IMMUNE-RESPONSE IMPAIRMENT, GENOTOXICITY AND MORPHOLOGICAL TRANSFORMATION-INDUCED BY TAENIA-SOLIUM METACESTODE

In chronic belminthic infections such as cysticercosis, where the para sites live for years, profound modulation of the host immune response had been reported. To evaluate the genotoxicity of a drug used to trea t cysticercosis, we observed the occurrence of genetic damage in cultu red lymphocytes from cysticercotic swine and patients who had not been exposed to the drug. The human lymphocytes also showed a slower proli feration. These data suggested that the disease itself was promoting g enetic damage in host lymphocytes which, in part, could explain the re tardation of the lymphocyte proliferation observed in cysticercotic pa tients. Pigs infected with Taenia solium cysticerci showed an increase d lymphocyte proliferation 6-8 weeks post infection, followed by an im paired proliferation after this period. Significant induction of siste r-chromatid exchanges was also observed in lymphocytes from infected p igs after the 6th week post infection. Additionally, it was found that a factor secreted by the cysticerci morphologically transformed prima ry fibroblasts in culture. The results strongly suggest that the paras ite produces genetic instability in the host cells, which could result in immunosuppression and malignant transformation of target cells.