학술논문
Identification of Human Antibody Fragment Clones Specific for Tetanus Toxoid in a Bacteriophage λ Immunoexpression Library
Document Type
research-article
Author
Source
Proceedings of the National Academy of Sciences of the United States of America, 1990 Oct 01. 87(20), 8095-8099.
Subject
Language
English
ISSN
00278424
Abstract
We have applied a molecular biology approach to the identification of human monoclonal antibodies. Human peripheral blood lymphocyte mRNA was converted to cDNA and a select subset was amplified by the polymerase chain reaction. These products, containing coding sequences for numerous immunoglobulin heavy- and κ light-chain variable and constant region domains, were inserted into modified bacteriophage λ expression vectors and introduced into Escherichia coli by infection to yield a combinatorial immunoexpression library. Clones with binding activity to tetanus toxoid were identified by filter hybridization with radiolabeled antigen and appeared at a frequency of 0.2% in the library. These human antigen binding fragments, consisting of a heavy-chain fragment covalently linked to a light chain, displayed high affinity of binding to tetanus toxoid with equilibrium constants in the nanomolar range but did not cross-react with other proteins tested. We estimate that this human immunoexpression library contains 20,000 clones with high affinity and specificity to our chosen antigen.