Intestinal graft versus native liver cytokine expression in a rat model of intestinal transplantation: effect of donor-specific cell augmentation

Combination of immature dendritic cells and anti-CD40L monoclonal antibody induces immune tolerance of intestinal allograft in rats

AIM: To investigate the combined effects of CD40L monoclonal antibody (mAb) and immature dendritic cells on donor-specific immune tolerance in rats undergoing small intestinal transplantation.

METHODS: DCs were collected from bone marrow progenitor cells of Wistar rats cultured with granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) in vitro. Seven days before transplantation of small intestine from Wistar donor rats, normal saline (group A, n = 15), immature dendritic cells (group B, n = 15), and immature dendritic cell anti-CD40L plus monoclonal antibody (group C, n = 15) were infused intravenously into SD recipient rats (n = 15), respectively. Small bowel transplantation was performed and the survival time of recipients was observed (n = 6). Histopathological examination was evaluated, and serum IL-2, IL-10 and interferon-γ (INF-γ) levels were measured by enzyme-linked immunosorbent assay (ELISA) (n = 5).

RESULTS: The survival time of recipients in group C was significantly longer than that in group A and group B (22.67 ± 7.09 d vs 7.17 ± 1.47 d, 11.00 ± 2.61 d, P < 0.01). The degree of the inflammatory infiltrated cells and intestinal mucosal structural destruction were significantly milder in group C. The concentration of serum IL-2 and INF-γ was much lower in group C than in group A and group B (IL-2: 225.4 ± 48.7 ng/L vs 374.1 ± 13.2, 353.6 ± 10.4 ng/L; INF-γ: 56.9 ± 2.6 ng/L vs 229.2 ± 20.6, 125.4 ± 18.5 ng/L, P < 0.05). The concentration of serum IL-10 was obviously higher in group C than in group A and group B (186.4 ± 10.6 ng/L vs 91.7 ± 5.4, 162.2 ± 8.1 ng/L, P < 0.05).

CONCLUSION: The pretreatment with immature donor dendritic cells plus anti-CD40L mAb can induce immune tolerance and prolong small bowel allograft survival after transplantation.

Prolongation of rat intestinal allograft survival by administration of donor interleukin-12 p35-silenced bone marrow-derived dendritic cells

Severe graft rejection remains an important obstacle in intestinal transplantation. In this study, we demonstrated that intravenous injection of interleukin (IL)-12 p35 siRNA-transfected dendritic cells (DCs) into recipient rats prolonged the survival of intestinal allografts. Serum IL-2 and interferon-gamma levels in the IL-12 p35 siRNA-transfected DCs treatment group were both significantly lower than in control groups at 7 days after transplantation. Further study is required to investigate the operative pathways and to optimize the strategy targeting dendritic cells to induce tolerance to intestinal allografts.