Alexandre Gidon

• Nore, Kristin Grotle; Louet, Claire; Bugge, Marit; Gidon, Alexandre; Jørgensen, Marthe Jøntvedt & Jenum, Synne [Vis alle 9 forfattere av denne artikkelen] (2023). The Cyclooxygenase 2 Inhibitor Etoricoxib as Adjunctive Therapy in Tuberculosis Impairs Macrophage Control of Mycobacterial Growth. Journal of Infectious Diseases. ISSN 0022-1899. 229(3), s. 888–897. doi: 10.1093/infdis/jiad390.
• Røst, Lisa M.; Louet, Claire; Bruheim, Per; Flo, Trude Helen & Gidon, Alexandre (2022). Pyruvate Supports RET-Dependent Mitochondrial ROS Production to Control Mycobacterium avium Infection in Human Primary Macrophages. Frontiers in Immunology. ISSN 1664-3224. 13. doi: 10.3389/fimmu.2022.891475. Fulltekst i vitenarkiv
• Basson, Adelle; Olaisen, Camilla; Selvik, Linn-Karina M.; Lyng, Randi Valsø; Lysvand, Hilde & Gidon, Alexandre [Vis alle 9 forfattere av denne artikkelen] (2022). The Streptococcus agalactiae R3 surface protein is encoded by sar5. PLOS ONE. ISSN 1932-6203. 17(7). doi: 10.1371/journal.pone.0263199. Fulltekst i vitenarkiv
• Niyonzima, Nathalie; Rahman, Jubayer; Kunz, Natalie; West, Erin; Freiwald, Tilo & Desai, Jigar V. [Vis alle 37 forfattere av denne artikkelen] (2021). Mitochondrial C5aR1 activity in macrophages controls IL-1β production underlying sterile inflammation . Science immunology. ISSN 2470-9468. 6(66), s. eabf2489–eabf2489. doi: 10.1126/sciimmunol.abf2489.
• Gidon, Alexandre; Louet, Claire; Røst, Lisa M.; Bruheim, Per & Flo, Trude Helen (2021). The Tumor Necrosis Factor Alpha and Interleukin 6 Auto-paracrine Signaling Loop Controls Mycobacterium avium Infection via Induction of IRF1/IRG1 in Human Primary Macrophages. mBio. ISSN 2161-2129. 12(5). doi: 10.1128/mBio.02121-21. Fulltekst i vitenarkiv Vis sammendrag

  Macrophages sense and respond to pathogens by induction of antimicrobial and inflammatory programs to alert other immune cells and eliminate the infectious threat. We have previously identified the transcription factor IRF1 to be consistently activated in macrophages during Mycobacterium avium infection, but its precise role during infection is not clear. Here, we show that tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) autocrine/paracrine signaling contributes to controlling the intracellular growth of M. avium in human primary macrophages through activation of IRF1 nuclear translocation and expression of IRG1, a mitochondrial enzyme that produces the antimicrobial metabolite itaconate. Small interfering RNA (siRNA)-mediated knockdown of IRF1 or IRG1 increased the mycobacterial load, whereas exogenously provided itaconate was bacteriostatic at high concentrations. While the overall level of endogenous itaconate was low in M. avium-infected macrophages, the repositioning of mitochondria to M. avium phagosomes suggests a mechanism by which itaconate can be delivered directly to M. avium phagosomes in sufficient quantities to inhibit growth. Using mRNA hybridization, we further show that uninfected bystander cells actively contribute to the resolution of infection by producing IL-6 and TNF-α, which, via paracrine signaling, activate IRF1/IRG1 and strengthen the antimicrobial activity of infected macrophages. This mechanism contributes to the understanding of why patients on anti-inflammatory treatment, e.g., with tocilizumab or infliximab, can be more susceptible to mycobacterial disease.

• Åsberg, Signe Elisabeth; Mediaas, Sindre Dahl; Marstad, Anne; Ryan, Liv; Louet, Claire & Sporsheim, Bjørnar [Vis alle 10 forfattere av denne artikkelen] (2020). Antibiotic treatment routes Mycobacterium avium to phagolysosomes without triggering proinflammatory cytokine production in human Mϕs. Journal of Leukocyte Biology. ISSN 0741-5400. doi: 10.1002/JLB.4HI0420-306R. Vis sammendrag

  Mycobacterium avium (Mav) causes chronic infections in immunocompromised patients that require long‐term antibiotic treatment. We have previously shown that Mav takes residence in host Mϕs and establishes a compartment (MavC) in which it is hidden from host defenses. Failure to establish the MavC traps Mav in Lamp1+ phagolysosomes where growth is prevented, and inflammatory signaling activated through TLRs 7/8. To elucidate how antibiotic treatment affects mycobacterial trafficking and host defenses, we infected human primary Mϕs with Mav for 4 days prior to treatment with a macrolide, aminoglycoside, and ethambutol. We show that Mav is killed and the MavC fuses with Lamp1+ lysosomes following antibiotic treatment. However, this does not result in nuclear translocation of NF‐κB or production of inflammatory cytokines, suggesting different Lamp1+ lysosomal compartments can form that differ in their innate signaling capabilities. Thus, we show that upon antibiotic treatment of a chronic infection, Mav is quietly disposed of by Mϕs.

• Gidon, Alexandre; Åsberg, Signe; Louet, Claire; Ryan, Liv; Haug, Markus & Flo, Trude Helen (2017). Persistent mycobacteria evade an antibacterial program mediated by phagolysosomal TLR7/8/MyD88 in human primary macrophages. PLoS Pathogens. ISSN 1553-7366. 13(8). doi: 10.1371/journal.ppat.1006551. Fulltekst i vitenarkiv
• Gidon, Alexandre; Feinstein, Timothy N.; Xiao, Kunhong & Vilardaga, Jean-Pierre (2015). Studying the regulation of endosomal cAMP production in GPCR signaling . Methods in Cell Biology. ISSN 0091-679X. doi: 10.1016/bs.mcb.2015.10.007.

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• Flo, Trude Helen; Gidon, Alexandre; Mediaas, Sindre Dahl & Bugge, Marit (2023). Spatiotemporal studies of host responses to mycobacteria in macrophages.
• Flo, Trude Helen; Beckwith, Kai Sandvold; Beckwith, Marianne Sandvold; Gidon, Alexandre; Mediaas, Sindre Dahl & Sætra, Ragnhild Sofie Ragnhildstveit [Vis alle 9 forfattere av denne artikkelen] (2022). Spatiotemporal Relations of Mycobacteria and Human Macrophages.
• Basson, Adelle; Olaisen, Camilla; Selvik, Linn-Karina M.; Lyng, Randi Valsø; Lysvand, Hilde & Gidon, Alexandre [Vis alle 9 forfattere av denne artikkelen] (2022). The Streptococcus agalactiae R3 surface protein is encoded by sar5.
• Flo, Trude Helen; Beckwith, Kai Sandvold; Beckwith, Marianne Sandvold; Gidon, Alexandre; Ullmann, Sindre & Sætra, Ragnhild Sofie Ragnhildstveit [Vis alle 7 forfattere av denne artikkelen] (2021). Mycobacterium tuberculosis infection in human macrophages.
• Flo, Trude Helen; Gidon, Alexandre; Mediaas, Sindre Dahl & Dragset, Marte Singsås (2020). AMR in mycobacterial infections and the search for new treatments.
• Mediaas, Sindre Dahl; Gidon, Alexandre; Haug, Markus & Flo, Trude Helen (2020). THE EFFECT OF HOST-DIRECTED THERAPY ON INTRANASAL MYCOBACTERIUM AVIUM INFECTION.
• Flo, Trude Helen; Beckwith, Kai Sandvold; Beckwith, Marianne Sandvold; Gidon, Alexandre; Ullmann, Sindre & Sætra, Ragnhild Sofie Ragnhildstveit (2019). Plasma membrane damage by Mycobacterium tuberculosis induce inflammasome activation and pyroptosis in host macrophages.
• Flo, Trude Helen; Gidon, Alexandre & Lerm, Maria (2018). Discovering new therapeutic targets and drugs to combat AMR tuberculosis: proteomics characterization and drug screening of mycobacterium-infected macrophages.
• Gidon, Alexandre; Louet, Claire & Flo, Trude Helen (2018). Single cell analysis reveals an IRF1/ACOD1 auto-paracrine loop controlled by IL-6/TNF-a to restrict persistent mycobacteria in human primary macrophage .
• Ostrop, Jenny; Kerntke, Christina; Gullik Sørbø, Håvard; Spanjers, Roos; Louet, Claire & Gidon, Alexandre [Vis alle 9 forfattere av denne artikkelen] (2017). FcRγ is a central adaptor subunit for immune receptors on human macrophages.
• Ostrop, Jenny; Kerntke, Christina; Gullik Sørbø, Håvard; Jozefowski, Katrin; Hupfer, Thomas & Louet, Claire [Vis alle 11 forfattere av denne artikkelen] (2017). FcRγ is a central adaptor subunit for immune receptors on myeloid cells.
• Gidon, Alexandre; Åsberg, Signe; Louet, Claire; Ryan, Liv; Haug, Markus & Flo, Trude Helen (2017). Persistent mycobacteria evade an antibacterial program mediated by phagolysosomal TLR7/8/MyD88 in human primary macrophages.
• Gidon, Alexandre (2017). Persistent mycobacteria evade an antibacterial program mediated by phagolysosomal TLR7/8/MyD88 in human primary macrophages.
• Gidon, Alexandre; Åsberg, Signe Elisabeth; Louet, Claire; Ryan, Liv & Flo, Trude Helen (2016). Mycobacterium avium interfering with phagosome maturation evades an antibacterial program activated by phagolysosomal TLR7/8/MyD88 in human primary macrophages.
• Gidon, Alexandre; Åsberg, Signe Elisabeth; Louet, Claire; Ryan, Liv & Flo, Trude Helen (2016). Inflammatory Encounters of Mycobacteria in Space and Time.
• Gidon, Alexandre; Åsberg, Signe Elisabeth; Louet, Claire; Ryan, Liv & Flo, Trude Helen (2016). Mycobacterium avium evades an antibacterial program mediated by phagolysosomal TLR7/8/MyD88 .
• Gidon, Alexandre; Åsberg, Signe Elisabeth; Louet, Claire; Ryan, Liv & Flo, Trude Helen (2016). Mycobacterium avium evades an antibacterial program mediated by phagolysosomal TLR7/8/MyD88.
• Gidon, Alexandre (2015). M.Avium induces Inflammatory Signaling from Lysosomal Compartments in Human Primary Macrophages.
• Gidon, Alexandre (2015). Traffic and Signaling: a close relationship in M. Avium infected Primary Human Macrophages.
• Åsberg, Signe; Flo, Trude Helen; Underhill, David & Gidon, Alexandre (2018). The Drug, the Bug and the Macrophage: Interactions between antibiotics, mycobacteria and macrophages at the single cell and subcellular level. NTNU. ISSN 978-82-326-3446-0.

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