Banca de DEFESA: BEATRIZ FILGUEIRAS SILVESTRE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : BEATRIZ FILGUEIRAS SILVESTRE
DATE: 09/12/2021
TIME: 14:00
LOCAL: Plataforma GoogleMeet
TITLE:

CHARACTERIZATION OF  IXODIDE CELL LINES AS A MODEL FOR  IN VITRO STUDY OF  TICK AND LEISHMANIA SPP  INTERACTION.

KEY WORDS:

canine leishmaniasis, tick cells, Leishmania spp, tick lipid metabolism.

PAGES: 77
BIG AREA: Ciências Biológicas
AREA: Parasitologia
SUBÁREA: Entomologia e Malacologia de Parasitos e Vetores
SUMMARY:

Leishmaniasis is a group of diseases caused by protozoa of the genus Leishmania
that affect humans and animals. Canine leishmaniasis is a disease of great public health
importance, since dogs are the main reservoir of the parasite. Most infected dogs come
from poor areas where there are ectoparasites, such as the Rhipicephalus sanguineus tick.
Its presence raised the hypothesis that this could be a vector of the parasite. The aim of
this work was to propose an in vitro model to study the interaction between Leishmania
spp. and Ixodid ticks, using the cell line from the Ixodes scapularis tick (IDE8). For this
analysis, IDE8 tick cells were incubated with L. amazonensis or L. infantum
promastigotes during: 2, 24 and 48 h at 34 ° C. The results showed that promastigotes
bind, interact with the tick cell membrane, are endocytosed, and remain within a
juxtaposed vacuole, as shown by transmission and scanning electron microscopy. The
association index between IDE8 and L. amazonensis did not change, but between IDE8
and L. infantum it increased approximately 7 times up to 48 h. Viability assay through
LDH activity demonstrated that IDE8 tick cell remain viable during infection with
parasites. Furthermore, L. infantum showed a survival 13 times higher than L.
amazonensis after interaction with IDE8. IDE8 tick cells infected with L. infantum also
showed a 2-fold increase in ROS production and an 8-fold increase in oxysterol
production. The lipids triacylglycerol, 1,2 and 1,3 diacylglycerols, monoacylglycerol and
esterified cholesterol, derived from fatty acids, also showed an increase after the
interaction. Therefore, our data indicate that Leishmania spp. are able to interact with
tick cells in vitro, survive, and modulate metabolic reactions in tick cells.

BANKING MEMBERS:
Presidente - 1545840 - LUCIA HELENA PINTO DA SILVA
Interno - 475.018.557-49 - ADIVALDO HENRIQUE DA FONSECA - UFRRJ
Interna - 1792175 - PATRICIA FAMPA NEGREIROS LIMA
Externa à Instituição - DANIELE PEREIRA DE CASTRO - FIOCRUZ
Externa à Instituição - EVELIZE FOLLY DAS CHAGAS - UFF