HTLV-1 Tax-induced CCL22 promotes cell-cell interactions between HTLV-1-infected cells and peripheral blood CCR4+CD4+ T cells [通常講演]
稗島 州雄; 長久保 大輔; 中山 隆志; 白川 愛子; 義江 修
The 13th International Conference on Human Retrovirology; HTLV and Related Viruses 2007年05月 Hakone The 13th International Conference on Human Retrovirology; HTLV and Related Viruses
Most Tax+ HTLV-1+ T cell lines produced large amounts of CCL22 in their culture supernatants. Transient Tax expression also expressed CCL22. siRNA-induced knockdown of Tax resulted in a significant reduction of CCL22 mRNA in Tax+ cells. These results indicated CCL22 is one of the target genes of Tax. By using PBMCs from healthy donors in chemotaxis assays, it was demonstrated that culture supernatants of Tax+ cells strongly mobilized CCR4+CD4+ T cells. The migration was blocked by pretreatment of the supernatants with anti-CCL22 neutralizing antibody or pretreatment of the PBMCs with a CCR4-specific inhibitor. Further, Tax+ cells showed significant CCR4-dependent cell-cell interactions with the sorted CCR4+CD4+ T cells. These results imply that HTLV-1+ T cells, which were vertically transmitted from the breast milk of a carrier mother, produced CCL22 upon expression of Tax and preferentially recruited CCR4+CD4+ T cells in the child.