Antibody Response to Tapeworm (Hymenolepis diminuta) in the Rat

Abstract

Hymenolepis diminuta, an unarmed, non-invasive tapeworm of the small intestine, is classically regarded as being non-immunogenic in the rat¹. In this host, no pathology is seen², no protective response is stimulated¹, and the host-parasite system appears to be maintained in equilibrium. Hopkins et al.³ suggested that transmucosal antigen transport may occur in such host-parasite systems, and produced evidence⁴ that the rejection of H. diminuta in mice is mediated immunologically. Here we present direct evidence of an antibody response to a parasite with no invasive phase, producing no pathology, and living in equilibrium in an environment which may be considered as entirely external to host tissue. This model may find application in the wider field of transmucosal antigen transport and presentation, for example as in food and pollen allergies, as well as serving to illustrate the distinction between the production of an immune response and the development of protective immunity in host-parasite systems.