OBJECTIVETo prolong murine heart allograft by modifying hematopoietic stem cells with virus interleukin-10 (vIL-10).

METHODSThe recombinant of murine stem cell virus (MSCVneo) vIL-10 was composed of MSCVneo and vIL-10 cDNA and transduced hematopoietic stem cells from CBA (H-2(K)) mice's bone marrow in vitro. The transduced hematopoietic stem cells were transplanted into a syngenic CBA (H-2(K)) mouse with lethal irradiation (900 rad) in the same day through penis vein. The mouse's heterotopic heart transplantation was conducted using CBA (H-2(K)) mice as recipients, which vIL-10 in serum were positive by enzyme-linked immunosorbent assay, and donors hearts from C57BL/6 (H-2b) mice. Five animals in each group were sacrificed to test histopathology changes, the expression of interleukin (IL)-2, IL-4, IL-6, mIL-10, interferon (IFN)-gamma, inducible nitric oxide synthase (iNOS), B7-1, B7-2 and CD(4)(+) and CD(8)(+) T cells subset infiltration in heart transplants with reverse transcriptase polymerase chain reaction, immunohistochemistry and regular pathology.

RESULTSSurvival time of mice's allografts experimental group was (80.0 +/- 33.3) days. And survival time of control groups were (10.4 +/- 1.0) days, (11.6 +/- 1.1) days and (11.2 +/- 1.7) days, respectively (P < 0.01). Heart transplants from experimental group were characterized by sparse lymphocytes infiltration, mild endocarditis and vasculitis and preserved myocardial architecture, which had acute rejection of grade I. Cardiac allografts from other control groups developed severe cellular rejection with severe infiltrating lymphocytes, myocyte injury and necrosis, interstitial edema and hemorrhage, which had acute rejection of grade III. The expression of IL-2, INF-gamma, B7-1, B7-2 and iNOS mRNA in allografts in experimental group markedly down-regulated, whereas that in allografts in control groups markedly upregulated (P < 0.05). CD(4)(+) and CD(8)(+) T cell subsets infiltration in heart transplants from experimental group decreased, and that in control groups increased (P < 0.05).

CONCLUSIONEngineering Hematopoietic stem cells with vIL-10 can protect cardiac allografts from acute rejection and prolong cardiac allografts survival.