Table of Contents

Ivonne Rubio, Post-Doc

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Introduction

Two commercial vaccines against HPV16 and HPV18 (Cervarix and Gardasil) are available and protect against about 70% of all high risk HPV infections, leaving 30% of the cases uncovered still. Recently, the N-terminal part of the HPV L2 protein was reported to contain several epitopes able to induce the production of neutralizing antibodies with cross-protection abilities (Gambhira et al., 2007; Kawana et al., 1999).

Although, the immunogenicity of the L2 protein is poor, the N-terminal part of the L2 protein represents a new alternative in the development of a cross-protective vaccine against several papillomavirus types.

Thioredoxin as a Vaccination Scaffold for HPV L2

Bacterial Thioredoxin contains an active site CXXC used normally to reduce the disulphide bonds produced during the cell metabolism. This active site was used to graft previously reported L2 peptides able to induce a cross-protective response. Using this strategy we were able to increase the immunogenicity of L2 peptides | © dkfz.de

Using bacterial Thioredoxin as a scaffold, we were able to increase the immunogenicity of putative L2 neutralizing epitopes. However, we observed that only a minor reactivity against these epitopes is in fact neutralizing.

L2-directed monoclonal antibodies

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The isolation of monoclonal antibodies (mAbs) permitted us to map the epitopes in L2 responsible for the induction of neutralizing, cross-neutralizing and non-neutralizing antibodies. The mAbs isolated also will permit us in future studies a better understanding of the mechanisms used for HPV during the infectious process in the cells.