Differences in CCR5 expression on peripheral blood CD4⁺CD28^- T-cells and in granulomatous lesions between localized and generalized Wegener's granulomatosis

Wegener's granulomatosis (WG) is an autoimmune disease characterized by granulomatous lesions and a necrotizing vasculitis. Th1-type-cells lacking CD28 are expanded independent of age and immunosuppressive therapy in WG. To address their migratory properties of CD4⁺CD28^- T-cells we studied the expression of the inducible inflammatory Th1-type chemokine receptor CCR5 in localized WG and generalized WG. Expansion of CD4⁺CD28^- T-cells was more prominent in generalized WG compared to localized WG. In localized WG a larger fraction of CD4⁺CD28^- T-cells displayed CCR5 expression compared to generalized WG. CCR5 expression was also higher in granulomatous lesions in localized WG. Higher levels of CCR5 expression on CD4⁺CD28^- T-cells in localized WG may favor stronger CCR5-mediated recruitment of this T-cell subset into granulomatous lesions in localized WG. Expansion of Th-1-type CD4⁺CD28^-CCR5⁺ effector memory T-cells might contribute to disease progression and autoreactivity, either directly, by maintaining the inflammatory response, or as a result of bystander activation.