P-233

A precise analysis of C5a inhibitory peptide on inflammatory mediators induced after islet transplantation

W. Nakanishi¹, M. Goto², A. Inagaki², S. Sekiguchi¹, K. Fujimori¹, N. Okada³, H. Okada⁴, S. Satomi^1
1 Tohoku University, Division of Advanced Surgical Science and Technology, Sendai, Japan; ² Tohoku University, New Industry Creation Hatchery Center , Sendai, Japan; ³ Nagoya City University, Division of Immunology, Nagoya, Japan; ⁴ Fukushimura Hospital, Choju medical Institute , Toyohashi, Japan

Objective: We have recently reported that C5a inhibitory peptide (C5aIP) prevents the instant blood-mediated inflammatory reaction by attenuating cross-talk between complement and coagulation cascade, thus could be a promising drug candidate (Transplantation:1358-1365:2010). C5aIP has also been shown to possess broad range of anti-inflammatory effects. Due to a methodological limitation, it was difficult to perform detailed analyses on wide range of inflammatory mediators in rat model. Therefore, in this study, we examined whether C5aIP could suppress various inflammatory cytokines induced after islet transplantation using mouse model.

Methods: Six islet equivalents/g of syngeneic mouse islet grafts were transplanted intraportally into two groups (Control group: n=8 and C5aIP group: n=6) of streptozotocin-induced diabetic mice. C5aIP group was treated with C5aIP (bolus: 4mg/kg just after islet infusion, continuous: 0.4mg/kg/hr). The control group was injected with equivalent amounts of saline. Serum samples were collected at 0, 6, and 24 hours after transplantation and analyses on 23 types of cytokines (IL-1a,1b,3,4,5,6,9,10,12,13,17,eotaxin, G-CSF, GM-CSF,INFgamma, KC, MCP-1, MIP-1, MIP-1b, RANTES, TNFalfa) were performed. Leukocytes in the recipient liver were isolated at 6 hs after transplantation, and production of IFN gamma was examined by FACS.

Results: No significant difference was detected in terms of major inflammatory cytokines in two groups. IFN gamma production on CD11b+Gr-1+cells in the liver was not significantly inhibited by C5aIP (Control 30.0% vs. C5aIP 24.1%).

Conclusions: These data suggest that beneficial effects of C5aIP on islet engraftment are mainly dependent on the blockade of cross-talk between complement and coagulation cascades, rather than the suppression of inflammatory mediators.

P-233

A precise analysis of C5a inhibitory peptide on inflammatory mediators induced after islet transplantation

W. Nakanishi¹, M. Goto², A. Inagaki², S. Sekiguchi¹, K. Fujimori¹, N. Okada³, H. Okada⁴, S. Satomi^1
1 Tohoku University, Division of Advanced Surgical Science and Technology, Sendai, Japan; ² Tohoku University, New Industry Creation Hatchery Center , Sendai, Japan; ³ Nagoya City University, Division of Immunology, Nagoya, Japan; ⁴ Fukushimura Hospital, Choju medical Institute , Toyohashi, Japan

Objective: We have recently reported that C5a inhibitory peptide (C5aIP) prevents the instant blood-mediated inflammatory reaction by attenuating cross-talk between complement and coagulation cascade, thus could be a promising drug candidate (Transplantation:1358-1365:2010). C5aIP has also been shown to possess broad range of anti-inflammatory effects. Due to a methodological limitation, it was difficult to perform detailed analyses on wide range of inflammatory mediators in rat model. Therefore, in this study, we examined whether C5aIP could suppress various inflammatory cytokines induced after islet transplantation using mouse model.

Methods: Six islet equivalents/g of syngeneic mouse islet grafts were transplanted intraportally into two groups (Control group: n=8 and C5aIP group: n=6) of streptozotocin-induced diabetic mice. C5aIP group was treated with C5aIP (bolus: 4mg/kg just after islet infusion, continuous: 0.4mg/kg/hr). The control group was injected with equivalent amounts of saline. Serum samples were collected at 0, 6, and 24 hours after transplantation and analyses on 23 types of cytokines (IL-1a,1b,3,4,5,6,9,10,12,13,17,eotaxin, G-CSF, GM-CSF,INFgamma, KC, MCP-1, MIP-1, MIP-1b, RANTES, TNFalfa) were performed. Leukocytes in the recipient liver were isolated at 6 hs after transplantation, and production of IFN gamma was examined by FACS.

Results: No significant difference was detected in terms of major inflammatory cytokines in two groups. IFN gamma production on CD11b+Gr-1+cells in the liver was not significantly inhibited by C5aIP (Control 30.0% vs. C5aIP 24.1%).

Conclusions: These data suggest that beneficial effects of C5aIP on islet engraftment are mainly dependent on the blockade of cross-talk between complement and coagulation cascades, rather than the suppression of inflammatory mediators.