Study of anti-lipid A antibodies of bacterial endotoxin from phage antibody library / 中华传染病杂志

ABSTRACT

Objective To study the treatment of sepsis caused by G - bacteria, anti-lipid A antibodies of bacterial endotoxin were screened from phage antibody library. Methods The mRNA was extracted from human B-lymphocytes against lipid A of bacterial endotoxin, reversely transcripted and amplified by polymerase chain reaction using general primers scanning Fd and light chain of IgG. The amplified fragments were inserted into pCOMB3 vector and electrotransfected competent E.coli XL 1-blue cells. Furthermore, the recombinant phage was lysed by coculture with helper VCSM13. Results Fab displayed on the surface as fusion protein with the N terminal of coat protein Ⅲ, and 4.8?10 6 clone library was established. Antibodies against lipid A of bacterial endotoxin were screened. Specific antibodies against lipid A of bacterial endotoxin were enriched by 100 times after three rounds of panning with lipid A.Conclusions Three clones exhibited specific binding to lipid A is identified by direct and competitive ELISA methods. The succcess of isolating anti-lipid A proves the usefulness of phage display system in human McAb preparation. The result shows that we have got the recombinant phage antibody.