title: Chemokine receptor Ccr5 deficiency induces alternative macrophage activation and improves long-term renal allograft outcome.
abstract: The chemokine (C-C motif) receptor 5 (CCR5) has been implicated in experimental and clinical allograft rejection. To dissect the function of CCR5 in acute and chronic renal allograft rejection, bilaterally nephrectomized WT and Ccr5-/- C57BL/6 mice were used as recipients of WT BALB/c renal allografts and analyzed 7 and 42 days after transplantation. Lesion scores (glomerular damage, vascular rejection, tubulointerstitial inflammation) and numbers of CD4+, CD8+, CD11c+ and alpha smooth muscle actin (alphaSMA)+ cells were reduced in allografts from Ccr5-/- recipients during the chronic phase. Increasing creatinine levels indicated deterioration of allograft function over time. While mRNA expression of Th1-associated markers decreased between 7 and 42 days, Th2-associated markers increased. Markers for alternatively activated macrophages (arginase 1, chitinase 3-like 3, resistin-like alpha, mannose receptor, C type 1), were strongly upregulated (mRNA and/or protein level) only in allografts from Ccr5-/- recipients at 42 days. Ccr5 deficiency shifted intragraft immune responses during the chronic phase towards the Th2 type and led to accumulation of alternatively activated macrophages. Additionally, splenocytes from unchallenged Ccr5-/- mice showed significantly increased arginase 1 and mannose receptor 1 mRNA levels, suggesting constitutive alternative activation of splenic macrophages. We conclude that Ccr5 deficiency favors alternative macrophage activation. This finding may be relevant for other inflammatory diseases that involve macrophage activation and may also influence future therapeutic strategies targeting CCR5.
authors.affiliation: Klinikum der Universität München, Medizinische Poliklinik-Innenstadt, München, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Dehmel
authors.forename: Shijun
authors.initials: S
authors.lastname: Wang
authors.forename: Claudia
authors.initials: C
authors.lastname: Schmidt
authors.forename: Eva
authors.initials: E
authors.lastname: Kiss
authors.forename: Robert P
authors.initials: RP
authors.lastname: Loewe
authors.forename: Silvia
authors.initials: S
authors.lastname: Chilla
authors.forename: Detlef
authors.initials: D
authors.lastname: Schlöndorff
authors.forename: Hermann-Josef
authors.initials: HJ
authors.lastname: Gröne
authors.forename: Bruno
authors.initials: B
authors.lastname: Luckow
mesh_terms: D000818:Animals; D016764:Cell Polarity; D005786:Gene Expression Regulation; D006085:Graft Survival; D007668:Kidney / Q000502:physiology; D016030:Kidney Transplantation / Q000276:immunology*; D008264:Macrophages / Q000166:cytology / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019713:Receptors, CCR5 / Q000172:deficiency / Q000276:immunology*; D013997:Time Factors; D014184:Transplantation, Homologous / Q000276:immunology; D016896:Treatment Outcome
chemical_list: D019713:Receptors, CCR5