[Induction of skin allograft tolerance in mice by using anti-alphabeta T cell receptor and anti-CD80 monoclonal antibodies combined with bone marrow transfusion].

Objective: To explore the role of anti-alphabeta T cell receptor (TCR) and anti-CD80 monoclonal antibodies (mAbs) combined with donor bone marrow cells (BMCs) infusion in the induction of murine skin allografts tolerance.

Methods: On day 0, 2 x 10(8) BMCs of BALB/c mice were injected into recipient C57BL/6 mice via the tail vein, meanwhile, an intraperitoneal injection of TCRalphabeta mAb (500 microg) was given. On day 2, CD80 mAb was administered intraperitoneally.

[Adenovirus-mediated CTLA4Ig and OX40Ig gene transfer induces long-term survival of cardiac allografts in rats].

Objective: To investigate the potential role of CTLA4Ig gene and OX40Ig protein in inducing transplantation tolerance and the mechanisms thereof.

Methods: Thirty Lewis rats underwent transplantation of the hearts of DA rats and then randomly divided into five equal groups: control group, blank virus AdEGFP treated group (adenovirus containing EGFP at the dose of 1-5 x 10(9) pfu/ml was infused via portal vein immediately after the operation), AdCTLA4Ig treated group, AdOX40Ig treated group, and AdCTLA4Ig-IRES-OX40Ig treated group. The cardiac allograft survival was monitored by daily palpation.

Preparation of arsenic trioxide-loaded albuminutes immuno-nanospheres and its specific killing effect on bladder cancer cell in vitro.

Background: Recently, arsenic trioxide (As2O3) was considered as a novel anti-tumor agent. However, it showed severe toxicity effect on normal tissue at the same time. To improve its therapeutic efficacy and decrease its toxicity,we prepared arsenic trioxide-loaded albuminutes immuno-nanospheres [As2O3-(HAS-NS)-BDI-1] targeted with monoclonal antibody (McAb) BDI-1 and tested its specific killing effect against bladder cancer cell.

[Effect of T suppressor cells on the maintenance phase of tolerance to cardiac allografts in the rats].

Objective: To study the role of T suppressor cells in immune tolerance to cardiac allografts in the rats.

Methods: Male DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into five groups: group 1: untreated, group 2: portal venous injection of 3 x 10(8) DA splenocytes to Lewis rat, group 3: intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, group 4: portal venous injection of 3 x 10(8) DA splenocytes combined with intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, 15 days later heart transplantation was performed. Group 5: intravenous injection 3 (108 splenocytes of group 4 to normal recipient, and then heart transplantation was performed.

Bone marrow stromal cell line co-transfected with IL-2 and IL-3 genes can accelerate restoration of T-cell immunity in allo-BMT mice.

Background: After T-cell depleted allogeneic bone marrow transplantation, impaired immune reconstitution is a major cause of morbidity and mortality in the recipient. The purpose of this study was to observe the effects of the gene-engineered bone marrow stromal cell line QXMSC1-IL-2 + IL-3 on the reconstitution of T-cell immunity in allo-BMT mice.

Methods: The bone marrow stromal cell line QXMSC1 was co-transfected with IL-2 and IL-3 genes using a Tet-on gene expression system.

[Induced tolerance to cardiac allografts with multiple intravenous injection of donor spleen cells].

Objective: To study the methods and mechanisms of immune tolerance in cardiac transplantation.

Methods: Male DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into five groups: untreated, intravenous injection of 1 x 10(8) DA splenocytes to Lewis rat, intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat, intravenous injection of 1 x 10(8) DA splenocytes combined with intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat, multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide, 11 days later heart transplantation was performed. Mean survival time (MST), histological changes, mixed lymphocyte reaction (MLR), the role of interleukin-2 (IL-2) to MLR and the role of tolerant rat splenocytes to MLR were measured after operation.

[Construction and biological activities of CTLA4Ig adenovirus vectors].

Aim: To construct CTLA4Ig adenovirus vectors (AdCTLA4Ig) by homologous recombination and study their activity, and to employ the vectors to induce cardiac transplantation tolerance by gene therapy.

Methods: CTLA4Ig gene was cloned to pCA13 adenovirus shuttle plasmid by recombination strategy. Construction of CTLA4Ig adenovirus vectors was performed by homologous recombination of pCA13 plasmid containing CTLA4Ig gene with adenovirus helper plasmid, followed by packaged with 293 cells.

[The improving effect of bone marrow stromal cell transfected with IL-3 gene on hematopoietic reconstitution in bone marrow transplantation of mice].

To study the improving effect of regulatable gene of IL-3 engineered bone marrow stromal cell on the hematopoietic reconstitution in allogeneic bone marrow transplantation, an inducible gene expression system was established in a bone marrow stromal cell line which expressed IL-3 gene induced by doxycycline (Dox). The lethally irradiated mice C57BL/6 (H-2(d)) were co-transplanted with allogeneic bone marrow (BALB/c, H-2(d), 1 x 10(7)/mice) in which T cell were depleted by monoclonal antibody anti-Thy1.2 added with complement and the gene engineered stromal cell QXMSC1tet-on + IL-3 (5 x 10(5)/mice) at the same time.

[Adenovirus-mediated CTLA4-FasL gene transfer induces long-term survival of cardiac allograft in rats].

Objective: To investigate the potential of exogenously expressed CTLA4-FasL in inducing transplantation tolerance using rat cardiac graft model and its related mechanisms.

Methods: The heart allograft of DA rat was placed in the abdomen of LEW rat, and adenoviruses containing CTLA4-FasL gene (AdCTLA4-FasL) adenovirus containing CTLA4Ig, and AdEGPP were infused at a dose of 5 x 10(9) pfu/ml via portal vein in different recipients respectively immediately after the operation. DA-->LEW cardiac graft controls and syngeneic LEW-LEW cardiac graft controls were used.

[The enhancing effects of IL-3 gene transfected murine bone marrow stromal cells on hematopoiesis under control of doxycycline].

To study enhancing effect of IL-3 gene transfected bone marrow stromal cell which can be induced by doxycycline (Dox) to express IL-3 cytokine on the proliferation and differentiation of hematopoietic stem cell, retrovirus vector system contained mIL-3 cDNA was established and bone marrow stromal cell line was transfected, and obtained QXMSC1Tet-on-IL-3, in which expression level of IL-3 can be modulated by Dox. The activities of IL-3 were measured under different Dox concentrations. The numbers of hematopoietic progenitors (CFU-GM, CFU-E, CFU-GEMM and LTC-IC) were measured and the capacity of QXMSC1Tet-on-IL-3 sustaining hematopoietic progenitor cell growth was evaluated.

[Accelerating hematopoietic recovery in allogeneic bone marrow transplantation mice by co-infusion of marrow stromal cells transduced with dual genes of IL-3/IL-6].

To observe whether bone marrow stromal cell line QXMSC1 (H-2(d)) engineered to secrete IL-3 and IL-6 can improved the hematopoiesis in allogeneic bone marrow transplantation (allo-BMT) mice, the stromal cell line QXMSC1IL-3/IL-6 was established by QXMSC1 cells transduced with the recombined retrovirus vector pL3SN containing mouse IL-3 cDNA and pL6SN containing human IL-6 cDNA. The lethally irradiated C57BL/6 (H-2(b)) mice were engrafted with bone marrow cells (1 x 10(7) cells/mouse BALB/c mice, H-2(d)) in which T cells were depleted by anti-Thy1.2 monoclonal antibody adding complement, and QXMSC1IL-3/IL-6 cells (5 x 10(5)/mouse) were co-infused at same time.