Kozawa Fumiya, Tamura Tomokazu, Takahashi Naoki, Kakizuka Taishi, Ichimura Taro, Shimada Rumi, Hashimoto Yasuyuki, Onizuska Hironoshin, Kashiwagi Sayaka, Kamasaki Tomoko, Amano Maho, Nagai Takeharu, Fukuhara Takasuke, Fujioka Yoichiro, Ohba Yusuke
Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15W7, Kita-ku, Sapporo, 060-8638, Japan.
Department of Microbiology and Immunology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15W7, Kita-ku, Sapporo, 060-8638, Japan.
Cell Commun Signal. 2025 Aug 2;23(1):361. doi: 10.1186/s12964-025-02357-y.
Influenza A viruses (IAVs) initially infect a few host cells before spreading to neighboring cells. However, the molecular mechanisms underlying this dissemination remain unclear. We have previously demonstrated that intracellular Ca plays a crucial role in facilitating IAV infection. This study aims to clarify the connections between intracellular Ca dynamics and spread of IAV infection.
Madin-Darby canine kidney (MDCK) cells stably expressing a Ca indicator for optical imaging were established. Cells were cultured in Matrigel to form monolayers, and cell-to-cell Ca dynamics within IAV-infected cells were analyzed using fluorescence microscopy.
IAV infection upregulated the frequency of intercellular calcium wave propagations (iCWPs), facilitating viral spread. ADP released from initially infected cells mediated iCWPs via the P2Y receptor. P2Y antagonist suppressed both the generation of iCWPs and spread of viral infection. Enhanced endocytosis by the surrounding cells that received ADP signaling upregulated viral entry. Expression of IAV matrix protein 2 (M2) in initially infected cells triggered iCWPs through ADP diffusion, thereby increasing infection. Conversely, an ion permeability-deficient mutation of M2 or inhibition of its ion channel activity suppressed iCWPs.
Intercellular calcium signaling plays a crucial role in the early expansion and establishment of IAV infection, presenting a potential target for IAV prophylaxis.
甲型流感病毒（IAV）最初感染少数宿主细胞，然后扩散到邻近细胞。然而，这种传播背后的分子机制仍不清楚。我们之前已经证明细胞内钙在促进IAV感染中起关键作用。本研究旨在阐明细胞内钙动态与IAV感染传播之间的联系。
建立稳定表达用于光学成像的钙指示剂的犬肾传代细胞（MDCK）。细胞在基质胶中培养以形成单层，并使用荧光显微镜分析IAV感染细胞内的细胞间钙动态。
IAV感染上调了细胞间钙波传播（iCWP）的频率，促进了病毒传播。最初感染的细胞释放的ADP通过P2Y受体介导iCWP。P2Y拮抗剂抑制了iCWP的产生和病毒感染的传播。接收ADP信号的周围细胞增强的内吞作用上调了病毒进入。最初感染的细胞中IAV基质蛋白2（M2）的表达通过ADP扩散触发iCWP，从而增加感染。相反，M2的离子通透性缺陷突变或其离子通道活性的抑制抑制了iCWP。
细胞间钙信号在IAV感染的早期扩展和建立中起关键作用，是IAV预防的潜在靶点。
