Preliminary Study On IL-7Rα Intervening AGVHD After Allogeneic Bone Marrow Transplantation

Objective:1.To establish a mouse model of acute graft-versus-host disease after allogeneic bone marrow transplantation;2.Analyse the relation between exogenous interleukin-7receptor alpha(IL-7Rα) and mouse aGVHD.Methods:In BALB/C (H-2d) female mice as recipients, grouped:the irradiation(group A),irradiation transplantation (group B),IL-7Ra in the intervention (group C), each10are accepted9Gy60Co total body irradiation,taking of C57BL/6(H-2b) of1×107donor bone marrow cells and2×107spleen cells, to detect the change of correlated index as follows:(1) Observe the General situation, lifetime;(2) Count the number of Peripheral white blood cells;(3) Histopathologic change was observed by microscope;(4) Chromosomal chimaera was detected by polymerase chain reaction (PCR);(5) Flow cytometry analyze T cell subsets;(6) cytokine levels in check by Elisa methods.Results:1.Establish a stable murine aGVHD model(1) the general status of different groups of mice, survival (30days observation):group A (simple irradiation group) body weight of mice continued to decline gradually failure death,30days survival rate was0.0%; group B (irradiation transplantation group)mice+6d weight to a minimum,+13d to rise, then fall again, and the emergence of aGVHD performance, survival rate was50%in30days; body weight of mice of group C (IL-7Rα in the intervention group) also fell to+6d lowest since ascending to+14d up to the highest after fluctuations in this range, and fatigue, anorexia, hair removal, arched aGVHD performance.(2) changes in peripheral blood leukocytes:A group of mice white blood cell count to a minimum at+14d, and the fluctuations in this range to+20d were all dead; group B and group C mice white blood cell count at+7d to minimizeSince then gradually rise.(3) of aGVHD pathological changes:A group of mice did not pathological features of aGVHD; C mice showing mild aGVHD pathology performance; Group B mice showed obvious pathological features of aGVHD:Liver visible liverenlargement of cells, the cell structure is unclear, the portal area of central venous and hepatic sinusoid dilatation and congestion of the liver sinusoids and exchange district lymphocytic infiltration; skin structural damage to the hair follicle to reduce, local lymphocytic infiltration; spleen specimens of spleen small normal beams and other structural damage between the macrophage and lymphocyte infiltration, splenic corpuscle fibrosis, the spleen cells decreased, partially visible splenic sinus expansion bleeding; intestinal villi necrosis, glands reduced the infiltration of lymphocytes.(4) detection of the chimeras:+14days after transplantation in group A did not detect the Y chromosome, the implantation is not successful; group B and group C are for the mouse Y chromosome detection, successful implantation.2.IL-7Ra protein on murine aGVHD(1) the general condition of two groups of mice, survival time and survival:the survival time is longer than group B (P<0.05),30-day survival rate higher than group B (P<0.05) to63.7%;mice fatigue, anorexia, hair removal, arched the aGVHD performance light in the B group.(2) white blood cell counts:group C and group B mice, white blood cell count dropped to the lowest value at+7days, then gradually rise, group C rising fast, up to day+14(4.53±0.21)×109/Lthan in group B (P<0.05).(3) of aGVHD pathology:liver, spleen, and skin histopathological changes in group C was significantly milder in group B, the small intestine specimens of group C and group B no significant difference.(4)Chimera detection:+14days after transplantation, group C and group B are chimeric physical examination, two groups of implanted successfully.(5)T cell subsets in recovery:group C and group B mouse T cell subsets after transplantation disorders, gradual recovery after+21d, group C faster recovery than in group B,+21d of CD3+T cells in the two groups were significantly different.(6)Changes in plasma levels of IL-7before and after transplantation:the content of group C and group B mice IL-7concentration in the plasma+7d after transplantation compared with before transplantation was significantly increased, but decreased gradually change over time; group C the rate of decline than Group B fast.Conclusion:1.To establish the stability of aGVHD mouse model;2.In aGVHD early plasma IL-7levels were significantly increased;exogenous IL-7Rα can reduce the plasma IL-7levels,thereby reducing the incidence of aGVHD after allogeneic bone marrow transplantation.