Ascaris lumbricoides: zonal localization of immunoreactive collagen in the cuticle

Monoclonal antibodies that were raised against cuticular components from the free-living nematode Panagrellus silusiae were found to react with a cuticular collagenous domain from Ascaris lumbricoides. One of these monoclonal antibodies was used to localize the collagenous epitope within sectioned Ascaris cuticles. By indirect immunofluorescence, accessible binding sites were observed in the basal zone of the cuticle. Immunological staining occurred in the innermost lamella of the basal zone, i.e., basal lamella, in which the fibrillar palisade gave a strong response. The three layers of the spiral fiber system of the basal zone exhibited a distinctive immunofluorescence pattern. In each of these layers, irregular shaped blocks, often quadrangular, were immunostained; whereas, adjacent blocks were immunonegative. Immunostaining was, for the most part, absent from the cortical and medial zones of the cuticle as well as from other tissues within the worm.