title: Visualizing infection of individual influenza viruses.
abstract: Influenza is a paradigm for understanding viral infections. As an opportunistic pathogen exploiting the cellular endocytic machinery for infection, influenza is also a valuable model system for exploring the cell's constitutive endocytic pathway. We have studied the transport, acidification, and fusion of single influenza viruses in living cells by using real-time fluorescence microscopy and have dissected individual stages of the viral entry pathway. The movement of individual viruses revealed a striking three-stage active transport process that preceded viral fusion with endosomes starting with an actin-dependent movement in the cell periphery, followed by a rapid, dynein-directed translocation to the perinuclear region, and finally an intermittent movement involving both plus- and minus-end-directed microtubule-based motilities in the perinuclear region. Surprisingly, the majority of viruses experience their initial acidification in the perinuclear region immediately following the dynein-directed rapid translocation step. This finding suggests a previously undescribed scenario of the endocytic pathway toward late endosomes: endosome maturation, including initial acidification, largely occurs in the perinuclear region.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Melike
authors.initials: M
authors.lastname: Lakadamyali
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Rust
authors.forename: Hazen P
authors.initials: HP
authors.lastname: Babcock
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhuang
mesh_terms: D000199:Actins / Q000737:chemistry; D000818:Animals; D001692:Biological Transport; D016466:CHO Cells; D002467:Cell Nucleus / Q000378:metabolism; D006224:Cricetinae; D004705:Endocytosis; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009975:Orthomyxoviridae / Q000472:pathogenicity* / Q000502:physiology*; D009976:Orthomyxoviridae Infections / Q000821:virology*; D013997:Time Factors
chemical_list: D000199:Actins