Q-One Biotech Limited, Todd Campus, West of Scotland Science Park, Glasgow,
G20 0XA, UK. cnairn@q-one.co.uk
Bovine polyomavirus
(BPyV)
is a member of the
Polyomaviridae, a virus that
was originally thought to be of simian origin but was later shown to be of
bovine origin, the primate cultures having been contaminated through the use
of foetal
bovine serum. The significance of this agent to the biotechnology industry
cannot be underestimated. The presence of BPyV
in serum batches poses a serious risk for the contamination of human
therapeutic products. The current PCR
based assays provide a means of detecting virus sequences but give no
indication as to the infectious nature of the virus. The communication
reports the successful development of an assay to detect infectious BPyV using
an in vitro amplification system followed by PCR. A lengthy culture period on
bovine cells was required before replicating BPyV could be detected and
distinguished from non-replicating virus in the cell culture supernatant. A
mock-test assay using foetal bovine serum positive for BPyV showed that there
was no evidence of replicating BPyV in the serum sample. The BPyV spiked serum
control showed that replicating virus was present thus confirming that the
serum itself did not inhibit replication of the virus. Cells harvested during
the culture period were subjected to fixation, embedding and sectioning and
examined by electron microscopy. Intact virus-like particles of approximately
40-50nm were observed in the nucleus of the bovine kidney cells, the site of
polyomavirus replication.
Simian immunodeficiency viruses from multiple lineages
infect human macrophages: implications for cross-species transmission.
Grimm TA, Beer BE, Hirsch VM, Clouse KA.
Laboratory of Cell Biology, Division of Monoclonal Antibodies, Office of
Theraputics Research and Review, Center for Bioligics Evaluations and Review,
US Food and Drugs Administration, National Institutes of Health , Rockville,
Maryland 20852, USA.
Zoonotic transfer of simian immunodeficiency virus (SIV) from chimpanzees and
sooty mangabeys to humans has been documented on at least seven occasions.
Several recently identified SIV isolates have also been shown to replicate
efficiently in human peripheral blood mononuclear cells (PBMCs) in vitro,
indicative of the potential for additional cross-species transmission via T
cell infection. Although SIV predominantly uses the macrophage-tropic HIV
chemokine coreceptor CCR5, little is known about the ability of SIV to infect
human macrophages. In this study, 16 SIV isolates belonging to five different
primate lentivirus lineages were tested for their ability to infect human
monocyte-derived macrophages (MDMs). Twelve of the viruses were capable of
infecting MDMs, and 11 of these were also able to replicate in human PBMCs.
The replication capacity of the isolates differed within and between the
various families and was dependent on particular donor macrophages. Our
results suggest that most simian lentiviruses characterized to date not only
have the ability to infect primary human T lymphocytes but also replicate
efficiently in macrophages, thereby increasing the potential for cross-species
transmission into the human population. Comparative studies using these
isolates may facilitate the identification of characteristics that contribute
to virus infectivity and pathogenicity.
Cross-species retroviral transmission from macaques to
human beings.
Brooks JI, Rud EW, Pilon RG, Smith JM, Switzer WM, Sandstrom PA.
Bureau of HIV/AIDS, STD, and TB, Centre for Infectious Disease Prevention and
Control, Health Canada, Ottawa, ON K1A 0L2, Canada.
Cross-species transmission of simian foamy virus (SFV) to human beings from
chimpanzees, baboons, and African green monkeys has been described. Although
macaques are the non-human primate most often handled in research, human
infection with SFV from macaques has not been reported. Two of 46
primate-facility workers tested positive for antibodies that reacted with an
immunoblot that contained macaque foamy virus antigens. Phylogenetic
assessment of a 96-bp fragment of amplified proviral DNA isolated from
peripheral-blood mononuclear cells from one infected individual was consistent
with SFV infection of macaque origin. Frequent use of macaques in biomedical
research, and identification of persistent retroviral infection from macaques
to human beings, could have implications for public-health policy and
occupational health and safety.
Induction of immune deficiency syndrome in rabbits by
bovine leukaemia virus.
Altanerova V, Ban J, Altaner C.
Department of Molecular Virology, Slovak Academy of Sciences, Bratislava,
Czechoslovakia.
Newborn rabbits were inoculated with
bovine leukaemia
virus (BLV).
The majority of infected rabbits produced antiviral antibodies. All the seroconverted
animals developed symptoms resembling AIDS and died several months after
inoculation. The course of experimental infection of rabbits with BLV
resembled in many respects the broad spectrum of clinical disorders associated
with AIDS induced by HIV. Antibody response to virus proteins was followed by
immune deficiency and signs of neuropathy, and the animals subsequently died
of opportunistic infections. Virus transmission from infected babies to the
mothers by contact was also observed. In some cases the virus was salvaged
from lymphocytes of rabbits with the immune deficiency syndrome. The
virus-specific sequences were found to be integrated at random in the DNA of
haematopoietic cells and of some organs. Slight expression of viral RNAs in
lymphocytes was found. Experimental infection of rabbits with BLV can be used
in experiments to understand AIDS induction.
Infection of human cell cultures with bovine visna virus.
Georgiades JA, Billiau A, Vanderschueren B.
Fibroblastoid cell cultures derived from leukaemic bone marrow were
successfully infected with BVV. After 2 months of subcultivation the cultures
showed the appearance of foci of altered cells, suggestive of malignant
transformation. Such foci were absent in non-inoculated cultures. Both control
and inoculated cultures had a limited life span, i.e. neither of them could be
developed into continuous transformed cell lines. The presence of at least
some BVV genome functions in the inoculated cells was demonstrated (i) by
immunofluorescence using a reference BVV serum, (ii) by detection in the
supernatant culture fluid of sedimentable particles bearing RNA-dependent DNA
polymerase activity with preference for Mg2+ ions, and (iii) by electron
microscopic detection of scarce cell-associated virus particles in one of the
infected cultures. Infectious BVV could not be rescued. In contrast to
leukaemic bone marrow cultures, diploid human embryonic fibroblasts of various
origin could not be infected with BVV.
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-- Albert Einstein, letter to a friend, 1901
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-- Thomas Jefferson, letter to William C. Jarvis, September 28, 1820
"What's the point of vaccination if it doesn't protect you from the unvaccinated?"
-- Sandy Gottstein
"Who gets to decide what the greater good is and how many will be sacrificed to it?"