Chemical p38 MAP kinase inhibition constrains tissue inflammation and improves antibiotic activity in Mycobacterium tuberculosis-infected mice

Host-modulating therapies have become an important focus in the development of novel concepts for improved management of tuberculosis (TB). Previous in vitro studies revealed that the p38 MAP kinase signaling pathway coordinates several inflammatory and stress responses in Mycobacterium tuberculosis (Mtb)-infected host cells. Here we extend these findings and show that in vivo treatment of Mtb-infected C57BL/6 mice with doramapimod, a p38 MAP-kinase inhibitor, results in reduced inflammation, granuloma formation and lung pathology. Moreover, doramapimod, together with standard antibiotic treatment, significantly reduced lung and spleen mycobacterial loads compared to antibiotic treatment alone. Our in vivo data suggest the opportunity to repurpose p38 MAPK inhibitors for adjunct host directed therapies. We also provide first data on safety of p38 MAPK inhibition which is of relevance for future application of these substances in inflammatory diseases and concomitant TB.