Targeting ALOX5/LTA4H driven granuloma caseation as a host-directed strategy for control of TB associated lung damage

Tuberculosis remains one of the major global health challenges with those previously exposed presenting persisting pulmonary dysfunction. Therefore, improved control measures are still required to prevent or reduce the TB-induced immunopathology in affected individuals. Host directed therapies that target host factors, have been suggested to improve on current treatments against TB. We previously reported a potential role for proteins which metabolize the arachidonic acids during TB immunopathogenesis. The study, therefore, sought to demonstrate the potential role of these proteins in TB-induced immunopathology. Using immune-histopathological assays, the association of macrophage driven ALOX5 signaling with severe pulmonary immunopathology during TB was demonstrated. Furthermore, using both in vitro and in vivo assays, the data demonstrated the contribution of ALOX5 signaling to TB-induced granulomatous inflammation. Interception of the signaling pathway through clinically approved pharmaceutical inhibitors, resulted in reduced lung damage during the disease. The resolution of TB-induced lung pathology further contributed to increased bactericidal activity. Taken together, our data strongly suggest a role for macrophage driven inflammation via ALOX5 signaling which can be targeted for the development of therapeutic treatment to prevent exacerbated TB-induced pulmonary immunopathology.