Alveolar type-2 (AT2) cells are necessary for the lung’s regenerative response to epithelial insults such as influenza. However, current methods to expand these cells rely on mesenchymal co-culture, complicating the possibility of transplantation following acute injury. Here we developed several mesenchyme-free culture conditions that promote growth of murine AT2 organoids. Transplanting dissociated AT2 organoids into influenza-infected mice demonstrated that organoids engraft and either proliferate as AT2 cells or unexpectedly adopt a basal cell-like fate associated with maladaptive regeneration. Alternatively, transplanted primary AT2 cells also robustly engraft, maintaining their AT2 lineage while replenishing the alveolar type-1 (AT1) cell population in the epithelium. Importantly, pulse oximetry revealed significant increase in blood-oxygen saturation in primary AT2 recipients, indicating that transplanted cells also confer increased pulmonary function after influenza. We further demonstrated that both acid installation and bleomycin injury models are also amenable to AT2 transplantation. These studies provide additional methods to study AT2 progenitor potential, while serving as proof-of-principle for adoptive transfer of alveolar progenitors in potential therapeutic applications.

肺泡2型（AT2）细胞对于肺部对上皮损伤（例如流感）的再生反应必不可少。然而，目前扩增这些细胞的方法依赖于间充质共培养，使急性损伤后移植的可能性变得复杂。在这里，我们开发了几种无间质培养条件，可促进鼠类AT2类器官的生长。将解离的AT2类器官移植到感染流感的小鼠中表明，类器官植入并以AT2细胞的形式增殖，或者出人意料地采取了与适应不良的再生相关的基底细胞样命运。或者，移植的原代AT2细胞也牢固植入，维持其AT2谱系，同时补充上皮细胞中的1型肺泡（AT1）细胞群体。重要的，脉搏血氧饱和度测定显示主要AT2接受者的血氧饱和度显着增加，表明移植的细胞在流感后还具有增强的肺功能。我们进一步证明了酸安装和博来霉素损伤模型也都适合AT2移植。这些研究提供了额外的方法来研究AT2祖细胞的潜力，同时作为潜在治疗应用中肺泡祖细胞过继转移的原理证明。