Therapy with nonglycosaminoglycan-binding mutant CCL7: a novel strategy to limit allograft inflammation.
Chemokines are immobilized by binding to glycosaminoglycans (GAGs). A non-GAG-binding mutant CCL7 (mtCCL7) was developed that retained its affinity for chemokine receptors. This mtCCL7 induced leukocyte chemotaxis in diffusion gradients but did not stimulate trans-endothelial migration (p<0.01). Unlike wild-type CCL7, mtCCL7 persisted in the circulation of BALB/c mice for more than 6 h and prevented leukocyte infiltration of skin isografts (p<0.05). Treatment with mtCCL7 marginally increased the survival of C57BL/6 to BALB/c skin allografts and reduced graft infiltration by CD3+ cells (p<0.05). Importantly, mtCCL7 promoted long-term (>40 day) graft survival following minor histocompatibility (HY) antigen mismatched C57BL/6 skin transplantation; control grafts were rejected by day 24. Treatment with mtCCL7 produced a significant decrease in the frequency of IFN-gamma producing donor-reactive splenic T cells, reduced CCR2 expression by circulating leukocytes for 6 h (p<0.01) and blocked the normal increase in affinity of alpha4beta1 integrins for VCAM-1 following transient chemokine stimulation. These data suggest that mtCCL7 persists in the circulation and reduces both specific T-cell priming and the capacity of circulating immune cells to respond to GAG-bound chemokine at sites of developing inflammation.
Ali
S
S
Applied Immunobiology and Transplantation Group, Institute of Cellular Medicine, Medical School, University of Newcastle Upon Tyne, NE2 4HH, UK. simi.ali@newcastle.ac.uk
O'Boyle
G
G
Hepplewhite
P
P
Tyler
J R
JR
Robertson
H
H
Kirby
J A
JA
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D054410:Chemokine CCL7 / Q000235:genetics* / Q000378:metabolism / Q000627:therapeutic use*; D002634:Chemotaxis, Leukocyte / Q000187:drug effects / Q000276:immunology; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism; D006085:Graft Survival / Q000187:drug effects / Q000276:immunology; D006182:H-Y Antigen / Q000008:administration & dosage; D066298:In Vitro Techniques; D007249:Inflammation / Q000276:immunology / Q000473:pathology / Q000517:prevention & control; D016023:Integrins / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016297:Mutagenesis, Site-Directed; D019707:Receptors, Chemokine / Q000187:drug effects; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use; D016038:Skin Transplantation / Q000276:immunology* / Q000473:pathology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D014184:Transplantation, Homologous
C515451:Ccl7 protein, mouse; D054410:Chemokine CCL7; D006025:Glycosaminoglycans; D006182:H-Y Antigen; D016023:Integrins; D019707:Receptors, Chemokine; D011994:Recombinant Proteins