AUTHOR=Hu Wanbin , Koch Bjørn E. V. , Lamers Gerda E. M. , Forn-Cuní Gabriel , Spaink Herman P. 

TITLE=Specificity of the innate immune responses to different classes of non-tuberculous mycobacteria

JOURNAL=Frontiers in Immunology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.1075473

DOI=10.3389/fimmu.2022.1075473

ISSN=1664-3224

ABSTRACT=<p><italic>Mycobacterium avium</italic> is the most common nontuberculous mycobacterium (NTM) species causing infectious disease. Here, we characterized a <italic>M. avium</italic> infection model in zebrafish larvae, and compared it to <italic>M. marinum</italic> infection, a model of tuberculosis. <italic>M. avium</italic> bacteria are efficiently phagocytosed and frequently induce granuloma-like structures in zebrafish larvae. Although macrophages can respond to both mycobacterial infections, their migration speed is faster in infections caused by <italic>M. marinum</italic>. Tlr2 is conservatively involved in most aspects of the defense against both mycobacterial infections. However, Tlr2 has a function in the migration speed of macrophages and neutrophils to infection sites with <italic>M. marinum</italic> that is not observed with <italic>M. avium</italic>. Using RNAseq analysis, we found a distinct transcriptome response in cytokine-cytokine receptor interaction for <italic>M. avium</italic> and <italic>M. marinum</italic> infection. In addition, we found differences in gene expression in metabolic pathways, phagosome formation, matrix remodeling, and apoptosis in response to these mycobacterial infections. In conclusion, we characterized a new <italic>M. avium</italic> infection model in zebrafish that can be further used in studying pathological mechanisms for NTM-caused diseases.</p>