Table 1.
(i) Absent or barely detectable expression of MHC class I. | |
(ii) Hair follicular melanocytes of the human anagen scalp are MHC class I-negative. | |
(iii) Downregulation of the MHC class I pathway-related molecules β2-microglobulin and transportation of antigen processing-2 (TAP-2). | |
(iv) Downregulation of interferon regulatory factor-1 expression. | |
(v) Upregulation of immunosuppressive factors such as TGF-β1 and TGF-β2, ACTH, and α-MSH. | |
(vi) Absence of MHC class II+ or NLDC-145+ Langerhans cells. | |
(vii) Sparse distribution of NK cells and CD4+ and CD8+ T cells. | |
(viii) Absence of lymphatics. |