Blastocystis hominis: evidence for caspase-3-like activity in cells undergoing programmed cell death
Related Experiment Video
Updated: Oct 5, 2026

Evaluation of Caspase Activation to Assess Innate Immune Cell Death
Published on: January 20, 2023
A M Nasirudeen1, M Singh, E H Yap
1Department of Microbiology, Faculty of Medicine, National University of Singapore, Singapore.
Abstract:
We have shown previously that the human intestinal protozoan, Blastocystis hominis, undergoes apoptosis-like programmed cell death (PCD) when exposed to a cytotoxic monoclonal antibody (mAb), 1D5. In the present study, ELISA and immunoblot assays employing chicken anti-CPP32 antibody suggest that caspase-3-like antigens exist in B. hominis. Using colorimetric and flow cytometric assays for caspase-3 activity, we also observed an increase in activity between 1 h and 6 h after exposure to mAb 1D5, with greatest activity at 6 h. These findings suggest that caspase-3-like proteases play an important role in B. hominis undergoing PCD, similar to the phenomenon in higher eukaryotic organisms.
Related Concept Videos
Caspases
Cellular Injury V: Apoptosis and Autophagy
Overview of Cell Death
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the 20th century...
Autophagic Cell Death
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
Apoptosis
The Extrinsic Apoptotic Pathway

