Combined treatment with chemokine receptor 5 blocker and cyclosporine induces prolonged graft survival in a mouse model of cardiac transplantation.
BACKGROUND
Inhibition of chemokine receptor 5 (CCR5), a chemokine receptor expressed on activated T cells, is efficacious in modulating inflammation and immunity as well as in patients with human immunodeficiency virus infection. This study examined the effect and mechanism of CCR5 blockade in combination with cyclosporine in prolonging cardiac allograft survival in mice.


METHODS
Hearts from BALB/c mice were transplanted into C57BL/10 recipients. They were administrated with anti-CCR5 antibody (Ab) or control Ab and cyclosporine or phosphate-buffered (PBS) saline, respectively. To investigate the role of regulatory cells, naïve mice (secondary recipients) underwent adoptive transfer of splenocytes from anti-CCR5 Ab plus cyclosporine-treated recipients and cardiac allograft transplantation.


RESULTS
Compared with recipients treated with control Ab plus PBS, allografts treated with anti-CCR5 Ab and cyclosporine showed significantly prolonged survival (p < 0.001), markedly decreased CD4+ and CD8+ T cells (p < 0.005), and increased frequency of CD4+CD25+Foxp3+ regulatory cells (23.98% +/- 1.55% vs 6.30% +/- 0.57%, p < 0.005). Adoptive transfer of CD4+CD25+ splenocytes from anti-CCR5 Ab plus cyclosporine-treated recipients induced significantly prolonged survival in secondary recipients (p < 0.01 vs adoptive transfer from naïve mice and recipients depleted of CD25+ cells).


CONCLUSIONS
CCR5 blockade combined with cyclosporine is effective in protecting the cardiac allograft in a robust murine model. This effect is partly mediated by regulatory cell recruitment and control of effector cell infiltration.
Jun
Li
L
Department of Cardiovascular Surgery, Union Hospital, Tongji Hospital, Tongji Medical College, Huazhong Science and Technology University, Wuhan, China.
Kailun
Zhang
Z
Aini
Xie
X
Lei
Xu
X
Guohua
Wang
W
Sihua
Wang
W
Ping
Ye
Y
Tucheng
Sun
S
Xionggang
Jiang
J
Wenwei
Chen
C
Jiahong
Xia
X
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology*; D065100:CCR5 Receptor Antagonists; D015704:CD4 Antigens / Q000378:metabolism; D016572:Cyclosporine / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006085:Graft Survival / Q000187:drug effects*; D016027:Heart Transplantation / Q000379:methods* / Q000473:pathology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D019713:Receptors, CCR5 / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism / Q000473:pathology; D014184:Transplantation, Homologous
D000888:Antibodies, Anti-Idiotypic; D065100:CCR5 Receptor Antagonists; D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D007166:Immunosuppressive Agents; D053645:Interleukin-2 Receptor alpha Subunit; D019713:Receptors, CCR5; D016572:Cyclosporine