Downregulation of semaphorin 4A in keratinocytes reflects the features of non-lesional psoriasis.

Psoriasis is a multifactorial disorder mediated by IL-17-producing T cells, involving immune cells and skin-constituting cells. Semaphorin 4A (Sema4A), an immune semaphorin, is known to take part in T helper type 1/17 differentiation and activation. However, Sema4A is also crucial for maintaining peripheral tissue homeostasis and its involvement in skin remains unknown.

CD69 Is Indispensable for Development of Functional Local Immune Memory in Murine Contact Hypersensitivity.

Local immune memory develops at the site of antigen exposure and facilitates a rapid and strong local adaptive defense upon re-exposure. Resident memory T (T) cells play a role in local immune memory, and their cell-surface molecules CD69 and CD103 promote their tissue residency. However, the contribution of these molecules to skin immune memory remains unclear.

Melanocyte-specific CD49a CD8 T cells in vitiligo lesion potentiate to maintain activity during systemic steroid therapy.

Vitiligo is a common depigmenting skin disease that is often difficult to treat. Even if repigmentation is achieved by treatment, recurrence in the same lesion is often found within a year after stopping treatment. As a background of these issues, a subset of CD8 T cells that recognize melanocyte-specific antigens or CD49a tissue-resident memory T cells that reside in the vitiligo lesion are thought to be involved.

Ganglioside GD3 May Suppress the Functional Activities of Benign Skin T Cells in Cutaneous T-Cell Lymphoma.

In cutaneous T-cell lymphoma (CTCL), which arises from skin-tropic memory T cells, malignant T cells and benign T cells are confined in the same skin lesions. It is thus difficult to evaluate the phenotypic characteristics and functional activities of benign T cells in CTCL. Disialoganglioside with three glycosyl groups (GD3) is increasingly expressed on the surface of solid malignant tumor cells and takes part in tumor progression and suppression of tumor immunity.