Expressions of interleukin-15 and osteopontin mRNA in early stage of acute rejection of renal allograft in rats

Abstract

To study the expressions of interleukin-15 (IL-15), osteopontin (OPN), granzyme B (GraB) and perforin (PFP) mRNA in early stage of acute rejection (AR) of renal allograft in rats. The rat renal transplantation model was established. Male Brown Norway and Lewis rats were used as donors and recipients. Four groups were designated: CsA group (BN-->LEW, n = 10, recipients were treated with CsA i.p.); AB group (BN-->LEW, n = 10, recipients were treated with anti-IL-15 neutralizing antibody i.p.); AR group (BN-->LEW, n = 10, recipients were treated with normal saline i.p.) and control group (LEW-->LEW, n = 6, recipients were treated with normal saline i.p.). The blood samples of recipients were drawn at Days 1, 3, 5 and 7 post-transplantation. The serum expressions of IL-15, OPN, PFP and GraB mRNA of recipients were detected by real-time PCR. Allograft tissues were analyzed by pathological assays. In comparison with other groups, the expressions of OPN, IL-15, PFP and GraB mRNA in AR group were gradually up-regulated and peaked at Day 5. The expressions of IL-15 mRNA in CsA and AB groups were 9685 +/- 1440 and 4346 +/- 741 respectively at Day 5 post-operation. It was significantly lower than that in AR group (17 022 +/- 2153, P < 0.01). The expression of IL-15 mRNA in AB group was significantly lower than that in CsA group (P < 0.01). The expressions of OPN mRNA in CsA and AB groups (13 226 +/- 1565 vs 19 112 +/- 2908) were both significantly lower than that in AR group (24 663 +/- 2449, P < 0.01). But the expression of OPN mRNA in AB group was higher than that in CsA group (P < 0.01). At Day 5 post-transplantation, both the expressions of PFP and GraB mRNA in AB and CsA groups was lower than that in AR group (P < 0.01). The pathological results showed that severe AR occurred at Day 7 post-transplantation in AR group and whereas the extent of rejection sign relieved in AB group. In early stage of AR of renal allograft in rats, the expressions of OPN, IL-15, PFP and GraB mRNA are up-regulated. Blocking IL-15/IL-15R pathway in early stage of AR can down-regulate the expressions of PFP and GraB mRNA.