NUCLEIC ACID MOLECULE AND USE THEREOF IN PREPARING HUMANIZED SINGLE-DOMAIN ANTIBODY

摘要

Provided are a nucleic acid molecule and a use thereof in preparing a single-domain antibody. The nucleic acid molecule comprises an immunoglobulin gene of a host animal or a fragment thereof. Same is characterized by comprising an IgH5'-terminal enhancer, a transduction element of IgM (Sμ) and IgM sequences of the host animal, wherein all of the IgM sequences are those of the host animal, wherein a CH1 sequence (IgM-dCH1) is deleted from IgM; an expression control element of IgG is derived from the host animal and comprises sequences such as Sγ, TM1, TM2 and PolyA; and Cγ sequences (Hinge, CH2 and CH3) of IgG are derived from the human sequence (Igγ-dCH1). The present invention guarantees the normal development of B-cells in a transgenic animal, and the transgenic animal expresses a human single-domain antibody, reducing artificial modification in later stages and improving the druggability of the antibody.