Antibody Development Against Tumor Surface Protein Shedding from Cells

Creative Biolabs provides customized antibody development services against tumor surface protein shedding from cells by advanced technical platform to help your projects. Our professional scientists have extensive experience in antibody production and bio-conjugation. Scientists at Creative Biolabs are committed to offering high-quality antibody development services for tumor surface protein to promote the development of innovative cancer treatments.

Ectodomain Shedding

The extracellular domain of membrane-anchored proteins is released from the cell surface as soluble proteins through a regulated proteolytic mechanism called ectodomain shedding. Ectodomain shedding has been implicated in various cellular processes such as cell adhesion, migration, proliferation, differentiation, and death. For instance, shedding of amyloid precursor protein (APP) is a crucial regulatory step in the generation of Aβ peptides that accumulate and form sticky patches in the brains of Alzheimer’s patients. Additionally, extracellular domain shedding of receptors allows the diffusion of soluble receptors into the extracellular space; these then bind and neutralize their ligands, resulting in dampening inflammatory responses. For example, the proteolytic cleavage of MICA/B is an important immune escape mechanism of various cancer cells and shed MICA/B might block NKG2D receptor interaction with its cellular ligands, which frequently correlates with impaired NK cell function.

Fig.1 Diagram of an ectodomain shedding ADAM metalloprotease.

Shedding Mechanism

This proteolysis process is mediated mainly by a disintegrin and metalloproteases (ADAM) or matrix metalloproteases (MMP). Ectodomain shedding occurs in the immediate extracellular juxtamembrane region. Studies have proved the relationship between O-glycosylation and shedding. Site-specific O-glycosylation regulated by distinct GalNAc-transferase isoforms may widely serve to coregulate ADAM mediated ectodomain shedding. As figure 2 shown, ADAMs (blue) contain 5 domains, a cytoplasmic domain (CD), a transmembrane domain (TMD), an EGF like domain (EGF), a disintegrin domain (DIS) and the protease (PROT) domain, which may or may not contain an active site (HEXGHXXGXXHD). ADAMs are participated in ectodomain shedding of type I or II transmembrane proteins (pink), leading to the release of a soluble extracellular domain and the generation of a membrane stub.

Fig.2 Proteolytically active and inactive ADAMs. (Weber, 2012)

Antibody Strategies

Shedding of soluble molecules is often enhanced in tumor cells. Besides using sheddase inhibitors, we can adopt different antibodies design strategies to deal with tumor surface protein shedding depending on individual protein shedding conditions. For instance, antibodies could be used to neutralize the soluble extracellular domain, thereby preventing soluble component-induced cell proliferation or other activities beneficial to tumor development. Antibodies can also be developed to directly binds to the cleavage site, inhibiting shedding fundamentally, thus human immune system could still recognize tumor markers and play a corresponding killing effect. It cannot be ignored that the membrane stub can also be used as targets for designing antibodies. Antibodies in the last two cases can be further conjugated with payload through linker to form antibody-drug conjugates (ADC) to fight against cancer.

Features

• Comprehensive technical platform, including Hybridoma Platform, B-Cell Sorting Platform, Phage Display Platform, Membrane Protein Platform, Advanced Organic Chemistry Synthesis Platform (DrugLnk), PtLnX™ conjugation platform.
• cGMP certified facilities. Creative Biolabs and our collaborators are able to manufacture recombinant antibodies, protein conjugates in cGMP certified facilities.
• 3D cell culture systems. Creative Biolabs has adopted and perfected 3D cell culture systems that convert 2-deminsional cell layers into 3-deminsional cell clusters to gain a more accurate antibody complex penetration and distribution profile in the mimicking of solid tumor micro-environment.
• Top professional team with rich experience in antibody design and modification.

Equipped with state-of-the-art research and manufacturing facilities, Creative Biolabs is dedicated to helping our clients design and prepare highly customized linker and drug-linker complexes using our featured services. With the novel technology platform and professional experiment services, Creative Biolabs gets ready to provide you with the best antibody services. Please feel free to contact us for more details.

Reference

1. Weber, S.; Saftig, P. Ectodomain shedding and ADAMs in development. Development. 2012, 139(20), 3693-3709.