Control of Giardiasis by IL-17 in Humans and Mice – Are the Questions all Answered?

ABSTRACT

For years, studies of the immune response to Giardia lamblia infection focused on the production of IgA by infected hosts and antigenic variation by the parasite to escape destruction by this IgA. A new study by Hanevik and colleagues (C.S. Sahaug, S. Sornes, D. Peirasmaki, S. Svard, N. Langlenad and K. Hanevik, Human memory CD4+ T cell responses against Giardia lamblia) highlights the emerging role of IL-17 in immunity against this parasite. Along with recent studies of animal infections with Giardia, this work shows that IL-17 appears to be essential for control of this infection and to be a key factor linking cellular and humoral immune responses.