Human T-cell leukemia virus type 1 (HTLV-1) infection and the chemokine system

Human T-cell leukemia virus type 1 (HTLV-1) is a human retrovirus that causes adult T-cell leukemia (ATL). ATL is a malignancy of mature CD4^＋ T cells with poor prognosis. HTLV-1 genome encodes a potent transcriptional regulator, namely, Tax, which plays a critical role in CD4^＋ T-cell transformation. However, Tax exerts its action only in the initial phase of ATL tumorigenesis because it is usually not detectable in ATL cells. A prominent role of the chemokine system is the regulation of leukocyte trafficking, including CD4^＋ T-cell. Here, we briefly summarize HTLV -1 infection and ATL and discuss the recent findings of the involvement of the chemokine system in HTLV-1 infection and ATL tumorigenesis