The Journal of Medical Microbiology, Vol 36, Issue 1 41-45, Copyright © 1992 by Society for General Microbiology
Immunochemical characterisation of a 29-Kda surface-associated molecule of Entamoeba histolytica and its recognition by serum from patients with amoebiasis
R. K. Shandil and V. K. Vinayak
Department of Experimental Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
A 29-Kda cytotoxic molecule of axenically-grown pathogenic Entamoeba
histolytica (strain HM1) was purified from an amoebic extract by
immuno-affinity chromatography with monoclonal antibodies. Immunoreactivity
of the purified 29-Kda molecule altered significantly (p less than 0.01)
after exposure to heat or trypsin, but remained unaltered after treatment
with sodium metaperiodate. The 29-Kda molecule was recognised by serum from
each of 13 patients with amoebic liver abscess. In an ELISA system, the
molecule produced significantly higher (p less than 0.01) OD readings with
these serum samples than with samples from asymptomatic cyst passers. No
serum from healthy subjects or from patients with idiopathic ulcerative
colitis or giardiasis had antibodies that reacted with the 29-Kda molecule.
The immune response to the 29-Kda amoebic protein in man may indicate a
specific role for this molecule in invasive amoebiasis.
