Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Parasite co-evolution alongside the mammalian immune system gave rise to several modulatory strategies by which they prevent exaggerated pathology and facilitate a longer worm survival. As little is known about the immunoregulatory potential of the zoonotic canine parasites <jats:italic>Ancylostoma caninum</jats:italic> and <jats:italic>Toxocara canis</jats:italic> in the natural host, the present study aimed to investigate whether their larval excretory-secretory (ES) products can modulate the canine immune system. We demonstrated TcES to increase the frequency of CD4+ Foxp3<jats:sup>high</jats:sup> T cells, while both AcES and TcES were associated with elevated Helios expression in Foxp3<jats:sup>high</jats:sup> lymphocytes. ES products were further capable of inducing IL-10 production by lymphocytes, which was mainly attributed to CD8+ T cells. ES treatment of PBMCs prior to mitogen stimulation inhibited polyclonal proliferation of CD4+ and CD8+ T cells. Moreover, monocyte-derived ES-pulsed dendritic cells reduced upregulation of MHC-II and CD80 in response to lipopolysaccharide. The data showed that regulation of the canine immune system by <jats:italic>A. caninum</jats:italic> and <jats:italic>T. canis</jats:italic> larvae comprises the modification of antigen-specific and polyclonal T cell responses and dendritic cell maturation.</jats:p>