To find out which genes are involved in a particular infection process, the technology platform "Gene Expression Analysis" is an essential tool for scientists at the Helmholtz Centre for Infection Research. Tailor-made gene chips are configured here for researchers at the center or for outside partners. Gene chips make it possible to test which genes are active during certain metabolic processes. Support and advice are also available when using standardized chips from external, commercial providers.
Our scientists investigate the genetic substances of various bacterial pathogens, such as Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus and viral pathogens such as hepatitis B virus and influenza virus. And they research molecular defence strategies used by the immune cells of host organisms. The understanding of the molecular relationships of how a pathogen transfers its pathogenicity to the host organism can be utilised, e.g., through specific pharmacologic interventions, to disrupt this mechanism in order to eliminate the infection hazard.
Which defence mechanisms are available to an organism is coded in its genes. But the coding gene sequence alone is not sufficient to understand how the molecular defence and the attack actually work. It is the interplay of further regulatory factors that facilitates a spatially and temporally well-coordinated emergence of effector molecules. Whether or not a gene can actually exert its effect in a cell depends not only on gene defects (mutations), but is also determined by so-called epigenetic factors. A chemical modification of the DNA (DNA methylation) or interactions of DNA-binding proteins (transcription factors) can facilitate or prevent the effective activation of effector molecules. In addition, so-called non-coding small RNA molecules (shRNA, microRNA, ncRNA) can prevent the processing into functional proteins even after successful gene activation of the effector molecules has taken place (gene expression). This is called RNA interference or RNAi.
The coexistence of pathogens with their hosts for thousands of years allowed pathogens to utilise the host's molecular machinery for their own purposes by intervening in the regulatory processes. It is important for the pathogen to find, recognise and infiltrate the right cells with the appropriate mechanism in the host. These molecules called pathogenicity factors are also subject to strict control in order for the infection process to be successful.
The scientists of the research group cooperate closely with researchers from other groups in the field of genome analysis at the HZI. They are searching for genetic determinants at the different levels of molecular information storage (DNA: Mutations, polymorphisms, chromosomal aberrations; RNA: Altered gene expression, RNAi; epigenetic: Methylation patterns, transcription factors). They use high resolution and other sophisticated systems in these experiments: HT capillary sequencing (96-plex Sanger sequencing), Next Generation Genome Analyzer (million-fold parallel sequencing), ultra-dense microarrays for genome analysis/gene expression.