Larval Taenia crassiceps secretes a protein with characteristics of murine interferon-gamma

Previous studies have shown that excretory/secretory products of larval Taenia crassiceps have immunomodulatory activities. We report here that one of these products, termed p66, possesses activities that mimic some characteristics of murine interferon-gamma (IFN-gamma). Purified p66 cross-reacts with anti-murine IFN-gamma on immunoblots and increases concanavalin-A-induced splenic T-cell proliferative responses of normal and chronically infected mice. It has also been shown that p66 induces enhanced IFN-gamma and interleukin-10 (IL-10) production in cells from infected or normal mice. Adherent and non-adherent peritoneal exudates cells were stimulated with p66 and showed that the adherent cells were induced to produce IL-10 and that the non-adherent cells were induced to produce IFN-gamma. p66 was shown as well to upregulate nitric oxide production in macrophages and two T-cell lines, IEL and YAC-1, were shown to be stimulated to produce IFN-gamma and IL-10, respectively, by p66. Although the significance of p66 in immunoregulation is not known, we show here that this molecule mimics characteristics of IFN-gamma.