Interferon-inducible protein 10, monokine induced by interferon gamma, and interferon-inducible T-cell alpha chemoattractant are produced by thymic epithelial cells and attract T-cell receptor (TCR) αβ+CD8+ single-positive T cells, TCRγδ+ T cells, and natural killer–type cells in human thymus

Abstract

Strong reactivity for interferon-inducible protein 10 (IP-10), monokine induced by interferon gamma (Mig), and interferon-inducible T-cell alpha chemoattractant (I-TAC) was found in epithelial cells mainly localized to the medulla of postnatal human thymus. The CXC chemokine receptor common to the 3 chemokines (CXCR3) was also preferentially expressed in medullary areas of the same thymuses and appeared to be a property of 4 distinct populations: CD3⁺T-cell receptor (TCR) αβ⁺CD8⁺ single-positive (SP) T cells, TCRγδ⁺ T cells, natural killer (NK)–type cells, and a small subset of CD3^+(low)CD4⁺CD8⁺TCRαβ⁺double-positive (DP) T cells. IP-10, Mig, and I-TAC showed chemoattractant activity for TCRαβ⁺CD8⁺ SP T cells, TCRγδ⁺ T cells, and NK-type cells, suggesting their role in the migration of different subsets of mature thymocytes during human thymus lymphopoiesis.