Inhibitory effect of neutralizing interleukin-17 antibody on corneal allograft rejection

Abstract

Background Interleukin-17 (IL-17)is a potent pro-inflammatory cytokine and plays a pathogenic role in autoimmune disease.It was confirmed that IL-17 is implicated in allograft rejection of many transplanted organs.Recent studies have foensed on the effect of IL-17 antagonists on allograft rejection.Objective This study aimed to investigate the inhibitory effect of anti-mouse IL-17 monoclonal antibody (mAb) on corneal allograft rejection.Methods Twenty-five 8 to 10-week-old C57BL/6 mice and 50 BALB/c mice were collected.Donor cornea grafts with 2 mm diameter from 25 C57BL/6 mice was transplanted to 50 eye of BALB/c mice to establish a model of corneal transplantation.The recipients were randomized into 2 groups,and neutralizing mouse IL-17antibody or isotype control antibody was intraperitoneally injected immediately after transplantation for experimental treatment,respectively.Allografts were scored clinically at appropriate time points after treatment based on Plskova criteria,and ≥5 was confirmed as rejection.Infiltrating cells in corneal graft were detected qualitatively and quantitatively by immunohistochemistry and reverse transcription-PCR separately.The cytokine levels of T helper type 1 (Th1),Th2,and Th17 in recipients' spleen wer(c) analyzcd by ELISA.The use of the animals followed the Statement of ARVO.Results Compared with the isotype control antibody group,the survival of grafts was improved in the IL-17mAb group(P＜0.05).The levels of neutrophile granulocyte mRNA,CD4+ and CD8+ T lymphotes mRNA were 2.22±0.10,1.64±0.04 and 1.32±0.10 in the IL-17 mAb group,showing a significant decline in comparison with those of the isotype control antibody group(3.61 ±0.08,2.69±0.06 and 2.17±0.04) (P=0.000,0.000,0.000).Interferon-γ(IFN-γ),IL-12 p40 and IL-17 concentrations in recipients ' splenocytes were (529.80 ± 13.83) ng/L,(539.58 ±10.74) ng/L and(173.70±8.11)ng/L in the IL-17 mAb group,and thosc in the isotype control antibody group were (741.48± 10.51) ng/L,(1156.90 ± 69.93) ng/L and (366.13± 7.93) ng/L,with significant differences between them (P=0.000,0.001,0.000).Conclusions Neutralization IL-17 bioactivity inhibits mouse corneal allograft rejection to a certain extent. Key words: Corneal transplantation; Interleukin-17; Neutralization antibody; Immune rejection