CD200 / CD200R Expression Levels In Allogeneic Hematopoietic Stem Cell Transplantation And The Significance Of

Background and ObjectiveCD200and its receptor CD200R are both type-1membrane glycoproteins, which are members of the immunoglobulin superfamily (IgSF). CD200is widely expressed on a variety of cell types, while the recently identified CD200R is expressed on myeloid cells and T cells. The immunomodulatory effects of CD200and CD200R interactions have been demonstrated in animal models and in vitro experiments. Besides the inhibition effects on macrophages, CD200/CD200R also play an important role in regulating the regulatory T cells, allergicreaction, autoimmune diseases, allograft, neurological diseases and other autoimmune-related diseases, etc. CD200is highly expressed in patients with acute leukemia, multiple myeloma, chronic lymphocytic leukemia and other malignant diseases. CD200is considered to be associated with the prognosis of these diseases, and it could be used as an independent prognostic factor. The relationship between CD200/CD200R and allogeneic hematopoietic stem cell transplantation has been reported rarely. Therefore, this paper mainly focuses on the role of CD200and its receptor in the graft versus host disease (GVHD).MethodsExperimental samples were collected from the allogeneic hematopoietic stem cell transplantation patients who were treated in Peking Union Medical College Hospital from February2013to December2013. Firstly, the expression levels of CD200and CD200R on CD19+cell, CD3+cell and dendritic cell (CD19-CD14-CDlc+) surface in each research group were detected by using flow cytometry, to determine whether there were expression differences among each group. Then, the mRNA levels of each research group were tested by using real-time quantitative polymerase chain reaction, to find the differences of mRNA expression levels among each group. Finally, the peripheral blood mononuclear cells of the patients and healthy controls were co-cultured with anti-CD200R1antibody for48hours, and the interleukin-10levels in the co-culture system were tested by using enzyme linked immunosorbent assay, to indirectly verify the function of CD200/CD200R.Results1、 The CD200expression levels on CD19+cells surface in the aGVHD group and non-aGVHD group were both lower than healthy control group.The CD200expression levels on CD19+cells surface in the non-aGVHD group were higher than the aGVHD group(P<0.05).2、There was no significant difference of the expression levels of CD19+CD200+cells between the cGVHD group and healthy control group. The expression levels of CD19+CD200+cells in the non-cGVHD group were higher than the cGVHD group and healthy control group(P<0.05).3、 There were no significant differences of CD200and CD200R expression levels on CD3+cells and dendritic cells among all research groups.4、 The CD200mRNA expression levels in the aGVHD group and cGVHD group were both lower than the healthy control group(P<0.05).5、 The CD200mRNA expression levels were lower in the aGVHD group than the non-aGVHD group, and were lower in the cGVHD group than the non-cGVHD group(P <0.05).6、 The CD200mRNA expression levels had no significant difference between the non-aGVHD patients and the healthy control group, but were higher in the non-cGVHD group than the healthy control group (P<0.05).7、There was no significant difference of the CD200R mRNA expression levels among all research groups.8、 After the peripheral blood mononuclear cells of the patients and healthy controls were co-cultured with anti-CD200R1antibody for48hours, the interleukin-10concentration decreased with the increasing concentrations of anti-CD200R1antibody in the co-culture system.ConclusionThe study showed that the patients with GVHD had a significantly lower CD200mRNA levels than the patients without GVHD and the healthy control group. The CD200expression levels of CD19+cells in the patients with aGVHD were also lower than the non-aGVHD group. These results indicate that CD200and CD19+CD200+cells play a role in the pathogenesis of GVHD.