Effects of Granulocyte Colony-Stimulating Factor on Proliferation and Apoptosis of B Cells in Bone Marrow of Healthy Donors.

BACKGROUND AND OBJECTIVE: The aim of this study was to investigate the effects of granulocyte colony-stimulating factor (G-CSF) on the proliferation and apoptosis of bone marrow (BM) B cells from healthy donors and its mechanism. MATERIALS AND METHODS: The proliferation ability and apoptosis of BM cells from healthy donors before and after in vivo G-CSF application were determined by multiparameter flow cytometry. The gene expression of B cells was detected by RNA-Seq. In vitro experiments were performed to investigate the effects of G-CSF on the proliferation and apoptosis of BM B cells through which gene. RESULTS: Treating healthy donors with G-CSF significantly decreased proliferation and increased apoptosis of BM B cells. The proliferation of CD19+CD27- B cell subgroup and CD19+CD24hiCD38hi B cell subset were also decreased. G-CSF also significantly altered proapoptotic genes, cell cycle arrest genes, and DNA replication and cell cycle genes, especially significantly increased SOCS1 expression of BM B cells. In vitro experiments showed that SOCS1 overexpression did not affect B cell proliferation ability and apoptosis. CONCLUSIONS: Our results suggest that extensive effects of G-CSF on BM B cells, such as inhibiting proliferation, inducing apoptosis, and altering a series of gene expression.

Early myeloid-derived suppressor cells (HLA-DR-/lowCD33+CD16-) expanded by granulocyte colony-stimulating factor prevent acute graft-versus-host disease (GVHD) in humanized mouse and might contribute to lower GVHD in patients post allo-HSCT.

INTRODUCTION: Myeloid-derived suppressor cells (MDSCs) are proposed to control graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the definition of human MDSCs has not yet reached consensus, and the mechanism of MDSCs to control GVHD remains unclear. METHODS: Immature myeloid cells (HLA-DR-/lowCD33+CD16-) were tested before and after granulocyte colony-stimulating factor (G-CSF) administration in healthy donor and isolated for suppression assays and co-culture with T cells in vitro. Isolated cells were infused in humanized mice for a xenogeneic model of acute GVHD. One hundred allo-HSCT recipients were enrolled prospectively to assess the role of HLA-DR-/lowCD33+CD16- cells in grafts on the occurrence of acute GVHD. RESULTS: In the present study, G-CSF mobilized HLA-DR-/lowCD33+CD16- cells with immunosuppressive properties in donor peripheral blood. These cells contained more interleukin-10+ and transforming growth factor-beta (TGF-ß)+ cells after G-CSF administration and inhibited the proliferation of autologous donor T cells in a TGF-ß-dependent manner. Meanwhile, these immature myeloid cells promoted regulatory T cell expansion and induced Th2 differentiation. Importantly, these cells prevented acute GVHD in a humanized mouse model. Moreover, clinical cohort results showed that the number of HLA-DR-/lowCD33+CD16- cells in the donor graft was the only independent risk factor inversely correlated with the incidence of grade II-IV acute GVHD in the recipients (HR 0.388, 95% CI 0.158-0.954, p = 0.039). CONCLUSION: HLA-DR-/lowCD33+CD16- cells represent functional MDSCs that may control acute GVHD in allo-HSCT.

Class I and II human leukocyte antibodies in pediatric haploidentical allograft candidates: prevalence and risk factors.

Donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) were associated with graft failure (GF) following haploidentical stem cell transplantation (Haplo-HSCT). The prevalence and risk factors of DSAs in pediatric candidates remain to be determined. In a prospective trial (ChiCTR-OPC-15006672), 486 children with hematological diseases were enrolled to screen for the presence of anti-HLA class I and II antibodies of immunoglobulin G type. Fifty two patients (10.7%) demonstrated positive panel-reactive antibody (PRA) for class I; 24 (4.9%), for class II; and 13 (2.7%), for both. Multivariate analysis showed diagnosis was the independent risk factor for antibodies, as acute lymphoblastic leukemia (ALL) patients (HR0.141, 95% CI: 0.037-0.538, p = 0.004) had a lower incidence of class II PRAs and DSAs against HLA-B, DQ, and DR, whereas myelodysplastic syndrome (MDS) patients had a higher incidence of PRAs for both class I and class II (HR4.790, 95% CI: 1.010-22.716, p = 0.049), and DSAs against HLA-A, B, C, DP, and DQ. Older age (>12 vs. ≤12) was associated with DSAs against HLA-DP (HR0.194, 95% CI: 0.041-0.918, p = 0.039). Our findings provided novel evidence for prevalence and risk factors for PRAs and DSAs in pediatric candidates receiving haplo-HSCT, possibly benefiting anti-HLA antibody monitoring and donor selection.

Prevalence and risk factors of antibodies to human leukocyte antigens in haploidentical stem cell transplantation candidates: A multi-center study.

We investigated the prevalence of and risk factors for antibodies to HLA in 1663 haploidentical transplant candidates. Among these cases, 349 (21.0%) showed positive panel-reactive antibody (PRA) either for class I or class II HLA. Multivariate analysis showed the following: i) risk factors associated with the prevalence of PRA either for class I or class II HLA were female gender (P = 0.018), prior transfusions (P < 0.001) or pregnancy (P < 0.001), and cases with MDS (P = 0.018); compared to other patients, subjects with ALL had a lower prevalence of class I antibodies (P = 0.017); and ii) risk factors associated with the prevalence of PRA both for class I and class II HLA were female gender (P = 0.014), prior transfusions (P = 0.003), previous pregnancy (P < 0.001), and diagnosis with MDS (P = 0.035). The percentages of antibodies against different antigens coded by the different HLA loci, including HLA-A, -B, -C, -DP, -DQ, and -DR, among all cases were 15.6%, 17.3%, 10.5%, 5.6%, 8.5%, and 9.7%, respectively. Risk factors associated with specific antibodies against HLA-A, -B, -C, -DP, -DQ, and -DR were female gender, prior transfusion, previous pregnancy, and underlying disease. Our findings suggest that gender, prior pregnancy, transfusion and underlying diseases are risk factors for HLA sensitization, which could guide HLA antibody monitor and donor selection.