Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA.
Toxins (Basel). 2024 Mar 7;16(3):138. doi: 10.3390/toxins16030138.
is a Gram-negative bacterium associated with localized aggressive periodontitis as well as some systemic diseases. The strains of most closely associated with disease produce more of a secreted leukotoxin (LtxA) than isolates from healthy carriers, suggesting a key role for this toxin in disease progression. LtxA is released into the bacterial cytosol in a free form as well as in association with the surface of outer membrane vesicles (OMVs). We previously observed that the highly leukotoxic strain JP2 produces two populations of OMVs: a highly abundant population of small (<100 nm) OMVs and a less abundant population of large (>300 nm) OMVs. Here, we have developed a protocol to isolate the OMVs produced during each specific phase of growth and used this to demonstrate that small OMVs are produced throughout growth and lack LtxA, while large OMVs are produced only during the exponential phase and are enriched with LtxA. Our results indicate that surface-associated DNA drives the selective sorting of LtxA into large OMVs. This study provides valuable insights into the observed heterogeneity of vesicles and emphasizes the importance of understanding these variations in the context of bacterial pathogenesis.
是一种革兰氏阴性菌，与局部侵袭性牙周炎以及一些系统性疾病有关。与疾病最密切相关的菌株比来自健康携带者的分离株产生更多的分泌性白细胞毒素（LtxA），这表明这种毒素在疾病进展中起关键作用。LtxA 以游离形式以及与外膜囊泡（OMV）表面结合的形式释放到细菌胞质溶胶中。我们之前观察到，高白细胞毒性的 JP2 菌株产生两种 OMV 群体：大量的小（<100nm）OMV 群体和较少的大（>300nm）OMV 群体。在这里，我们开发了一种分离在每个特定生长阶段产生的 OMV 的方案，并利用该方案证明小 OMV 在整个生长过程中产生且缺乏 LtxA，而大 OMV 仅在指数生长期产生并且富含 LtxA。我们的结果表明，表面相关的 DNA 驱动 LtxA 选择性地分拣到大 OMV 中。这项研究为观察到的 囊泡异质性提供了有价值的见解，并强调了在细菌发病机制背景下理解这些变化的重要性。
