流式技术测定乙型肝炎患者外周血特异性CD8＋T细胞及其临床意义

目的 探讨流式细胞技术检测乙型肝炎患者HBV特异性CD8＋T细胞的水平并分析其临床意义.方法 采用HLA-A2分子胞外段与HBV核心表位肽core18-27结合的HLA-肽五聚体（Pentamers）对25例急性乙肝患者、35例慢性乙肝患者和10例正常健康人的外周血进行染色,设计流式细胞技术检测其针对该肽段的特异性CD8＋T细胞数量,以占总计数CD8＋细胞数的百分比表示.结果 12例HLA-A2＋的急性乙肝患者急性期可检测到高水平的特异性CD8＋T细胞,中位数为2.93%（1.12%～4.63%）,16例HLA-A2＋的慢性乙肝患者特异性CD8＋T细胞水平较低,中位数为0.75%（＜0.01%～1.76%）,两组之间差异有统计学意义（P＜0.01）.10例HLA-A2＋正常对照组、13例HLA-A2-急性乙肝对照组和19例HLA-A2慢性乙肝对照组的特异性CD8＋T细胞均不超过0.02%.结论 HLA-肽五聚体流式细胞技术能在体外直接检测HBV特异性的CD8＋T细胞数量,其水平可能影响着HBV感染者体内病毒的清除,且与乙肝的不同临床转归有关.     

一种狂犬病实验室诊断用单克隆抗体制备新路线的探索

目的 探索采用合成肽作为免疫原制备狂犬病实验室诊断用单克隆抗体的可行性.方法 以狂犬病病毒CVS-11核蛋白355-369位B细胞线性抗原表位合成肽与钥孔戚血蓝蛋白（Keyhole Limpe hemocyanin,KLH）大分子耦联后免疫BALB/c小鼠,利用经典杂交瘤细胞技术制备单克隆抗体.采用间接酶联免疫吸附试验（enzyme-linked immunosorbent assay,ELISA）和间接荧光试验（indirect fluorescent assay,IFA）筛选和鉴定杂交瘤细胞株.结果 经过对杂交瘤细胞株上清的间接ELISA和IFA筛选获得阳性杂交瘤细胞株2B1D11,该杂交瘤细胞株产生的抗体经纯化后在IFA中可以有效检出感染犬脑组织和BHK-21细胞的狂犬病病毒.结论 采用合成肽作为免疫原制备狂犬病实验室诊断用抗体在技术上是可行的.     

青霉源抗菌肽类霉肽素的体外抑菌活性研究

目的研究抗菌肽类霉肽素（AF）的体外抑菌活性。方法通过抑菌圈法和二倍稀释法检测AF的抗菌谱和对金黄色葡萄球菌的MIC;通过检测在AF中传代菌的敏感性确定细菌是否容易对AF产生抗药菌;将AF和细菌在不同温度和pH环境作用后检测抑菌活性,明确AF发挥活性的最适温度和pH值。结果AF对大部分供试细菌和抗药菌有效,对金黄色葡萄球菌的MIC为0．8mg／ml,金黄色葡萄球菌在AF中传代200代后敏感性不变。在14℃到30℃之间AF的抑菌活性随温度升高而降低,在pH3到pH10之间AF的活性随pH值升高而降低。结论AF是一种对抗性菌有效的广谱抗菌肽,而且不容易诱导细菌产生抗药性。     

心肌肽素对大鼠心脏缺血-再灌注损伤的治疗作用

目的:研究多肽类物质心肌肽素对大鼠心脏缺血-再灌注损伤的治疗作用。方法:在大鼠冠脉结扎致心肌缺血-再灌注损伤模型上,观察心肌肽素治疗性给药对缺血大鼠血浆中肌酸磷酸激酶(CPK)、乳酸脱氢酶(LDH)活性及脂质过氧化终产物(MDA)含量的影响。结果:心肌肽素治疗性给药能明显降低血浆CPK、LDH的活性与MDA含量,其作用具有明显的量效关系。结论:心肌肽素对心脏缺血-再灌注损伤有治疗作用,提示可能与其抗脂质过氧化和影响心肌酶的活性有关。     

HIV感染者体内抗小分子多肽抗体与病情发展的初步研究

目的 研究HIv感染者体内抗—R7v含量与病情发展的关系。方法 用ELISA、中和沉淀等方法检测HIv感染者、长期生存者、艾滋病患者等的抗—R7v含量。结果 抗—R7v检出率在无症状组和长期生存组较高，在进展者和艾滋病患者中较低，溶解处理标本后抗—R7v含量及阳性率明显提高。结论 抗—R7V主要通过于扰HIV与CCB5、CxCR4结合，使HIV不能进入CD4^ T淋巴细胞内，并阻止病毒的复制。     

低聚肽调节免疫功能及其对冠状病毒感染的影响

低聚肽是蛋白质分解为氨基酸过程中的中间产物,其不仅具有蛋白质的营养支撑作用,还具有强大的调节抗氧化和免疫功能的作用。本文就动物、植物和微生物来源的低聚肽对免疫系统的调控作用进行了论述,对其提高免疫系统功能及对冠状病毒感染的防御作用进行了分析,旨在为更合理地利用不同来源和性质的低聚肽制备而成的复合肽类产品,更有效地增强人体免疫功能,为预防和治疗新型冠状病毒肺炎(COVID-19)提供营养支撑。     

Neonatal damage to the rat's infraorbital nerve upregulates both galanin and neuropeptide Y in individual vibrissae-related primary afferent axons

Previous studies in adult animals have suggested that the peptides galanin and neuropeptide Y (NPY) may be upregulated in the same primary afferent neurons after peripheral axotomy. The present study was undertaken to determine whether such upregulation occurred in vibrissae-related primary afferent neurons and their axons after damage to the infraorbital nerve [ION; the trigeminal (V) branch that innervates the vibrissae follicles]. Double-labelling experiments demonstrated that approximately 75% of axotomized V ganglion cells and the central arbors of vibrissae-related primary afferents expressed both galanin and NPY after perinatal, but not adult, nerve damage. However, additional experiments demonstrated that the sensitive periods for lesion-induced upregulation of the two peptides and the period over which they were expressed after neonatal ION transection differed substantially. Staining for both peptides was increased after ION damage on P-0 through P-14, but only galanin staining was increased in vibrissae-related primary afferents after lesions on P-21. Galanin expression was elevated in vibrissae-related primary afferents in rats killed 3,8, and 15 days after neonatal ION transection, while increased NPY was observed at only the middle time point. The lesion-induced increases in galanin and NPY in vibrissae-related ION primary afferents suggest that these peptides may modulate central V reorganization after such damage.     

Amide molecular clocks in drosophila proteins: potential regulators of aging and other processes

After synthesis and folding, peptides and proteins undergo changes in charge and conformation through nonenzymatic deamidation of asparaginyl and glutaminyl residues. Each amide has a specific deamidation rate that is genetically determined by the sequence of residues immediately adjacent in the peptide chain and by secondary, tertiary, and quaternary structure. By means of experimentally verified computations, we have determined the deamidation rates of 49 Drosophila peptides and proteins. These rates demonstrate that deamidation provides molecular clocks that are suitable for the regulation of Drosophila aging, development, and other biochemical processes. We have also determined the rates of deamidation for 17,886 other proteins from a wide variety of organisms. The distribution function of these deamidation rates demonstrates the suitability of amide residues as biomolecular clocks.     

Immunogenicity and T cell recognition in swine of foot-and-mouth disease virus polymerase 3D

Immunization of domestic pigs with a vaccinia virus (VV) recombinant expressing foot-and-mouth disease virus (FMDV) 3D protein conferred partial protection against challenge with infectious virus. The severity reduction of the clinical symptoms developed by the challenged animals occurred in the absence of significant levels of anti-3D circulating antibodies. This observation suggested that the partial protection observed was mediated by the induction of a 3D-specific cellular immune response. To gain information on the T cell recognition of FMDV 3D protein, we conducted in vitro proliferative assays using lymphocytes from outbred pigs experimentally infected with FMDV and 90 overlapping peptides spanning the complete 3D sequence. The use of pools of two to three peptides allowed the identification of T cell epitopes that were efficiently recognized by lymphocytes from at least four of the five animals analyzed. This recognition was heterotypic because anti-peptide responses increased upon reinfection of animals with a FMDV isolate from a different serotype. The results obtained with individual peptides confirmed the antigenicity observed with peptide pools. Detection of cytokine mRNAs by RT-PCR in lymphocytes stimulated in vitro by individual 3D peptides revealed that IFN-gamma mRNA was the most consistently induced, suggesting that the activated T cells belong to the Th 1 subset. These results indicate that 3D protein contains epitopes that can be efficiently recognized by porcine T lymphocytes from different infected animals, both upon primary and secondary (heterotypic) FMDV infection. These epitopes can extend the repertoire of viral T cell epitopes to be included in subunit and synthetic FMD vaccines.