Phlogistic and chemotactic activities of alveolar hydatid cyst antigen.

Alveolar hydatid cyst antigen (AHCA) absorbed with Sepharose-coupled anti-mouse Ig or its Sephacryl S-300 fractions was assayed for phlogistic/chemotactic and amyloidogenic properties in C57BL/6J mice. The in vivo and in vitro biological properties of the antigen were assessed by intradermal or intraperitoneal routes in mice or in Boyden chambers, respectively. In both these assays the chemotactic activity of the antigen was found to be dose dependent. A single intradermal injection of the antigen, containing 35 or 70 micrograms protein, showed a peak inflammatory cell response in the dermal layers at 6 hr. Neutrophils were the dominant cellular infiltrates and the number of monocytoid cells, except at 24 hr, remained relatively low. Antigen concentrations ranging from 1 to 200 micrograms protein per Boyden chamber showed peak neutrophilic and monocytoid cell responses with 100 micrograms of the antigen. We therefore conclude that intense inflammatory response and amyloidogenesis in alveolar hydatid cyst-infected murine hosts are directly attributable to the parasite antigen.