ABSTRACT
BACKGROUND@#With the rise of multicolor flow cytometry, flow cytometry has become an important means to detect the immune microenvironment of lung cancer, but most of them are used to detect the proportion of cell subsets or the function of major cell subsets, and they cannot be detected at the same time. Therefore, a reliable 21-color flow cytometry protocol was established to detect the immune cell subsets in human non-small cell lung cancer (NSCLC) tumor tissues.@*METHODS@#Cell membrane surface antibodies cluster of differentiation (CD)45, CD3, CD19, CD4, CD8, programmed cell death 1 (PD-1), CD39, CD103, CD25, CD127, chemokine receptor 8 (CCR8), CD56, CD11c, human leukocyte antigen (HLA)-DR, CD38, CD27, CD69, CD62L, CD45RA, CCR7 and nucleic acid dye L/D were used to develop the protocol. Firstly, antibody titration experiments, voltage optimization, subtraction of one color staining and single color staining experiments were carried out for each antibody, and after the experimental conditions and detection schemes were determined, the feasibility of the scheme was verified by using peripheral blood mononuclear cells (PBMCs) specimens of six healthy adult volunteers. Tumor tissue samples from 6 NSCLC patients were tested and analyzed.@*RESULTS@#The established 21-color flow cytometry protocol was used to detect the tumor tissue samples of 6 NSCLC patients, and the proportion of each cell subset in lung cancer tissue, as well as the immunophenotype and differentiation of the main cell population, were analyzed.@*CONCLUSIONS@#The successfully established 21-color flow cytometry protocol is suitable for the detection of PBMCs and NSCLC tissue samples, which provides an effective new idea for monitoring the immune microenvironment status in lung cancer.
Subject(s)
Adult , Humans , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/pathology , Flow Cytometry , Leukocytes, Mononuclear/pathology , Lung/pathology , Tumor MicroenvironmentABSTRACT
Objective:To investigate the significance of multicolor flow cytometry (MFC) monitoring of minimal residual disease (MRD) in the course of allogeneic hematopoietic stem cell transplantation (allo-HSCT) after CD19-chimeric antigen receptor(CAR)-T cell immunotherapy for patients with refractory, relapsed B-cell acute lymphoblastic leukemia (r/r B-ALL).Methods:37 patients with r/r B-ALL admitted to Hebei Yanda Lu Daopei Hospital from January to July 2019, aged 15 (6, 19) years old, including 24 males and 13 females, were treated with CD19-CAR-T cell immunotherapy bridging allo-HSCT. MFC with cytoplasmic CD79a antibody to set up B-cell gates was used to monitor patients′ bone marrow (BM), cerebrospinal fluid (CSF), and tissue samples on day 0 (prior to the CAR-T cell immunotherapy), day 15, day 28 post CAR-T cell immunotherapy, and post transplantation.The MRD values of these samples were analyzed to evaluate the residual tumor cells and metastasis. The killing effect of the CAR-T cells was evaluated by the recovery of CD19+B cells before transplantation and the period between the timepoint when CD19+B cells was recovered and the timepoint when CAR-T cells were infused. Peripheral blood CAR-T cells were counted at different time points. Statistic analysis was performed by Kaplan-Meie assay and Log-rank test to analyze the difference of univariate cumulative survival.Results:(1)Among the 37 patients, 8 died and 29 survived. 5 patients relapsed after transplantation, of which 4 relapsed patients died and 1 survived. (2)MFC MRD negative remission rate of the death group was lower than that of the survival group at the following time points: post-CAR-T therapy and prior to transplantation (5/8 vs. 28/29, χ 2=7.540, P=0.006); day 15 of the CAR-T cell reinfusion (3/8 vs. 24/29, χ 2=6.512, P=0.011); day 28 of the reinfusion (3/8 vs. 276/29, χ 2=10.065, P=0.002). The probability of extramedullary MFC MRD positive tumor infiltration in the death group was higher than that in the survival group(7/8 vs. 14/29, χ 2=3.931, P=0.047). After CAR-T cell immunotherapy, the recovery period of CD19-positive cells in the death group, or the time for CAR-T cells to kill CD19-positive cells, was shorter than that in the survival group [42.00 days(30.00,49.00) vs. 55.00 days(41.50,73.50), Z=0.022, P=0.020]. Conclusion:The positive results of MRD by MFC at the following timepoints may predict unfavorable outcomes, such as post-CAR-T therapy and prior to transplantation, day 15 and 28 of the CAR-T cell immunotherapy, which may provide some guidance for clinical management.
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Objective: To explore the factors affecting cell loss in multicolor flow cytometry of mouse immune cells. Methods: C57BL/6J mice were used in the experiment. Splenocytes were isolated and resuspended twice with buffers of different types, compositions and pH; then the number of viable cells was counted to observe which factors affected the amount of cell loss during staining. Results: During flow cytometric labeling of mouse immune cells, buffer types significantly affected the amount of cell loss. Washing with PBS buffer containing potassium ions caused obvious cell loss, while slight shift in buffer pH and whether or not FBS/BSA was added had no significant effect on cell loss. Moreover, centrifugation speed also significantly affected cell loss. Conclusion: The use of potassium-containing PBS buffer during flow cytometric staining of mouse immune cells resulted in significant cell loss. The potassium-free PBS buffer and moderate centrifugation speed should be recommended.