title: Abnormal immunomodulatory ability on memory T cells in humans with severe aplastic anemia.
abstract: Severe aplastic anemia (SAA) is a bone marrow failure disease induced by hyperfunctional autoimmunic Th1 lymphocytes. Memory T cells (TM) are a component of the adaptive immune system. They ensure the host of more aggressive and faster immune response to efficiently eliminate the specific antigens after re-exposure and thus play a key role in T-cell functions. In this study we investigate the quantities and functions of memory T cells in SAA patients before and after immunosuppressive therapy (IST) to further clarify the mechanism of SAA apoptosis of bone marrow hematopoietic cells. Results showed that the percentage of CD4+ effector T cells in peripheral blood and bone marrow lymphocytes was decreased in SAA patients. The ratio of CD4+ memory T lymphocytes to CD8+ memory T subsets (CD4+/CD8+TM) in SAA patients was also lower. The percentage of CD8+ effector T cells in peripheral blood and CD8+ central memory T cells in the bone marrow lymphocytes was significantly higher in newly diagnosed patients. Furthermore, the median expressions of perforin and granzyme B on memory T cells were higher in SAA patients compared to those in normal controls. After IST, the quantities and functions of memory T cells return to normal level. Therefore, we concluded that the abnormal immunomodulatory ability on memory T cells may contribute to the imbalance of Th1/Th2 subsets and thus lead to over-function of T lymphocytes and hematopoiesis failure in SAA.
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Mengying
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Fu
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Huaquan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Shaoxue
authors.initials: S
authors.lastname: Ding
authors.affiliation: Department of Hematology, The General Hospital of Tianjin Medical University Tianjin, China.
authors.forename: Zonghong
authors.initials: Z
authors.lastname: Shao
mesh_terms: D056704:Adaptive Immunity / Q000502:physiology*; D000328:Adult; D000741:Anemia, Aplastic / Q000276:immunology* / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D056747:Immunomodulation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D055815:Young Adult
keywords: Severe aplastic anemia; ganzyme B; memory T cells; perforin