Figure 2.

Reovirus virions enter host cells through receptor-mediated endocytosis. We propose potential fates for incoming virions that reach host endosomes. (A) Particles undergo disassembly within endosomes, which mediates pore formation in the endosome for the deposition of transcriptionally active cores to initiate replication. (B) A proportion of the particles may be unable to exit endosomes properly, where they are degraded to release genomic RNA. (C) Partially degraded particles enter the cytoplasm where they fall apart. (D) Intact cores are deposited into the cytoplasm, but later fall apart or are degraded by the host. In B–D, reovirus genomic RNA is made available to the host for sensing by RIG-I-like receptors (RLRs) and the subsequent induction of infectious subvirion particles (ISVP). Each of these possibilities could happen within the same cell, such that the virus can both establish infection and be sensed.