Dillon Nicholas A, Lamont Elise A, Rather Muzafar A, Baughn Anthony D
Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080.
Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN 55455.
bioRxiv. 2024 Dec 18:2024.12.17.628853. doi: 10.1101/2024.12.17.628853.
Pyrazinamide (PZA) is a critical component of tuberculosis first-line therapy due to its ability to kill both growing and non-replicating drug-tolerant populations of within the host. Recent evidence indicates that PZA acts through disruption of coenzyme A synthesis under conditions that promote cellular stress. In contrast to its bactericidal action , PZA shows weak bacteriostatic activity against in axenic culture. While the basis for this striking difference between and PZA activity has yet to be resolved, recent studies have highlighted an important role for cell-mediated immunity in PZA efficacy. These observations suggest that host-derived antimicrobial activity may contribute to the bactericidal action of PZA within the host environment. In this study we show that the active form of PZA, pyrazinoic acid (POA), synergizes with the bactericidal activity of host-derived reactive oxygen species (ROS). We determined that POA can promote increased cellular oxidative damage and enhanced killing of . Further, we find that the thiol oxidant diamide is also able to potentiate PZA activity, implicating thiol oxidation as a key driver of PZA susceptibility. Using a macrophage infection model, we demonstrate the essentiality of interferon-γ induced ROS production for PZA mediated clearance of . Based on these observations, we propose that the sterilizing activity of PZA can be mediated through its synergistic interaction with the host oxidative burst leading to collateral disruption of coenzyme A metabolism. These findings will enable discovery efforts to identify novel host- and microbe-directed approaches to bolster PZA efficacy.
吡嗪酰胺（PZA）是结核病一线治疗的关键组成部分，因为它能够杀死宿主体内生长和非复制性耐药物种。最近的证据表明，PZA在促进细胞应激的条件下通过破坏辅酶A合成发挥作用。与其杀菌作用相反，PZA在无菌培养中对结核分枝杆菌显示出较弱的抑菌活性。虽然结核分枝杆菌和PZA活性之间这种显著差异的基础尚未得到解决，但最近的研究强调了细胞介导的免疫在PZA疗效中的重要作用。这些观察结果表明，宿主衍生的抗菌活性可能有助于PZA在宿主环境中的杀菌作用。在本研究中，我们表明PZA的活性形式吡嗪酸（POA）与宿主衍生的活性氧（ROS）的杀菌活性协同作用。我们确定POA可以促进细胞氧化损伤增加和结核分枝杆菌杀伤增强。此外，我们发现硫醇氧化剂二酰胺也能够增强PZA活性，这表明硫醇氧化是PZA敏感性的关键驱动因素。使用巨噬细胞感染模型，我们证明了干扰素-γ诱导的ROS产生对于PZA介导的结核分枝杆菌清除至关重要。基于这些观察结果，我们提出PZA的杀菌活性可以通过其与宿主氧化爆发的协同相互作用来介导，从而导致辅酶A代谢的附带破坏。这些发现将有助于发现新的宿主和微生物导向方法来增强PZA的疗效。
