Chemokine receptor desensitization in tumor-bearing mice

We found that the murine breast cancer cell line 4T1 constitutively produce d several chemokines capable of recruiting T cells. Additionally, supernata nts from the tumor cell line mediated chemotaxis of T cells in a pertussis toxin-sensitive manner, indicating that these chemokines were functional. H owever, we also found an impaired chemotactic ability of splenic T cells in mice bearing these same tumors. The receptors for RANTES, MCP-1, and SLC w ere desensitized. Thus, the impaired chemotactic ability of T cells in tumo r-bearing mice may explain why tumors that secrete chemokines grow progress ively in a host. (C) 2001 Academic Press.