Molecular cloning of bovine chemokine receptors and expression by WC1 +γδ T cells

Chemokine receptors mediate leukocyte migration into secondary lymphoid tissues and localization to peripheral inflammation sites. We describe full-length cDNA sequences of bovine chemokine receptors CCR5, CCR7, CXCR3 and CXCR5 and transcript expression by WCl+ gamma delta T cells, a unique cell population with proinflammatory characteristics that comprises a large proportion of mononuclear cells in young ruminants. Bovine chemokine sequences were more similar to those of humans than were murine sequences to humans, ranging from 84% to 91%. Transcript analysis showed that antigen stimulation of WCl+ gamma delta T cells induced IFN-gamma production and substantially increased CCR5 and CXCR3 expression when compared with freshly isolated (ex vivo) cells. CCR7 transcripts were minimally expressed in ex vivo and proliferating WCl+ gamma delta T cells and CXCR5 expression was negligible. These results confirm the proinflammatory nature of WCl+ gamma delta T cells is reflected by its chemokine receptor expression and suggest WCl+ gamma delta T cells are unlikely to transit through secondary lymphoid tissues. (c) 2006 Elsevier Ltd. All rights reserved.