Akademik Veri Yönetim Sistemi
BALKAN SUMMIT 4th INTERNATIONAL APPLIED SCIENCES CONGRESS, Edirne, Türkiye, 10 - 11 Nisan 2021, ss.1
Theileria annulata is a protozoan parasite belong to the Apicomplexa phylum. A significant
feature of T. annulata is the abilitiy of the schizont stage to induce host cell transformation
which leads to continuous proliferation of the infected cell and the parasite like cancer cells.
The only and specific drug used against Therileria is BW720C (buparvaquone). Theileria are
exposed to the host cell’s autophagy process. Autophagy is an intracellular catabolic process
by which cells degrade and recycle their own constituents like long lived proteins, organelles
and infectious organisms through a controlled lysosomal mechanism. It is an important process
for cell survival, differentiation, development, growth and death. The signalling pathways to
leading the activation of autophagy are starvation, drug treatments, oxidative stress and
hormonal stimulation. Ta9 is a complex protein harbouring different regions capable of
activating the AP-1 transcription factor which plays a pivotal role in Theileria-induced
leukocyte transformation and secreted into the infected leukocyte cytosol by the parasite. First,
the autophagosome and proteosome function were blocked with using inhibitors and Ta9 levels
were observed in T. annulata infected B cell line. This cell line was starved for nutrients to see
the effect of starvation on autophagy and also the dying parasite was observed using BW720C.
Inhibition of the autophagosome leads to an increase in the levels of Ta9. This strongly suggests
that Ta9 is rapidly degraded by the autophagosome and when Theileria is alive the intracellular
pool of Ta9 rapidly replenished. Proteosome inhibitors slightly induced autophagy in T.
annulata infected B cell line. The equilibrium between Ta9 production by the parasite and its
degradation by digestive organelles determines the overall level of Ta9 protein. Furthermore,
when the parasite is alive it could block the host cell autophagy process, because when the
parasite was killed with BW720C, macroautophagosome formation co-localized with dying
parasites which was shown with autophagic marker. Future studies should be concerned how
autophagy is regulated in T. annulata infected cell line and how autophagy process could be
used for struggle against the parasite.
Keywords: Autophagy, inhibition, starvation, Theileria annulata