Method for screening antibodies

Abstract

The invention discloses a method for screening antibodies, which comprises the following steps of: 1) displaying a target protein on the cell membrane surface of an in vitro eukaryocyte to obtain eukaryocyte of which the surface is provided with the target protein; and 2) respectively displaying each protein to be screened in a protein library on the surface of bacteria protoplast to obtain a bacteria rotoplast library of which the surface is provided with proteins to be screened. The invention provides a screening method for screening the antibodies for specifically identifying human cell surface antigens by taking complete human cells as the antigens through the APEx display technology. An APEx bacteria display system has an antibody library (more than or equal to 109) equivalent to that of a phage display system, and has the capacity of displaying complete IgG antibodies. The established method is favorable for screening more antibodies for identifying cell surface molecular markers, and has great promotion function for disease diagnosis and treatment.

Description

technical field The invention relates to a method for screening antibodies. Background technique High-throughput antibody screening by means of protein display technology has become one of the main methods for antibody production. Phage display technology, ribosome display technology and yeast display technology have been widely used in the screening of new antibodies and the improvement of antibody affinity. The displayed antibodies can bind to the target antigen and be quickly screened from the complex antibody library. Commonly used antigens for antibody screening are known soluble purified antigens. However, the molecular markers of many diseases are located on the surface of the cell membrane and have complex post-translational modifications, such as glycosylation (Ohtsubo K, Marth JD: Glycosylation in cellular mechanisms of health and disease. Cell 2006, 126(5): 855- 867.). Glycosylation loss will affect protein folding efficiency and stability (Shental-Bechor D, L...

AI Technical Summary

Problems solved by technology

However, due to the limited display efficiency of phage display technology, not all sequences can be well expressed in phage

Moreover, during the process of phage amplification, due to the different nature of the insert fragments, there may be differences in growth, which may result in loss of library diversity.

In addition, phage display systems have difficulty displaying larger molecular weight proteins, so they cannot successfully display complete IgG antibody molecules

However, yeast display technology is difficult to construct a large enough antibody library due to the impact of transformation efficiency

Images