With this aim to develop new therapeutic approaches to (drug-resistant- tuberculosis, we aim to wetermine how mycobacterial cell wall mycolic acids interfere ith the host cell function and hereby facilitate intracellular replication of the bacilli. Using mouse models, the interrelation between mycolic acids-facilitated intracellular replication, disturbed macrophage cholesterol metabolic pathways and the cholesteroid nature of mycolic acids will be verified.