Targeting and cytotoxicity of chimeric antigen receptor T cells grafted with PD1 extramembrane domain.

BACKGROUND: Immunosuppression induced by programmed cell death protein 1 (PD1) presents a significant constraint on the effectiveness of chimeric antigen receptor (CAR)-T therapy. The potential of combining PD1/PDL1 (Programmed cell death 1 ligand 1) axis blockade with CAR-T cell therapy is promising. However, developing a highly efficient and minimally toxic approach requires further exploration. Our attempt to devise a novel CAR structure capable of recognizing both tumor antigens and PDL1 encountered challenges since direct targeting of PDL1 resulted in systemic adverse effects. METHODS: In this research, we innovatively engineered novel CARs by grafting the PD1 domain into a conventional second-generation (2G) CAR specifically targeting CD19. These CARs exist in two distinct forms: one with PD1 extramembrane domain (EMD) directly linked to a transmembrane domain (TMD), referred to as PE CAR, and the other with PD1 EMD connected to a TMD via a CD8 hinge domain (HD), known as PE8HT CAR. To evaluate their efficacy, we conducted comprehensive assessments of their cytotoxicity, cytokine release, and potential off-target effects both in vitro and in vivo using tumor models that overexpress CD19/PDL1. RESULTS: The findings of our study indicate that PE CAR demonstrates enhanced cytotoxicity and reduced cytokine release specifically towards CD19 + PDL1 + tumor cells, without off-target effects to CD19-PDL1 + tumor cells, in contrast to 2G CAR-T cells. Additionally, PE CAR showed ameliorative differentiation, exhaustion, and apoptosis phenotypes as assessed by flow cytometry, RNA-sequencing, and metabolic parameter analysis, after encountering CD19 + PDL1 + tumor cells. CONCLUSION: Our results revealed that CAR grafted with PD1 exhibits enhanced antitumor activity with lower cytokine release and no PD1-related off-target toxicity in tumor models that overexpress CD19 and PDL1. These findings suggest that our CAR design holds the potential for effectively addressing the PD1 signal.

Efficacy and safety of human umbilical cord-derived mesenchymal stem cells (hUC-MSC PLEB001) for the treatment of grade II-IV steroid-refractory acute graft-versus-host disease: a study protocol for a multicenter, randomized, double-blind, placebo-controlled, phase II trial.

BACKGROUND: Systemic corticosteroid therapy failure is quite common in patients with newly diagnosed acute graft-versus-host disease (aGVHD). Growing evidence has suggested that mesenchymal stem cell (MSC) therapy could be a promising treatment option for aGVHD due to its distinctive immunomodulating functions. However, there is a lack of randomized well-controlled clinical trials. METHODS: This is a clinical trial protocol for a multicenter, randomized, double-blind, placebo-controlled phase II study. The aim of the trial is to evaluate the efficacy and safety of the administration of the human umbilical cord-derived MSC product hUC-MSC PLEB001 in patients with grade II-IV, steroid-refractory aGVHD. A total of 96 patients will be randomized 1:1 to receive MSC or placebo treatment twice per week for 4 weeks, in addition to second-line therapy according to institutional standards. Patients who achieve partial response (PR) at day 28 will be eligible to receive further infusions twice per week for an additional 4 weeks. DISCUSSION: This study will evaluate the efficacy and safety of MSC therapy in patients who have failed first-line steroid treatment for grade II-IV aGVHD. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), ChiCTR2000035740. Registered on 16 August 2020.

[Efficacy and Safety of Allogeneic Hematopoietic Stem Cell Transplantation with Decitabine-containing Regimen in Myelodysplastic Syndromes and Myelodysplastic Syndromes Transformed Acute Myeloid Leukemia].

OBJECTIVE: To evaluate the efficacy and safety of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with decitabine (Dec)-conditioning regimen in the treatment of myelodysplastic syndrome (MDS) and MDS transformed acute myeloid leukemia (MDS-AML). METHODS: The characteristics and efficacy data of 93 patients with MDS and MDS-AML who received allo-HSCT in our center from April 2013 to November 2021 were retrospectively analyzed. All patients were administered by myeloablative conditioning regimen containing Dec (25 mg/m2 /d×3 d). RESULTS: Among the 93 patients, 63 males and 30 females, were diagnosed as MDS（n ＝77）, MDS-AML（n ＝16）. The incidence of I/II grade regimen-related toxicity (RRT) was 39.8%, and III grade RRT was only found in 1 patient (1%). Neutrophil engraftment was successful in 91 (97.8%) patients after a median neutrophil engraftment time of 14 (9-27) days; Successful platelet engraftment was achieved in 87 (93.5%) patients, with a median engraftment time of 18 (9-290) days. The incidence of acute graft versus host disease（aGVHD） and grade III-IV aGVHD was 44.2% and 16.2%, respectively. The incidence of chronic graft versus host disease（cGVHD） and moderate-to-severe cGVHD was 59.5% and 37.1%, respectively. Of the 93 patients, 54 (58%) developed posttransplant infections, among which lung infection (32.3%) and bloodstream infection (12.9%) were the most common. The median follow-up after transplantation was 45 (0.1-108) months. The 5-year overall survival (OS) rate, disease-free survival (DFS) rate, treatment-related mortality, and cumulative incidence of relapse were 72.7%, 68.4%, 25.1%, and 6.5%, respectively. And the 1-year graft-versus-host disease/relapse-free survival rate was 49.3%. The patients in different group of relative high-risk prognostic scoring or low-risk prognostic scoring, with or without poor-risk mutation(s), with mutations number ≥3 or <3 had similar 5-year OS rate (more than 70%). Multivariate analysis showed that the incidence of grade III-IV aGVHD was the independent risk factor affecting OS（P =0.008）and DFS (P =0.019). CONCLUSION: Allo-HSCT with Dec-conditioning regimen is feasible and effective in the treatment of patients with MDS and MDS-AML, especially those in high prognostic risk and with poor-risk mutations.

Expert consensus on microtransplant for acute myeloid leukemia in elderly patients -report from the international microtransplant interest group.

Recent studies have shown that microtransplant (MST) could improve outcome of patients with elderly acute myeloid leukemia (EAML). To further standardize the MST therapy and improve outcomes in EAML patients, based on analysis of the literature on MST, especially MST with EAML from January 1st, 2011 to November 30th, 2022, the International Microtransplant Interest Group provides recommendations and considerations for MST in the treatment of EAML. Four major issues related to MST for treating EAML were addressed: therapeutic principle of MST (1), candidates for MST (2), induction chemotherapy regimens (3), and post-remission therapy based on MST (4). Others included donor screening, infusion of donor cells, laboratory examinations, and complications of treatment.

Circulating mitochondrial DNA is associated with anemia in newly diagnosed hematologic malignancies.

Recent reports discovered that red blood cells (RBCs) could scavenge cell-free mitochondrial DNA (mtDNA), which drives the accelerated erythrophagocytosis and innate immune activation characterized by anemia and inflammatory cytokine production. However, the clinical value of the circulating mtDNA copy number alterations in hematologic malignancies is poorly understood. Our data showed that in comparison to healthy group, the patients group had significantly higher mtDNA and histone H4 levels. Moreover, we observed that RBC-bound mtDNA and histone H4 were negatively correlated with hemoglobin in patients. In addition, cytokines and chemokines levels in patients differed significantly from normal controls (21 higher, 7 lower). Our study suggested that both circulating mtDNA and histone H4 were associated with anemia in hematologic malignancies, which helps to further understand the potential mechanism of anemia development in patients with hematologic malignancies. This information may play a vital role in the specific therapeutic interventions for leukemia in the future.

Allogeneic haematopoietic stem cell transplantation with decitabine-containing preconditioning regimen in TP53-mutant myelodysplastic syndromes: A case study.

Myelodysplastic syndrome (MDS) with TP53 mutations has a poor prognosis after transplantation, and novel therapeutic means are urgently needed. Decitabine (Dec) monotherapy has demonstrated improved overall response rates in MDS and acute myeloid leukaemia, although these responses were not durable. This study aimed to preliminary evaluate the efficacy of a Dec-containing allogeneic haematopoietic stem cell transplantation (allo-HSCT) preconditioning regimen in TP53-mutant MDS. Nine patients with TP53-mutant myelodysplastic syndromes received the decitabine-containing preconditioning regimen and subsequent myeloablative allo-HCT between April 2013 and September 2021 in different centres. At a median follow-up of 42 months (range, 5 to 61 months), the overall survival (OS) was 89% (8/9), progression-free survival (PFS) was 89% (8/9), and relapse incidence was 11.1%. The incidence of severe acute (grade III-IV) graft-versus-host disease (GVHD) was 22.2% (2/9) and that of chronic moderate-to-severe GVHD was 11.1% (1/9). The 1-year GVHD-free/relapse-free survival (GRFS) was 56% (5/9). In conclusion, we found real-world clinical data that supports the use of a Dec-containing preconditioning regimen before allo-HSCT for possible improved outcomes in TP53-mutant MDS patients; there is therefore an urgent call for an in-depth exploration of the involved mechanism to confirm these preliminary findings.

[Analysis of Factors Influencing Autologous Peripheral Blood Stem Cells Mobilization in Patients with Lymphoma and Multiple Myeloma].

OBJECTIVE: To analyze the factors influencing the mobilization of autologous peripheral blood stem cells (auto-PBSCs) in patients with lymphoma and multiple myeloma, and provide reference for optimizing the autologous stem cell mobilization regimen. METHODS: Clinical data of 33 multiple myeloma and lymphoma patients received auto-PBSCs mobilization in our center from January 2015 to December 2018 were collected, the correlation of mobilization failure rate with gender, age, courses of chemotherapy before mobilization, does of recombinant human granulocyte colony stimulating factor (rhG-CSF), type of disease, and chemotherapy regimen were retrospectively analyzed. RESULTS: Type of disease and course of pre-mobilization chemotherapy could affect the mobilization failure rate (P<0.05). The mobilization failure rate of lymphoma patients was 42.1%, which was significantly higher than 7.1% of multiple myeloma patients (P=0.026). The mobilization failure rate was higher in the group with chemotherapy courses≥5 before mobilization (P=0.016). Age, gender, dose of rhG-CSF, and chemotherapy regimen had no significant correlation with mobilization failure rate (P>0.05). CONCLUSION: Multi-course chemotherapy before collection and lymphoma patients are poor factors negatively impacting on auto-PBSCs mobilization.

CD19 CAR-T Cells With Membrane-Bound IL-15 for B-Cell Acute Lymphoblastic Leukemia After Failure of CD19 and CD22 CAR-T Cells: Case Report.

Objectives: At present, reinfusions of chimeric antigen receptor (CAR)-T cell have exhibited limited efficacy, while their efficacy on extramedullary relapse remains to be further elucidated in B-cell acute lymphoblastic leukemia (B-ALL). Although combination with IL-15 demonstrated the potential to enhance antitumor activity of CAR-T, the efficacy of this approach remains to be validated clinically. Methods: We reported a patient with B-ALL with extramedullary relapse after allogeneic stem cell transplantation and who was resistant to chemotherapy and radiotherapy. In total, he received four treatments with CAR-T cells repeatedly under the status of disease progression. Results: First, the patient received autologous murine CAR19-CD28-CD3ζ-T cells and achieved full resolution of extramedullary leukemia lasting 8 months. After systemic disease relapse, he received autologous humanized CAR22-41BB-CD3ζ-tEGFR-T cells and achieved complete remission (CR) with incomplete blood count recovery (CRi) with minimal residual disease (MRD) negativity in the bone marrow and shrinkage of extramedullary leukemia. Over 2 months later, he experienced a relapse of the systemic disease and he received autologous murine CAR19-41BB-CD3ζ-mIL15-T cells and achieved CRiMRD- lasting 5 months with the strongest expansion and persistence of CAR. Finally, on relapse of CD19- medullary disease, he received allogeneic humanized CAR22-41BB-CD3ζ-tEGFR-T cells but only achieved a transient decrease in the number of blasts. No CAR-T-cell-related encephalopathy syndrome was observed, and all side effects were manageable. Conclusion: Our report hints the feasibility and safety of CD19 CAR-T cell expressing membrane-bound IL-15 for patient with B-ALL even if relapsed after multiple CAR-T-cell therapies.

Cytoplasmic NEAT1 Suppresses AML Stem Cell Self-Renewal and Leukemogenesis through Inactivation of Wnt Signaling.

As an essential component of paraspeckles, nuclear paraspeckle assembly transcript 1 (NEAT1) localizes in the nucleus, promoting progression of various malignant solid tumors. Herein, an adverse effect of NEAT1 is reported, showing that the short isoform, NEAT1_1 suppresses acute myeloid leukemia (AML) development. NEAT1_1 is downregulated in leukemia stem cells (LSCs) and its decreased expression correlates with recurrence in AML patients. It is demonstrated that NEAT1_1 suppresses leukemogenesis and LSC function but is dispensable for normal hematopoiesis. Mechanistically, NEAT1_1 is released from the nucleus into the cytoplasm of AML cells, regulated by transcription factor C/EBPß and nuclear protein NAP1L1. Cytoplasmic NEAT1_1 interacts with Wnt component DVL2 and E3 ubiquitin ligase Trim56, facilitates Trim56-mediated DVL2 degradation, and thus suppresses Wnt signaling. Collectively, the findings show NEAT1_1 is translocated from the nucleus to the cytoplasm and acts as a tumor suppressor in AML.

A Retrospective Observation of Treatment Outcomes Using Decitabine-Combined Standard Conditioning Regimens Before Transplantation in Patients With Relapsed or Refractory Acute Myeloid Leukemia.

Hypomethylating agents, decitabine (DAC) and azacitidine, can act as prophylactic and pre-emptive approaches after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and a non-intensive bridging approach before allo-HSCT. However, they are rarely used as a part of conditioning regimens in patients with relapsed or refractory acute myeloid leukemia (AML). This retrospectively study included a total of 65 patients (median, 37; range, 13-63) with relapsed or refractory AML who were treated by allo-HSCT after myeloablative conditioning regimens without or with DAC (high-dose DAC schedule, 75 mg/m2 on day -9 and 50 mg/m2 on day -8; low-dose DAC schedule, 25 mg/m2/day on day -10 to -8). DAC exerted no impact on hematopoietic reconstitution. However, patients who were treated with the high-dose DAC schedule had significantly higher incidence of overall survival (OS, 50.0%) and leukemia-free survival (LFS, 35.0%), and lower incidence of relapse (41.1%) and grade II-IV acute graft versus host disease (aGVHD, 10.0%) at 3 years, when compared with those treated with standard conditioning regimens or with the low-dose DAC schedule. In conclusion, high-dose DAC combined with standard conditioning regimens before allo-HSCT is feasible and efficient and might improve outcomes of patients with relapsed or refractory AML, which provides a potential approach to treat these patients.

A multicenter retrospective study on the real-world outcomes of autologous vs. allogeneic hematopoietic stem cell transplantation for peripheral T-cell lymphoma in China.

BACKGROUND: There were few studies on real-world data about autologous hematopoietic stem cell transplantation (auto-HSCT) or allogeneic HSCT (allo-HSCT) in peripheral T-cell lymphoma (PTCL). This study aimed to investigate the clinical outcomes of patients who received auto-HSCT or allo-HSCT in China. METHODS: From July 2007 to June 2017, a total of 128 patients who received auto-HSCT (n  = 72) or allo-HSCT (n  = 56) at eight medical centers across China were included in this study. We retrospectively collected their demographic and clinical data and compared the clinical outcomes between groups. RESULTS: Patients receiving allo-HSCT were more likely to be diagnosed with stage III or IV disease (95% vs. 82%, P = 0.027), bone marrow involvement (42% vs. 15%, P = 0.001), chemotherapy-resistant disease (41% vs. 8%, P = 0.001), and progression disease (32% vs. 4%, P < 0.001) at transplantation than those receiving auto-HSCT. With a median follow-up of 30 (2-143) months, 3-year overall survival (OS) and progression-free survival (PFS) in the auto-HSCT group were 70%(48/63) and 59%(42/63), respectively. Three-year OS and PFS for allo-HSCT recipients were 46%(27/54) and 44%(29/54), respectively. There was no difference in relapse rate (34%[17/63] in auto-HSCT vs. 29%[15/54] in allo-HSCT, P = 0.840). Three-year non-relapse mortality rate in auto-HSCT recipients was 6%(4/63) compared with 27%(14/54) for allo-HSCT recipients (P = 0.004). Subanalyses showed that patients with lower prognostic index scores for PTCL (PIT) who received auto-HSCT in an upfront setting had a better outcome than patients with higher PIT scores (3-year OS: 85% vs. 40%, P = 0.003). Patients with complete remission (CR) undergoing auto-HSCT had better survival (3-year OS: 88% vs. 48% in allo-HSCT, P = 0.008). For patients beyond CR, the outcome of patients who received allo-HSCT was similar to that in the atuo-HSCT group (3-year OS: 51% vs. 46%, P = 0.300). CONCLUSIONS: Our study provided real-world data about auto-HSCT and allo-HSCT in China. Auto-HSCT seemed to be associated with better survival for patients in good condition (lower PIT score and/or better disease control). For patients possessing unfavorable characteristics, the survival of patients receiving allo-HSCT group was similar to that in the auto-HSCT group.

Observation on the effect of adoptive immunotherapy with activated autologous lymphocytes in the treatment of primary hepatocellular carcinoma / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：评价活化自体淋巴细胞过继性免疫治疗（adoptive immunotherapy，AIT）是否有助于改善原发性肝细胞癌的临床疗效。方法：选取2016年8月至2018年12月在中国人民解放军总医院第五医学中心确诊的64例原发性肝细胞癌患者，通过分层随机法分为免疫治疗组（n=29）和对照组（n=35）。免疫治疗组患者取60 ml外周血分离制备单个核细胞并在含OKT-3和IL-2的培养基中活化培养，回输前进行质控检测。免疫治疗组中的Ⅰ~Ⅲ期患者（n=14）于一线治疗后接受自体淋巴细胞输注（3个月内输注6次），Ⅳ期患者（n=15）仅接受自体淋巴细胞输注；对照组患者接受肝细胞癌相关的其他治疗。疗效评估的主要终点是2年无复发生存（relapse-free survival，RFS）率，次要终点为无进展生存期（progression-free survival，PFS）和总生存期（overall survival，OS）。结果：入组患者中位随访时间为2.8年（0.2~4.2年）。免疫治疗组29名患者共接受了167次（计划174次，完成率96%）预定淋巴细胞输注（平均每人次回输9.30×109个细胞，其中CD3+HLA-DR细胞约占63%），治疗期间未观察到3级或4级不良反应发生。与对照组相比，免疫治疗组患者2年RFS率显著升高（62.1% vs 22.9%，OR=0.181，95%CI：0.06~0.54，P=0.002），中位PFS（28 vs 8个月，P=0.004）和中位OS（38 vs 34个月，P=0.915）均显著延长。在Ⅰ~Ⅲ期患者中，免疫治疗组（n=14）2年RFS率较对照组（n=18）显著升高（92.9% vs 33.3%，OR=0.38，95%CI：0.004~0.368，P=0.005），中位PFS明显延长（38 vs 14.5个月，P=0.005），而两组OS间无显著差异；Ⅳ期患者两组间PFS（P=0.077）及OS（P=0.994）均未见显著差异。结论：活化自体淋巴细胞AIT为安全可行的肝细胞癌辅助性治疗方法，可提高Ⅰ~Ⅲ期肝细胞癌一线治疗后RFS率、延长患者RFS时间，而对进展期肝细胞癌患者的PFS和OS无明显影响。

Secretion of human soluble programmed cell death protein 1 by chimeric antigen receptor-modified T cells enhances anti-tumor efficacy.

BACKGROUND AIMS: Chimeric antigen receptor (CAR) T cells have achieved favorable responses in patients with hematologic malignancies, but the outcome has been far from satisfactory in the treatment of tumors with high expression of immunosuppressive molecules. To overcome this limitation, we modified CAR T cells to secrete types of human soluble programmed cell death protein 1 (PD-1) called sPD-1 CAR T cells. METHODS: To compare the effector function between second (conventional second-generation CAR targeting CD19) and sPD-1 CAR T cells, we measured cytotoxicity, cytokine secretion and activation markers incubated with or without tumor cells expressing CD19 and/or programmed cell death ligand 1 (PD-L1). Furthermore, the anti-tumor efficacy of second and sPD-1 CAR T cells was determined using an NSG mouse model bearing NALM-6-PD-L1. Finally, the underlying mechanism was investigated by metabolic parameters and RNA sequencing analysis of different CAR T cells. RESULTS: Compared with second CAR T cells, sPD-1 CAR T cells enhanced killing efficiency toward CD19+PD-L1+ tumor cells in vitro. Furthermore, sPD-1 CAR T cells reduced the tumor burden and prolonged overall survival of the NSG (NOD-SCID-IL2rg) mice bearing NALM-6-PD-L1. To explore the effect of soluble PD-1 on CAR T cells, we found that sPD-1 CAR T cells exhibited higher levels of activation and ameliorative profiles of differentiation, exhaustion, glycolysis and apoptosis. CONCLUSIONS: With constitutive soluble PD-1 secretion, sPD-1 CAR T cells have tended to eradicate tumors with a high expression of PD-L1 more effectively than second CAR T cells. This may be due to soluble PD-1 enhancing apoptosis resistance, aerobic metabolism and a more "stem" differentiation of CAR T cells. Overall, our study presents a feasible strategy to increase the efficacy of CAR T cells.

The Association of Circulating T Follicular Helper Cells and Regulatory Cells with Acute Myeloid Leukemia Patients.

OBJECTIVE: This study aims to investigate the association of circulating T follicular helper (cTfh) cells and T follicular regulatory (cTfr) cells with acute myeloid leukemia (AML) patients. METHODS: A total of 22 newly diagnosed, untreated AML patients as well as 26 healthy controls were enrolled. Percentages of cTfh and cTfr cells were detected using flow cytometry. RESULTS: Compared to healthy controls, a significantly higher percentage of cTfr cells was observed in AML patients (4.10 ± 11.18 vs. 0.63 ± 0.38%) (p < 0.05). In addition, a significantly lower cTfh/cTfr ratio was found in the AML patients' group when compared to the control group (9.04 ± 9.19 vs. 11.66 ± 5.68) (p < 0.05). A lower level of plasma IL-2 and TGF-ß1 was found in AML patients. Based on the complete remission (CR) response after one cycle of inductive chemotherapy, patients were divided into two groups at sample collection: AML with and without CR. Significantly lower percentages of cTfr cells and a higher cTfh/cTfr ratio were found in the group of AML patients with CR than in the AML patients without CR. CONCLUSION: There was a significantly higher percentage of cTfr cells in AML patients. cTfr cells may have a potential association with the pathogenesis of AML patients.

Quantitative Analysis of Thymus-Independent Donor-Derived T Cell Expansion in Transplant Patients.

Although thymus-independent donor-derived T cell expansion may determine the occurrence of graft-versus-host disease (GVHD) and relapse after transplantation, the characteristics and dynamics of the expansion process remain unclear. To address this issue, we monitored T cell receptor ß repertoire at day 0, day 28, and day 61 after transplantation in 30 patients with hematologic malignancies by next-generation sequencing. The clonality index showed an increasing clonality over time (P = .001). The top 200 clonotypes accounted for more than half of the total clonotypes (median frequency, 63.55%) at day 61, and there was a remarkable overlapping between the top 200 clonotypes of each repertoire and its former repertoire (>50%). A normalized index, called the T Cell Response Index (TCRI), was designed on the basis of rank-shift analysis to quantify antigen-driven expansion. The TCRI during the first month was not related to relapse or GVHD (P> .05), whereas the TCRI during the second month was related to relapse (P = .006). Recipients with a TCRI below 1.0 during the second month had a higher cumulative relapse rate (31.25% versus 0%, P = .0323) and had a lower 1-year survival rate (56.25% versus 78.57%, P = .281). The clonotypes with strong competitiveness in the second month in the nonrelapse group preferentially used TRBV2, TRBV12-3, TRBJ1-1 and TRBJ1-5 segments (P< .01). In conclusion, homeostatic expansion predominates in the first month due to nonspecific T cell proliferation, whereas antigen-driven expansion predominates in the second month and results in a graft-versus-tumor (GvT) effect. Moreover, TCRI could serve as a quantitative indicator of GvT against relapse within the first year. The difference in V and J segment usage reveals that T cells responsible for potent GvT effect are similar among patients.

CRISPR-Edited Stem Cells in a Patient with HIV and Acute Lymphocytic Leukemia.

The safety of CRISPR (clustered regularly interspaced short palindromic repeats)-based genome editing in the context of human gene therapy is largely unknown. CCR5 is a reasonable but not absolutely protective target for a cure of human immunodeficiency virus type 1 (HIV-1) infection, because CCR5-null blood cells are largely resistant to HIV-1 entry. We transplanted CRISPR-edited CCR5-ablated hematopoietic stem and progenitor cells (HSPCs) into a patient with HIV-1 infection and acute lymphoblastic leukemia. The acute lymphoblastic leukemia was in complete remission with full donor chimerism, and donor cells carrying the ablated CCR5 persisted for more than 19 months without gene editing-related adverse events. The percentage of CD4+ cells with CCR5 ablation increased by a small degree during a period of antiretroviral-therapy interruption. Although we achieved successful transplantation and long-term engraftment of CRISPR-edited HSPCs, the percentage of CCR5 disruption in lymphocytes was only approximately 5%, which indicates the need for further research into this approach. (Funded by the Beijing Municipal Science and Technology Commission and others; ClinicalTrials.gov number, NCT03164135.).

Prevalence and risk factors of human pegivirus type 1 infection in hematopoietic stem cell transplantation patients.

OBJECTIVES: To investigate the prevalence, risk factors, and genotypes of human pegivirus type 1 (HPgV-1) in hematopoietic stem cell transplantation (HSCT) patients. METHODS: One hundred and eighty-eight HSCT patients and 694 healthy blood donors were investigated retrospectively, including their demographic information and HPgV-1 infection status. RESULTS: When compared with healthy blood donors, a significantly higher HPgV-1 prevalence (18.6% vs. 2.3%) and a high risk of HPgV-1 infection (odds ratio 9.7) were observed in HSCT patients (p<0.05). The number of transfusions in patients with RNA test conversions (negative to positive) was significantly higher than the number in patients without conversions (negative to negative) (median 10 vs. 1) (p<0.05). Although HPgV-1 infection is independent of age, sex, blood type, hepatitis B virus infection, hepatitis C virus infection, marriage status, and type of hematological malignancy (p>0.05), race might be a risk factor for infection (p<0.05). The great majority (95.7%) of HPgV-1-positive patients were infected with genotype 3. CONCLUSIONS: HPgV-1 is highly prevalent in HSCT patients, and blood transfusions can significantly increase the risk of HPgV-1 infection. Thus, HPgV-1 screening is recommended in HSCT patients to reduce the potential impact of infection on survival, as well as in their blood and stem cell donors to reduce the risk of infection after transfusions, unless the beneficial effects of HPgV-1 infection in immunocompromised patients are clearly confirmed.

Long-term efficacy of dendritic cell vaccines combined with cytokine-induced killer cells in the treatment of metastatic renal cell carcinoma / 中国肿瘤生物治疗杂志

@# Objective: To evaluate the long-term clinical efficacy and follow-up of dendritic cell (DC) vaccines in combination with cytokine-induced killer cell (CIK) treatment in metastatic renal cell carcinoma. Methods: From January 2011 to December 2013, 29 patients with metastatic renal cell carcinoma (pathologically confirmed as renal clear cell carcinoma) were treated by DC vaccines-CIK at the Department of Hematopoietic Stem Cell Transplantation, the Fifth Medical Center of Chinese PLA General Hospital. The 29 patients included 24 male and 5 female, with a median age of 57(32-81) years old. Mature DC vaccine was obtained by gene transfection technology and CIK cells were obtained by i n v i t r o culture; and DC vaccine-CIK was infused back to patients through lymphatic drainage area and vein by each course. Twelve patients received first line treatment, 6 patients received second line treatment after the disease progression by targeted drug therapy or cytokine therapy, and 11 patients received third-linetreatment or above. The long-term clinical efficacy and overall survival rate were evaluated. Results: The median follow-up time was 5 (1-7) years. Treatment cycle was over 2 (2-23) cycles. One case (3.4%) achieved complete remission, 9 cases (31%) achieved partial responses, 13 cases (44.8%) demonstrated stable disease over 3 months and 6 patients (20.7%) developed progressive disease. The objective response rate was 34.4%,and the disease control rate was 79.2%. Stable disease for more than one year realized in 19 cases (65.5%). The 1-, 3- and 5-year survival rates were 93.1% (27/29), 65.5% (20/29) and 51.7% (15 / 29), respectively. Neither the median progression-free survival (PFS) nor the median survival time was achieved. No adverse reactions above grade 3 were observed during treatment. Conclusion: DC vaccines-CIK therapy for the treatment of metastatic renal cell carcinoma is affirmative; it achieved good disease control and long-term survival with controllable safety, and prolonged the survival time for advanced renal cell carcinoma patients.