The Study On The Effect Of Methoxy Polyethyleneglycol Camouflage T Cell Surface Antigen In Allogeneic Bone Marrow Transplantation

Background: GVHD is a kind of important complication in allogeneic bone marrow transplantation. T lymphocyte in donor bone marrow plays the key effect. GVHD is preventable via several ways while GVL might be weakened. mPEG is a kind of chemical compound without immunity, which can camouflage the antigen on T lymphocyte surface in different degree.Objective: If modification of T cell surface antigen by mPEG alleviates GVHD reaction while preserves GVL effect in allogeneic bone marrow transplantation in mouse model.Methods: 1. 60 BALB/c^H-2d mice were divided into 3 groups after irradiated by ⁶⁰Coγ. RPMI1640 0.5ml was given to group A in vein. Group B was infused into the bone marrow cells (1×10⁷) mixed with the spleen cells (1×10⁷) of donor615^H-2d mice. Group C was transplanted the same dose cells, which were camouflaged with mPEG before infusion. GVHD were assessed between group B and group C by survival time and Thomas GVHD grade in pathology. 2. Sixty(BALB/c^H-2d×615^H-2d)F₁ mice were divided into four groups. Mice in group D were only irradiated with 8.0Gy Co Y , and mice in other groups were inoculated into abdominal cavity with lxlO6 L615 cells in 3days before irradiated with the same dose ⁶⁰Co γ . BALB/c^H-2d mice were killed to obtain bone marrow cells and spleen cells. The bone marrow cells (1×10⁷) mixed with the spleen cells (1×10⁷) , which were camouflaged with or without mPEG, were transplanted into irradiated leukemia mice in group G and F. GVL effects were evaluated by L615 cells proportion in peripheral blood change and survival time.