Red blood cells (RBCs) express the nucleic acid-binding toll-like receptor 9 (TLR9) and bind CpG-containing DNA. However, whether human RBCs express other nucleic acid-binding TLRs is unknown. Here we show that human RBCs express the RNA sensor TLR7. TLR7 is present on the red cell membrane and is associated with the RBC membrane protein Band 3. In patients with SARS-CoV2-associated sepsis, TLR7-Band 3 interactions in the RBC membrane are increased when compared with healthy controls. In vitro, RBCs bind synthetic ssRNA and RNA from ssRNA viruses. Thus, RBCs may serve as a previously unrecognized sink for exogenous RNA, expanding the repertoire of non-gas exchanging functions performed by RBCs.

红细胞 (RBC) 表达核酸结合 Toll 样受体 9 (TLR9​​) 并结合含有 CpG 的 DNA。然而，人类红细胞是否表达其他核酸结合 TLR 尚不清楚。在这里，我们展示了人类红细胞表达 RNA 传感器 TLR7。 TLR7 存在于红细胞膜上，并与红细胞膜蛋白带 3 相关。在 SARS-CoV2 相关脓毒症患者中，与健康对照相比，红细胞膜中的 TLR7-带 3 相互作用增加。在体外，红细胞结合合成的 ssRNA 和来自 ssRNA 病毒的 RNA。因此，红细胞可能充当以前未被识别的外源RNA库，扩大了红细胞执行的非气体交换功能的范围。