OR04

Despite immense efforts to end tuberculosis, infections with strains of the Mycobacterium tuberculosis complex (MTBC) still cause extensive global mortality and morbidity. Previous studies showed that MTBC infection can lead to detrimental epigenetic modifications of host cells, resulting in immune exhaustion. Macrophages play a critical role in host defense against MTBC and understanding epigenetic alterations in response to infection can provide valuable insights into host-pathogen interactions and immune response.

In our study, we aim to investigate changes in the epigenetic makeup of human macrophages, such as DNA methylation, gene expression, and histone modifications, during early-stage infection with different MTBC strains. Studying epigenetic changes in infected macrophages requires a robust protocol allowing for high quality DNA and RNA extraction while sterilizing infectious samples.

We developed a protocol that ensures biosafety while maintaining the integrity of nucleic acids. To achieve this, we tested a variety of DNA/RNA extraction protocols for their capacity to efficiently inactivate Mycobacterium tuberculosis and analyzed the resulting nucleic acid quality. To our surprise, even commercially available reagents did not lead to a complete inactivation of the samples. The final protocol developed, allows for high quality DNA/RNA extraction, while all sterility controls remained negative.

In conclusion, our study provides a robust protocol for studying the epigenetic alterations that occur in infected macrophages while ensuring sterility and preserving DNA and RNA integrity. This protocol can be valuable for future studies aimed at understanding the complex interplay between MTBC and host cells.