ABNORMALITY OF CD8+ CD28- SUPPRESSOR T CELLS IN PRIMARY IMMUNE THROMBOCYTOPENIA
(Abstract release date: 05/19/16)
EHA Library. Li H. 06/09/16; 132971; E1422
Dr. Huiyuan Li
Contributions
Contributions
Abstract
Abstract: E1422
Type: Eposter Presentation
Background
Primary immune thrombocytopenia (ITP) is an acquired disorder characterized by autoantibody-mediated platelet destruction and insufficient platelet production. Multiple factors have been implicated in ITP pathogenesis, including loss of immune tolerance. CD8+CD28- suppressor cells (Ts), which have been identified in recent years, play important roles in maintenance of peripheral immune tolerance. Thus Ts cells are involved in immune escape of tumor and pathogenesis of several autoimmune diseases. Ma et. al. found steroid treatment selectively increased Ts proportion in both the passive and active mice models of ITP, suggesting Ts may be involved in ITP . However, until now, the role of Ts cells in ITP etiology was not clear yet.
Aims
To evaluate whether the number and the regulatory functions of Ts were abnormal in ITP patients, and found the reasons for these defects.
Methods
A total of 90 active ITP patients, 21 ITP patients in remission and 93 age- and sex-matched healthy donors (HCs) were enrolled in this study. And (1) the proportion of CD8+CD28- Ts cell was detected by flow cytometric analysis (FACS). (2) The CD8+CD28-Ts, CD8+CD28+/CD4+ effector cells and CD4-CD8- cells (as antigen presenting cells, APCs) were sorted by MACS, and then mixed lymphocyte reaction and BrdU method were used for evaluating the inhibitory rate of Ts cells. Here, Transwell (TW) experiments were also performed to identify soluble cytokines or direct cell-contact was involved in immune regulation of Ts cells. (3) The sorted Ts and APC were co-cultured with PHA and IL-2, then after 48 hours, CD80, CD86, ILT3 and ILT4 expressions on CD14+ monocyte were analyzed by FACS. And the proliferation of APC were detected by BrdU corporation after 72 hours. (4) Peripheral blood mononuclear cells were activated by PHA and IL-2 for 24 hous, following ICOS, PD-1 expression on Ts cells surface and IL-10 expression in Ts cells (were reactivated by PMA, BFA and Ionomycin for final 4 hours) were examined by FACS.
Results
(1) The percent of Ts cells in peripheral blood from active ITP patients were lower than those of HCs, although Ts proportion seems elevated in patients with remission, there was no difference between ITP patients in remission and active ITP patients or HCs. (2) Ts cells both from HCs and ITP patients inhibited CD8+CD28+/CD4+ effector cells proliferation in quantity dependent manner. The inhibition effect of Ts on CD4+ effector cells at ratio 1:2 and inhibition effect of Ts on CD8+CD28+ effector cells at ratio 1:4 were significantly lower in ITP patients than that in the HCs. (3) Ts cells from HCs and ITP patients suppressed effector cells proliferation both in the presence and absence of a TW; In addition, the suppressive degree of Ts cell from HCs is greater in the absence of TW, while no difference was found between presence and absence of TW groups in ITP patients. Thus, the results suggested that both the soluble mediators and direct cell-contact were involved in suppressive function of Ts cells, and the cell-contact regulated ability of Ts cells form ITP patients may be have defect. (4) The ICOS expressions on Ts cell surface with or without activation were both decreased in ITP patients than that in HCs. However, the PD-1 and IL-10 expressions of Ts cells were not different between ITP patients and HCs. (5) Ts cell inhibited proliferation of APCs both in HCs and ITPs. However, inhibition rate will decreased in ITPs than that of HCs. Moreover, Ts from HCs could down-regulated CD80, up-regulated of ILT3 and ILT4 expressions on CD14+ monocytes, but these abilities were disappeared in Ts cells from ITP patients.
Conclusion
The down-regulation of number and inhibitory function of Ts cells in active patients indicated that Ts defect was involved in pathogenesis of ITP. In addition, decreased ICOS expression on Ts cell surface and loss the ability of regulating co-stimulator expression on APCs were partly illustrated the reasons for defect s of Ts.
Session topic: E-poster
Keyword(s): Immune thrombocytopenia (ITP), Regulatory T cell
Type: Eposter Presentation
Background
Primary immune thrombocytopenia (ITP) is an acquired disorder characterized by autoantibody-mediated platelet destruction and insufficient platelet production. Multiple factors have been implicated in ITP pathogenesis, including loss of immune tolerance. CD8+CD28- suppressor cells (Ts), which have been identified in recent years, play important roles in maintenance of peripheral immune tolerance. Thus Ts cells are involved in immune escape of tumor and pathogenesis of several autoimmune diseases. Ma et. al. found steroid treatment selectively increased Ts proportion in both the passive and active mice models of ITP, suggesting Ts may be involved in ITP . However, until now, the role of Ts cells in ITP etiology was not clear yet.
Aims
To evaluate whether the number and the regulatory functions of Ts were abnormal in ITP patients, and found the reasons for these defects.
Methods
A total of 90 active ITP patients, 21 ITP patients in remission and 93 age- and sex-matched healthy donors (HCs) were enrolled in this study. And (1) the proportion of CD8+CD28- Ts cell was detected by flow cytometric analysis (FACS). (2) The CD8+CD28-Ts, CD8+CD28+/CD4+ effector cells and CD4-CD8- cells (as antigen presenting cells, APCs) were sorted by MACS, and then mixed lymphocyte reaction and BrdU method were used for evaluating the inhibitory rate of Ts cells. Here, Transwell (TW) experiments were also performed to identify soluble cytokines or direct cell-contact was involved in immune regulation of Ts cells. (3) The sorted Ts and APC were co-cultured with PHA and IL-2, then after 48 hours, CD80, CD86, ILT3 and ILT4 expressions on CD14+ monocyte were analyzed by FACS. And the proliferation of APC were detected by BrdU corporation after 72 hours. (4) Peripheral blood mononuclear cells were activated by PHA and IL-2 for 24 hous, following ICOS, PD-1 expression on Ts cells surface and IL-10 expression in Ts cells (were reactivated by PMA, BFA and Ionomycin for final 4 hours) were examined by FACS.
Results
(1) The percent of Ts cells in peripheral blood from active ITP patients were lower than those of HCs, although Ts proportion seems elevated in patients with remission, there was no difference between ITP patients in remission and active ITP patients or HCs. (2) Ts cells both from HCs and ITP patients inhibited CD8+CD28+/CD4+ effector cells proliferation in quantity dependent manner. The inhibition effect of Ts on CD4+ effector cells at ratio 1:2 and inhibition effect of Ts on CD8+CD28+ effector cells at ratio 1:4 were significantly lower in ITP patients than that in the HCs. (3) Ts cells from HCs and ITP patients suppressed effector cells proliferation both in the presence and absence of a TW; In addition, the suppressive degree of Ts cell from HCs is greater in the absence of TW, while no difference was found between presence and absence of TW groups in ITP patients. Thus, the results suggested that both the soluble mediators and direct cell-contact were involved in suppressive function of Ts cells, and the cell-contact regulated ability of Ts cells form ITP patients may be have defect. (4) The ICOS expressions on Ts cell surface with or without activation were both decreased in ITP patients than that in HCs. However, the PD-1 and IL-10 expressions of Ts cells were not different between ITP patients and HCs. (5) Ts cell inhibited proliferation of APCs both in HCs and ITPs. However, inhibition rate will decreased in ITPs than that of HCs. Moreover, Ts from HCs could down-regulated CD80, up-regulated of ILT3 and ILT4 expressions on CD14+ monocytes, but these abilities were disappeared in Ts cells from ITP patients.
Conclusion
The down-regulation of number and inhibitory function of Ts cells in active patients indicated that Ts defect was involved in pathogenesis of ITP. In addition, decreased ICOS expression on Ts cell surface and loss the ability of regulating co-stimulator expression on APCs were partly illustrated the reasons for defect s of Ts.
Session topic: E-poster
Keyword(s): Immune thrombocytopenia (ITP), Regulatory T cell
Abstract: E1422
Type: Eposter Presentation
Background
Primary immune thrombocytopenia (ITP) is an acquired disorder characterized by autoantibody-mediated platelet destruction and insufficient platelet production. Multiple factors have been implicated in ITP pathogenesis, including loss of immune tolerance. CD8+CD28- suppressor cells (Ts), which have been identified in recent years, play important roles in maintenance of peripheral immune tolerance. Thus Ts cells are involved in immune escape of tumor and pathogenesis of several autoimmune diseases. Ma et. al. found steroid treatment selectively increased Ts proportion in both the passive and active mice models of ITP, suggesting Ts may be involved in ITP . However, until now, the role of Ts cells in ITP etiology was not clear yet.
Aims
To evaluate whether the number and the regulatory functions of Ts were abnormal in ITP patients, and found the reasons for these defects.
Methods
A total of 90 active ITP patients, 21 ITP patients in remission and 93 age- and sex-matched healthy donors (HCs) were enrolled in this study. And (1) the proportion of CD8+CD28- Ts cell was detected by flow cytometric analysis (FACS). (2) The CD8+CD28-Ts, CD8+CD28+/CD4+ effector cells and CD4-CD8- cells (as antigen presenting cells, APCs) were sorted by MACS, and then mixed lymphocyte reaction and BrdU method were used for evaluating the inhibitory rate of Ts cells. Here, Transwell (TW) experiments were also performed to identify soluble cytokines or direct cell-contact was involved in immune regulation of Ts cells. (3) The sorted Ts and APC were co-cultured with PHA and IL-2, then after 48 hours, CD80, CD86, ILT3 and ILT4 expressions on CD14+ monocyte were analyzed by FACS. And the proliferation of APC were detected by BrdU corporation after 72 hours. (4) Peripheral blood mononuclear cells were activated by PHA and IL-2 for 24 hous, following ICOS, PD-1 expression on Ts cells surface and IL-10 expression in Ts cells (were reactivated by PMA, BFA and Ionomycin for final 4 hours) were examined by FACS.
Results
(1) The percent of Ts cells in peripheral blood from active ITP patients were lower than those of HCs, although Ts proportion seems elevated in patients with remission, there was no difference between ITP patients in remission and active ITP patients or HCs. (2) Ts cells both from HCs and ITP patients inhibited CD8+CD28+/CD4+ effector cells proliferation in quantity dependent manner. The inhibition effect of Ts on CD4+ effector cells at ratio 1:2 and inhibition effect of Ts on CD8+CD28+ effector cells at ratio 1:4 were significantly lower in ITP patients than that in the HCs. (3) Ts cells from HCs and ITP patients suppressed effector cells proliferation both in the presence and absence of a TW; In addition, the suppressive degree of Ts cell from HCs is greater in the absence of TW, while no difference was found between presence and absence of TW groups in ITP patients. Thus, the results suggested that both the soluble mediators and direct cell-contact were involved in suppressive function of Ts cells, and the cell-contact regulated ability of Ts cells form ITP patients may be have defect. (4) The ICOS expressions on Ts cell surface with or without activation were both decreased in ITP patients than that in HCs. However, the PD-1 and IL-10 expressions of Ts cells were not different between ITP patients and HCs. (5) Ts cell inhibited proliferation of APCs both in HCs and ITPs. However, inhibition rate will decreased in ITPs than that of HCs. Moreover, Ts from HCs could down-regulated CD80, up-regulated of ILT3 and ILT4 expressions on CD14+ monocytes, but these abilities were disappeared in Ts cells from ITP patients.
Conclusion
The down-regulation of number and inhibitory function of Ts cells in active patients indicated that Ts defect was involved in pathogenesis of ITP. In addition, decreased ICOS expression on Ts cell surface and loss the ability of regulating co-stimulator expression on APCs were partly illustrated the reasons for defect s of Ts.
Session topic: E-poster
Keyword(s): Immune thrombocytopenia (ITP), Regulatory T cell
Type: Eposter Presentation
Background
Primary immune thrombocytopenia (ITP) is an acquired disorder characterized by autoantibody-mediated platelet destruction and insufficient platelet production. Multiple factors have been implicated in ITP pathogenesis, including loss of immune tolerance. CD8+CD28- suppressor cells (Ts), which have been identified in recent years, play important roles in maintenance of peripheral immune tolerance. Thus Ts cells are involved in immune escape of tumor and pathogenesis of several autoimmune diseases. Ma et. al. found steroid treatment selectively increased Ts proportion in both the passive and active mice models of ITP, suggesting Ts may be involved in ITP . However, until now, the role of Ts cells in ITP etiology was not clear yet.
Aims
To evaluate whether the number and the regulatory functions of Ts were abnormal in ITP patients, and found the reasons for these defects.
Methods
A total of 90 active ITP patients, 21 ITP patients in remission and 93 age- and sex-matched healthy donors (HCs) were enrolled in this study. And (1) the proportion of CD8+CD28- Ts cell was detected by flow cytometric analysis (FACS). (2) The CD8+CD28-Ts, CD8+CD28+/CD4+ effector cells and CD4-CD8- cells (as antigen presenting cells, APCs) were sorted by MACS, and then mixed lymphocyte reaction and BrdU method were used for evaluating the inhibitory rate of Ts cells. Here, Transwell (TW) experiments were also performed to identify soluble cytokines or direct cell-contact was involved in immune regulation of Ts cells. (3) The sorted Ts and APC were co-cultured with PHA and IL-2, then after 48 hours, CD80, CD86, ILT3 and ILT4 expressions on CD14+ monocyte were analyzed by FACS. And the proliferation of APC were detected by BrdU corporation after 72 hours. (4) Peripheral blood mononuclear cells were activated by PHA and IL-2 for 24 hous, following ICOS, PD-1 expression on Ts cells surface and IL-10 expression in Ts cells (were reactivated by PMA, BFA and Ionomycin for final 4 hours) were examined by FACS.
Results
(1) The percent of Ts cells in peripheral blood from active ITP patients were lower than those of HCs, although Ts proportion seems elevated in patients with remission, there was no difference between ITP patients in remission and active ITP patients or HCs. (2) Ts cells both from HCs and ITP patients inhibited CD8+CD28+/CD4+ effector cells proliferation in quantity dependent manner. The inhibition effect of Ts on CD4+ effector cells at ratio 1:2 and inhibition effect of Ts on CD8+CD28+ effector cells at ratio 1:4 were significantly lower in ITP patients than that in the HCs. (3) Ts cells from HCs and ITP patients suppressed effector cells proliferation both in the presence and absence of a TW; In addition, the suppressive degree of Ts cell from HCs is greater in the absence of TW, while no difference was found between presence and absence of TW groups in ITP patients. Thus, the results suggested that both the soluble mediators and direct cell-contact were involved in suppressive function of Ts cells, and the cell-contact regulated ability of Ts cells form ITP patients may be have defect. (4) The ICOS expressions on Ts cell surface with or without activation were both decreased in ITP patients than that in HCs. However, the PD-1 and IL-10 expressions of Ts cells were not different between ITP patients and HCs. (5) Ts cell inhibited proliferation of APCs both in HCs and ITPs. However, inhibition rate will decreased in ITPs than that of HCs. Moreover, Ts from HCs could down-regulated CD80, up-regulated of ILT3 and ILT4 expressions on CD14+ monocytes, but these abilities were disappeared in Ts cells from ITP patients.
Conclusion
The down-regulation of number and inhibitory function of Ts cells in active patients indicated that Ts defect was involved in pathogenesis of ITP. In addition, decreased ICOS expression on Ts cell surface and loss the ability of regulating co-stimulator expression on APCs were partly illustrated the reasons for defect s of Ts.
Session topic: E-poster
Keyword(s): Immune thrombocytopenia (ITP), Regulatory T cell
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