Fully human recombinant antibodies against EphA2 from a multi-tumor patient immune library suitable for...

Area of Science:

• Oncology
• Immunology
• Biotechnology

Background:

• Enhanced EphA2 expression is a hallmark of many epithelial cancers, making it a promising target for anti-tumor therapies.
• Therapeutic monoclonal antibodies targeting immune checkpoints have demonstrated significant efficacy in cancer treatment.

Purpose of the Study:

• To construct a fully human single-chain variable fragment (scFv) immune library from peripheral blood mononuclear cells (PBMCs) of cancer patients.
• To screen for high-affinity scFvs targeting EphA2 using phage display technology.
• To evaluate the therapeutic potential of modified anti-EphA2 antibodies in tumor models.

Main Methods:

• Construction of an scFv immune library from 200 cancer patient PBMCs.
• Phage display technology for screening high-affinity anti-EphA2 scFvs.
• Modification of scFvs into scFv-Fc and IgG1 formats, with affinity assessment.
• Validation of antibody binding to EphA2 protein, tumor cells, and tissues via various assays.
• Assessment of anti-tumor activity of engineered antibodies.

Main Results:

• High-affinity anti-EphA2 scFvs were successfully screened from the patient-derived immune library.
• Modified antibodies, particularly 77-IgG1, exhibited significantly enhanced affinity, reaching the picomolar range (10⁻¹² M).
• Recombinant anti-EphA2 antibodies demonstrated binding to EphA2 in vitro and in tumor tissues, and inhibited tumor cell growth.

Conclusions:

• Immune libraries derived from cancer patients are a valuable resource for identifying high-affinity therapeutic antibodies.
• Engineered anti-EphA2 scFv-Fc and IgG1 antibodies show promise for further development in tumor immunotherapy.
• The fully human scFv immune library offers broad applicability for specific antibody discovery.