[Construction of CD138-targeted chimeric antigen receptor- modified T cells and their effect in multiple myeloma therapy].

Objective: To construct a novel chimeric antigen receptor T (CAR-T) cell targeting CD138 and to investigate its cytotoxicity against myeloma cells. Methods: The hybridoma strain that can stably secrete the CD138 monoclonal antibody (mAb) was prepared and obtained through monoclonal antibody screening technology. The hybridoma strain cells were intraperitoneally injected into mice to produce ascites containing monoclonal antibodies, which were then collected and purified to obtain pure CD138 mAb. Further examinations were performed to assess the biological characteristics of CD138 mAb. The variable region sequence of this antibody was amplified through reverse transcription polymerase chain reaction and was used as the antigen recognition domain of CD138 CAR, which was subsequently expressed on the surface of T cells by lentiviral infection. Flow cytometry was employed to assess the phenotype of CD138 CAR-T cells. In vitro cytotoxicity and degranulation assays were performed to evaluate their antitumor effects. Results: ① We successfully prepared anti-human CD138 antibody hybridoma cell lines and screened a hybridoma cell strain, 5G2, which could persistently and stably secrete the anti-CD138 antibody. ② The purified CD138 (5G2) mAb can especially recognize CD138(+) cells with a binding affinity constant (K(D)) of 6.011×10(-9) mol/L and showed no significant binding activity with CD138(-) cells. ③The variable region sequence of the CD138 (5G2) antibody was obtained using molecular cloning technology, and CD138 (5G2) CAR was successfully constructed and expressed on T cells through lentivirus infection and, concurrently, demonstrated effective binding to recombinant human CD138 protein.④ The proliferation of T cells transduced with the CD138 (5G2) CAR was highly efficient. The phenotype analysis revealed that CD138 (5G2) CAR-T cells exhibited a greater tendency to differentiate into central memory T cells and memory stem T cells, with a reduced proportion of terminally differentiated effector memory subsets. ⑤CD138 (5G2) CAR-T cells demonstrated specific cytotoxicity against CD138(+) myeloma cell line H929, whereas CD138(-) cell line K562 remained unaffected. The percentage of residual H929 cells was (12.92±8.02) % after co-culturing with CD138 (5G2) CAR-T cells, while (54.25±15.79) % was left in the Vector-T group (E∶T=1∶2; P<0.001). ⑥Results of degranulation assays demonstrated a significant activation of CD138 (5G2) CAR-T cells after co-culture with the H929 cell line, whereas no significant activation was observed in Vector-T cells [ (25.78±3.35) % vs (6.13±1.30) %, P<0.001]. ⑦After co-culturing with CD138(+) cells, CD138 (5G2) CAR-T cells exhibited a significant increase in cytokine secretion compared to the Vector-T group [interleukin-2: (1 697.52±599.05) pg/ml vs (5.07±1.17) pg/ml, P<0.001; interferon-γ: (3 312.20±486.38) pg/ml vs (9.28±1.46) pg/ml, P<0.001; and tumor necrosis factor-α: (1 837.43±640.49) pg/ml vs (8.75±1.65) pg/ml, P<0.001]. However, no significant difference was observed in cytokine secretion levels between the two groups after co-culturing with CD138(-) cells. Conclusion: This study successfully prepared a novel monoclonal antibody against CD138, and CAR-T cells constructed with the antigen recognition domain derived from this 5G2 mAb demonstrated effective antitumor activity against myeloma cells. This can be used as a new option for the detection of the CD138 antigen and proposes a novel strategy for multiple myeloma immunotherapy.

[Preparation of a dual-specific antibody targeting human CD123 and exploration of its anti-acute myeloid leukemia effects].

Objective: To construct a novel dual-specific antibody targeting human CD123 (CD123 DuAb) and study its effects in acute myeloid leukemia (AML) . Methods: Based on the variable region of the CD123 monoclonal antibody independently developed at our institution, the CD123 DuAb expression plasmid was constructed by molecular cloning and transfected into ExpiCHO-S cells to prepare the antibody protein. Through a series of in vitro experiments, its activation and proliferation effect on T cells, as well as the effect of promoting T-cell killing of AML cells, were verified. Results: ① A novel CD123 DuAb plasmid targeting CD123 was successfully constructed and expressed in the Expi-CHO eukaryotic system. ②The CD123 DuAb could bind both CD3 on T cells and CD123 on CD123(+) tumor cells. ③When T cells were co-cultured with MV4-11 cells with addition of the CD123 DuAb at a concentration of 1 nmol/L, the positive expression rates of CD69 and CD25 on T cells were 68.0% and 44.3%, respectively, which were significantly higher than those of the control group (P<0.05). ④Co-culture with CD123 DuAb at 1 nmol/L promoted T-cell proliferation, and the absolute T-cell count increased from 5×10(5)/ml to 3.2×10(6)/ml on day 9, and CFSE fluorescence intensity decreased significantly. ⑤ With the increase in CD123 DuAb concentration in the culture system, T-cell exhaustion and apoptosis increased. When the CD123 DuAb was added at a concentration of 1 nmol/L to the culture system, the proportion of CD8(+) PD-1(+) LAG-3(+) T cells was 10.90%, and the proportion of propidium iodide (PI) (-) Annexin Ⅴ(+) T cells and PI(+) Annexin Ⅴ(+) T cells was 18.27% and 11.43%, respectively, which were significantly higher than those in the control group (P<0.05). ⑥ The CD123 DuAb significantly activated T cells, and the activation intensity was positively correlated with its concentration. The expression rate of CD107a on T cells reached 16.05% with 1 nmol/L CD123 DuAb, which was significantly higher than that of the control group (P<0.05). ⑦The CD123 DuAb promoted cytokine secretion by T cells at a concentration of 1 nmol/L, and the concentration of IFN-γ and TNF-α in the supernatant of the co-culture system reached 193.8 pg/ml and 169.8 pg/ml, respectively, which was significantly higher than that of the control group (P<0.05). ⑧When CD123 DuAb was added at a concentration of 1 nmol/L to the co-culture system of T cells and CD123(+) tumor cells, the killing intensity of T cells significantly increased, and the residual rates of CD123(+) MV4-11 cells, CD123(+) Molm13 cells, and CD123(+) THP-1 cells were 7.4%, 6.7%, and 14.6% on day 3, respectively, which were significantly lower than those in the control group (P<0.05) . Conclusion: In this study, a novel CD123 DuAb was constructed and expressed. In vitro experiments verified that the DuAb binds to CD123(+) tumor cells and T cells simultaneously, promotes T-cell activation and proliferation, and facilitates their anti-leukemia effect, which provides a basis for further clinical research.

Bosentan and ambrisentan in the treatment of idiopathic pulmonary fibrosis: a meta-analysis.

OBJECTIVE: The aim is to showcase the effectiveness and safety of bosentan or ambrisentan in individuals diagnosed with idiopathic pulmonary fibrosis (IPF) and offer fresh evidence for the management of this condition. MATERIALS AND METHODS: For this research, we conducted a meta-analysis of randomized controlled trials by searching various databases, including the Cochrane Library, Excerpta Medica Database, PubMed, and Web of Science. The retrieval was conducted until November 2021. We analyzed the variances in 6-minute walk distance (6MWD), death, diffusion capacity for carbon monoxide (DLCO), forced vital capacity (FVC), hospitalization, IPF worsening, mean pulmonary arterial pressure, serious adverse events (SAEs), Short Form-36 improved, and St. George's Respiratory Questionnaire between the treatment and control groups. RESULTS: A sum of six studies involving 1,928 participants were found to meet the inclusion criteria. The quality of evidence was high. The control group had significantly higher values for 6MWD, DLCO, and FVC compared to the ambrisentan treatment group. The rates of hospitalization and IPF worsening were considerably greater in comparison with the control group. The bosentan group exhibited significantly reduced rates of hospitalization and IPF worsening in comparison with the control group. Both drugs did not cause any raising in death or SAEs when in comparison with the control group. CONCLUSIONS: The findings of this research validate the effectiveness and safety of bosentan for treating IPF patients. This medication can enhance the quality of life for individuals with IPF without causing any significant increase in SAEs. However, it does not have a notable influence on the long-term prognosis. The findings of this research do not endorse the utilization of ambrisentan in individuals diagnosed with IPF.

[Establishment and validation of nomogram prediction model for complicated acute appendicitis].

Objective: To establish and internally validate a nomogram model for predicting complicated acute appendicitis (CA). Methods: The clinical data from 663 acute appendicitis patients from the First Affiliated Hospital of Anhui University of Traditional Chinese Medicine from October 2015 to October 2022 were retrospectively analyzed. There were 411 males and 252 females, aged (M (IQR)) 41 (22) years (range: 18 to 84 years). There were 516 cases of CA and 147 cases of uncomplicated acute appendicitis. The minimum absolute contraction and selection operator regression model was used to screen the potential relative factors of CA, and the screened factors were included in the Logistic regression model for multivariate analysis. Software R was used to establish a preoperative CA nomogram prediction model, the receiver operating characteristic curve of the model was drawn, and the value of area under the curve (AUC) was compared to evaluate its identification ability, and the Bootstrap method was used for internal verification. Results: The elderly (age≥60 years) (OR=2.428, 95%CI: 1.295 to 4.549), abdominal pain time (every rise of 1 hour) (OR=1.089, 95%CI: 1.072 to 1.107), high fever (body temperature≥39 ℃) (OR=1.122, 95%CI: 1.078 to 1.168), total bilirubin (every rise of 1 µmol/L) (OR=2.629, 95%CI: 1.227 to 5.635) were independent relative factors of CA (all P<0.05). The AUC of this model was 0.935 (95%CI: 0.915 to 0.956). After internal verification using the Bootstrap method, the model still had a high discrimination ability (AUC=0.933), and the predicted CA curve was still in good agreement with the actual clinical CA curve. Conclusion: The clinical prediction model based on the elderly (age≥60 years), prolonged abdominal pain time, high fever (body temperature≥39 ℃), and increased total bilirubin can help clinicians effectively identify CA.

[Research advances on improving the therapeutic efficacy of mesenchymal stem cell-derived exosomes in wound repair].

How to promote high-quality wound healing is a common problem for plastic surgery and burn physicians. In recent years, numerous animal studies have demonstrated that mesenchymal stem cell-derived exosomes promote wound repair through multiple mechanisms and are promising cell-free therapeutic agents with broad prospect of application. How to enhance the therapeutic efficacy of exosomes, optimize their drug delivery strategy, and improve their biological properties are the challenges to be overcome in order to move from basic research to clinical application of exosome therapy for wound repair. This article focuses on methods to improve the wound repair potential of mesenchymal stem cell-derived exosomes, and reviews the recent research advances on improving the therapeutic efficacy of mesenchymal stem cell-derived exosomes in wound repair from three aspects, including pretreatment of parental mesenchymal stem cells, hydrogel bio-scaffold loaded with exosomes, and engineered exosomes, to provide a reference for further clinical studies.

[Interventional effect and mechanism of fermentation liquid of Dendrobium officinale leaves on alcoholic hepatitis mice].

Objective: To explore the intervention effect and mechanism of Dendrobium officinale leaf fermentation liquid on alcoholic hepatitis (AH) mice. Methods: Seventy inbred C57BL/6J male mice aged 6-8 weeks were selected and randomly divided into normal group (NG), model group (MG), liquid feed control group (CG), silybum group (SI), low-dose group (DL), medium-dose group (DM), and high-dose group (DH) of Dendrobium officinale fermentation liquid, with 10 mice in each group. NG group was given common feed, CG group was given control feed (LB alcoholic liquid control feed), SI group was given LB alcoholic liquid feed and silybum by gavage, DL, DM and DH groups were given LB alcoholic liquid feed and 25%, 50% and 100% concentration of Dendrobium officinale leaf fermentation liquid by gavage. An AH model was established by feeding LB alcoholic liquid feed for 8 weeks.At week 8, alanine Transaminase (ALT), triglyceride (TG), transferrin (TRF), interleukin (IL)-6, IL-10, and IL-1ß, tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ) were detected in eye blood of mice. Liver tissues were stained with HE, Oil Red O, Prussian blue and immunofluorescence ROS. The contents of glutathione(GSH) and malondialdehyde (MDA) in liver tissue homogenate were detected. To analyze the intervention effect and mechanism of Dendrobium officinale leaf fermentation solution on AH mice, the mRNA and protein relative expression levels of adenylate activated protein kinase (AMPK), AMPKß1, phosphorylated AMPKß1 (p-AMPKß1), tumor suppressor gene p53 (p53), solsolic vector family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GXP4) were detected by polymerase chain reaction (PCR) and Western blot. Results: Compared with MG group, the serum ALT and TG levels in the DL, DM, and DH groups were all reduced [ALT: (45.94±19.85), (45.73±22.62), and (41.68±7.13) vs (75.51±17.76) U/L, respectively; TG: (0.90±0.23), (0.69±0.22) and (0.41±0.20) vs (1.28±0.19) mmol/L, respectively, all P<0.05]; IL-6, IL-1ß, TNF-α, IFN-γ were decreased (all P<0.05). The serum TRF and IL-10 levels in the DM and DH groups were increased (all P<0.05). Compared with MG group, the liver tissue MDA of mice in DL, DM and DH groups was decreased [(0.41±0.05), (0.40±0.03), and (0.43±0.14) vs (0.64±0.06)µmol/g, respectively], GSH was increased (all P<0.05). Compared with MG, mRNA expression levels of AMPK (1.36±0.11, 1.61±0.17, 1.68±0.11 vs 0.80±0.12, respectively), SLC7A11 (0.91±0.12, 0.97±0.12, 0.99±0.13 vs 0.60±0.14, respectively) and GPX4 (0.51±0.11, 0.63±0.17, 0.83±0.15 vs 0.42±0.14, respectively) in the liver tissue of DL, DM and DH groups were all increased (all P<0.05). Compared with MG group, DL, DM and DH groups showed the relative expression levels of AMPKß1, p-AMPKß1, SLC7A11 and GPX4 were increased in the liver tissue of mice, while the relative expression levels of p53 protein were decreased (all P<0.05). Compared with MG group, DL, DM and DH groups reduced the degree of hepatic steatosis and inflammation in the lobules, while the iron and ROS staining in the liver tissue became lighter. Conclusion: Dendrobium officinale leaf fermentation liquid can alleviate the severity of AH in mice, and its mechanism may be related to the up-regulation of AMPK to inhibiting the p53/SLC7A11/GPX4 mediated Ferroptosis pathway.

[Application and clinical significance of intercellular proximity labeling technique in chronic myelogenous leukemia].

Objective: This study aimed to explore the application of interaction-dependent fucosyl-biotinylation (FucoID), a chemical biology-based proximity labeling technique, in capturing tumor antigen-specific T cells and its clinical value in chronic myelogenous leukemia (CML) . Methods: Flow cytometry and fluorescence microscopy were employed to evaluate the experimental parameters for FucoID in CML. Peripheral blood samples were obtained from 14 newly diagnosed CML patients in the chronic phase. These samples underwent flow cytometry-based sorting and were subsequently labeled with FucoID to facilitate the isolation of tumor cells and T cells, followed by the immunophenotypic identification of tumor antigen-specific T cells. Finally, the diagnostic and therapeutic potential of FucoID in CML was assessed. Results: Initially, the experimental parameters for FucoID in CML were established. The proportion of CD3(+) T cells in patients was (8.96±6.47) %, exhibiting a marked decrease compared with that in healthy individuals at (38.89±22.62) %. The proportion of tumor-specific antigen-reactive T cells was (3.34±4.49) %, which demonstrated interpatient variability. In addition, the proportion of tumor-specific antigen-active T cells in CD4(+) T cells was (3.95±1.72) %, which was generally lower than the proportion in CD8(+) T cells at (5.68±2.18) %. Compared with those in tumor-specific antigen-nonreactive T cells, CCR7(-)CD45RA(-) effector memory T cells and CCR7(-)CD45RA(+) effector T cells were highly enriched in tumor-specific antigen-reactive T cells. Moreover, the intensity of tumor immune reactivity in patients exhibited a significant correlation with white blood cell count (WBC) and hemoglobin (HGB) levels in peripheral blood, while no such correlation was observed with other clinical baseline characteristics. Conclusion: The combination of FucoID and flow cytometry enables the rapid identification and isolation of tumor antigen-specific T cells in CML. The successful application of this method in CML and the implications of our findings suggest its potential clinical value in the field of hematologic malignancies.

[Establishment of leukemia cell model with inducible AML1-ETO expression and its effect on fatty acid metabolism in leukemia cells].

Objective: To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE fusion gene expression. Methods: The doxycycline (Dox) -dependent expression of the AE fusion gene in the U937 cell line (U937-AE) were established using a lentivirus vector system. The Cell Counting Kit 8 methods, including the PI and sidanilide induction, were used to detect cell proliferation, cell cycle-induced differentiation assays, respectively. The effect of the AE fusion gene on the biological function of U937-AE cells was preliminarily explored using transcriptome sequencing and metabonomic sequencing. Results: ①The Dox-dependent Tet-on regulatory system was successfully constructed to regulate the stable AE fusion gene expression in U937-AE cells. ②Cell proliferation slowed down and the cell proliferation rate with AE expression (3.47±0.07) was lower than AE non-expression (3.86 ± 0.05) after inducing the AE fusion gene expression for 24 h (P<0.05). The proportion of cells in the G(0)/G(1) phase in the cell cycle increased, with AE expression [ (63.45±3.10) %) ] was higher than AE non-expression [ (41.36± 9.56) %] (P<0.05). The proportion of cells expressing CD13 and CD14 decreased with the expression of AE. The AE negative group is significantly higher than the AE positive group (P<0.05). ③The enrichment analysis of the transcriptome sequencing gene set revealed significantly enriched quiescence, nuclear factor kappa-light-chain-enhancer of activated B cells, interferon-α/γ, and other inflammatory response and immune regulation signals after AE expression. ④Disorder of fatty acid metabolism of U937-AE cells occurred under the influence of AE. The concentration of the medium and short-chain fatty acid acylcarnitine metabolites decreased in cells with AE expressing, propionyl L-carnitine, wherein those with AE expression (0.46±0.13) were lower than those with AE non-expression (1.00±0.27) (P<0.05). The metabolite concentration of some long-chain fatty acid acylcarnitine increased in cells with AE expressing tetradecanoyl carnitine, wherein those with AE expression (1.26±0.01) were higher than those with AE non-expression (1.00±0.05) (P<0.05) . Conclusion: This study successfully established a leukemia cell model that can induce AE expression. The AE expression blocked the cell cycle and inhibited cell differentiation. The gene sets related to the inflammatory reactions was significantly enriched in U937-AE cells that express AE, and fatty acid metabolism was disordered.

[A case of corrosive digestive tract and lung injury caused by ingestion of pipeline dredging agent].

Ingestion of corrosive substances can severely burn the upper digestive tract leading to bleeding or perforation, and may even be life-threatening. Less commonly, damage to the trachea and bronchi is involved. In this paper, a case of corrosive digestive tract injury and lung injury after oral administration of pipeline dredging agent (the main components are hydroxide, sodium carbonate, sodium hypochlorite, etc.) was analyzed. After active rescue treatment, the patient died of massive hemoptysis. It is suggested that serious complications may occur after ingestion of corrosive substances. Timely diagnosis and reasonable medical management are needed to improve the level of recognition and treatment of such diseases.

IL-17A as a new circulating bioindicator for non-small cell lung cancer diagnosis and prognosis.

OBJECTIVE: Lung cancer (LC) is the highest contributor to cancer-associated mortality worldwide. Approximately 85% of all LC incidences involve non-small cell LC (NSCLC). Unfortunately, owing to a significant lack of sensitive and robust bioindicators, most patient diagnoses occur at advanced stages of the disease, thereby resulting in extremely poor patient outcomes. Herein, we elucidated the role of interleukin-17A (IL-17A) among NSCLC patients. MATERIALS AND METHODS: Circulating IL-17A content was measured using enzyme-linked immunosorbent assay (ELISA), and its diagnostic and prognostic abilities were assessed using the receiver operating characteristic (ROC) curve and Kaplan-Meier analysis, respectively. RESULTS: Our analysis revealed that circulating IL-17A levels were significantly augmented among NSCLC vs. control samples. Moreover, based on our area under the curve (AUC) analysis, circulating IL-17A levels fared considerably better than the standard bioindicator carcinoembryonic antigen (CEA) in both testing and validation cohorts. Notably, we also revealed that the circulating IL-17A levels were accurately and reliably predicted in early-stage NSCLC patients. Besides, we demonstrated a strong correlation between elevated circulating IL-17A expression and worse prognosis among NSCLC patients. CONCLUSIONS: Herein, we demonstrated that circulating IL-17A levels can serve as reliable and potent diagnostic and prognostic bioindicators for NSCLC.

[Effects of interferon regulatory factor 9 on the biological phenotypes in PML-RARα-induced promyelocytic leukemia].

Objective: To investigate the prognostic significance of interferon regulatory factor 9 (IRF9) expression and identify its role as a potential therapeutic target in acute promyelocytic leukemia (APL) . Methods: The gene expression profile and survival data applied in the bioinformatic analysis were obtained from The Cancer Genome Atlas and Beat acute myeloid leukemia (AML) cohorts. A dox-induced lentiviral system was used to induce the expression of PML-RARα (PR) in U937 cells, and the expression level of IRF9 in U937 cells treated with or without ATRA was examined. We then induced the expression of IRF9 in NB4, a promyelocytic leukemia cell line. In vitro studies focused on leukemic phenotypes triggered by IRF9 expression. Results: ①Bioinformatic analysis of the public database demonstrated the lowest expression of IRF9 in APL among all subtypes of AML, with lower expression associated with worse prognosis. ②We successfully established a PR-expression-inducible U937 cell line and found that IRF9 was downregulated by the PR fusion gene in APL, with undetectable expression in NB4 promyelocytic cells. ③An IRF9-inducible NB4 cell line was successfully established. The inducible expression of IRF9 promoted the differentiation of NB4 cells and had a synergistic effect with lower doses of ATRA. In addition, the inducible expression of IRF9 significantly reduced the colony formation capacity of NB4 cells. Conclusion: In this study, we found that the inducible expression of PR downregulates IRF9 and can be reversed by ATRA, suggesting a specific regulatory relationship between IRF9 and the PR fusion gene. The induction of IRF9 expression in NB4 cells can promote cell differentiation as well as reduce the colony forming ability of leukemia cells, implying an anti-leukemia effect for IRF9, which lays a biological foundation for IRF9 as a potential target for the treatment of APL.

[Preparation of CD33 targeted bispecific- and trispecific-T cell engagers and their cytotoxicity on leukemia cells].

Objective: To investigate the effect of CD33-targeted bi-specific and tri-specific T-cell engagers on T-cell proliferation and explore their cytotoxicity on leukemia cells. Methods: The CD33-targeted bi-specific T-cell engager (CD33-BiTE) and tri-specific T-cell engager (CD33-TriTE) expression vectors were successfully constructed and expressed through a eukaryotic cell expression system. CD33-BiTE and CD33-TriTE were purified by affinity chromatography. The effects of CD33-BiTE and CD33-TriTE on T cells were analyzed through in vitro experiments. Results: ① CD33-BiTE and CD33-TriTE were successfully constructed and purified and could compete with flow cytometry antibodies for binding to the target cells. ② After 12 days of co-culture with CD33-BiTE and CD33-TriTE, the number of human T cells were expanded to 33.89±19.46 and 81.56±23.62 folds, respectively. CD33-TriTE induced a stronger proliferation of T cells than CD33-BiTE (P<0.05) . ③ Both CD33-BiTE and CD33-TriTE induced specific dose-dependent cytotoxicity on CD33(+) leukemia cells. ④ Compared to CD33-TriTE, leukemia cells were prone to express PD-L1 when co-cultured with T cells and CD33-BiTE. CD33-TriTE induced powerful cytotoxicity on leukemia cells with high PD-L1 expression. Conclusion: CD33-BiTE and CD33-TriTE expression vectors were constructed, and fusion proteins were expressed in eukaryotic cells. Our results support the proliferative and activating effects of BiTE and TriTE on T cells. Compared to that of CD33-BiTE, CD33-TriTE induced a stronger proliferative effect on T cells and a more powerful cytotoxicity on leukemia cells with high PD-L1 expression.

[Comparison of the efficacy of IA and HAD induction regimens in the treatment of patients with newly diagnosed acute myeloid leukemia: a single-center study].

Objective: To compare the efficacy of two induction regimens, namely, idarubicin combined with cytarabine (IA) versus the combination of homoharringtonine, daunorubicin, and cytarabine (HAD) , in adult patients with newly diagnosed de novo acute myeloid leukemia (AML) . Methods: From May 2014 to November 2019, 199 patients diagnosed with AML receiving either the IA or HAD regimens were assessed for overall survival (OS) , relapse-free survival (RFS) , as well as the CR rate and the MRD negative rate after induction therapy. The differences in prognosis between the two induction therapy groups was assessed according to factors, including age, white blood cell (WBC) count, NPM1 mutation, FLT3-ITD mutation, 2017 ELN risk stratification, CR(1) transplantation, and the use of high-dose cytarabine during consolidation therapy, etc. Results: Among the 199 patients, there were 104 males and 95 females, with a median age of 37 (15-61) years. Ninety patients received the IA regimen, and 109 received the HAD regimen. Comparing the efficacy of the IA and HAD regimens, the CR rates after the first induction therapy were 71.1% and 63.3%, respectively (P=0.245) , and the MRD negative rates after the first induction therapy were 53.3% and 48.6%, respectively (P=0.509) . One patient in the IA group and two in the HAD group died within 60 days after induction. The two-year OS was 61.5% and 70.6%, respectively (P=0.835) , and the two-year RFS was 51.6% and 57.8%, respectively (P=0.291) . There were no statistically significant differences between the two groups. Multivariate analysis showed that the ELN risk stratification was an independent risk factor in both induction groups; CR(1) HSCT was an independent prognostic factor for OS and RFS in the IA patients and for RFS in the HAD patients but not for OS in the HAD patients. Age, WBC level, NPM1 mutation, and FLT3-ITD mutation had no independent prognostic significance. Conclusion: The IA and HAD regimens were both effective induction regimens for AML patients.

[Preparation of CD52-targeted chimeric antigen receptor-modified T cells and their anti-leukemia effects].

Objective: To construct chimeric antigen receptor (CAR) T cells targeting CD52 (CD52 CAR-T) and validate the effect of CD52 CAR-T cells on CD52-positive leukemia. Methods: A second-generation CD52-targeting CAR bearing 4-1BB costimulatory domain was ligated into a lentiviral vector through molecular cloning. Lentivirus was prepared and packaged by 293 T cells with a four-plasmid system. Fluorescein was used to label cell surface antigens to evaluate the phenotype of CD52 CAR-T cells after infection. Flow cytometry and ELISA were used to evaluate the specific cytotoxicity of CD52 CAR-T cells to CD52-positive cell lines in vitro. Results: ①A pCDH-CD52scFv-CD8α-4-1BB-CD3ζ-GFP expressing plasmid was successfully constructed and used to transduce T cells expressing a novel CD52-targeting CAR. ②On day 6, CD52-positive T cells were almost killed by CD52-targeted CAR-T post lentivirus transduction [CD52 CAR-T (4.48 ± 4.99) %, vs Vector-T (56.58±19.8) %, P=0.011]. ③T cells transduced with the CAR targeting CD52 showed low levels of apoptosis and could be expanded long-term ex vivo. ④The CD52 CAR could promote T cell differentiation into central and effector memory T cells, whereas the proportion of T cells with a CD45RA(+) effector memory phenotype were reduced. ⑤CD52 CAR-T cells could specifically kill CD52-positive HuT78-19t cells but had no killing effect on CD52-negative MOLT4-19t cells. For CD52 CAR-T cells, the percentage of residual of HuT78-19t cells was (2.66±1.60) % at an the E:T ratio of 1∶1 for 24 h, while (56.66±5.74) % of MOLT4-19t cells survived (P<0.001) . ⑥The results of a degranulation experiment confirmed that HuT78-19t cells significantly activated CD52 CAR-T cells but not MOLT4-19t cells[ (57.34±11.25) % vs (13.06± 4.23) %, P<0.001]. ⑦CD52 CAR-T cells released more cytokines when co-cultured with HuT78-19t cells than that of vector-T cells [IFN-γ: (3706±226) pg/ml, P<0.001; TNF-α: (1732±560) pg/ml, P<0.01]. Conclusions: We successfully prepared CD52 CAR-T cells with anti-leukemia effects, which might provide the foundation for further immunotherapy.

[Efficacy and safety of IAC regimen for relapse/refractory acute myeloid leukemia: a prospective randomized controlled study].

Objective: To evaluate the efficacy and toxicity profiles of idarubicin, cytarabine, and cyclophosphamide (IAC) in relapse/refractory acute myeloid leukemia (AML) . Methods: This study was a prospective, randomized controlled clinical trial with the registration number NCT02937662. The patients were randomly divided into two groups. The experimental group was treated with an IAC regimen, and the regimen of the control group was selected by doctors according to medication experience. After salvage chemotherapy, allogeneic hematopoietic stem cell transplantation (allo-HSCT) was conducted as far as possible according to the situation of the patients. We aimed to observe the efficacy, safety, and toxicity of the IAC regimen in relapse/refractory AML and to explore which is the better regimen. Results: Forty-two patients were enrolled in the clinical trial, with a median age of 36 years (IAC group, 22 cases and control groups, 20 cases) . ①The objective response rate was 71.4% in the IAC group and 40.0% in the control group (P=0.062) ; the complete remission (CR) rate was 66.7% in the IAC group and 40.0% in the control group (P=0.121) . The median follow-up time of surviving patients was 10.5 (range:1.7-32.8) months; the median overall survival (OS) was 14.1 (range: 0.6-49.1) months in the IAC group and 9.9 (range: 2.0-53.8) months in the control group (P=0.305) . The 1-year OS was 54.5% (95%CI 33.7%-75.3%) in the IAC group and 48.2% (95%CI 25.9%-70.5%) in the control group (P=0.305) , with no significant difference between these two regimens. ②The main hematologic adverse events (AEs) were anemia, thrombocytopenia, and neutropenia. The incidence of grade 3-4 hematologic AEs in the two groups was 100% (22/22) in the IAC group and 95% (19/20) in the control group. The median time of neutropenia after chemotherapy in the IAC group and control group was 20 (IQR: 8-30) and 14 (IQR: 5-50) days, respectively (P=0.023) . ③The CR rate of the early relapse (relapse within 12 months) group was 46.7% and that of the late relapse (relapse after 12 months) group was 72.7% (P=0.17) . The median OS time of early recurrence was 9.9 (range:1.7-53.8) months, and that of late recurrence patients was 19.3 (range: 0.6-40.8) months (P=0.420) , with no significant differences between the two groups. The 1-year OS rates were 45.3% (95%CI 27.2%-63.3%) and 66.7% (95%CI 40.0%-93.4%) , respectively (P=0.420) . Survival analysis showed that the 1-year OS rates of the hematopoietic stem cell transplantation group and non-hematopoietic stem cell transplantation group were 87.5% (95%CI 71.2%-100%) and 6.3% (95%CI 5.7%-18.3%) , respectively. The OS rate of the hematopoietic stem cell transplantation group was significantly higher than that of the non-hematopoietic stem cell transplantation group (P<0.001) . Conclusion: The IAC regimen is a well-tolerated and effective regimen in relapsed/refractory AML; this regimen had similar efficacy and safety with the regimen selected according to the doctor's experience for treating relapsed/refractory AML. For relapsed/refractory patients with AML, allogeneic hematopoietic stem cell transplantation should be attempted as soon as possible to achieve long-term survival.

[Clinical and genetic characteristics of patients with newly diagnosed acute promyelocytic leukemia: a single-center retrospective of 790 cases].

Objective: To retrospectively analyze the data of Chinese patients with newly diagnosed acute promyelocytic leukemia (APL) to preliminarily discuss the clinical and cytogenetic characteristics. Methods: From February 2004 to June 2020, patients with newly diagnosed APL aged ≥ 15 years who were admitted to the Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College were chosen. Clinical and laboratory features were retrospectively analyzed. Results: A total of 790 cases were included, with a male to female ratio of 1.22. The median age of the patients was 41 (15-76) years. Patients aged between 20 and 59 predominated, with 632 patients (80%) of 790 patients classified as low and intermediate risk and 158 patients (20%) of 790 patients classified as high risk. The white blood cell, platelet, and hemoglobin levels at diagnosis were 2.3 (0.1-176.1) ×10(9)/L, 29.5 (2.0-1220.8) ×10(9)/L, and 89 (15-169) g/L, respectively, and 4.8% of patients were complicated with psoriasis. The long-form type of PML-RARα was most commonly seen in APL, accounting for 58%. Both APTT extension (10.3%) and creatinine>14 mg/L (1%) are rarely seen in patients at diagnosis. Cytogenetics was performed in 715 patients with newly diagnosed APL. t (15;17) with additional chromosomal abnormalities were found in 155 patients, accounting for 21.7%; among which, +8 was most frequently seen. A complex karyotype was found in 64 (9.0%) patients. Next-generation sequencing was performed in 178 patients, and 113 mutated genes were discovered; 75 genes had an incidence rate>1%. FLT3 was the most frequently seen, which accounted for 44.9%, and 20.8% of the 178 patients present with FLT3-ITD. Conclusions: Patients aged 20-59 years are the most common group with newly diagnosed APL. No obvious difference was found in the ratio of males to females. In terms of risk stratification, patients divided into low and intermediate risk predominate. t (15;17) with additional chromosomal abnormalities accounted for 21% of 715 patients, in which +8 was most commonly seen. The long-form subtype was most frequently seen in PML-RARα-positive patients, and FLT3 was most commonly seen in the mutation spectrum of APL.

[Functional investigation of chimeric antigen receptor T cells targeting LMP1 antigen].

Objective: This study aimed to create a type of CAR-T cells that targets LMP1 antigen and study its immunotherapeutic effect on LMP1-positive hematological malignancies. Methods: To generate LMP1 CAR-T cells, a plasmid expressing LMP1 CAR was created using molecular cloning technology, and T cells were infected with LMP1 CAR lentivirus. The effects of LMP1 CAR-T cells on specific cytotoxicity against LMP1-positive tumor cell lines infected with the EB virus had been confirmed. Results: ① LMP1 protein expressing on EB virus-positive lymphoma cells surface was verified. ② The LMP1 CAR-expressing plasmid was created, and LMP1 CAR-T cells were obtained by infecting T cells with a lentivirus packaging system, with an infection efficiency of more than 80% . ③LMP1 CAR-T cells have a 4∶1 effect-to-target ratio in killing LMP1-positive lymphoma cells. The killing effect of LMP1 CAR-T cells on Raji cells was enhanced after 48 h of coculture, but there was no significant killing effect on Ramos, which are LMP1-negative lymphoma cells. ④After coculture with LMP1-positive lymphoma cells at a ratio of 1∶1 for 5 h, the degranulation effect was enhanced. The proportion of CD107a(+) T cells in the LMP1 CAR-T cell treatment group was significantly higher than that in the vector-T cell group [ (13.25±2.94) % vs (1.55±0.05) % , t=3.972, P=0.017]. ⑤After coculture with LMP1-positive lymphoma cells, the proportion of CD69(+) and CD25(+) T cells in the LMP1 CAR-T cell group was significantly higher than that in vector-T cell group [ (7.40±0.41) % vs (3.48±0.47) % , t=6.268, P=0.003; (73.00±4.73) % vs (57.67±2.60) % , t=2.842, P=0.047]. ⑥After coculture with LMP1-positive lymphoma cells, cytokine secretion in the LMP1 CAR-T cell group was higher than that in the vector-T cell group [interferon-gamma: (703±73) ng/L vs (422±87) ng/L, t=2.478, P=0.068; tumor necrosis factor-alpha: (215±35) ng/L vs (125±2) ng/L, t=2.536, P=0.064]. Conclusion: In this study, we found that the LMP1 protein is only found on the surface of the EBV-positive tumor cell. Simultaneously, we created an LMP1 CAR-expressing plasmid and obtained LMP1 CAR-T cells by infecting T cells with a lentivirus packaging system. Furthermore, we demonstrated that LMP1 CAR-T cells could specifically kill LMP1-positive tumor cells in vitro. The degranulation and activation effects of LMP1 CAR-T cells were enhanced after coculture with LMP1-positive tumor cells, indicating a potential clinical application.