Intracerebral inoculation of immunocompetent mice with lymphocytic choriomeningitis virus (LCMV) normally results in fatal CD8+ T cell mediated meningoencephalitis. However, in CXCL10-deficient mice, the virus-induced CD8+ T cell accumulation in the neural parenchyma is impaired, and only 30–50% of the mice succumb to the infection. Similar results are obtained in mice deficient in the matching chemokine receptor, CXCR3. Together, these findings point to a key role for CXCL10 in regulating the severity of the LCMV-induced inflammatory process. For this reason, we now address the mechanisms regulating the expression of CXCL10 in the CNS of LCMV-infected mice. Using mice deficient in type I IFN receptor, type II IFN receptor, or type II IFN, as well as bone marrow chimeras expressing CXCL10 only in resident cells or only in bone marrow-derived cells, we analyzed the up-stream regulation as well as the cellular source of CXCL10. We found that expression of CXCL10 initially depends on signaling through the type I IFN receptor, while late expression and up-regulation requires type II IFN produced by the recruited CD8+ T cells. Throughout the infection, the producers of CXCL10 are exclusively resident cells of the CNS, and astrocytes are the dominant expressors in the neural parenchyma, not microglial cells or recruited bone marrow-derived cell types. These results are consistent with a model suggesting a bidirectional interplay between resident cells of the CNS and the recruited virus-specific T cells with astrocytes as active participants in the local antiviral host response.

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Skin biomarkers for disease severity and treatment response in atopic dermatitis (AD) are needed. Biopsies cause scarring and tape stripping represents an alternative minimally invasive method for stratum corneum sampling. In this study, we examined the gene expression of cytokines in skin biopsies and cytokines in stratum corneum tape strips collected from adults with AD. We collected punch biopsies and tape strips from healthy controls (<i>n</i> = 6) and subjects with AD (<i>n</i> = 12) at baseline and after 2 weeks of topical treatment with mometasone furoate 0.1% cream. We found that IFN-γ, IL-13, and IL-10 mRNA (biopsies) and IL-1β protein expression levels (tape strips) were significantly increased in lesional AD skin compared to healthy control skin. Treatment with topical corticosteroid led to a significant decrease in mRNA levels for IL-13 and IL-4R but no significant differences in cytokine protein levels measured in tape strips. Finally, we found no significant correlations between cytokine levels in tape strips and mRNA levels in skin biopsies.