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Immunohistological studies on an Onchocerca volvulus ankyrin (EI)
Author(s) -
Erttmann K. D.,
Gallin M. Y.,
Eggert P.,
Büttner D. W.
Publication year - 1996
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/j.1365-3156.1996.tb00081.x
Subject(s) - onchocerca volvulus , biology , basal lamina , labelling , anatomy , pathology , microbiology and biotechnology , ultrastructure , immunology , onchocerciasis , medicine , biochemistry
Summary The distribution of an Onchocerca volvulus ankyrin, designated EI, was studied in different O. volvulus stages and other helminths by immunohistochemistry using rabbit antibodies raised against the recombinant EI protein. In adult O. volvulus the protein designated EI was localized to the extracellular clefts as well as to the cytoplasm adjacent to the cell membrane in the area of the basal labyrinth in hypodermis, intestine and uterus and to a lesser extent in oviduct and vas deferens. Neuronal cell bodies were also labelled. No labelling of the basal laminae, muscles or epithelia of ovary or testis was observed. Detection of the Ei protein was associated with embryonic development. Germ cells and early morulae showed no reaction; labelling was first seen in late morulae, corresponding to the stage of gastrulation, and increased in the following embryonic stages. In microfilariae the nerve ring and the cephalic space, which represents the anterior nerve‐enriched portion of the body, were labelled. In third‐stage larvae of O. volvulus labelling was associated with the hypodermis, and in those of Anisakis sp. the cytoplasm adjacent to the membrane of the excretory gland cell and the basal labyrinth of the hypodermis were labelled. Following anthelminthic treatment a disruption of the labelling pattern of the EI protein was observed in adult O. volvulus with leakage of the protein into neighbouring areas. Damage to the worm was associated with reduction and finally loss of EI protein labelling. No EI protein was detected in dead adult worms, embryos or microfilariae. Labelling of the same organs was observed in 8 other Onchocerca species and in several other nematodes, but no reaction was seen in trematodes. The results indicate that the EI protein is associated with neuronal structures of O. volvulus , that its presence is developmentally regulated and that it has cross‐reactive homologues in other nematodes. The results suggest that EI is a functional protein. It may be useful for the assessment of parasite damage and death as well as in the characterization of the filarial nervous system.