重组抗体工程及其在肿瘤靶向及癌症治疗中的应用

在过去的十几年中,重组抗体工程在基础研究、医学和药物生产上已经成为最有希望的领域之一。重组抗体及其片段在正在进行诊断和治疗的临床试验中占所有生物蛋白的30％以上。研究集中在抗体作为理想的癌症靶向试剂方面,最近由于FDA批准使用第一个工程化治疗抗体而使热度达到极点。过去的几年中,在设计、筛选及生产新型工程化抗体方面已经取得了重大进展。改革的筛选方法已经能够分离出高亲和力的癌－靶向及抗病毒的抗体,后能够抑制病毒用于基因治疗。癌症诊断和治疗的另一个策略是将重组抗体片段与放射性同位素、药物、毒素、酶以及生物传感器表面进行融合。双特异性抗体及相关融合蛋白也已经生产出来用于癌症的免疫治疗,在抗癌疫苗以及T细胞补充策略上有效地增强了人免疫应答。     

双特异性纳米抗体的研究进展及其应用

从纳米抗体的研究进展,双特异性纳米抗体在感染类疾病、肿瘤以及免疫系统疾病治疗领域的研究成果、研究热点及发展前景等方面综述了双特异性纳米抗体的研究进展并分析了未来可能的发展方向。首先比较了纳米抗体与全长单克隆抗体之间的差异并阐述了双特异性纳米抗体具备的独特优势;继而概括了双特异性纳米抗体的发展历程,并对新冠病毒的中和性抗体、CAR-T细胞治疗和免疫检查点治疗抗体等研究热点进行了深入分析;最后对双特异性纳米抗体的应用前景进行分析,指出双特异性纳米抗体能够克服目前全长抗体治疗过程中存在的缺陷,成为一种极具发展潜力的抗体形式。     

双特异性抗体构建在肿瘤临床治疗中的应用

双特异性抗体(Bispecific antibody,BsAb)是具有两个不同抗原结合位点的抗体,可分为含Fc段和不含Fc段的BsAb,不同结构的BsAb具有不同的特点和应用领域。相比于传统的单克隆抗体,BsAb的灵敏度和特异性更高。更重要的是,BsAb具有募集免疫细胞、双重阻断信号通路等功能,在免疫诊断和治疗中扮演重要角色。随着全球环境的恶化以及人们生活习惯的不规律,肿瘤的发病率越来越高,成为仅次于心脑血管疾病的全球第二大致死疾病,全球每年有1200万新发癌症病例。肿瘤的治疗手段包括手术切除、放化疗和靶向治疗等。肿瘤免疫疗法是近几年新兴的治疗方法,其通过激发自身免疫系统的能力来清除肿瘤细胞。传统的单抗药物虽在肿瘤靶向治疗和免疫治疗中取得了一定的疗效,但肿瘤具有高度的异质性和可塑性,常常引发肿瘤耐药性的出现。双特异性抗体能够同时靶向多个靶点,目前已用于肿瘤的临床治疗,并取得了一定的治疗效果。文中就双特异性抗体在肿瘤临床治疗中的研究进展和应用作一综述。     

基于单克隆抗体的肿瘤免疫疗法研究进展

一百多年前,"魔术子弹"学说首次提出了具有靶向特异性的抗体可以用来治疗疾病。此后,随着单克隆抗体制备技术的成熟,以及癌症血清疗法的发展,靶向肿瘤抗原的治疗性抗体开始进入临床,至今已有20余种抗体药物用于癌症的治疗。近两年,以免疫检查点蛋白拮抗剂、双特异性抗体、抗体药物偶联药物等为代表的新一代抗体药物,不断在治疗恶性肿瘤上取得突破性进展。本文回顾了抗肿瘤抗体的发展历程,总结了新一代抗体药物的作用机制与构建策略,以及主要临床副作用。并对基于抗体的肿瘤免疫疗法未来发展趋势进行了展望。     

新型抗体药物在肝细胞癌免疫治疗中的研究进展

肝细胞癌(hepatocellular carcinoma, HCC)免疫疗法中最常用的是Ig G单克隆抗体(monoclonal antibodies,mAbs),其具有血清半衰期长、稳定性高、靶向能力强等优点。单克隆抗体药物在临床取得的重大进展推动了各种新型治疗性抗体的发展,例如抗体-药物偶联物、放射性核素标记抗体、小分子抗体、双特异性细胞激动剂、免疫细胞因子、免疫毒素以及免疫促凋亡分子等。近年来抗体的小型化和多功能化是在复杂肿瘤微环境中治疗HCC的富有临床潜力的策略。该文总结了各种类型的新型抗体的结构、作用机制及其在HCC免疫治疗中的研究进展,并对其应用前景进行展望。     

基因工程双特异抗体研究进展

双特异抗体特别是双特异性单链抗体、亮氨酸接链双特异性抗体、双特异性单链抗体毒素等是近几年来发展起来的很有前途的监床诊疗生物制剂 ,本文对其基因构建、边接肽设计、表达产物及活性等方面的新进展作了重点论述。     

双特异性抗体靶向治疗及动物模型的设计

由于双特异性抗体可以同时结合两种不同的抗原,因此和传统的单克隆抗体相比,往往可以更好的发挥靶向治疗的作用.随着各种生物技术的发展,不同靶向的双特异性抗体被构建出来并被用于肿瘤治疗的研究.本文综述了人工产生的双特异性抗体在靶向治疗中的进展,并且探讨了用于肿瘤治疗的动物模型的建立.     

抗人类免疫缺陷病毒1型感染的双特异性抗体的构建及其功能研究

靶向人类免疫缺陷病毒（human immunodeficiency virus，HIV）流行毒株的广谱中和抗体（broadly neutralizing antibody, bNAb）单一疗法最终会导致机体出现病毒逃逸突变，然而基于广谱中和抗体开发的双特异性或多特异性抗体则表现出较好的中和效力和广谱性。根据已公布的单链可变区基因抗体序列，经密码子优化后合成一种由单基因编码的双特异性抗体iMab-PGT151，经双酶切和测序对重组质粒进行了验证。酶联免疫吸附试验检测双特异性抗体的结合特异性，检测U87细胞裂解液中的荧光素酶活性以定量分析双特异性抗体对HIV-1假病毒的中和作用；间接免疫荧光染色法检测双特异性抗体iMab-PGT151对人喉癌上皮细胞的反应性；酶联免疫吸附试验检测该抗体对心磷脂的结合能力，验证其自体反应性。结果显示，构建的双特异抗体iMab-PGT151能够成功表达，可分别结合亲本抗体的各个配体，具有双特异性，能100%中和20株假病毒，IC50值为0.084 μg/mL。与亲本抗体相比，该抗体具有更强的中和效力和广谱度，无自体反应性，具有临床适用性。所构建的双特异性抗体iMab-PGT151将可能成为预防和治疗HIV-1感染的有效候选药物之一。     

双特异性抗体药物应用进展

基因工程的飞速发展推动了新型双功能抗体药物的成功研制。目前双功能抗体药物主要应用于肿瘤的免疫治疗、自身免疫疾病和感染类疾病的治疗,在组织再生和临床诊断领域也有应用。就双特异性抗体的发展史进行了简要回顾,对其在免疫治疗、组织再生和临床诊断等领域中的应用进展进行了综述,并展望了未来的发展方向,以期为新型双特异性抗体药物的研制提供参考。     

双价,双特异性单链抗体

双价、双特异性单链抗体是最近几年才出现的一类新的基因工程抗体分子,它在临床诊断和治疗上有着广泛的应用前景,尤其是在肿瘤和病毒的诊治方面更具突出优势。本对其性质,制备方法及应用前景作了系统的综述。     

治疗性单克隆抗体研究进展

杂交瘤技术使鼠源单克隆抗体（鼠单抗）被广泛用于人类疾病的诊断和研究,建立了治疗性抗体的第一个里程碑。但随后出现的人抗鼠抗体等副作用极大地限制了鼠单抗的临床应用。随着生物学技术的发展和抗体基因结构的阐明,应用DNA重组技术和抗体库技术对鼠单抗进行人源化改造,先后出现了嵌合抗体、改型抗体和全人抗体,同时也涌现了各种单抗衍生物,它们从不同角度克服了鼠单抗临床应用的不足,未人类疾病治疗带来新的曙光。我们就上述治疗性抗体人源化的研究进展做简要综述。     

基因工程抗体研究进展

临床治疗中人抗鼠抗体反应的出现使鼠源性单克隆抗体的应用受到了极大的限制。为降低其免疫原性,人们利用基因工程技术对鼠源抗体进行改造,以减少其鼠源成分。简要概述了目前研究比较多的几种基因工程抗体及其临床应用。     

嵌合抗体研究进展

抗体在疾病诊断,治疗和预防中发挥着重要作用,近几年来将基因工程应用到抗体生产的基因工程抗体技术发展迅速,本就基因工程抗体中的重要组成部分－嵌合抗体的研究进展加以综述。     

Monoclonal antibody therapeutics with up to five specificities: Functional enhancement through fusion of target-specific peptides

The recognition that few human diseases are thoroughly addressed by mono-specific, monoclonal antibodies (mAbs) continues to drive the development of antibody therapeutics with additional specificities and enhanced activity. Historically, efforts to engineer additional antigen recognition into molecules have relied predominantly on the reformatting of immunoglobulin domains. In this report we describe a series of fully functional mAbs to which additional specificities have been imparted through the recombinant fusion of relatively short polypeptides sequences. The sequences are selected for binding to a particular target from combinatorial libraries that express linear, disulfide-constrained, or domain-based structures. The potential for fusion of peptides to the N- and C- termini of both the heavy and light chains affords the bivalent expression of up to four different peptides. The resulting molecules, called zybodies, can gain up to four additional specificities, while retaining the original functionality and specificity of the scaffold antibody. We explore the use of two clinically significant oncology antibodies, trastuzumab and cetuximab, as zybody scaffolds and demonstrate functional enhancements in each case. The affect of fusion position on both peptide and scaffold function is explored, and penta-specific zybodies are demonstrated to simultaneously engage five targets (ErbB2, EGFR, IGF-1R, Ang2 and integrin αvβ3). Bispecific, trastuzumab-based zybodies targeting ErbB2 and Ang2 are shown to exhibit superior efficacy to trastuzumab in an angiogenesis-dependent xenograft tumor model. A cetuximab-based bispecific zybody that targeting EGFR and ErbB3 simultaneously disrupted multiple intracellular signaling pathways; inhibited tumor cell proliferation; and showed efficacy superior to that of cetuximab in a xenograft tumor model.     

Isolation and optimization of camelid single-domain antibodies: Dirk Saerens' work on nanobodies

It is well established that all camelids have unique antibodies circulating in their blood. Unlike antibodies from all other species, these special antibodies are devoid of light chains, and are composed of a heavy chain homodimer. These so-called heavy-chain antibodies (HCAbs) are expressed after a V-D-J rearrangement and require dedicated constant gamma genes. An immune response is raised in these HCAbs following a classical immunization protocol. These HCAbs are easily purified from serum, and their antigen-binding fragment interacts with parts of the target that are less antigenic to conventional antibodies. The antigen binding site of the dromedary HCAb comprises one single domain, referred to as VHH or nanobody (Nb), therefore, a strategy was designed to clone the Nb repertoire of an immunized dromedary and to select the Nb with specificity for our target antigens. The monoclonal Nb is produced well in bacteria, is very stable and highly soluble, and it binds the antigen with high affinity and specificity. Currently, the recombinant Nb has been developed successfully for research purposes, as a probe in biosensors, to diagnose infections, or to treat diseases such as cancer or trypanosomiasis.     

Monoclonal antibodies: technologies for early discovery and engineering

Antibodies are essential in modern life sciences biotechnology. Their architecture and diversity allow for high specificity and affinity to a wide array of biochemicals. Combining monoclonal antibody (mAb) technology with recombinant DNA and protein expression links antibody genotype with phenotype. Yet, the ability to select and screen for high affinity binders from recombinantly-displayed, combinatorial libraries unleashes the true power of mAbs and a flood of clinical applications. The identification of novel antibodies can be accomplished by a myriad of in vitro display technologies from the proven (e.g. phage) to the emerging (e.g. mammalian cell and cell-free) based on affinity binding as well as function. Lead candidates can be further engineered for increased affinity and half-life, reduced immunogenicity and/or enhanced manufacturing, and storage capabilities. This review begins with antibody biology and how the structure and genetic machinery relate to function, diversity, and in vivo affinity maturation and follows with the general requirements of (therapeutic) antibody discovery and engineering with an emphasis on in vitro display technologies. Throughout, we highlight where antibody biology inspires technology development and where high-throughput, “big data” and in silico strategies are playing an increasing role. Antibodies dominate the growing class of targeted therapeutics, alone or as bioconjugates. However, their versatility extends to research, diagnostics, and beyond.     

Structural understanding of stabilization patterns in engineered bispecific Ig‐like antibody molecules

Bispecific immunoglobulin‐like antibodies capable of engaging multiple antigens represent a promising new class of therapeutic agents. Engineering of these molecules requires optimization of the molecular properties of one of the domain components. Here, we present a detailed crystallographic and computational characterization of the stabilization patterns in the lymphotoxin‐beta receptor (LTβR) binding Fv domain of an anti‐LTβR/anti‐TNF‐related apoptosis inducing ligand receptor‐2 (TRAIL‐R2) bispecific immunoglobulin‐like antibody. We further describe a new hierarchical structure‐guided approach toward engineering of antibody‐like molecules to enhance their thermal and chemical stability. Proteins 2009. © 2009 Wiley‐Liss, Inc.     

治疗性抗体的研究进展

作为一种具有靶向性的生物大分子,单克隆抗体始终是人们关注的热点之一,被广泛用于治疗肿瘤、病毒感染和抗移植排斥等。但鼠源单克隆抗体的临床应用受限于诱导产生人抗鼠抗体、肿瘤渗入量低、亲和力低和半衰期短等。随着分子生物学技术的发展及其向各学科的渗透,通过基因操作技术对抗体进行改造,可使其适用于多种疾病的治疗。抗体人源化已经成为治疗性抗体的发展趋势,同时各种抗体衍生物也不断涌现,它们从不同角度克服了抗体本身的应用局限,也为治疗人类疾病提供了利器。本文简要介绍上述技术的基本原理、特点和治疗性抗体的研究进展。     

噬菌体抗体库技术及其应用研究进展

噬菌体呈现抗体库是近年发展的一项分子生物学新技术,它的建立是抗体技术领域中的一次革命性进展。它以其独特的构建和筛选系统,彻底改变了抗体制备的传统途径,使抗体工程技术进入了一个新的发展阶段,并对生物学领域中许多技术的发展起到了巨大的推动作用。该技术是迄今发展最成熟、应用最广泛的制备抗体技术。我们简要综述此项技术的研究应用进展。