[Modulation of inflammatory cells in helminth infections]

In this review, different mechanisms by which helminthic parasites modulate the activities of inflammatory cells are considered. Examples are presented of parasitic products interfering with lymphocytes and their products such as antibodies, then modifying both regulation and effector response of the immune system. Furthermore, examples of interference on the complement system are illustrated. Parasites such as Ancylostoma caninum produce factors such as the neutrophil inhibitory factor (NIF) capable of inhibiting the neutrophil-endothelium adhesion, whereas Trichinella spiralis produces a glycoprotein, the 45gp, which inhibits different neutrophil functions. Parasites are also able to modulate the function of the monocytes-macrophages which in some infections play a crucial role; the modulation of NO synthesis is also relevant to the host-parasite relationship. Finally, the different anti-oxidant systems of helminthic parasites are described. The comprehension of such evasion mechanisms of the immune response is necessary to develop vaccines and new drugs, but it is also useful to clarify the contribution of parasites to immune system evolution.