Abstract: Newcastle Disease Virus (NDV), an avian
paramyxovirus, is a highly contagious, generalised virus disease of
domestic poultry and wild birds characterized by gastro-intestinal,
respiratory and nervous signs. In this study, it was shown that NDV
strain AF2240 and V4-UPM are cytolytic to Human Promyelocytic
Leukemia, HL60 and Human T-lymphoblastic Leukemia, CEM-SS
cells. Results from MTT cytolytic assay showed that CD50 for NDV
AF2240 against HL60 was 130 HAU and NDV V4-UPM against
HL60 and CEM-SS were 110.6 and 150.9 HAU respectively.
Besides, both strains were found to inhibit the proliferation of cells in
a dose dependent manner. The mode of cell death either by apoptosis
or necrosis was further analyzed using acridine orange and propidium
iodide (AO/PI) staining. Our results showed that both NDV strains
induced primarily apoptosis in treated cells at CD50 concentration. In
conclusion, both NDV strains caused cytolytic effects primarily via
apoptosis in leukemia cells.