Clathrin-independent entry of baculovirus triggers uptake of E. coli in non-phagocytic human cells.
The prototype baculovirus, Autographa californica multiple nucleopolyhedrovirus, an insect pathogen, holds great potential as a gene therapy vector. To develop transductional targeting and gene delivery by baculovirus, we focused on characterizing the nature and regulation of its uptake in human cancer cells. Baculovirus entered the cells along fluid-phase markers from the raft areas into smooth-surfaced vesicles devoid of clathrin. Notably, regulators associated with macropinocytosis, namely EIPA, Pak1, Rab34, and Rac1, had no significant effect on viral transduction, and the virus did not induce fluid-phase uptake. The internalization and nuclear uptake was, however, affected by mutants of RhoA, and of Arf6, a regulator of clathrin-independent entry. Furthermore, the entry of baculovirus induced ruffle formation and triggered the uptake of fluorescent E. coli bioparticles. To conclude, baculovirus enters human cells via a clathrin-independent pathway, which is able to trigger bacterial uptake. This study increases our understanding of virus entry strategies and gives new insight into baculovirus-mediated gene delivery in human cells.
Department of Biological and Environmental Science/Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland.
Johanna P
JP
Laakkonen
Anna R
AR
Mäkelä
Elina
E
Kakkonen
Paula
P
Turkki
Sari
S
Kukkonen
Johan
J
Peränen
Seppo
S
Ylä-Herttuala
Kari J
KJ
Airenne
Christian
C
Oker-Blom
Maija
M
Vihinen-Ranta
Varpu
V
Marjomäki
D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000502:physiology; D000251:Adenosine Triphosphatases / Q000502:physiology; D001483:Base Sequence; D002460:Cell Line; D002966:Clathrin / Q000502:physiology*; D004705:Endocytosis; D004926:Escherichia coli / Q000502:physiology*; D006801:Humans; D008563:Membrane Lipids / Q000378:metabolism; D017924:Nucleopolyhedroviruses / Q000502:physiology*; D010587:Phagocytosis; D034622:RNA Interference
D000089982:ADP-Ribosylation Factor 6; D002966:Clathrin; D008563:Membrane Lipids; D000251:Adenosine Triphosphatases; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human