杀菌性/通透性增加蛋白的生物学功能及其应用

杀菌性/通透性增加(BPI)蛋白是哺乳动物中性粒细胞中存在的一种碱性蛋白,它能与革兰氏阴性菌脂多糖结合,增加外膜对抗菌药的通透性,具有中和内毒素和杀灭细菌的生物学作用,在革兰氏阴性菌感染的治疗方面有良好的发展前景。文章主要从分子生物学和病理学角度出发,对 BPI 蛋白的生物学杀菌活性和作用机理进行了综述,并展望了其应用前景。     

猪杀菌性/通透性增强蛋白(BPI)的功能及其在抗病育种中应用的研究进展

杀菌性/通透性增强蛋白（bactericidal/permeability-increasing protein,BPI）有较强的杀菌作用（主要为革兰氏阴性菌）和中和脂多糖（lipopolysaccharide,LPS）的活性,以及增强单核细胞和嗜中性粒细胞对病原菌的吞噬功能。近年来,BPI的生物学功能受到广泛关注,被称为机体内的“超级抗生素”,BPI基因被很多学者作为抗病候选基因进行探索。作者综述了猪BPI基因的结构、生物学功能及其与猪抗性的关系等,阐述了BPI基因在猪抗病育种中的研究进展及应用前景,为下一步猪BPI基因的功能研究及其在抗病育种实践中的应用提供理论依据。     

杀菌/通透性增加蛋白研究现状及应用前景

杀菌/通透性增加蛋白(BPI)是中性粒细胞内存在的一种碱性蛋白,是一个分子质量介于50～60 ku的阳性蛋白,它主要存在于人、牛、兔等哺乳动物多形核粒细胞(PN4NL)的嗜天青颗粒中及其表面,它能与革兰氏阴性菌脂多糖(LPS)结合,具有中和内毒素和杀灭细菌的作用,在革兰氏阴性菌感染的治疗方面有良好的应用前景,人类最初注意杀菌性/通透性增加蛋白是因其具有杀菌作用,但随后发现它还具有较强的颉颃内毒素的作用。近年来国外对其研究颇多,并逐渐发现其还具有很多其他功能,如抗真菌、杀灭寄生虫等作用,其被学者称为未来的“超级抗生素”。     

牛杀菌／通透性增加蛋白氮端基因克隆和序列分析

目的克隆杀菌/通透性增加蛋白(BPI)cDNA,构建重组体pGEM-T-easy-BPI,进行序列鉴定。方法应用RT-PCR技术,参照Genbank报道的序列,从牛嗜中性粒细胞mRNA中扩增出杀菌/通透性增加蛋白238个氨基酸,并与pGEM-T-easy连接,构建基因重组体,进行序列测定.结果获得长度为713bp的活性基因。序列分析证实该片段中有1个点突变,但氨基酸序列相同。结论:成功克隆出BPI基因,经序列测定,确认为牛BPI基因,为进一步表达该基因奠定了基础。     

重组BPI蛋白对淋巴细胞增殖及绒毛尿囊膜血管生成的影响

为研究绵羊重组杀菌性/通透性增加蛋白(recombinant bectericidal/permeability increasing protein,r BPI)的生物学功能,用MTT法检测r BPI对绵羊淋巴细胞增殖的影响;用鸡胚绒毛尿囊膜(chorioallantoic membrane,CAM)检测其对微血管生成的影响。结果表明,与对照组相比,r BPI淋巴细胞增殖作用差异均不显著(P0.05);1.8μmol/L和540 nmol/L r BPI组对微血管生成的抑制率分别是57.2%和48.7%。说明r BPI对淋巴细胞没有明显的增殖作用,但对微血管的生成具有抑制作用,且随着r BPI浓度增加抑制作用加强。     

猪脂多糖结合蛋白家族及其基因的研究进展

本文介绍了脂多糖结合蛋白(LBP)、杀菌/通透性增加蛋白(BPI)、磷脂酯转移蛋白(PLTP)、胆固醇酯转移蛋白(CETP)的结构和功能,并综述了猪脂多糖结合蛋白家族基因的研究进展。     

牛杀菌／通透性增加蛋白氮端基因的克隆和序列分析

本试验应用RT-PCR技术,参照Genbank报道的序列,从荷斯坦牛中性粒细胞mRNA中扩增出杀菌／通透性增加蛋白（BPI）氮端基因（713bp）,并与pGEM-T-easy载体连接,构建基因重组体pGEM-T-easy-BPI,进行序列测定。结果表明获得长度为713bp的BPI氮端基因。序列分析证实该片段与安哥斯牛BPI氮端基因相比有1个点突变,为同义突变。该基因的克隆为进一步表达该基因奠定了基础。     

13个物种BPI基因编码区生物信息学分析

本研究采用生物信息学的方法比较不同物种BPI基因编码区CDS序列,分析人、小家鼠、褐家鼠、牛、白颊长臂猿、原鸡、家兔、野猪、猕猴、家马、非洲爪蟾、毛猩猩、犬 13个物种BPI基因编码区的遗传多样性,且对BPI氨基酸序列组成、信号肽、疏水性/亲水性、跨膜结构、二级结构及保守结构域进行预测分析。结果表明,在13个物种的29条BPI基因CDS序列中,共检测到532个多态位点,生成了15种单倍型,BPI基因在种群间及种群内均存在较大的遗传变异,BPI基因具有较强的密码子偏爱性。BPI蛋白理论等电点均大于7,呈碱性,N端大都有信号肽,肽链表现为亲水性,基本属于跨膜蛋白和分泌蛋白。BPI蛋白主要二级结构元件为α螺旋、β折叠和无规则卷曲,有2个保守结构域BPI1和BPI2。     

绵羊感染支原体后杀菌通透性增加蛋白(BPI)mRNA表达水平的变化

为了检测巴什拜羊和盘羊杂交羊在感染绵羊肺炎支原体(MO)前后杀菌通透性增加蛋白(BPI)表达水平的变化,对试验羊攻毒MO,在感染前(第0天)及感染后的第2、5、7、14及21天,颈静脉采血分离中性粒细胞,采用Real-time q PCR方法检测BPI的表达水平。结果显示,感染后第5天,2组BPI相对表达量升高。巴什拜羊BPI持续升高,杂交羊在第7天表达水平最高,在14-21天则逐渐降低。在第7天,巴什拜羊高于杂交羊(P0.05),在第14-21天,巴什拜羊极显著高于杂交羊(P0.01)。说明绵羊感染MO后初期BPI有明显升高趋势,在后期巴什拜羊和杂交羊的BPI变化有差异,这对研究支原体肺炎发病机理提供参考。     

杀菌通透性增加蛋白研究概况

随着生产和食品安全的需要,应用无毒、安全的新型抗菌剂替代抗生素,已成为当前国内外治疗和预防动物革兰阴性细菌(GNB)感染的一项重要内容.因此寻找特异杀灭GNB并中和内毒素的有效防治措施一直是关注的焦点.在抗菌肽中,杀菌/通透性增加蛋白(bactericidal/permeability-increasing protein,BPI)对GNB的潜在作用和选择作用是独一无二的[1].     

猪BPI蛋白重组载体的构建及真核表达

试验旨在构建猪BPI真核表达载体,获得猪源BPI重组蛋白.根据GenScript's CloneEZ^® PCR Cloning Kit试剂盒,将BPI编码序列克隆至pUC57载体上,酶切与测序鉴定无误后,将重组质粒pUC57-BPI转染293-6E细胞,并利用SDS-PAGE和Western blotting方法检测其表达水平.结果显示,本试验成功构建了猪源BPI蛋白真核表达载体pUC57-BPI,并在293-6E细胞培养上清中检测到猪源BPI重组蛋白的表达.该猪源BPI重组蛋白体外表达系统的建立为今后深入研究猪BPI的生物学功能以及猪抗菌蛋白的制备提供了试验基础.     

A peptide derived from human bactericidal/permeability-increasing protein (BPI) exerts bactericidal activity against Gram-negative bacterial isolates obtained from clinical cases of bovine mastitis

Gram-negative bacteria are responsible for approximately one-third of the clinical cases of bovine mastitis and can elicit a life-threatening, systemic inflammatory response. Lipopolysaccharide (LPS) is a membrane component of Gram-negative bacteria and is largely responsible for evoking the inflammatory response. Antibiotic and anti-inflammatory therapy for treating Gram-negative infections remains suboptimal. Bactericidal/permeability-increasing protein (BPI) is a neutrophil-derived protein with antimicrobial and LPS-neutralizing properties. Select peptide derivatives of BPI are reported to retain these properties. The objective of this study was to evaluate the antimicrobial activity of a human BPI-derived synthetic peptide against clinical bovine mastitis isolates of Gram-negative bacteria. A hybrid peptide was synthesized corresponding to two regions of human BPI (amino acids 90-99 and 148-161), the former of which has bactericidal activity and the latter of which has LPS-neutralizing activity. The minimum inhibitory (MIC) and bactericidal (MBC) concentrations of this peptide against various genera of bacteria were determined using a broth microdilution assay. The MIC's were determined to be: 16-64 microg/ml against Escherichia coli; 32-128 microg/ml against Klebsiella pneumoniae and Enterobacter spp.; and 64-256 microg/ml against Pseudomonas aeruginosa. The MBC's were equivalent to or 1-fold greater than corresponding MIC's. The peptide had no growth inhibitory effect on Serratia marcescens. The antimicrobial activity of the peptide was retained in the presence of serum, but severely impaired in milk. Further functional evaluation of the peptide demonstrated its ability to completely neutralize LPS. Together, these data support additional investigations into the therapeutic application of BPI to the treatment of Gram-negative infections in cattle.     

Research Progress on Function of Pig Bactericidal/Permeability-increasing Protein (BPI) and Its Application in Resistance Breeding

Bactericidal/permeability-increasing protein (BPI) has a strong effect on sterilization (mainly for G^- bacteria),neutralizing the activity of lipopolysaccharide (LPS) and enhancing the phagocytosis of mononuclear cells and neutrophils to pathogenic bacteria.The biological functions of BPI have been researched widely in recent years,which is known as "super antibiotic" and has been explored by many scholars as a candidate gene for resistance.This author summarized the research progress and application prospect of the BPI gene in the pig resistant breeding by introducing the structure,biological function of BPI gene and its relationship with the resistance,which was aimed to provide theoretical references and basis for the function research of pig BPI gene and its practical application in resistance breeding in future.     

Molecular cloning and characterization of LPS-binding protein/bactericidal permeability-increasing protein (LBP/BPI) from olive flounder,Paralichthys olivaceus

A lipopolysaccharide (LPS)-binding protein/bactericidal permeability-increasing protein (LBP/BPI) homolog was isolated from peripheral blood leukocytes cDNA library of olive flounder Paralichthys olivaceus. The isolated LBP/BPI cDNA is 2806 bp in length with a 1419 bp open reading frame (ORF) that encodes a protein of 472 amino acid residues. The LPS-binding domain is well conserved in the N-terminal barrel, showing high sequence identities with other teleost LBP/BPI as well as those of mammals. RT-PCR analysis revealed that mRNA expression of LBP/BPI was significantly elevated in all tested tissues (liver, gill, intestine, head kidney, and spleen) after intraperitoneal injection of the gram-negative bacterium Edwardsiella tarda or the gram-positive bacterium Streptococcus iniae. This expression pattern profile corresponded to that of acute inflammatory cytokines, suggesting that it plays a role in the innate immune response, in particular, the acute phase response.     

BPI基因在梅山猪初生断奶以及成年阶段的组织表达谱分析

为探讨杀菌/通透性增强蛋白(BPI)基因在梅山猪从初生到成年各个时期不同组织中的表达规律,利用qPCR检测初生、断奶、性成熟、体成熟4个重要发育时期(即1、35、134、158日龄)梅山猪的心脏、肝脏、脾脏、肺脏、肾脏、胃、肌肉、胸腺、淋巴结、十二指肠、空肠和回肠12个组织中BPI基因的表达水平。结果表明:4个不同发育阶段BPI基因的组织表达谱在心脏、肝脏、脾脏、肌肉和胸腺中均表现出相对一致的规律,即BPI基因的表达量一直处于极低水平,而在肠道组织中从初生到成年各时期均高度表达;BPI基因在胃中的表达程度随着日龄增长而显著提高;在小肠组织中,35日龄断奶仔猪BPI基因的表达水平极显著高于其他3个日龄。综上,推断肠道中BPI基因的高度表达是仔猪从初生就具有的抵抗大肠杆菌等病原感染属固有免疫的一部分,而在胃中的表达很可能是其后天为了抵御不断侵染的大肠杆菌等病原的结果。