-The in situ distribution of NK cells in rat liver during the first 28 days of an experimental infection with F. hepatica was investigated. NK cells were distributed homogeneously throughout the hepatic parenchyma in uninfected animals. The total number of hepatic mononuclear cells increased significantly following infection, but the proportion of NK cells did not change. After infection, these cells were found around the portal space, around the centrolobular vein, in the periportal fibrosis and in the band of collagen. However, no NK cells could be detected in or around the granuloma during infection. The frequency of both IL-2-and IFNÎł -producing NK cells was higher on day 7 postinfection (pi) but only the percentage of IFNÎł + CD161 + subsets remained elevated thereafter, whereas the percentage of both IL-2 + CD161 + and IL-4 + CD161 + subsets returned to the baseline. The number of CD161 + IL10 + cells did not change significantly. These results suggest that NK cells could be another source for the early production of IFNÎł but provide no evidence that these cells are involved in early events associated with granuloma formation.
Fasciola hepatica / NK cells / cytokine / flow cytometry / immunohistochemistryRĂ©sumĂ© -Ăvaluation de la rĂ©ponse des cellules NK hĂ©patiques pendant la phase prĂ©coce d'infestation par Fasciola hepatica chez le rat. Nous avons suivi la localisation et la distribution hĂ©patique des cellules NK durant les 28 premiers jours d'une fasciolose expĂ©rimentale chez le rat. Chez les animaux non infestĂ©s, les cellules NK sont distribuĂ©es de façon homogĂšne dans tout le foie. Chez les animaux infestĂ©s, ces cellules sont localisĂ©es prĂ©fĂ©rentiellement au niveau des espaces portes, autour des veines centrolobulaires, dans les bandes de collagĂšne et dans la zone de fibrose pĂ©ri-portale. En revanche, aucune de ces cellules n'a Ă©tĂ© dĂ©tectĂ©e ni autour ni au sein du granulome. Le