Generation of human antibody fragments against Streptococcus mutans using a phage display chain shuffling approach

Michael B Kuepper,Rainer Fischer,Ricarda Finnern,Stefan Barth,Julian Kc Ma,Holger Spiegel,Michael Huhn

doi:10.1186/1472-6750-5-4

Abstract

BackgroundCommon oral diseases and dental caries can be prevented effectively by passive immunization. In humans, passive immunotherapy may require the use of humanized or human antibodies to prevent adverse immune responses against murine epitopes. Therefore we generated human single chain and diabody antibody derivatives based on the binding characteristics of the murine monoclonal antibody Guy's 13. The murine form of this antibody has been used successfully to prevent Streptococcus mutans colonization and the development of dental caries in non-human primates, and to prevent bacterial colonization in human clinical trials.ResultsThe antibody derivatives were generated using a chain-shuffling approach based on human antibody variable gene phage-display libraries. Like the parent antibody, these derivatives bound specifically to SAI/II, the surface adhesin of the oral pathogen S. mutans.ConclusionsHumanization of murine antibodies can be easily achieved using phage display libraries. The human antibody fragments bind the antigen as well as the causative agent of dental caries. In addition the human diabody derivative is capable of aggregating S. mutans in vitro, making it a useful candidate passive immunotherapeutic agent for oral diseases.

Highlights

Common oral diseases and dental caries can be prevented effectively by passive immunization
Human recombinant singlechain fragment variable (scFv) antibodies against SAI/II Human scFv antibody fragments based on the murine monoclonal antibody Guy's 13 were constructed using two consecutive rounds of variable-domain shuffling and phage-library selection (Figure 1)
A chimeric scFv was generated by amplifying the murine Guy's 13 heavy chain variable region, and inserting it into a human light chain variable region phage display library

Summary

Introduction

Common oral diseases and dental caries can be prevented effectively by passive immunization. Passive immunotherapy may require the use of humanized or human antibodies to prevent adverse immune responses against murine epitopes. The murine form of this antibody has been used successfully to prevent Streptococcus mutans colonization and the development of dental caries in non-human primates, and to prevent bacterial colonization in human clinical trials. Dental caries is one of the most common infectious diseases of humans. Streptococcus mutans has been identified as the major etiological agent of the disease. Two groups of proteins from mutans streptococci represent primary candidates for a human caries vaccine: i) glucosyltransferase enzymes, which synthesize adhesive glycans and allow microbial accumulation, and ii) cell surface fibrillar proteins that mediate adherence to the salivary pellicle [2]. The bacterial adhesin SAI/II [3], a (page number not for citation purposes)

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