While absence of perforin prevented the splenic atrophy in IFNγ-deficient mice, fibrosis did not disappear. Moreover,

double-deficient mice developed extreme splenomegaly, were unable to control the viral load and displayed chronic immune activation. Thus, IFNγ and perforin act in concert to minimize pathology and control the viral load in mice chronically infected with MHV68. Furthermore, while certain aspect of the virus-induced pathology in IFNγ-deficient mice may be alleviated in double-deficient mice, other aspects are exaggerated, and the normal architecture of the spleen is completely destroyed. We believe that these findings add to the understanding of the virus/host interaction during chronic gammaherpes virus infection. “
“Using ELISA, we have quantified the levels of IL-2 and IFN-γ in the oral mucosa, MK2206 ear skin and regional and distant lymph nodes in an experimental murine model of contact sensitivity (CS), induced by the hapten oxazolone (OXA). Compared to normal conditions, the levels of IL-2

peaked early (4–6 h) after hapten exposure Daporinad nmr in the hapten-exposed tissues analysed both during the first hapten exposure (sensitization) and the second (elicitation) phase, thereafter quickly to subside. The oral mucosa displayed maximal 24-fold increase in IL-2 levels after sensitization and 39-fold increase after elicitation. Respective figures for ear skin were ×27 and ×35 and for regional lymph nodes Bumetanide ×8 and ×9, respectively. The distant lymph nodes displayed only minor cytokine increases at any time. IFN-γ-levels did not increase after sensitization with OXA. An increase in IFN-γ was seen after the second exposure, peaking at 8–24 h, thereafter quickly subsiding. The oral mucosa IFN-γ increased ×14 after elicitation, the ear skin ×8 and regional lymph nodes ×37. The weight of the four

regional lymph nodes increased from 10 to 38 mg, and the total number of cells in these lymph nodes was increased ×11, peaking 48 h after the elicitation. We conclude that in CS reactions, tissue levels of IL-2 increased in buccal mucosa, ear skin and in regional lymph nodes after hapten exposure and re-exposure, IFN-γ appeared only after re-exposure to the hapten. The increased weight of the regional lymph nodes was mainly attributed to cell proliferation. The common ectodermal origin and the similarity of the CS reactions on skin and in buccal mucosa indicate that these tissues share common immunological patterns of Th1 cell reactivity, at least in dealing with haptens like OXA. Being the initial part of the digestive tract, the oral mucosa is exposed to a vast array of foreign molecules. The B-cell side of the immune defence produces secretory IgA into the oral cavity like into the rest of the intestinal canal [1]. Concerning the T-cell defence, two opposed theories exist as to its nature.