This optical image
shows a cell (in blue) with the ATCV-1 viral particles (pink dots).
(October 22, 2015) New
research led by the University of Nebraska-Lincoln has provided the first
direct evidence that an algae-infecting virus can invade and potentially
replicate within some mammalian cells.
Known as Acanthocystis turfacea chlorella virus 1, or
ATCV-1, the pathogen is among a class of chloroviruses long believed to take up
residence only in green algae. That thinking changed with a 2014 study from
Johns Hopkins University and UNL that found gene sequences resembling those of
ATCV-1 in throat swabs of human participants.
The new study, published in the Journal of Virology,
introduced ATCV-1 to macrophage cells that serve critical functions in the
immune responses of mice, humans and other mammals. By tagging the virus with
fluorescent dye and assembling three-dimensional images of mouse cells, the
authors determined that ATCV-1 successfully infiltrated them.
University of
Nebraska researchers (from left) James Van Etten, Irina Agarkova,
Thomas Petro and
David Dunigan co-authored a new study showing that a virus
native to green
algae can invade and likely replicate within the cells of mice.
(Craig
Chandler/University Communications)
The authors also measured a three-fold increase in ATCV-1
within 24 hours of introducing the virus. The relatively modest spike
nevertheless suggests that ATCV-1 can replicate within the macrophage cells,
according to co-author David Dunigan.
Though a few studies have documented viruses jumping from
one biological kingdom to another, chloroviruses were previously thought to
have a limited "host range" that stopped well short of the animal
kingdom, Dunigan said.
"A few years ago, no one I know would have made a
prediction like this," said Dunigan, research professor of plant pathology
and member of the Nebraska Center for Virology. "You probably would've
been laughed out of the room. But we are now in the middle of something that is
so very interesting."