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J Parasit Dis Diagn Ther 2017
Volume 2 Issue 3
Tropical Medicine 2017
Notes:
Page 42
September 7-8, 2017 | Edinburgh, Scotland
4
th
International Conference on
Tropical Medicine, Infectious Diseases & Public Health
PLASMODIUM BERGHEI ADHERENCE
AND ENDOTHELIAL PROTEIN
C RECEPTOR EXPRESSION IN
EXPERIMENTALMALARIA-ASSOCIATED
ACUTE RESPIRATORY DISTRESS
SYNDROME
Ortolan L S
a
, Sercundes M K
a
, Debone D
a
, Murillo O
a
, Marinho C.R.F
a
and
Epiphanio S
a
a
University of São Paulo, Brazil
Introduction:
Malaria-associated acute respiratory
distress syndrome (ARDS) often results in morbidity and
mortality. Nevertheless, little research has been done on
ARDS. Recently, murine models have been used to study
malaria-associated ARDS; however, the effect mechanism of
adhesion of infected erythrocytes to murine lung endothelial
cells remains unknown. The aim of this study was to elucidate
the effects and mechanism of infected erythrocytes adhesion
to murine lung endothelial cells and aspects of the innate
immune response that will bring important contribution
to the understanding of malaria-associated ARDS.
Methods:
DBA/2 mice were infected with 106 infected red
blood cells (iRBC) of Plasmodium berghei ANKA (PbA)
and classified as ARDS or HP (hyperparasitemia) before
death, on the 7th day after infection (dai). Perfused lungs
of mice classified as ARDS or HP were collected and the
EPCR, ICAM, VCAM and PbA mRNA expression was
analyzed by qRT-PCR and lung tissue sections were stained
with H&E to analyze the parasite localization or hemozoin
concentration by polarized light. DBA/2 mice were also
infected with P. berghei ANKA luciferase and analyzed in vivo
on the 7
th
dai to identify the parasite distribution. Primary
culture of DBA/2 mice microvascular lung endothelial cells
(DBA-PMLEC) were stimulated with IFN- gamma (50ng/
ml), TNF (50ng/ml) and mature forms of iRBC were added
for 1 hour and then removed to check the capacity of iRBC to
adhere to DBA-PMLEC. In addition, transwells membranes
were used containing peritoneal macrophages (MΦ) or bone
marrow’s neutrophils (BMN) and stimulated with iRBC to
analyze if soluble factors from these cells affect the capacity
of iRBC to adhere in DBA-PMLEC. Dexamethasone was
administered to the mice to verify the effect of the anti-
inflammatory in the experimental model. Stimulated cells
were collected to mRNA analyses (ICAM, VCAM, CD36 and
EPCR).
Results:
Microscopy analyses have shown the presence of
iRBC in close contact with endothelial cells in lung tissue
sections. Higher levels of 18s Plasmodium berghei ANKA
mRNA expression and hemozoin were observed in perfused
in lungs of ARDSmice compared toHP (qRT-PCR). P. berghei
ANKA luciferase is distributed in the peripheral blood and
tissue of DBA/2 mice but when mice were perfused, the
(luciferase/luciferin) signal was more concentrated in lungs.
ICAM-1, VCAM, and EPCR expression is altered in
TNF-stimulated cells. IRBC-PbA in contact with MΦ or
BMN increase iRBC-PbA cytoadhesion in (DBA-PMLEC)
and MΦ produce TNF. Dexamethasone-treated mice have
lower gene expression of VCAM, EPCR and less TNF
in serum (compared to untreated controls) and die with
hyperparasitemia symptoms.
Conclusion:
Our data suggest that P. berghei ANKA infected
erythrocytes adhere to DBA-PMLEC and TNF suggested
modulating EPCR expression. Financial support: CAPES,
CNPq and FAPESP.
Biography
Luana dos Santos Ortolan is a biologist graduated from University Fundação
Santo André, São Paulo, Brazil (2009) and has a Master's Degree in Chemical
Biology from Federal University of São Paulo, Brazil (2013). She is currently
a PhD candidate in Immunology at the Institute of Biomedical Sciences of the
University of São Paulo, Brazil.
luana_ortolan@yahoo.com.brOrtolan L S et al., J Parasit Dis Diagn Ther 2017