 years were abstracted for episodes of fever. At age 6 to 7 years, children underwent allergy testing. We examined fevers occurring within 6-month intervals in the first 2 years of life and outcomes at age 6 to 7 years. The primary outcome measures were allergic sensitization, asthma, asthma with allergic sensitization, and asthma without allergic sensitization. RESULTS: In the unadjusted analysis each episode of fever between 7 and 12 months of age was associated with a lower odds of allergic sensitization (odds ratio [OR], 0.71; 95% CI, 0.54-0.93) and asthma with allergic sensitization (OR, 0.43; 95% CI, 0.21-0.90) at age 6 to 7 years. Likewise, every 1 degrees C increase in the maximum temperature between 7 and 12 months was associated with a lower odds of allergic sensitization (OR, 0.77; 95% CI, 0.61-0.96) and asthma with allergic sensitization (OR, 0.62; 95% CI, 0.40-0.94). After adjusting for potential confounders, each episode of fever between 7 and 12 months was associated with a lower likelihood of asthma with allergic sensitization (adjusted OR, 0.33; 95% CI, 0.11-0.94) at age 6 to 7 years. CONCLUSIONS: Both the timing and intensity of childhood fevers appear to be important factors in the development of allergies and asthma.     

Association between functional alterations of senescence and senility and disorders of gait and balance

OBJECTIVES:

Declines in cognition and mobility are frequently observed in the elderly, and it has been suggested that the appearance of gait disorders in older individuals may constitute a marker of cognitive decline that precedes significant findings in functional performance screening tests. This study sought to evaluate the relationship between functional capacities and gait and balance in an elderly community monitored by the Preventive and Integrated Care Unit of the Hospital Adventista Silvestre in Rio de Janeiro, RJ, Brazil.

METHODS:

Elderly individuals (193 females and 90 males) were submitted to a broad geriatric evaluation, which included the following tests: 1) a performance-oriented mobility assessment (POMA) to evaluate gait; 2) a mini-mental state examination (MMSE); 3) the use of Katz and Lawton scales to assess functional capacity; 4) the application of the geriatric depression scale (GDS); and 5) a mini-nutritional assessment (MNA) scale.

RESULTS:

Reductions in MMSE, Katz and Lawton scores were associated with reductions in POMA scores, and we also observed that significant reductions in POMA scores were present in persons for whom the MMSE and Katz scores did not clearly indicate cognitive dysfunction. We also demonstrated that a decline in the scores obtained with the GDS and MNA scales was associated with a decline in the POMA scores.

CONCLUSIONS:

Considering that significant alterations in the POMA scores were observed prior to the identification of significant alterations in cognitive capacity using either the MMSE or the Katz systems, a prospective study seems warranted to assess the predictive capacity of POMA scores regarding the associated decline in functional capacity.