Journal of Clinical Virology - Volume 82 - Supplement 1 - September 2016

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S100 Abstracts / Journal of Clinical Virology 82S (2016) S1–S142
(p < 0.001). Stratified analysis showed that the increase in BKPyV-
seroreactivity was correlated with the height of the peak viral load
measured after transplantation.
Conclusion: In kidney recipients that experience active BKPyV
infection, BKPyV-seroreactivity is correlated with BKPyV viremia
and dependent of the peak viral load. Based on our previous findings
showing that donor BKPyV-seroreactivity predicts BKPyV infec-
tion in recipients we believe our current findings provide a
template to understand BKPyV infection in general, where BKPyV-
seroreactivity in an individual reflects primary BKPyV replication
in the past and the level of latent virus in the kidneys. In that way
BKPyV-seroreactivity in kidney donors can predict the amount of
latent, potentially infectious virus in the kidney allograft.
Reference
[1] Wunderink, et al., Am. J. Transplant. (2016).
Abstract no: 323
Presentation at ESCV 2016: Poster 159
Frequent HHV6 DNA positivity in children with
severe burn injury
K. Labská ∗ .Marinenko atˇejková
H. Pˇribylová , M. Pumannová , H. ˇSuca ,
R. Zajíˇce
1 National Institute of Public Health, Prague, Czech
Republic
2 Prague Burn Centre, University Hospital Kralovske
Vinohrady, Prague, Czech Republic
3 Third Faculty of Medicine, Charles University,
Prague, Czech Republic
4 Prague Burn Centre, University Hospital Kralovske
Vinohrady, Czech Republic
Background: Burn injury harms human immunity at multi-
ple levels including decrease of cell mediated immunity and the
cytokine storm. Such conditions are well known trigger of her-
pesvirus reactivation. Aimof our study is to elucidate the frequency
and possible impact of herpesvirus reactivation in children with
severe burn injury.
Methods: Enrollment criteria: age under 10, severe burn injury
(grade II, >5% BSA), fever (day 3 after onset) and low inflammatory
parameters (CRP, PCT, normal WBC).
Enrolled childrenwere tested for HSV, VZV, EBV, CMV and HHV6
DNA in blood by multiplex PCR (Seeplex Meningitis – V1, Seegene)
and real-time PCR (CMV HHV6,7,8 R-gene, Biomerieux). Tests for
anti HHV6 antibodies and avidity were performed by IIF and EIA
(IgM – Anti HHV6 IIFT IgM, Euroimmun, IF-VIDITEST anti-HHV-6
IgG, Vidia and IgG ELISA-VIDITEST anti-HHV-6 IgG, Vidia).
Results: Up to date we have enrolled 17 children. The mean
age of affected children was 2 (median 2, range from 1 to 7 years).
Themost frequently detected viruswas HHV6 (10/17), among these
twice in combination with CMV and EBV, once in combination with
EBV. All of themwere HHV6 type B with viral load ranging from 91
to 2410 copies per ml of whole blood (median 323 cp/ml). Only one
HHV6 DNA positive child was negative for HHV6 IgG and IgM anti-
bodies (ELISA and IIF). Two children with HHV6 DNA were positive
for anti HHV6 IgM antibodies. The remaining 7 were IgM negative.
All patients positive for HHV6 IgG by EIA had high-avid antibod-
ies. History of exanthema subitum was known only in one child.
No rashes or cytopenias were observed during the hospitalization
period.
Conclusion: We have not observed any typical clinical signs
previously described for active HHV6 infection in immunocompro-
mised patients in our group. Our patients are of age close to time
of HHV6 primary infection. The presence of HHV6 DNA in blood
is probably a residue of HHV6 integration to the blood progenitor
cells during the primary infection, although none of the children
had recent primary infection due to the presence of high-avid anti-
bodies.
Abstract no: 329
Presentation at ESCV 2016: Poster 160
BK polyomavirus infection activates the type I
interferon response in human fibroblasts,
depending on the cGAS-STING pathway
Celine Bressollette-Bodin ∗, Cécile Peltier ,
Lise Chauveau , Olivier Schwartz
1 UMR1064 Centre de Recherche en Transplantation
et Immunologie, Nantes University, Nantes, France
2 Unité Virus Immunité, Institut Pasteur, Paris, France
BK polyomavirus (BKPyV) associated nephropathy is one of the
major causes of renal allograft dysfunction. Immunosuppressive
therapy favors viral reactivation and nephropathy can develop due
to local inflammation and insufficiency of the antiviral immune
response. Recent studies have focused on the BKPyV-specific T cell
responses, however how BKPyV is detected and whether it induces
an innate immune response remain mostly unknown.
Our aim was to investigate innate responses to BKPyV infection
in permissive cells and identify intracellular sensors involved in the
recognition of the virus.
Human foreskin fibroblastes (HFF) and human renal proxi-
mal epithelial cells (hRPTECs) were infected with BKPyV (Gardner
strain), and Chikungunya or IFNa as positive controls. IFNb, MxA,
IL1b and IL18 gene expression were measured by RT-qPCR, nor-
malized to GAPDH, and results expressed as fold induction over
mock-infected cells. At the protein level, MxA expression was mea-
sured using flow cytometry and IFN type I levels were measured
using a bioassay (HL116 cells) in the supernatant of infected and
control cells. We show that BKPyV infection activates MxA expres-
sion and type I IFN in HFF, but not in hRPTECs.
To identify intracellular receptors involved in the sensing of
BKPyV during infection of HFF, we transfected cells with different
siRNA targeting molecules known to be involved in the recogni-
tion of viral nucleic acids (IFI16, cGAS, DNA PK, STING, IRF3). Total
RNA was harvested at 3 and 6 dpi. Silencing was assessed by RT-
qPCR, normalized to GAPDH and plotted as fold induction over the
siSCR condition. We observed a significant inhibition of MxA and
IFN type I induction after six days post infection when cGAS, STING
and IRF3 were silenced, suggesting the involvement of this sensing
pathway in the recognition of BKPyV during viral multiplication in
permissive cells.
Moreover, BKPyV DNA replication was measured using in house
quantitative PCRwith andwithout IFN . DNA viral loads after three
and six days post infection were significantly lower in cells culti-
vated with IFN , compared to untreated cells, showing that IFN
restricts BKPyV replication in HFF and HRPTECs.
Altogether, our results show that BKPyV is restricted by IFN type
I. BKPyV infection in hRPTECs does not activate strongly the type
I interferon response, when this response is significant in HFF. In
HFF, this activation depends on the cGAS-STING-IRF3 pathway.