Schrell Leon, Fuchs Hannah L, Dickmanns Antje, Scheibner David, Olejnik Judith, Hume Adam J, Reineking Wencke, Störk Theresa, Müller Martin, Graaf-Rau Annika, Diederich Sandra, Finke Stefan, Baumgärtner Wolfgang, Mühlberger Elke, Balkema-Buschmann Anne, Dobbelstein Matthias
Department of Molecular Oncology, Göttingen Center of Molecular Biosciences (GZMB), University Medical Center Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany.
Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald, Insel Riems, Germany.
Antiviral Res. 2025 Jan;233:106046. doi: 10.1016/j.antiviral.2024.106046. Epub 2024 Dec 3.
RNA viruses present a constant threat to human health, often with limited options for vaccination or therapy. Notable examples include influenza viruses and coronaviruses, which have pandemic potential. Filo- and henipaviruses cause more limited outbreaks, but with high case fatality rates. All RNA viruses rely on the activity of a virus-encoded RNA-dependent RNA polymerase (RdRp). An antiviral nucleoside analogue, 4'-Fluorouridine (4'-FlU), targets RdRp and diminishes the replication of several RNA viruses, including influenza A virus and SARS-CoV-2, through incorporation into nascent viral RNA and delayed chain termination. However, the effective concentration of 4'-FlU varied among different viruses, raising the need to fortify its efficacy. Here we show that inhibitors of dihydroorotate dehydrogenase (DHODH), an enzyme essential for pyrimidine biosynthesis, can synergistically enhance the antiviral effect of 4'-FlU against influenza A viruses, SARS-CoV-2, henipaviruses, and Ebola virus. Even 4'-FlU-resistant mutant influenza A virus was re-sensitized towards 4'-FlU by DHODH inhibition. The addition of uridine rescued influenza A virus replication, strongly suggesting uridine depletion as a mechanism of this synergy. 4'-FlU was also highly effective against SARS-CoV-2 in a hamster model of COVID. We propose that the impairment of endogenous uridine synthesis by DHODH inhibition enhances the incorporation of 4'-FlU into viral RNAs. This strategy may be broadly applicable to enhance the efficacy of pyrimidine nucleoside analogues for antiviral therapy.
RNA病毒对人类健康构成持续威胁，通常在疫苗接种或治疗方面选择有限。显著的例子包括具有大流行潜力的流感病毒和冠状病毒。丝状病毒和亨尼帕病毒引发的疫情范围较窄，但病死率很高。所有RNA病毒都依赖病毒编码的RNA依赖性RNA聚合酶（RdRp）的活性。一种抗病毒核苷类似物4'-氟尿苷（4'-FlU）靶向RdRp，并通过掺入新生病毒RNA和延迟链终止来减少包括甲型流感病毒和SARS-CoV-2在内的几种RNA病毒的复制。然而，4'-FlU的有效浓度在不同病毒之间有所不同，因此需要增强其疗效。在这里，我们表明，二氢乳清酸脱氢酶（DHODH）的抑制剂（嘧啶生物合成所必需的一种酶）可以协同增强4'-FlU对甲型流感病毒、SARS-CoV-2、亨尼帕病毒和埃博拉病毒的抗病毒作用。即使是对4'-FlU耐药的甲型流感病毒突变株，通过抑制DHODH也会重新对4'-FlU敏感。添加尿苷可挽救甲型流感病毒的复制，强烈表明尿苷耗竭是这种协同作用的一种机制。在新冠仓鼠模型中，4'-FlU对SARS-CoV-2也非常有效。我们提出，通过抑制DHODH来损害内源性尿苷合成可增强4'-FlU掺入病毒RNA的能力。这种策略可能广泛适用于增强嘧啶核苷类似物在抗病毒治疗中的疗效。
