Regulation of the Immune Response in Cysticercosis: Lessons from an Old Acquainted Infection

Abstract

In the last decades, we have learned some critical lessons about the relationship between the human body and its interaction with many infectious diseases, where regularly, the immune system has a major role in protection. We learned to differentiate between the immune response occurring in either an intracellular or extracellular parasitic infection, between innate and adaptive immune response, between either inflammatory or anti-inflammatory responses, and finally, we learned to recognize very particular mechanisms, such as the inability of the immune system to respond during very particular scenarios, such as the inability of T cells to both proliferate and produce cytokines even after their exposure to mitogens or specific-antigens. Along with our increase in the knowledge in immunology, we figured out that immunoregulation and immunosuppression are processes used by many parasites to reduce the capacity of the immune system to eliminate them, and to persist in the host favoring their transmission and also to complete their life cycles. Immunoregulation involves several mechanisms such as anergy, apoptosis, induction of both suppressive cytokines and membrane-bound molecules, as well as specialized cell populations of the immune system like regulatory T cells, Alternative Activated Macrophages, or Myeloid-derived Suppressor Cells, that together modify the outcome of the immune response. In this chapter we will review the general differences between the different types of immunoregulation, the kind of cellular populations of the immune system used by the helminths Taenia solium and Taenia crassiceps to induce immunoregulation and immunosuppression and also, the mechanisms used by these parasites such as mimicking molecules of the immune system to replace directly these mechanisms. Understanding and deciphering all these regulatory mechanisms could be useful to develop new tools to control this infection.