Comparative transcriptomic analysis of human macrophages during Mycobacterium avium versus Mycobacterium tuberculosis infection
The treatment of Mycobacterium avium (Mav) infection, responsible for over 80% of non-tuberculous mycobacterial pulmonary disease, remains challenging due to rising antibiotic resistance and unsatisfactory success rates. Hence, there is  a need for a deeper understanding of host–pathogen interactions to inform the development of alternative therapeutic approaches, like host-directed therapy (HDT), aimed at improving host antimycobacterial defenses.. However, compared to Mycobacterium tuberculosis (Mtb) infections, knowledge of host-pathogen interactions for Mav infection is still limited. To address this knowledge gap, we performed a genome-wide host transcriptomic analysis of Mav-infected primary human macrophages —the primary host cell—alongside Mtb-infected macrophages to leverage insights from Mtb research. Our findings show substantial overlap in the gene expression patterns between Mav-infected and Mtb-infected macrophages, including induction of cytokine responses and modulation of various G-protein coupled receptors (GPCRs) involved in (lipid-mediated) macrophage immune functions. Notable differences were observed in nerve growth factor (NGF) signaling and genes of the GTPase of immunity-associated protein (GIMAP) family. This study laid a foundation for identifying both shared and Mav-specific host response pathways, providing direction for future investigations into host-pathogen interactions during Mav infection and the identification of novel targets for HDT.