Clinical analysis of long-term survival and influencing factors of chimeric antigen receptor T-cell therapy in relapsed/refractory acute B-cell lymphoblastic leukemia / 中华血液学杂志

Objective: To analyze the survival and influencing factors of chimeric antigen receptor (CAR) T-cell therapy in relapsed/refractory acute B-cell lymphoblastic leukemia (R/R B-ALL) . Methods: Clinical information of patients who received CAR-T-cell therapy and achieved complete remission of R/R B-ALL between May 2015 and June 2018 at the Shaanxi Provincial People's Hospital was obtained. Kaplan-Meier analysis was used to evaluate the overall survival (OS) and leukemia-free survival (LFS) times of patients, and Cox regression analysis was performed to analyze the prognostic factors that affect patient survival after CAR-T therapy. Results: Among the 38 patients with R/R B-ALL, 21 were men, with a median age of 25 (6-59) years and a median OS time of 18 (95% CI 3-33) months. Multivariate Cox regression analysis showed that positive MLL-AF4 fusion gene expression was an independent risk factor for OS and LFS (OS: HR=4.888, 95% CI 1.375-17.374, P=0.014; LFS: HR=6.683, 95% CI 1.815-24.608, P=0.004). Maintenance therapy was a protective factor for OS and LFS (OS: HR=0.153, 95% CI 0.054-0.432, P<0.001; LFS: HR=0.138, 95% CI 0.050-0.382, P<0.001). In patients with MRD negative conversion, LFS benefit (HR=0.209, 95% CI 0.055-0.797, P=0.022) and OS difference was statistically insignificant (P=0.111). Moreover, patients with high tumor burden were risk factors for OS and LFS at the level of 0.1 (OS: HR=2.662, 95% CI 0.987-7.184, P=0.053; LFS: HR=2.452, 95% CI 0.949-6.339, P=0.064) . Conclusion: High tumor burden and high-risk genetics may affect the long-term survival rate of patients with R/R B-ALL receiving CAR-T, and lenalidomide-based maintenance therapy may improve their prognosis.

Influence of dendritic cells on biological activity of the homologous CIK cells and its anti-leukemia effect in vitro / 中国实验血液学杂志

This study was aimed to investigate the effect of cord blood dendritic cells (DCs) on the in vitro proliferation capability, immunophenotype changes, level of secreted cytokines and activity against leukemia cells of the homologous cytokine-induced killer (CIK) cells. DCs and CIK cells were induced from cord blood mononuclear cells. They were co-cultured at the ratio of 1:5, and CIK cells from cord blood or DC-CIK cells from peripheral blood were cultured as controls. Immunophenotypic changes were analyzed by flow cytometry, increased number of cells were counted by trypan-blue staining, the killing activity to leukemia cells was assayed by MTT, the levels of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12) in the cultured supernatant were detected by ELISA. The results showed that the proliferation capability of cord blood DC-CIK cells was significantly higher than that of cord blood CIK cells and peripheral blood DC-CIK cells (p < 0.05 and p < 0.05). Under the same condition, the rate of double positive cells with CD3(+)CD8(+) and CD3(+)CD56(+) in CIK cells was significantly enhanced by co-culture with cord blood DCs (p < 0.05). The level of IL-12, IFN-γ, and TNF-α in cultured supernatants of cord blood DC-CIK cells increased noticeably on day 3 as compared with CIK cells cultured alone (p < 0.01, p < 0.05, p < 0.05). Within the effector-target ratio range between 2.5:1 to 20:1, the activity of cord blood DC-CIK cells against all subtypes of acute leukemia cells was much higher than that of CIK cells (p < 0.05), and there was no significant difference among all subtypes of acute leukemia cells, which was the same with the killing effect of peripheral blood DC-CIK cells against leukemia cells. It is concluded that the proliferation capability and anti-leukemia effect of the homologous CIK cells can be enhanced by cord blood DCs. The proliferation capability of cord blood DC-CIK cells is stronger than that of peripheral blood DC-CIK cells, but there is no significant differences of cytotoxicity between DCs and CIK cells. As the cord blood is easily gained and does not easily cause a serious graft rejection, the DC-CIK cells should be clinically applied more extensively as novel immune therapy.

Biological activity of DC-CIK cells and its effect against leukemia cells in vitro / 中国实验血液学杂志

This study was aimed to investigate the effect of dendritic cells (DC) on the proliferation capability, immunophenotype changes, level of secreted cytokines and activity against leukemia of cytokine-induced killer (CIK) cells in vitro. DCs and CIK cells were induced from peripheral blood mononuclear cells of healthy volunteers. They were co-cultured meanwhile CIK cells were cultured alone as controls. Increased number of cells were counted by trypan-blue staining; the killing activity was detected by MTT assay; immunophenotype changes were analyzed by flow cytometry; the IL-12 and INF-gamma levels of the cultured supernatants were detected by ELISA kits. The results showed that the proliferation capability of DC-CIK cells was significantly higher than that of CIK cells (p < 0.05). Under the same condition, the ratio of double positive cells such as CD3(+) CD8(+), CD3(+) CD56(+) in CIK cells was significantly enhanced by co-cultured with DC cells (p < 0.05). The levels of IL-12 and INF-gamma in cultured supernatants of DC-CIK cells increased noticeably on day 3 as compared with CIK cells cultured alone (p < 0.01, p < 0.05). Within the effector-target ratio range between 5:1 to 40:1, the activity of DC-CIK cells against leukemia cells were much higher than that of CIK cells (p < 0.05), and this effect showed a positive correlation with the effector-target ratio. It is concluded that the proliferation capability of DC-CIK cells, the level of their secreted cytokines and their activity against leukemia cells are significantly higher than those of CIK cells. This research may suggest an approach for clinical immunotherapy against leukemia with DC-CIK cells.

Influence of IFN-alpha on function of CML-DC in vitro and expression of chemokine with its receptor / 中国实验血液学杂志

To study the influence of IFN-alpha on function of CML-DC cultured in vitro and expression of chemokine and its chemokine receptor, bone marrow mononuclear cells from 13 CML patients were cultured in the fetal calf serum culture system supplemented with rhSCF, rhFlt-3L for expansion system, and adding rhGM-CSF, rhTNF-alpha, rhIL-4, with or without rhIFN-alpha to induce DCs. After incubation for two weeks, the phenotypes of CML-DC were analyzed by direct immunofluorescence and flow cytometry. The concentration of MIP-3beta expressed by CML-DC in the supernatant were analyzed by ELISA. The proliferative ability of T cells from healthy volunteers stimulated by CML-DCs were measured by MTT assay. The results showed that expression of CD86, CD83, CD40, MHC-I class molecules, CCR7, the concentration of MIP-3beta expressed by CML-DC, and the proliferative ability of T cells stimulated by CML-DCs in IFN-alpha group were all significantly higher than that in control group (P < 0.01). It is concluded that the immunophenotype of CML-DCs can be partially changed by IFN-alpha to accelerate the maturation of CML-DCs, enhance the capacity of CML-DCs, and stimulate allogeneic T lymphocyte proliferation.

Influence of interferon type I on dendritic cells in vitro - review / 中国实验血液学杂志

Dendritic cells(DC) are specialized antigen-presenting cells that prime naive T cells to induce initial immune responses. The immature DC capture and process antigens in the periphery, then emigrate to lymphoid organs. There they complete their maturation by upregulating HLA-I, II molecules, costimulatory molecules (eg. CD80, CD86) and adhesive molecules (eg. CD50, CD54, CD58). More studies showed that in vitro only interferons type I (IFN-alpha, beta) accelerate DC maturation in a dose-dependent manner. The DC induced by IFN type I highly express HLA-A, B, C, HLA-DR, costimulatory molecules and adhesive molecules, and they express enhancing effect of T-cells stimulatory activity in vitro. Progress of research in this field was summarized in this paper.