targetSCAPE and ultraSCAPE: Simultaneous identification and deep profiling of human antigen-specific T cells and other immune cell subsets by mass cytometry.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15204-e15204
Author(s):  
Brian Abel ◽  
Faris Kairi ◽  
Alessandra Nardin ◽  
Evan Newell ◽  
Michael Fehlings
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Cell ◽  
T Cell Subsets ◽  
Single Sample ◽  
High Dimensional ◽  
Cell Populations ◽  
Mass Cytometry ◽  
Immune Cell Subsets

e15204 Background: During clinical trial immune monitoring, especially in the field of immunotherapy, it is critical to collect in-depth phenotypic information from multiple immune cell populations in order to assess the biological activity of the immunotherapy, to identify biomarkers of response or disease progression, and/or to identify new drug targets. However, patient samples such as peripheral blood mononuclear cells or tissues, are often scarce and current methods face limitations in either achieving a sufficient depth of analysis and/or cell throughput. Methods: In order to identify therapy-relevant antigens and to facilitate a concurrent in-depth characterization of T cells directed towards these targets, immunoSCAPE leverages the high-dimensional immune profiling capabilities of mass cytometry and a unique methodology allowing the identification and characterization of rare antigen-specific T-cell subsets (targetSCAPE). By implementing a new cutting-edge technology that combines flow and mass cytometry in parallel with a combinatorial live cell barcoding strategy, we further increased the high-dimensional phenotyping capacities to over 100 different marker molecules on up to four different immune cell subsets simultaneously within the same sample. Results: We isolated 4 different immune cell populations from a single sample and combined 3 different phenotypic panels consisting of 35 makers each together with a combinatorial tetramer multiplex and phenotyping panel for deep profiling of myeloid cells, NK cells, B cells and T cells. We demonstrate the potential of this novel immuno-phenotyping method, by tracking virus-specific T cells while simultaneously characterizing 4 immune cell subsets with over 100 distinct phenotypic markers from a single sample, which is currently impossible employing modern flow cytometers or classical mass cytometry methods. Conclusions: With its ability to provide an unprecedented picture of the immune status within a single sample, including T cell specificity information and in-depth profiling of relevant immune cell subsets, ultraSCAPE in combination with targetSCAPE can provide detailed insights on the effects of immunotherapy on the immune cell population. Information learned from in-depth immune phenotyping of several immune cell subsets such as T, B, NK and myeloid cell subsets can be leveraged for the development of novel diagnostics, biomarker discovery and monitoring therapeutic strategies in immunotherapy clinical trials.

scholarly journals Identification of Human Immune Cell Subtypes Most Vulnerable to IL-1β-induced Inflammatory Signaling Using Mass Cytometry

2020 ◽  
Author(s):  
Hema Kothari ◽  
Corey M. Williams ◽  
Chantel McSkimming ◽  
Mythili Vigneshwar ◽  
Eli R. Zunder ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
T Cell Subsets ◽  
Effector Memory ◽  
High Morbidity ◽  
Cytokine Storm ◽  
Mass Cytometry ◽  
Immune Cell Subsets

ABSTRACTIL-1β has emerged as a key mediator of the cytokine storm linked to high morbidity and mortality from COVID-19 and blockade of the IL-1 receptor (IL-1R) with Anakinra has entered clinical trials in COVID-19 subjects. Yet, knowledge of the specific immune cell subsets targeted by IL-1β and IL-1β-induced signaling pathways in humans is limited. Utilizing mass cytometry (CyTOF) of human peripheral blood mononuclear cells, we identified effector memory CD4 T cells and CD4−CD8low/-CD161+ T cells as the circulating immune subtypes with the greatest expression of p-NF-κB in response to IL-1β stimulation. Notably, CCR6 distinctly identified T cells most responsive to IL-1β. Other subsets including CD11c myeloid dendritic cells (mDCs), classical monocytes (CM), two subsets of natural killer cells (CD16−CD56brightCD161− and CD16−CD56dimCD161+) and a population of lineage−(Lin-) cells expressing CD161 and CD25 also showed IL-1β-induced expression of p-NF-kB. The IL-1R antagonist, Anakinra significantly inhibited IL-1β-induced p-NF-kB in the CCR6+ T cells and CD11c mDCs with a trending inhibition in CD14 monocytes and Lin−CD161+CD25+ cells. IL-1β also induced a rapid but much less robust increase in p-p38 expression as compared to p-NF-kB in the majority of these same immune cell subsets. Prolonged IL-1β stimulation greatly increased p-STAT3 and to a much lesser extent p-STAT1 and p-STAT5 in T cell subsets, monocytes, DCs and the Lin−CD161+CD25+ cells suggesting IL-1β-induced production of downstream STAT-activating cytokines, consistent with its role in cytokine storm. Interindividual heterogeneity and inhibition of this activation by Anakinra raises the intriguing possibility that assays to measure IL-1β-induced p-NF-kB in CCR6+ T cell subtypes could identify those at higher risk of cytokine storm and those most likely to benefit from Anakinra therapy.

scholarly journals Global immune characterization of HBV/HCV-related hepatocellular carcinoma identifies macrophage and T-cell subsets associated with disease progression

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Guohe Song ◽  
Yang Shi ◽  
Meiying Zhang ◽  
Shyamal Goswami ◽  
Saifullah Afridi ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
T Cell Subsets ◽  
M2 Macrophage ◽  
Advanced Hcc ◽  
Immune Cell Subsets

AbstractDiverse immune cells in the tumor microenvironment form a complex ecosystem, but our knowledge of their heterogeneity and dynamics within hepatocellular carcinoma (HCC) still remains limited. To assess the plasticity and phenotypes of immune cells within HBV/HCV-related HCC microenvironment at single-cell level, we performed single-cell RNA sequencing on 41,698 immune cells from seven pairs of HBV/HCV-related HCC tumors and non-tumor liver tissues. We combined bio-informatic analyses, flow cytometry, and multiplex immunohistochemistry to assess the heterogeneity of different immune cell subsets in functional characteristics, transcriptional regulation, phenotypic switching, and interactions. We identified 29 immune cell subsets of myeloid cells, NK cells, and lymphocytes with unique transcriptomic profiles in HCC. A highly complex immunological network was shaped by diverse immune cell subsets that can transit among different states and mutually interact. Notably, we identified a subset of M2 macrophage with high expression of CCL18 and transcription factor CREM that was enriched in advanced HCC patients, and potentially participated in tumor progression. We also detected a new subset of activated CD8+ T cells highly expressing XCL1 that correlated with better patient survival rates. Meanwhile, distinct transcriptomic signatures, cytotoxic phenotypes, and evolution trajectory of effector CD8+ T cells from early-stage to advanced HCC were also identified. Our study provides insight into the immune microenvironment in HBV/HCV-related HCC and highlights novel macrophage and T-cell subsets that could be further exploited in future immunotherapy.

scholarly journals Potent Anti-Tumor Activity of Bcma CAR-T Therapy Against Heavily Treated Multiple Myeloma and Dynamics of Immune Cell Subsets Using Single-Cell Mass Cytometry

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1859-1859 ◽  
Author(s):  
Yongxian Hu ◽  
Zhang Yanlei ◽  
Guoqing Wei ◽  
Chang alex Hong ◽  
He Huang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Immune Cell ◽  
Cell Mass ◽  
Mass Cytometry ◽  
Car T Cells ◽  
Car T Cell ◽  
Immune Cell Subsets ◽  
Car T

Background BCMA CAR-T cells have demonstrated substantial clinical activity against relapsed/refractory multiple myeloma (RRMM). In different clinical trials, the overall response rate (ORR) varied from 50% to 100%. Complete remission (CR) rate varied from 20% to 80%. Here we developed a BCMA CAR-T cell product manufactured via lentiviral vector-mediated transduction of activated T cells to express a second-generation CAR with 4-1BB costimulatory domain and evaluated the efficacy and safety, moreover, dynamics of immune cell subsets using single-cell mass cytometry during treatment were analyzed. Methods Our trial (ChiCTR1800017404) is a phase 1, single-arm, open-label single center study to evaluate the safety and efficacy of autologous BCMA CAR-T treatment for RRMM. Patients were subjected to a lymphodepleting regimen with Flu and Cy prior to CAR-T infusion. BCMA CAR-T cells were administered as a single infusion at a median dose of 3.5 (1 to 6) ×106/kg. MM response assessment was conducted according to the International Uniform Response Criteria. Cytokine-release syndrome (CRS) was graded as Lee DW et al described (Blood.2014;124(2):188-195). Phenotypic analysis of peripheral blood mononuclear cells (PBMCs), frozen BCMA CAR-T aliquots, phenotype and in vivo kinetics of immune cell subsets after CAR-T infusion were performed by single-cell mass cytometry. Results As of the data cut-off date (August 1st, 2019), 33 patients, median age 62.5 (49 to 75) years old were infused with BCMA CAR-T cells. The median observation period is 8.0 (0.7 to 18) months. ORR was 100% (The patient who died of infection at 20 days after CAR-T infusion were excluded). All the 32 patients achieved MRD negative in bone marrow by flow cytometry in 2 weeks after CAR-T infusion. Partial response (4 PR, 12.1%), VGPR (7 VGPR, 21.2%), and complete response (21 CR, 63.6%) within 12 weeks post CAR-T infusion were achieved. Durable responses from 4 weeks towards the data cut-off date were found in 28/33 patients (84.8%) (Figure 1a). All patients had detectable CAR-T expansion by flow cytometry from Day 3 post CAR-T cell infusion. The peak CAR-T cell expansion in CD3+ lymphocytes of peripheral blood (PB) varied from 35% to 95% with a median percentage of 82.9%. CRS was reported in all the 33 patients, including 4 with Grade 1, 13 with Grade 2 and 16 with Grade 3. During follow-up, 1-year progression-free survival (PFS) was 70.7% (Figure 1b) and overall survival (OS) was 71.7% (Figure 1c). Multivariate analysis of patients with PR and patients with CR+VGPR revealed that factors including extramedullary infiltration, age>60 years old, high-risk cytogenetics, late stage and CAR-T cell dose were not associated with clinical response (P>0.05). Single-cell mass cytometry revealed that the frequency of total T cells, CD8+ T cells, NK cells and CD3+CD56+ NKT cells in PB was not associated with BCM CAR-T expansion or clinical response. CD8+ Granzyme B+ Ki-67+ CAR-T cells expanded prominently in CRS period. As serum cytokines increased during CRS, non-CAR-T immune cell subsets including PD1+ NK cells, CD8+ Ki-67+ ICOS+ T cells expanded dominantly implying that non-CAR-T cells were also activated after CAR-T treatment. After CRS, stem cell like memory CAR-T cells (CD45RO+ CCR7- CD28- CD95+) remain the main subtype of CAR-T cells (Figure 1d). Conclusions Our data showed BCMA CAR-T treatment is safe with prominent efficacy which can overcome the traditional high-risk factors. We also observed high expansion level and long-term persistence of BCMA CAR-T cells contribute to potent anti-myeloma activity. Stem cell like memory CAR-T cells might be associated with long-term persistence of BCMA CAR-T cells. These initial data provide strong evidence to support the further development of this anti-myeloma cellular immunotherapy. Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Role of Circulating T Follicular Helper Cells and Stem-Like Memory CD4+ T Cells in the Pathogenesis of HIV-2 Infection and Disease Progression

2021 ◽  
Vol 12 ◽  
Author(s):  
Sivasankaran Munusamy Ponnan ◽  
K.K. Vidyavijayan ◽  
Kannan Thiruvengadam ◽  
Nancy Hilda J ◽  
Manikannan Mathayan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Disease Progression ◽  
Neutralizing Antibodies ◽  
Immune Cell ◽  
Adaptive Immune Response ◽  
T Cell Subsets ◽  
Follicular Helper ◽  
Immune Cell Subsets

CD4+ T cells are critical players in the host adaptive immune response. Emerging evidence suggests that certain CD4+ T cell subsets contribute significantly to the production of neutralizing antibodies and help in the control of virus replication. Circulating T follicular helper cells (Tfh) constitute a key T cell subset that triggers the adaptive immune response and stimulates the production of neutralizing antibodies (NAbs). T cells having stem cell-like property, called stem-like memory T cells (Tscm), constitute another important subset of T cells that play a critical role in slowing the rate of disease progression through the differentiation and expansion of different types of memory cell subsets. However, the role of these immune cell subsets in T cell homeostasis, CD4+ T cell proliferation, and progression of disease, particularly in HIV-2 infection, has not yet been elucidated. The present study involved a detailed evaluation of the different CD4+ T cell subsets in HIV-2 infected persons with a view to understanding the role of these immune cell subsets in the better control of virus replication and delayed disease progression that is characteristic of HIV-2 infection. We observed elevated levels of CD4+ Tfh and CD4+ Tscm cells along with memory and effector T cell abundance in HIV-2 infected individuals. We also found increased frequencies of CXCR5+ CD8+ T cells and CD8+ Tscm cells, as well as memory B cells that are responsible for NAb development in HIV-2 infected persons. Interestingly, we found that the frequency of memory CD4+ T cells as well as memory B cells correlated significantly with neutralizing antibody titers in HIV-2 infected persons. These observations point to a more robust CD4+ T cell response that supports B cell differentiation, antibody production, and CD8+ T cell development in HIV-2 infected persons and contributes to better control of the virus and slower rate of disease progression in these individuals.

scholarly journals Longitudinal immune cell profiling in early systemic lupus erythematosus

2021 ◽  
Author(s):  
Takanori Sasaki ◽  
Sabrina Bracero ◽  
Joshua Keegan ◽  
Lin Chen ◽  
Ye Cao ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
T Cells ◽  
T Cell ◽  
Lupus Erythematosus ◽  
Immune Cell ◽  
Cell Populations ◽  
Mass Cytometry ◽  
Systemic Lupus ◽  
Tfh Cells ◽  
One Year

Objective: To investigate the immune cell profiling and their longitudinal changes in systemic lupus erythematosus (SLE). Methods: We employed mass cytometry with three different 38-39 marker panels (Immunophenotyping, T cell/monocyte, and B cell) in cryopreserved peripheral blood mononuclear cells (PBMCs) from nine patients with early SLE, 15 patients with established SLE, and 14 non-inflammatory controls. We used machine learning-driven clustering, FlowSOM (Flow Self-Organizing Maps) and dimensional reduction with tSNE (t-distributed Stochastic Neighbor Embedding) to identify unique cell populations in early and established SLE. For the nine early SLE patients, longitudinal mass cytometry analysis was applied to PBMCs at three time points (at enrollment, six months post-enrollment, and one year post-enrollment). Serum samples were also assayed for 65 cytokines by Luminex multiplex assay, and associations between cell types and cytokines/chemokines assessed. Results: T peripheral helper cells (Tph cells), T follicular helper cells (Tfh cells) and several Ki67+ proliferating subsets (ICOS+ Ki67+ CD8 T cells, Ki67+ regulatory T cells, CD19int Ki67hi plasmablasts, and Ki67hi PU.1hi monocytes) were increased in early SLE. Longitudinal mass cytometry and multiplex serum cytokine assays of samples from early SLE patients revealed that Tfh cells and CXCL10 decreased at one year post-enrollment. CXCL13 correlated positively with several of the expanded cell populations in early SLE. Conclusions: Two major helper T cell subsets and unique Ki67+ proliferating immune cell subsets were expanded in the early phase of SLE, and the immunologic features characteristic of early SLE evolved over time.

scholarly journals B cell, CD8+ T cell and gamma delta T cell infiltration alters alveolar immune cell homeostasis in HIV-infected Malawian adults

2018 ◽  
Vol 2 ◽  
pp. 105 ◽  
Author(s):  
Andrew Mwale ◽  
Annemarie Hummel ◽  
Leonard Mvaya ◽  
Raphael Kamng'ona ◽  
Elizabeth Chimbayo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Immune Cell ◽  
Cell Populations ◽  
Monocyte Subset ◽  
Gamma Delta ◽  
Cell Homeostasis ◽  
Tract Infections ◽  
The Impact

Background: HIV infection is associated with increased risk to lower respiratory tract infections (LRTI). However, the impact of HIV infection on immune cell populations in the lung is not well defined. We sought to comprehensively characterise the impact of HIV infection on immune cell populations in the lung. Methods: Twenty HIV-uninfected controls and 17 HIV-1 infected ART-naïve adults were recruited from Queen Elizabeth Central Hospital, Malawi. Immunophenotyping of lymphocyte and myeloid cell populations was done on bronchoalveolar lavage fluid and peripheral blood cells. Results: We found that the numbers of CD8 + T cells, B cells and gamma delta T cells were higher in BAL fluid of HIV-infected adults compared to HIV-uninfected controls (all p<0.05). In contrast, there was no difference in the numbers of alveolar CD4 + T cells in HIV-infected adults compared to HIV-uninfected controls (p=0.7065). Intermediate monocytes were the predominant monocyte subset in BAL fluid (HIV-, 63%; HIV+ 81%), while the numbers of classical monocytes was lower in HIV-infected individuals compared to HIV-uninfected adults (1 × 10 5 vs. 2.8 × 10 5 cells/100ml of BAL fluid, p=0.0001). The proportions of alveolar macrophages and myeloid dendritic cells was lower in HIV-infected adults compared to HIV-uninfected controls (all p<0.05). Conclusions: Chronic HIV infection is associated with broad alteration of immune cell populations in the lung, but does not lead to massive depletion of alveolar CD4 + T cells. Disruption of alveolar immune cell homeostasis likely explains in part the susceptibility for LRTIs in HIV-infected adults.

Abstract P143: Salt-sensitivity And Salt-resistance Differentially Modulate Renal And Colonic T Regulatory Cells

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Patrick A Molina ◽  
Claudia J Edell ◽  
Rachel Q Muir ◽  
Jackson C Colson ◽  
Craig L Maynard ◽  
...  
Keyword(s):  
T Cells ◽  
Drinking Water ◽  
T Cell ◽  
T Regulatory Cells ◽  
Immune Cell ◽  
Salt Resistance ◽  
Functional Adaptation ◽  
Cell Populations ◽  
Protective Mechanisms ◽  
Host Protection

High salt diets (HSD) promote both inflammation and immunosuppression as shown in numerous studies utilizing salt-sensitive or hypertensive models. However, mechanisms involved in the homeostatic immune response to HSD, alone, have not been fully elucidated. Regulatory T cells (FOXP3 + CD4 + T cells) play a role in host protection against disease or environmental stressors. Further, recent studies show that RORt + expression by Tregs may represent a functional adaptation by Tregs in response to alterations to the diet. Thus, we hypothesized that these Treg populations may expand in response to HSD alone, and a hypertensive insult prior to the HSD blunts this response. We designed experiments to determine whether Tregs and RORt + Tregs expand in response to HSD or with LNAME hypertension followed by HSD. We evaluated the following groups in male C57BL/6J mice: NSD (normal salt diet, 0.4% NaCl), LNAME/NSD (0.5mg/ml for 3-wks in drinking water, followed by 3-wks NSD), HSD (4% NaCl+1% NaCl in drinking water, 2-wks), or LNAME/HSD (0.5mg/mL for 3-wks in drinking water, with 1-wk NSD followed by 2-wks HSD). Following immune cell isolation, we utilized flow cytometry to phenotype renal and colonic T cells. Data are expressed as frequency of means (% of CD4 + TCRbeta + T cells)±SEM (n=3-8/group) compared to NSD. In kidneys, HSD significantly expanded Tregs and RORt + Tregs, while LNAME/HSD group was unchanged compared to controls (% Treg: NSD: 5.7±0.5; L-NAME: 6.5±0.5; HSD: 9.2±1.0**; LNAME/HSD: 6.2±0.3; % RORt + Treg: NSD: 0.4±0.07; L-NAME: 0.6±0.13; HSD: 1.8±0.41***; LNAME/HSD: 0.6±0.14; **p<0.01, ***p<0.001). In the colon, HSD significantly expanded Tregs and RORt + Tregs, whereas the LNAME/HSD group had no change in these T cell populations (% Treg: NSD: 36±2; LNAME: 42±1; HSD: 46±2*; LNAME/HSD: 43±2; % RORt + Tregs: NSD: 16±1; LNAME: 19±1; HSD: 23±1*; LNAME/HSD: 20±2; *p<0.05). These data suggest that Tregs and RORt + Tregs expand in response to HSD in the kidney and colon, with a greater magnitude of expansion by RORt + Tregs. However, this expansion of T cell populations is not evident in mice pre-exposed to a hypertensive insult. We propose that HSD stimulates pathways that promote Treg expansion, which may be associated with salt-resistance and protective mechanisms.

scholarly journals Delineation of an immunosuppressive gradient in hepatocellular carcinoma using high-dimensional proteomic and transcriptomic analyses

2017 ◽  
Vol 114 (29) ◽  
pp. E5900-E5909 ◽  
Author(s):  
Valerie Chew ◽  
Liyun Lai ◽  
Lu Pan ◽  
Chun Jye Lim ◽  
Juntao Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
Transcription Factor ◽  
T Cell ◽  
Tumor Antigens ◽  
Cell Subset ◽  
High Dimensional ◽  
Mass Cytometry ◽  
Chemotactic Gradient ◽  
Activation Status

The recent development of immunotherapy as a cancer treatment has proved effective over recent years, but the precise dynamics between the tumor microenvironment (TME), nontumor microenvironment (NTME), and the systemic immune system remain elusive. Here, we interrogated these compartments in hepatocellular carcinoma (HCC) using high-dimensional proteomic and transcriptomic analyses. By time-of-flight mass cytometry, we found that the TME was enriched in regulatory T cells (Tregs), tissue resident memory CD8+ T cells (TRMs), resident natural killer cells (NKRs), and tumor-associated macrophages (TAMs). This finding was also validated with immunofluorescence staining on Foxp3+CD4+ and PD-1+CD8+ T cells. Interestingly, Tregs and TRMs isolated from the TME expressed multiple markers for T-cell exhaustion, including PD-1, Lag-3, and Tim-3 compared with Tregs and TRMs isolated from the NTME. We found PD-1+ TRMs were the predominant T-cell subset responsive to anti–PD-1 treatment and significantly reduced in number with increasing HCC tumor progression. Furthermore, T-bet was identified as a key transcription factor, negatively correlated with PD-1 expression on memory CD8+ T cells, and the PD-1:T-bet ratio increased upon exposure to tumor antigens. Finally, transcriptomic analysis of tumor and adjacent nontumor tissues identified a chemotactic gradient for recruitment of TAMs and NKRs via CXCR3/CXCL10 and CCR6/CCL20 pathways, respectively. Taken together, these data confirm the existence of an immunosuppressive gradient across the TME, NTME, and peripheral blood in primary HCC that manipulates the activation status of tumor-infiltrating leukocytes and renders them immunocompromised against tumor cells. By understanding the immunologic composition of this gradient, more effective immunotherapeutics for HCC may be designed.

scholarly journals Autocrine, Not Paracrine, Interferon-Gamma Gene Delivery Enhances Ex Vivo Antigen-Specific Cytotoxic T Lymphocyte Stimulation and Killing

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Dazhi Zhang ◽  
Yong Liu ◽  
Min Shi ◽  
Chang Xuan You ◽  
Maohua Cao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Gene Delivery ◽  
Immune Cell ◽  
Cytotoxic T Lymphocyte ◽  
Ex Vivo ◽  
Cell Populations ◽  
Adeno Associated Virus ◽  
Th1 Response ◽  
Compare And Contrast

The adoptive transfer of antigen-specific cytotoxic T lymphocytes (CTL) shows promise in the treatment of cancer and infectious diseases. We utilize adeno-associated virus-(AAV-) based antigen gene-loaded dendritic cells (DCs) to stimulate such antigen-specific CTL. Yet further improvements in CTL stimulation and killing may result by gene delivery of various Th1-response interferons/cytokines, such as interferonγ(IFN-γ), as the delivered gene can continuously produce that interferon. However which immune cell type should optimally express IFN-γis unclear as the phenotypes of both DC and T cells are enhanced by it. Here, we used AAV to compare and contrast IFN-γgene delivery into DC or T cells, and versus the addition of exogenous IFN-γ, for stimulating carcinoembryonic antigen-(CEA-) specific CTL. It was found that AAV/IFN-γdelivery into T cells (autocrine) resulted in T cell populations with the highest CD8(+)/CD4(+) ratio, highest IFN-γ(+)/IL-4(+) ratio, highest CD69(+),CD8(+) levels, and lowest CD4(+)/CD25(+) levels, all consistent with the strongest Th1 response. Most importantly, AAV/IFN-γtransduction of T cells resulted in antigen-specific T cell populations with the highest killing capabilities, 49% above other treatments. These data strongly suggest that AAV/IFN-γautocrine gene delivery into T cells is worthy of further study towards maximizing the generation of antigen-specific anticancer CTL killers.

Mezagitamab Induces Immunomodulatory Effect in Patients with Relapsed/Refractory Multiple Myeloma (RRMM)

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Michael Abadier ◽  
Jose Estevam ◽  
Deborah Berg ◽  
Eric Robert Fedyk
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
B Cells ◽  
Nk Cells ◽  
Peripheral Blood ◽  
Immune Cell ◽  
Cell Populations ◽  
Landscape Changes ◽  
Ki 67 ◽  
Immune Cell Subsets

Background Mezagitamab is a fully human immunoglobulin (Ig) G1 monoclonal antibody with high affinity to CD38 that depletes tumor cells expressing CD38 by antibody- and complement-dependent cytotoxicity. CD38 is a cell surface molecule that is highly expressed on myeloma cells, plasma cells, plasmablasts, and natural killer (NK) cells, and is induced on activated T cells and other suppressor cells including regulatory T (Tregs) and B (Bregs) cells. Data suggest that immune landscape changes in cancer patients and this may correlate with disease stage and clinical outcome. Monitoring specific immune cell subsets could predict treatment responses since certain cell populations either enhance or attenuate the anti-tumor immune response. Method To monitor the immune landscape changes in RRMM patients we developed a mass cytometry panel that measures 39-biomarkers to identify multiple immune cell subsets, including T cells (naïve, memory, effector, regulatory), B cells (naïve, memory, precursors, plasmablasts, regulatory), NK cells, NKT cells, gamma delta T cells, monocytes (classical, non-classical and intermediate), dendritic cells (mDC; myeloid and pDC; plasmacytoid) and basophils. After a robust analytical method validation, we tested cryopreserved peripheral blood and bone marrow mononuclear cells from 19 RRMM patients who received ≥ 3 prior lines of therapy. Patients were administered 300 or 600 mg SC mezagitamab on a QWx8, Q2Wx8 and then Q4Wx until disease progression schedule (NCT03439280). We compared the percent change in immune cell subsets at baseline versus week 4 and week 16. Results CD38 is expressed at different levels on immune cells and sensitivity to depletion by mezagitamab generally correlates positively with the density of expression. CD38 is expressed at high densities on plasmablasts, Bregs, NK-cells, pDC and basophils at baseline and this was associated with reductions in peripheral blood and bone marrow (plasmablasts, 95%, Bregs, 90%, NK-cells, 50%, pDC, 55% and basophils, 40%) at week 4 post treatment. In contrast, no changes occurred in the level of total T-cells and B-cells, which is consistent with low expression of CD38 on most cells of these large populations. Among the insensitive cell types, remaining NK-cells acquired an activated, proliferative and effector phenotype. We observed 60-150% increase in activation (CD69, HLA-DR), 110-200% increase in proliferation (Ki-67), and 40-375% increase in effector (IFN-γ) markers in peripheral blood and bone marrow. Importantly, NK-cells which did not express detectable CD38, also exhibited a similar phenotype possibly by a mechanism independent of CD38. Consistent with these data, the remaining CD4 and CD8 T-cell populations exhibited an activated effector phenotype as observed by 40-200% increase in activation, 60-200% increase in proliferation and 40-90% increase in effector markers in peripheral blood. A potential explanation for this acquisition of activated effector phenotypes could be a reduction in suppressive regulatory lymphocytes. Next, we measured levels of Tregs and Bregs, and observed that Bregs which are CD24hiCD38hi were reduced to 60-90% in peripheral blood and bone marrow. In contrast, total Tregs were reduced by only 5-25% because CD38 expression in Tregs appears as a spectrum where only ~10-20% are CD38+, and thus CD38+ Tregs were reduced more significantly (45-75%), reflecting the selectively of mezagitamab to cells expressing high levels of CD38. CD38+ Tregs are induced in RRMM patients, thus we looked at the phenotype of CD38-, CD38mid, and CD38high -expressing Tregs. We observed higher level of markers that correlate with highly suppressive Tregs such as Granzyme B, Ki-67, CTLA-4 and PD-1 in CD38high Tregs. Accordingly, the total Treg population exhibited a less active phenotype after exposure to mezagitamab, which selectively depleted the highly suppressive CD38+ Tregs. Conclusions Chronic treatment with mezagitamab is immunomodulatory in patients with RRMM, which is associated with reductions in tumor burden, subpopulations of B and T regulatory cells, and characterized by conventional NK and T cells exhibiting an activated, proliferative and effector phenotype. The immune landscape changes observed is consistent with the immunologic concept of converting the tumor microenvironment from cold-to-hot and highlights a key mechanistic effect of mezagitamab. Disclosures Berg: Takeda Pharmaceuticals Inc: Current Employment.

Sign in / Sign up

Export Citation Format

Share Document