Differential expression of binding sites for chemokine RANTES on human T lymphocytes

✍ Scribed by Iku Utsunomiya; Kenji Tani; Wanghua Gong; Joost J. Oppenheim; Ji Ming Wang

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 656 KB
• Volume: 27
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830270617

✦ Synopsis

Differential expression of binding sites for chemokine RANTES on human T lymphocytes

The C-C chemokine RANTES, a T lymphocyte chemoattractant, is considered an important mediator of inflammation, allergy, and host defense against HIV-1 infection. In this study, we investigated the modulation of binding of RANTES to T lymphocytes. Human peripheral blood CD3' T cells, when freshly isolated from buffy-coat blood, expressed a considerable number of high-affinity binding sites for RANTES. These cells also showed significant chemotactic migration in response to RANTES in vitro. After 6-15 h incubation at 37°C the binding of RANTES, but not of macrophage inflammatory protein-la (MIP-la) or of monocyte chemotactic protein-3 (MCP-3), consistently increased. Scatchard analyses indicated that the number of binding sites for RANTES increased about threefold by 15 h without any change in the affinity. The increase in RAN-TES binding was no longer detected by 24 h. This increase in the specific binding was mainly attributable to CD4' T cells and was not associated with increased chemotactic activity of these cells in response to RANTES. Incubation with anti-CD3 antibody for 15 h markedly reduced the binding capability of T cells for RANTES and was associated with decreased chemotactic activity. On the other hand, when T cells were incubated with interleukin-2 (IL-2) for 1 week, the specific binding for all three C-C chemokines, RANTES, MIP-la, and MCP-3 was markedly increased in comparison to cells cultured in the absence of IL-2. These results suggest that the expression of binding sites on T cells for RANTES is differentially modulated, indicating the existence of novel receptors for RANTES that do not bind MIP-la.