Red blood cells (RBCs) are able to interact and communicate with endothelial cells (ECs). Under some pathological or even normal conditions, the adhesion of RBCs to the endothelium can be observed. Presently, the mechanisms and many aspects of the interaction between RBCs and ECs are not fully understood. In this work, we considered the interaction of single RBCs with single ECs in vitro aiming to quantitatively determine the force of this interaction using laser tweezers. Measurements were performed under different concentrations of proaggregant macromolecules and in the presence or absence of tumor necrosis factor (TNF-$\alpha$) activating the ECs. We have shown that the strength of interaction depends on the concentration of fibrinogen or dextran proaggregant macromolecules in the environment. A nonlinear increase in the force of cells interaction (from 0.4 pN to 21 pN) was observed along with an increase in the fibrinogen concentration (from 3$$mg/mL to 9$$mg/mL) in blood plasma, as well as with the addition of dextran macromolecules (from 10$$mg/mL to 60$$mg/mL). Dextran with a higher molecular mass (500$$kDa) enhances the adhesion of RBCs to ECs greater compared to the dextran with a lower molecular mass (70$$kDa). With the preliminary activation of ECs with TNF-$\alpha$, the force of interaction increases. Also, the adhesion of echinocytes to EC compared to discocytes is significantly higher. These results may help to better understand the process of interaction between RBCs and ECs.

红细胞 (RBC) 能够与内皮细胞 (EC) 相互作用和交流。在某些病理甚至正常情况下，可以观察到红细胞与内皮的粘附。目前，红细胞和内皮细胞之间相互作用的机制和许多方面尚未完全了解。在这项工作中，我们考虑了单个 RBC 与单个 EC在体外的相互作用，旨在使用激光镊子定量确定这种相互作用的力。在不同浓度的促聚集大分子和存在或不存在肿瘤坏死因子（TNF-$\alpha$) 激活 EC。我们已经表明相互作用的强度取决于环境中纤维蛋白原或葡聚糖前聚集大分子的浓度。观察到细胞相互作用力的非线性增加（从 0.4 pN 到 21 pN）以及纤维蛋白原浓度的增加（从 3$$毫克/毫升至 9$$毫克/毫升）在血浆中，以及添加葡聚糖大分子（从 10$$毫克/毫升至 60$$毫克/毫升）。具有较高分子量的葡聚糖（500$$kDa) 与较低分子量的葡聚糖相比，增强了红细胞对 ECs 的粘附 (70$$kDa)。随着 TNF 对 ECs 的初步激活，$\alpha$，相互作用力增加。此外，与盘状细胞相比，棘细胞对 EC 的粘附显着更高。这些结果可能有助于更好地理解 RBC 和 EC 之间的相互作用过程。