The Functional Relevance of the Type 1 Cytokines IFN-γ and IL-2 in Alopecia Areata of C3H/HeJ Mice

The study investigated the involvement of type 1 cytokines IFN-γ and IL-2 in alopecia areata (AA) using C3H/HeJ mice. Results showed that IFN-γ knockout mice were completely resistant to AA, as evidenced by the lack of perifollicular lymphocytic infiltrate and reduced T cell activation markers, while IL-2 heterozygous mice had a significantly lower incidence of AA, with only 47% developing the condition compared to 90% of normal mice. This resistance was linked to decreased T cell activation and fewer perifollicular CD4+ and CD8+ cell infiltrates. The study concluded that IFN-γ and IL-2 play a crucial role in T cell activation in AA pathogenesis, with IFN-γ being particularly significant. Immunohistochemistry and FACS analysis were used to support these findings.