Peripheral Taenia infection increases immunoglobulins in the central nervous system.

Human cysticercosis is a disease caused by larvae of the cestode Taenia solium. It is an important common cause of adult-onset seizures world-wide where it exacts a debilitating toll on the health and well-being of affected communities. It is commonly assumed that the major symptoms associated with cysticercosis are a result of the direct presence of larvae in the brain. As a result, the possible effects of peripherally located larvae on the central nervous system are not well understood. To address this question, we utilised the Taenia crassiceps intra-peritoneal murine model of cysticercosis, where larvae are restricted to the peritoneal cavity. In this model, previous research has observed behavioural changes in rodents but not the development of seizures. Here we used ELISAs, immunoblotting and the Evans Blue test for blood-brain barrier permeability to explore the central effects of peripheral infection of mice with T. crassiceps. We identified high levels of parasite-targeting immunoglobulins in the sera of T. crassiceps-infected mice. We show that the T. crassciceps larvae themselves also contain and release host immunoglobulins over time. Additionally, we describe, for the first known time, significantly increased levels of IgG within the hippocampi of infected mice, which are accompanied by changes in blood-brain barrier permeability. However, these T. crassiceps-induced changes were not accompanied by alterations to the levels of proinflammatory, pro-seizure cytokines in the hippocampus. These findings contribute to the understanding of systemic and neuroimmune responses in the T. crassiceps model of cysticercosis, with implications for the pathogenesis of human cysticercosis.