Localization of the major immunogen and other glycoproteins of the louse Polyplax spinulosa.

A 31-kDa.immunogenic glycoprotein of Polyplax spinulosa was localized on louse sections using indirect immunofluorescence with specific antibodies of louse-infested rats and using fluorescein-labelled lectins. Antibodies of infested rats reacted specifically with midgut epithelium and semi-digested content of the gut. They did not bind to other louse tissues including salivary glands. The lectins concanavalin A and wheat germ agglutinin bound strongly to the immunogen, the gut and its semidigested contents. Electrophoretic and blotting analysis showed the presence of a 31-kDa glycoprotein component reacting with specific rat antibodies, concanavalin A and wheat germ agglutinin in louse faeces. The result indicates that the 31-kDa immunogen is secreted by the midgut epithelium into the gut lumen and faeces. We suggest that rats become immunized by scratching the lice faeces into the skin.