The Significance Of Treg Cells And T Iymphocyte Subsets In Acute Myelocytic Leukemia

The immune system had used a variety of mechanisms to maintain their immune tolerance, and protected the body to cope with the destruction of foreign antigens.Regulatory T cells(Treg cells) were a effectively conventional T cells of suppression,and its main function were to limit inappropriate immune or excessive immune.According to different sources, CD4+ regulatory T cells included two types: "natural" Treg(n Treg) and induced Treg(i Treg). n Treg and i Treg must maintain the balance between the inhibition of potential autoimmunity and control of infection,in order to maintain the normal operation of the body’s functions. To achieve this balance was often Contradictory with over-expression or under-expression of Treg. Currently, the treatment of AML patients mainly depend on chemotherapy and bone marrow transplantation, which had achieved a certain effect, but because of its high cost of treatment and greater damage to the body, that had not produced satisfactory results.Because Treg had been shown to suppress the local anti-tumor immune response,This was the foundation for research. This research was to further explore the changes of Treg in AML patients and the effect in vivo, which would opened up a new path for the immunotherapy of malignant hematological disease.Objective : To explore the alterations,relationship and clinical significance of CD4+CD25+CD127low/-regulatory T cells and lymphocyte subsets in peripheral blood of patients with acute myelocytic leukemia(AML).Methods : The level of peripheral blood lymphocyte subsets and Treg cells of 30untreated AML patients and 30 complete remission(CR) patients were tested by flow cytometry,and were compared with that of 30 normal controls.Results:The proportions of Treg cells were much higher in untreated AML patients and CR patients than in normal controls, while the mean proportion of Treg cells in untreated AML patients was higher than that in CR patients(P<0.05). The proportions of NK(CD3-CD16+CD56+)cells in untreated AML patients and CR patients were both decreased compared with normal controls,and the mean proportion of NK cells in untreated AML patients was lower than that in CR patients(P<0.05).Compared with the normal controls,the proportions of CD3+T cell, CD4+T cell,and the ratio of CD4+/CD8+decreased in untreated AML patients(P<0.05), but the proportions of CD8+T cell was higher than in normal controls; the proportions of CD3+T cell, CD4+ T cell, CD8+T cell and the ratio of CD4+/CD8+ in CR patients were close to the proportions in normal controls, but there was significant difference between CR patients and untreated AML patients(P<0.05).Conclusion:The increase of Treg cells, CD8+T cell and decrease of NK cells, CD3+T cell, CD4+T cell, and the ratio of CD4+/CD8+ in peripheral blood of patients with AML indicate that the immune function of patients with AML is depressed. Treg cells control the immune response of CD8+T cells,at the same time inhibit the natural immune response of NK cells,play a major role In the disorders of CD4+T cells and CD8+T cell balance,and closely relate with the development of AML. The immune treatment of patients with AML will be optimised by reducing the amount of Treg cells or removing the suppression function.