Category: Antibody Library

Brief Introduction and Advantages of Antibody Library Techniques

Antibody library techniques have not only enabled the simple and convenient production of genetically engineered antibodies, but have also provided a new way to manufacture humanized antibodies. The antibody library was first amplified from B cells by PCR in the heavy and light chain of the antibody and then ligated into the appropriate vector to express the randomized antibody library. Compared with hybridoma technology, more antibodies can be obtained by recombining the immune library with the same immune donor, creating a more diverse range of rare natural antibodies in vitro. The immune antibody library can be used to isolate non-immune libraries that are not prone to obtain antibodies which are specific properties that human immune and disease-related, and can also be used for molecular-level immunity system research. Immunization libraries can also maintain links between heavy and light chains in natural cells if necessary, and can also amplify individual cells with high throughput. Multiple circular screening is done after completing the construction of the antibody library to obtainthe eligible antibody.

Advantages of antibody library techniques to obtain monoclonal antibodies:

  • Exempting the cell fusion from the protocol avoids having to repeat the cumbersome subcloning procedure, which can cause unstable hybrid tumors.
  • Expanded screening capacity; hybrid screening techniques can be applied to thousands of clones, and the antibody library can screen more than 106 clones
  • It is easy to construct a variety of genetically engineered antibodies with the antibody gene obtained directly from antibody library techniques.
  • Antibodies obtained by antibody library techniques can be expressed in E. coli, allowing the advantages of a prokaryotic expression system to be utilized in some assays.
  • Antibodies such as poor immunogenic antibodies, toxic antigen antibodies, and some human antibodies that are difficult to obtain with other techniques can be yielded more easily with antibody library techniques.

Synbio Technology provides professional antibody library technique sequencing services. RACE technology and our professional PCR amplification system can minimize the amplification bias of the antibody library genes. With our NGS analysis platform, Synbio Technologies can provide accurate, rapid, and affordable antibody library sequencing services.

Antibody Library Technology Screen Out the Specific Antibody

Humanized antibodies are derived from non-human species, modified to more closely resemble existing, natural human antibodies. Their applications have a great deal of potential in medicine and immunology due to the wide range of variability that humanized antibodies provide. Compared with heterologous antibodies, they also circumvent certain immune side effects to the human body. From chimeric antibodies to CDR-grafting to humanized antibodies, each major breakthrough has helped expand the field of antibody preparation and advance the cutting edge of antibody library technology .

The development of therapeutic antibodies has been tending toward the use of fully humanized antibodies, which are typically derived from antibody libraries. The development of antibody library technology makes it possible to more easily obtain antibodies in vitro. Antibody fragments can be immobilized on the surface of certain mediums, and specific antibody fragments can be obtained by multiple rounds of exposure to a certain antigen, followed by elution and signal amplification. Due to the competitive binding screening mechanism, antibodies with a high-copy number will be preferentially screened out from the library. After 1-2 rounds of screening, high-affinity and low-copy antibodies can then be screened by antibody library sequencing.

The classical antibody library displays phage coat protein III and VIII protein fusion scFv (single-chain variable fragment) on the surface of phage. Fully humanized scFv can be screened out by several rounds of antigen screening. There is now an improved way to screen for scFv completely in vitro, starting from the scFv antibody library. No terminator is inserted during in vitro transcription, following which a RNA-ribosome-scFv complex is formed. The complex which specifically combines to the target molecule can be obtained by a screening method similar to phage display. Finally, the RNA of the complex is separated and PCR amplification follows. The introduction of mutations along with the PCR amplification could stimulate the affinity maturation process and could be one option to amplify the affinity of the secondary antibody library.

Synbio Technologies provides antibody library sequencing services. Combining with our next generation sequencing technology, we offer a complete assessment of immune system diversity and comprehensive observation and analysis of T cells and B cells. These technologies and services. Our services are widely applicable to topics such as disease surveillance, antibody production, vaccine research, medicine, and immunology.

Antibody Library Applications

The application of antibodies has expanded from being an immunologically important protein to an important research tool and a rapidly growing class of therapeutic agents. Since the successful generation of monocolonal antibodies from antibody libraries in 1980’s, many biotech companies and research institutes started constructing antibody libraries. Depending on the methods of construction, antibody libraries can be divided into four categories: naïve antibody libraries, fully synthetic libraries, semi-synthetic antibody libraries and combinatorial antibody libraries.

Naïve antibody libraries

Naïve antibody libraries are based on B-cells from unimmunized or healthy donors. A representative naïve antibody library is constructed by Cambridge Antibody Technology Group Plc (CAT) in 1990’s. In 1996, CAT published its 10E10-sized naïve antibody library in Nature Biotechnology. Such antibody library has been successfully used to generate monoclononal antibodies, among which the most successful one is the immunosuppressant adalimumab (Humira), whose global sale in 2013 was as high as 10.6 billion US dollars.

Fully synthetic libraries

Fully synthetic libraries are those made by in vitro randomization of the three complementarity-determining regions (CDRs) of the variable region in both the light chain and heavy chain with PCR. A good example of such library is Human Combinatorial Antibody Library (HuCAL) by Morphosys AG., which was sold to Bio-RAD in December 2012. It now offers customized monoclonal antibodies generated from HuCAL, the only currently available provider of such services.

Semi-synthetic antibody libraries

In semi-synthetic libraries, genes encoding the CDR are mainly isolated from nature sources, and thus providing large diversity. In 2000, BioInvent reported its 2x10E9- sized semi-synthetic antibody library in Nature Biotechnology. Three antibody drugs generated from such library are currently in clinical development

Combinatorial antibody libraries

Combinatorial antibody library is the hybrid of two or three other types of antibody libraries. It keeps the advantage of high diversity from nature sources while allowing engineering and optimization with synthetic methods. It allows both the rapid generation of antibodies and the isolation of rare antibodies. It offers bright future for antibodies to be used not only in simple antigen binding, but in probing cellular function as well as generating therapeutic agents for inflammation and cancer therapy.

Gene Synthesis Driving Synthetic Biology Applications

DNA sequencing has been vital to the development of synthetic biology in many ways. Sequencing enables researchers to determine the DNA sequence in just about any gene, and enables the construction of vast databases that can hold entire genomes. Genome databases are an important resource for downstream synthetic biology applications such as protein expression, directed evolution, and metabolic engineering. In addition, the low cost of DNA sequencing enables more efficient quality control of large DNA constructs, a key step in gene synthesis.

Reductions in the production costs of genes and their key raw materials, oligos, are driving demand for synthetic biology products. Gene synthesis is key to many synthetic biology applications, and their availability at low cost increases the number of gene synthesis applications and customers, driving sales up.

The growing proteomics market is driving demand for more efficient protein expression in novel host systems. This in turn is driving the demand for synthetic genes that have been optimized for heterologous gene expression. Such optimized genes allow for expressing the desired protein product more efficiently, since they can be tailored to the intended host cell system. Gene synthesis will penetrate into the genetic engineering market among pharmaceutical and biotech companies developing new products. Gene synthesis provides a high level of flexibility to the customer and, as its cost decreases, its services are rapidly permeating the classical genetic engineering market to become standard tools among end users.

Synthetic biology applications driven by gene synthesis technology:

  • HGP-Write

The Human Genome Project – Write, formally announced on 2 June 2016, is a ten-year extension of the Human Genome Project, to synthesize the human genome. The human genome consists of three billion DNA nucleotides, which were described in the Human Genome Project – Read program, completed in 2003. With the advancement of gene synthesis technology, the time and cost of gene synthesis is approaching Moors’ Law. Many researchers expect that the ability to synthesize large portions of the human genome could lead to many scientific and medical advances.

  • Antibody Library

The traditional humanized antibody library refers to a group of re-expressed antibodies which have been transformed by gene cloning and DNA recombination technology based on mouse monoclonal antibody. Synbio Technologies designed and developed unique antibody humanization strategies based on advanced concepts and technologies in synthetic biology. This, combined with the integration of efficient phage display and cell surface display technology, have allowed Synbio Tech to easily provide fast and efficient humanized antibody services.

  • DNA storage

DNA storage (using DNA as a data carrier) technology is a relatively new discovery that may have monumental implications on the future of bioinformatics and data science. Text, images, audio, and video documents could be transformed into “A, T, C, G” format and stored in artificial synthesized DNA. Scientists from Synbio Technologies have mastered next generation gene synthesis technology which greatly reduces the manufacturing cost of DNA synthesis. Combined with our patented DNA StudioTMsoftware, DNA storage is closer than ever to spearheading the next generation of storage technology.

Gene Synthesis Related Services

  • Codon Optimization
  • Vector Construction
  • Small Genome Synthesis
  • Pathway Synthesis