The reproductive status determines tolerance and resistance to Mycobacterium marinum in Drosophila melanogaster

• Published in: Evolution, medicine, and public health Vol. 11; no. 1; pp. 332 - 347
• Main Authors: Arch, Marta, Vidal, Maria, Fuentes, Esther, Abat, Anmaw Shite, Cardona, Pere-Joan
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 01.01.2023
• Subjects: Original; reproductive status; immunity; mycobacterial infections; Mycobacterium marinum; Drosophila melanogaster; sexual dimorphism
• ISSN: 2050-6201; 2050-6201
• DOI: 10.1093/emph/eoad029

Abstract Sex and reproductive status of the host have a major impact on the immune response against infection. Our aim was to understand their impact on host tolerance or resistance in the systemic Mycobacterium marinum infection of Drosophila melanogaster. We measured host survival and bacillary load at time of death, as well as expression by quantitative real-time polymerase chain reaction of immune genes (diptericin and drosomycin). We also assessed the impact of metabolic and hormonal regulation in the protection against infection by measuring expression of upd3, impl2 and ecR. Our data showed increased resistance in actively mating flies and in mated females, while reducing their tolerance to infection. Data suggests that Toll and immune deficiency (Imd) pathways determine tolerance and resistance, respectively, while higher basal levels of ecR favours the stimulation of the Imd pathway. A dual role has been found for upd3 expression, linked to increased/decreased mycobacterial load at the beginning and later in infection, respectively. Finally, impl2 expression has been related to increased resistance in non-actively mating males. These results allow further assessment on the differences between sexes and highlights the role of the reproductive status in D. melanogaster to face infections, demonstrating their importance to determine resistance and tolerance against M. marinum infection. Lay Summary We show how the sex and the reproductive status of the host affects the the tolerance and resistance levels of the infection by Mycobacterium marinum and alters the innnate immune response of the host using the Drosophila melanogaster model.