TY - JOUR
T1 - Impaired genome encapsidation restricts the in vitro propagation of human parvovirus B19
AU - Wolfisberg, Raphael
AU - Ruprecht, Nico
AU - Kempf, Christoph
AU - Ros, Carlos
N1 - Copyright © 2013 Elsevier B.V. All rights reserved.
PY - 2013/10
Y1 - 2013/10
N2 - The lack of a permissive cell culture system hampers the study of human parvovirus B19 (B19V). UT7/Epo is one of the few established cell lines that can be infected with B19V but generates none or few infectious progeny. Recently, hypoxic conditions or the use of primary CD36+ erythroid progenitor cells (CD36+ EPCs) have been shown to improve the infection. These novel approaches were evaluated in infection and transfection experiments. Hypoxic conditions or the use of CD36+ EPCs resulted in a significant acceleration of the infection/transfection and a modest increase in the yield of capsid progeny. However, under all tested conditions, genome encapsidation was impaired seriously. Further analysis of the cell culture virus progeny revealed that differently to the wild-type virus, the VP1 unique region (VP1u) was exposed partially and was unable to become further externalized upon heat treatment. The fivefold axes pore, which is used for VP1u externalization and genome encapsidation, might be constricted by the atypical VP1u conformation explaining the packaging failure. Although CD36+ EPCs and hypoxia facilitate B19V infection, large quantities of infectious progeny cannot be generated due to a failure in genome encapsidation, which arises as a major limiting factor for the in vitro propagation of B19V.
AB - The lack of a permissive cell culture system hampers the study of human parvovirus B19 (B19V). UT7/Epo is one of the few established cell lines that can be infected with B19V but generates none or few infectious progeny. Recently, hypoxic conditions or the use of primary CD36+ erythroid progenitor cells (CD36+ EPCs) have been shown to improve the infection. These novel approaches were evaluated in infection and transfection experiments. Hypoxic conditions or the use of CD36+ EPCs resulted in a significant acceleration of the infection/transfection and a modest increase in the yield of capsid progeny. However, under all tested conditions, genome encapsidation was impaired seriously. Further analysis of the cell culture virus progeny revealed that differently to the wild-type virus, the VP1 unique region (VP1u) was exposed partially and was unable to become further externalized upon heat treatment. The fivefold axes pore, which is used for VP1u externalization and genome encapsidation, might be constricted by the atypical VP1u conformation explaining the packaging failure. Although CD36+ EPCs and hypoxia facilitate B19V infection, large quantities of infectious progeny cannot be generated due to a failure in genome encapsidation, which arises as a major limiting factor for the in vitro propagation of B19V.
KW - CD36 Antigens/metabolism
KW - Cell Line
KW - Erythroid Precursor Cells/virology
KW - Humans
KW - Oxygen/metabolism
KW - Parvovirus B19, Human/physiology
KW - Virus Assembly
KW - Virus Cultivation/methods
KW - Virus Replication
U2 - 10.1016/j.jviromet.2013.06.003
DO - 10.1016/j.jviromet.2013.06.003
M3 - Journal article
C2 - 23764418
SN - 0166-0934
VL - 193
SP - 215
EP - 225
JO - Journal of Virological Methods
JF - Journal of Virological Methods
IS - 1
ER -