Toxocara canis excretion-secretion antigen (TES) action on cellular line Neuro-2a

ECHENIQUE CLAUDIA; BANCHIO CLAUDIA; MAGARO HORTENSIA

Rosario

Congreso; SAIB; 2006

Toxocara canis, a dog roundworm, produces Visceral Larva Migrans (VLM), Ocular Larva Migrans and Covert Toxocarosis in paratenic host as a man. The commitment of the Central Nervous System (CNS) has been described as a VLM manifestation. In previous studies, we found T. canis larvae  in CNS by  PCR and brain maceration. The parasite produces the antigen of excretion-secretion (TES), that is, a set of glycoproteins and secreted enzymes  like superoxide dismutase. TES is able to induce oxidative stress in hepatocytes and macrophages. The aim of this work was to study the action of TES on Neuro-2a. Nitric oxide (NO) levels were measured by Griess reagent in the supernatant of cell cultures. Reactive oxygen species (ROS) were determined by measuring cell fluorescence with DFCH-DA. Neuron viability was evaluated by MTT method, reading the formed formazan salts at 540 nm. The hightest NO level, 14µM nitrite±0.05/mg of protein was observed in neurons tried with 40 µg/ml of TES. ROS was 12000±584 IF/mg protein in cultures tried with 100 µg/ml with regard to the value obtained without TES. It was observed a decrease (40%) in cell viability respect the one observed in cell control, p<0.01. These in vitro cell injuries, based on NO and ROS generation, could act in vivo, amplificating protein, DNA and lipids injuries and eventually could induce necrosis or apoptosis, that is, cell death.