Department of Medical Biology, UiT The Arctic University of Norway, Tromsø, Norway.
Gastrointestinal Surgery Unit, University Hospital of North Norway, Tromsø, Norway.
mSphere. 2024 Mar 26;9(3):e0070223. doi: 10.1128/msphere.00702-23. Epub 2024 Feb 28.
Phage treatment has regained attention due to an increase in multiresistant bacteria. For phage therapy to be successful, phages must reach their target bacteria in sufficiently high numbers. Blood-borne phages are believed to be captured by macrophages in the liver and spleen. Since liver sinusoids also consist of specialized scavenger liver sinusoidal endothelial cells (LSECs) and Kupffer cells (KCs), this study investigated the contribution of both cell types in the elimination of phage K1Fg10b::gfp (K1F) in mice. Circulatory half-life, organ, and hepatocellular distribution of K1F were determined following intravenous administration. Internalization of K1F and effects of phage opsonization on uptake were explored using primary mouse and human LSEC and KC cultures. When inoculated with 10 virions, >95% of the total K1F load was eliminated from the blood within 20 min, and 94% of the total retrieved K1F was localized to the liver. Higher doses resulted in slower elimination, possibly reflecting temporary saturation of liver scavenging capacity. Phage DNA was detected in both cell types, with a KC:LSEC ratio of 12:1 per population following cell isolation. Opsonization with plasma proteins increased time-dependent cellular uptake in both LSECs and KCs . Internalized phages were rapidly transported along the endocytic pathway to lysosomal compartments. Reduced viability of intracellular K1F corroborated inactivation following endocytosis. This study is the first to identify phage distribution in the liver at the hepatocellular level, confirming clearance of K1F performed mostly by KCs with a significant uptake also in LSECs.IMPORTANCEFaced with the increasing amounts of bacteria with multidrug antimicrobial resistance, phage therapy has regained attention as a possible treatment option. The phage field has recently experienced an emergence in commercial interest as research has identified new and more efficient ways of identifying and matching phages against resistant superbugs. Currently, phages are unapproved drugs in most parts of the world. For phages to reach broad clinical use, they must be shown to be clinically safe and useful. The results presented herein contribute to increased knowledge about the pharmacokinetics of the T7-like phage K1F in the mammalian system. The cell types of the liver that are responsible for rapid phage blood clearance are identified. Our results highlight the need for more research about appropriate dose regimens when phage therapy is delivered intravenously and advise essential knowledge about cell systems that should be investigated further for detailed phage pharmacodynamics.
噬菌体治疗由于多药耐药菌的增加而重新受到关注。为了使噬菌体治疗成功，噬菌体必须以足够高的数量到达其靶细菌。人们认为血液来源的噬菌体被肝脏和脾脏中的巨噬细胞捕获。由于肝窦也由专门的清除性肝窦内皮细胞（LSEC）和枯否细胞（KC）组成，因此本研究调查了这两种细胞类型在清除小鼠噬菌体 K1Fg10b::gfp（K1F）中的作用。在静脉给药后，确定了 K1F 的循环半衰期、器官和肝细胞分布。使用原代小鼠和人 LSEC 和 KC 培养物探索了 K1F 的内化及其对摄取的噬菌体调理作用。当接种 10 个病毒粒子时，超过 95%的总 K1F 负荷在 20 分钟内从血液中消除，并且 94%的总回收 K1F 定位到肝脏。更高的剂量导致消除速度较慢，这可能反映了肝脏清除能力的暂时饱和。噬菌体 DNA 存在于两种细胞类型中，细胞分离后每个群体的 KC:LSEC 比值为 12:1。用血浆蛋白调理可增加 LSEC 和 KC 中时间依赖性细胞摄取。内化的噬菌体沿着内吞途径迅速转运到溶酶体区室。细胞内 K1F 的活力降低证实了内吞作用后的失活。本研究首次在肝细胞水平上鉴定了肝内噬菌体的分布，证实 K1F 的清除主要由 KC 完成，LSEC 也有显著摄取。
重要性
面对具有多药抗微生物耐药性的细菌数量不断增加，噬菌体治疗作为一种可能的治疗选择重新受到关注。噬菌体领域最近随着研究确定了识别和匹配针对耐药超级细菌的噬菌体的新的、更有效的方法，重新引起了商业兴趣。目前，噬菌体在世界大部分地区都未获得批准。为了使噬菌体广泛应用于临床，必须证明它们在临床上是安全和有用的。本文的研究结果有助于增加对哺乳动物系统中 T7 样噬菌体 K1F 的药代动力学的了解。确定了负责快速清除噬菌体的肝脏细胞类型。我们的研究结果强调了在静脉内给予噬菌体治疗时需要进一步研究适当的剂量方案，并为进一步研究详细的噬菌体药效动力学提供了关于细胞系统的重要知识。
