Survey of chemokine receptor expression reveals frequent co-expression of skin-homing CCR4 and CCR10 in adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATLL) is a malignancy of mature T-cell origin with multi-organ involvement. Because the chemokine receptors play crucial roles in tissue-specific homing of mature lymphocytes, particular chemokine receptors expressed on ATLL cells may be involved in their tissue infiltration. We thus performed a comprehensive survey on the chemokine receptor expression in ATLL. ATLL cells expressed transcripts of CCR1, CCR4, CCR7, CCR8, CCR10 and CXCR4 but hardly expressed those of CCR2, CCR3, CCR5, CCR6, CCR9, CXCR1, CXCR2, CXCR3 and CXCR5. These results were confirmed at the protein level by flow cytometric analysis. Notably, patients who have skin lesions showed significantly higher levels of CCR10 mRNA expression than patients without skin lesions. ATLL cells migrated efficiently to the CCR4 ligand, CCL22, and moderately to the CCR10 ligands, CCL27 and CCL28. Moreover, ATLL skin lesions consistently contained transcripts of CCR10 and its ligands CCL27 and CCL28 besides those of CCR4 and its ligands CCL17 and CCL22 that have been reported previously. Collectively, the frequent co-expression of CCR4 and CCR10, the known pair of skin-homing chemokine receptors, may play an important role in ATLL invasion into the skin.