In this study, hemocytes and fat body changes were investigated after activation the immune
response of the third instar larvae of Sarcophaga argyrostoma by injecting the larvae
with MDA-MB-231cancer cell lines. To investigate the changes in hemolymph and fat body
tissue, light and transmission electron microscopy (TEM) were used. Apoptosis demonstration
in the larval flesh fly after injection was immunohistochemically tracked using a marker
of caspase initiator activity; namely caspase-3 antibody.The results showed remarkable changes
in morphology, viability and the spreading ability of immunocompetent hemocytes and
fat body cells between normal and immunized S. argyrostoma larvae. In hemocytes, multicellular
aggregates were formed to entrap invading cancer cells, in addition to membrane blebbing,
cytoplasm vacuolization, cell and organelle swelling, and chromatin condensation.
Meanwhile, in fat body cells of injected larvae, depletion of lipid droplets, changes in the appearance
of protein granules and degrade of basement membrane overlying the fat body were
observed. These features are typical for apoptotic and autophagal cell death which were confirmed
by detection of apoptotic fat body cells after cancer cell injection using activated
caspase-3 immunostaining.