RESEARCH NETWORK FOR INFECTOGENOMICS
VA-5 Reverse vaccinology against chlamydial infections
Chlamydia are bacteria, which need to invade host cells for their replication, i.e. they grow within cells and are therefore less accessible for the immune system. The bacteria are responsible for a number of infections in humans including conjunctivitis, trachoma –an infection of the eye which probably affects about 400 million people and some 6 million are blind as a result-, sexually transmitted diseases like urethritis and Lymphogranuloma venereum, but also infections of the upper respiratory tract including ambulant acquired pneumonia. Although these infections can be treated with antibiotics, it is unlikely that the microorganisms are eliminated completely. From a clinical as well as an economical point of view prevention of the different diseases by a suitable vaccine would be much more efficient. Therefore, this project will define antigens derived in this case from Chlamydia pneumoniae which are suitable for a vaccine. Finding suitable antigens is alleviated by the complete elucidation of the genomic sequence of the microorganism. However, a successful vaccine consists not only of a suitable antigen, but it contains additional compounds which stimulate the immune system in the right way. Recent scientific progress demonstrates that certain DNA-sequences –also called CpG-DNA and found originally in bacteria- stimulate the immune system in such a way that protective responses are induced. Therefore, CpG-DNA is combined with the antigen in that both compounds are packed into microspheres. The technology introduced here combines recent advances in the field of CpG-DNA immuobiology with the enormous gain of information provided by sequencing the genome of microorganisms. The practical and commercial aspect of this project is based on the fact that a technology of general use is generated which allows the combination of CpG-DNA with any antigen to induce protective immune responses against persistent infections which are typical for Chlamydia.