Institute of Hygiene, University Hospital Münster, 48149 Münster, Germany.
Biomedical Technology Center of the Medical Faculty, University of Münster, 48149 Münster, Germany.
Cells. 2023 Feb 27;12(5):762. doi: 10.3390/cells12050762.
Quantitative phase imaging (QPI) is a non-invasive, label-free technique used to detect aberrant cell morphologies caused by disease, thus providing a useful diagnostic approach. Here, we evaluated the potential of QPI to differentiate specific morphological changes in human primary T-cells exposed to various bacterial species and strains. Cells were challenged with sterile bacterial determinants, i.e., membrane vesicles or culture supernatants, derived from different Gram-positive and Gram-negative bacteria. Timelapse QPI by digital holographic microscopy (DHM) was applied to capture changes in T-cell morphology over time. After numerical reconstruction and image segmentation, we calculated single cell area, circularity and mean phase contrast. Upon bacterial challenge, T-cells underwent rapid morphological changes such as cell shrinkage, alterations of mean phase contrast and loss of cell integrity. Time course and intensity of this response varied between both different species and strains. The strongest effect was observed for treatment with -derived culture supernatants that led to complete lysis of the cells. Furthermore, cell shrinkage and loss of circular shape was stronger in Gram-negative than in Gram-positive bacteria. Additionally, T-cell response to bacterial virulence factors was concentration-dependent, as decreases in cellular area and circularity were enhanced with increasing concentrations of bacterial determinants. Our findings clearly indicate that T-cell response to bacterial stress depends on the causative pathogen, and specific morphological alterations can be detected using DHM.
定量相位成像（QPI）是一种非侵入性、无标记的技术，用于检测疾病引起的异常细胞形态，因此提供了一种有用的诊断方法。在这里，我们评估了 QPI 区分人类原代 T 细胞暴露于不同细菌种类和菌株时特定形态变化的潜力。用无菌细菌决定因素（即膜泡或培养上清液）挑战细胞，这些决定因素来自不同的革兰氏阳性和革兰氏阴性细菌。通过数字全息显微镜（DHM）进行时程 QPI 以捕获 T 细胞形态随时间的变化。在进行数值重建和图像分割后，我们计算了单个细胞的面积、圆度和平均相位对比度。在细菌挑战下，T 细胞经历了快速的形态变化，如细胞收缩、平均相位对比度的改变和细胞完整性的丧失。这种反应的时间进程和强度在不同的物种和菌株之间有所不同。观察到的最强效应是用源自培养上清液的处理引起的细胞完全裂解。此外，革兰氏阴性菌比革兰氏阳性菌的细胞收缩和失去圆形形状的程度更强。此外，T 细胞对细菌毒力因子的反应呈浓度依赖性，因为随着细菌决定因素浓度的增加，细胞面积和圆度的降低增强。我们的研究结果清楚地表明，T 细胞对细菌应激的反应取决于病原体，并且可以使用 DHM 检测到特定的形态改变。
