IFITM3 Clusters on Virus Containing Endosomes and Lysosomes Early in the Influenza A Infection of Human Airway Epithelial Cells

Kummer, Susann; Avinoam, Ori; Kräusslich, Hans-Georg

To determine whether IAV and IFITM3 clustering can be detected on recycling endosomes, we compared uninfected and IAV-infected A549 cells at different time points. Some co-localization of NP with IFITM3 and Rab11 signals was observed on apparently vesicular structures in the extranuclear space of IAV infected A549 cells at 1-6 h p.i. (Figure 7A-C) . However, the co-localization of IFITM3 and Rab11 was already present in the uninfected A549 cells, with no significant change of co-localization during the course of infection, as shown by the MCC analysis ( Figure S4 ). The uptake of IAV particles into recycling endosomes is expected to lead to an abortive infection, as recycling endosomes do not undergo acidification during trafficking. It is likely that rare events of an enhanced