scholarly journals Specificity of CD8-Targeted Fusosomes in Human PBMCs Using Single Cell RNA and T Cell Receptor Sequencing

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3983-3983
Author(s):  
Hina Iftikhar ◽  
Nikolas Balanis ◽  
Chamith Fonseka ◽  
Christopher Bandoro ◽  
Patricia Cruite ◽  
...  
Keyword(s):  
T Cells ◽  
Single Cell ◽  
T Cell Receptor ◽  
Cell Types ◽  
Cell Receptor ◽  
Specific Cell ◽  
Human Pbmcs ◽  
The Past

Abstract Introduction: The ability to deliver genes to specific cell types in vivo would have a profound therapeutic impact for a diverse set of diseases. For example, targeting T cells for in vivo delivery of a chimeric antigen receptor (CAR) to treat B cell malignancies would improve access to CAR T therapies by overcoming the limitations of ex vivo manufacturing such as high costs, wait times and manufacturing failures. We have developed a novel paramyxovirus-based integrating vector (fusosomes) that specifically targets cell surface receptors for targeted gene delivery. Fusosomes, engineered to target CD8α, a cell surface protein expressed on CD8+ T cells, can bind and specifically deliver a genetic payload through membrane fusion. To evaluate the specificity of fusosome-mediated delivery to cells expressing CD8α in vitro, single cell RNA sequencing (scRNA-seq) and T cell receptor sequencing (scTCR-seq) were performed on human PBMCs treated with CD8α-targeted fusosomes with a GFP payload. scRNA-seq is a tool that can be used to detect the transgene delivered by our fusosomes in specific cell populations by measuring mRNA expression of the receptor targeted by the fusosome (e.g., CD8α) and the genetic payload delivered by the fusosome in the same cell. Transcriptome information to understand potential pathway changes induced by delivery of the transgene is also captured. Methods: scRNA-seq was performed using the 10X Genomics system on human PBMCs in vitro. Activated and resting PBMCs from a single donor were transduced with CD8α-targeted fusosomes. Cells were then harvested 3 days post-transduction for scRNA-seq and scTCR-seq. Following library preparation and Illumina sequencing, read processing and bioinformatics analyses were performed using 10X Genomics Cell Ranger and the Seurat R package. Results: In the PBMCs transduced with fusosomes, > 9,000 cells were barcoded with > 1,900 median genes detected per cell. scRNA-seq identified multiple cell types in PBMCs with approximately 25% of cells expressing CD8α transcripts. Fusosome-associated transcripts were seen in about 54% of the cells expressing CD8α and in particular, T cells classified as CD8+ using known markers and classification algorithms based on reference data sets. Subsequently, scTCR-seq data were used to confirm the identity of T cells. Comparison of the results showed an overlap of > 87% of cells classified as T cells by the two independent methods. Visualization by UMAP and inference based on a reference dataset showed that naïve (Tn), central memory (Tcm), effector memory (Tem) and mucosal-associated invariant T cells were transduced by the CD8α-targeted fusosomes. In addition, fusosome-associated transcripts were detected in about 19% of NK cells where approximately 62% of these NK cells also expressed CD8α. Overall, our CD8α-targeted fusosomes have a specificity of > 93% in resting PBMCs based on CD8α expression. A subset of cells may have detectable GFP transcripts at the time of analysis, but not CD8α transcripts due to limited sequencing depth per cell. Summary: Our in vitro scRNA-seq and scTCR-seq data demonstrate that our CD8α-targeted fusosomes are highly specific for cells expressing CD8α transcripts in resting PBMCs. These data highlight the potential for utilizing single cell sequencing technologies to comprehensively characterize the specificity of our fusosomes, and to identify key biological pathways that may play a role in specificity, transduction efficiency and clinical efficacy. As next steps, we will use similar approaches to characterize in vivo transduction in animal models. Disclosures Iftikhar: Sana Biotechnology: Current Employment. Balanis: Sana Biotechnology: Ended employment in the past 24 months. Fonseka: Sana Biotechnology: Current Employment. Bandoro: Sana Biotechnology: Ended employment in the past 24 months. Cruite: Sana Biotechnology: Current Employment. Davis: Sana Biotechnology: Current Employment. Amatya: Sana Biotechnology: Current Employment. Frye: Sana Biotechnology: Current Employment. Pepper: Sana Biotechnology: Current Employment. Laska: Sana Biotechnology: Current Employment. Fry: Sana Biotechnology: Current Employment, Current equity holder in publicly-traded company. Shah: Sana Biotechnology: Current Employment. Paliwal: Sana Biotechnology: Current Employment. Chaivorapol: Sana Biotechnology: Current Employment.

scholarly journals Single-cell RNA sequencing reveals ex vivo signatures of SARS-CoV-2-reactive T cells through ‘reverse phenotyping’

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David S. Fischer ◽  
Meshal Ansari ◽  
Karolin I. Wagner ◽  
Sebastian Jarosch ◽  
Yiqi Huang ◽  
...  
Keyword(s):  
T Cells ◽  
Single Cell ◽  
Rna Sequencing ◽  
Ex Vivo ◽  
Severe Disease ◽  
Human Leukocyte ◽  
Cell Receptor ◽  
Single Cell Rna Sequencing

AbstractThe in vivo phenotypic profile of T cells reactive to severe acute respiratory syndrome (SARS)-CoV-2 antigens remains poorly understood. Conventional methods to detect antigen-reactive T cells require in vitro antigenic re-stimulation or highly individualized peptide-human leukocyte antigen (pHLA) multimers. Here, we use single-cell RNA sequencing to identify and profile SARS-CoV-2-reactive T cells from Coronavirus Disease 2019 (COVID-19) patients. To do so, we induce transcriptional shifts by antigenic stimulation in vitro and take advantage of natural T cell receptor (TCR) sequences of clonally expanded T cells as barcodes for ‘reverse phenotyping’. This allows identification of SARS-CoV-2-reactive TCRs and reveals phenotypic effects introduced by antigen-specific stimulation. We characterize transcriptional signatures of currently and previously activated SARS-CoV-2-reactive T cells, and show correspondence with phenotypes of T cells from the respiratory tract of patients with severe disease in the presence or absence of virus in independent cohorts. Reverse phenotyping is a powerful tool to provide an integrated insight into cellular states of SARS-CoV-2-reactive T cells across tissues and activation states.

scholarly journals 173 Expression of a membrane-tethered IL-15/IL-15 receptor fusion protein enhances the persistence of MSLN-targeted TRuC-T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Fusion Protein ◽  
T Cell Receptor ◽  
Cytokine Production ◽  
Cell Receptor ◽  
Great Promise ◽  
And Function

BackgroundAdoptive cell therapies have shown great promise in hematological malignancies but have yielded little progress in the context of solid tumors. We have developed T cell receptor fusion construct (TRuC®) T cells, which are equipped with an engineered T cell receptor that utilizes the full complement of TCR signaling subunits and recognizes tumor-associated antigens independent of HLA. In clinical trials, mesothelin (MSLN)-targeting TRuC-T cells (TC-210 or gavo-cel) have shown unprecedented results in patients suffering from advanced mesothelioma and ovarian cancer. To potentially increase the depth of response, we evaluated strategies that can promote intra-tumoral T cell persistence and function. Among the common ??-chain cytokines, IL-15 uniquely supports the differentiation and maintenance of memory T cell subsets by limiting terminal differentiation and conferring resistance to IL-2 mediated activation-induced cell death (AICD). In the studies described here, we evaluated the potential of IL-15 as an enhancement to TRuC-T cell phenotype, persistence and function against MSLN+ targets.MethodsPrimary human T cells were activated and transduced with a lentiviral vector encoding an anti-MSLN binder fused to CD3ε alone or co-expressed with a membrane-tethered IL-15rα/IL-15 fusion protein (IL-15fu). Transduced T cells were expanded for 9 days and characterized for expression of the TRuC, IL-15rα and memory phenotype before subjecting them to in vitro functional assays to evaluate cytotoxicity, cytokine production, and persistence. In vivo efficacy was evaluated in MHC class I/II deficient NSG mice bearing human mesothelioma xenografts.ResultsIn vitro, co-expression of the IL-15fu led to similar cytotoxicity and cytokine production as TC-210, but notably enhanced T-cell expansion and persistence upon repeated stimulation with MSLN+ cell lines. Furthermore, the IL-15fu-enhanced TRuC-T cells sustained a significantly higher TCF-1+ population and retained a stem-like phenotype following activation. Moreover, the IL-15fu-enhanced TRuCs demonstrated robust in vivo expansion and intra-tumoral accumulation as measured by ex vivo analysis of TRuC+ cells in the tumor and blood, with a preferential expansion of CD8+ T cells. Finally, IL-15fu-enhanced TRuC-T cells could be observed in the blood long after the tumors were cleared.ConclusionsThese pre-clinical studies suggest that the IL-15fu can synergize with TC-210 to increase the potency and durability of response in patients with MSLN+ tumors.Ethics ApprovalAll animal studies were approved by the respective Institutional Animal Care and Use Committees.

scholarly journals A Novel Approach for the Treatment of T Cell Malignancies: Targeting T Cell Receptor Vβ Families

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 631
Author(s):  
Jie Wang ◽  
Katarzyna Urbanska ◽  
Prannda Sharma ◽  
Reza Nejati ◽  
Lauren Shaw ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Lymphomas ◽  
Novel Approach ◽  
T Cell Malignancies

Peripheral T cell lymphomas (PTCLs) are generally chemotherapy resistant and have a poor prognosis. The lack of targeted immunotherapeutic approaches for T cell malignancies results in part from potential risks associated with targeting broadly expressed T cell markers, namely T cell depletion and clinically significant immune compromise. The knowledge that the T cell receptor (TCR) β chain in human α/β TCRs are grouped into Vβ families that can each be targeted by a monoclonal antibody can therefore be exploited for therapeutic purposes. Here, we develop a flexible approach for targeting TCR Vβ families by engineering T cells to express a chimeric CD64 protein that acts as a high affinity immune receptor (IR). We found that CD64 IR-modified T cells can be redirected with precision to T cell targets expressing selected Vβ families by combining CD64 IR-modified T cells with a monoclonal antibody directed toward a specific TCR Vβ family in vitro and in vivo. These findings provide proof of concept that TCR Vβ-family-specific T cell lysis can be achieved using this novel combination cell–antibody platform and illuminates a path toward high precision targeting of T cell malignancies without substantial immune compromise.

scholarly journals Evidence for in vivo clonal proliferation of unique population of blood CD4-/CD8- T cells bearing T-cell receptor alpha and beta chains in two normal men

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2965-2972 ◽  
Author(s):  
Y Kusunoki ◽  
Y Hirai ◽  
S Kyoizumi ◽  
M Akiyama
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Nk Cell ◽  
Cell Receptor ◽  
Cell Markers ◽  
Clonal Proliferation ◽  
Alpha Beta

Abstract Rare T lymphocytes bearing CD3 surface antigen and T-cell receptor (TCR) alpha and beta chains, but lacking both CD4 and CD8 antigens, viz, TCR alpha beta+CD4–8- cells, appear at a frequency of 0.1% to 2% in peripheral blood TCR alpha beta+ cells of normal donors. Here we report two unusual cases, found among 100 healthy individuals studied, who showed an abnormally elevated frequency of these T cells, ie, 5% to 10% and 14% to 19%. Southern blot analyses of the TCR alpha beta+CD4–8- clones all showed the identical rearrangement patterns for each individual, demonstrating that these are derivatives of a single T cell. The same rearrangement patterns were also observed for the freshly isolated lymphocytes of TCR alpha beta+CD4-CD8- fraction, which excludes the possible bias in the processes of in vitro cloning. These TCR alpha beta+CD4–8- T cells were found to express other mature T-cell markers such as CD2, CD3, and CD5 antigens, as well as natural killer (NK) cell markers (CD11b, CD16, CD56, and CD57 antigens) for both individuals. Further, although lectin-dependent or redirected antibody- dependent cell-mediated cytotoxicities were observed for both freshly sorted lymphocytes of TCR alpha beta+CD4–8- fraction and in vitro established clones, NK-like activity was not detected.

scholarly journals The Caspase 8 Inhibitor c-FLIPL Modulates T-Cell Receptor-Induced Proliferation but Not Activation-Induced Cell Death of Lymphocytes

2002 ◽  
Vol 22 (15) ◽  
pp. 5419-5433 ◽  
Author(s):  
Susanne M. A. Lens ◽  
Takao Kataoka ◽  
Karen A. Fortner ◽  
Antoine Tinel ◽  
Isabel Ferrero ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Death Receptor ◽  
Cell Receptor ◽  
Caspase 8 ◽  
Activation Induced Cell Death

ABSTRACT The caspase 8 inhibitor c-FLIPL can act in vitro as a molecular switch between cell death and growth signals transmitted by the death receptor Fas (CD95). To elucidate its function in vivo, transgenic mice were generated that overexpress c-FLIPL in the T-cell compartment (c-FLIPL Tg mice). As anticipated, FasL-induced apoptosis was inhibited in T cells from the c-FLIPL Tg mice. In contrast, activation-induced cell death of T cells in c-FLIPL Tg mice was unaffected, suggesting that this deletion process can proceed in the absence of active caspase 8. Accordingly, c-FLIPL Tg mice differed from Fas-deficient mice by showing no accumulation of B220+ CD4− CD8− T cells. However, stimulation of T lymphocytes with suboptimal doses of anti-CD3 or antigen revealed increased proliferative responses in T cells from c-FLIPL Tg mice. Thus, a major role of c-FLIPL in vivo is the modulation of T-cell proliferation by decreasing the T-cell receptor signaling threshold.

scholarly journals T-cell calcium dynamics visualized in a ratiometric tdTomato-GCaMP6f transgenic reporter mouse

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Tobias X Dong ◽  
Shivashankar Othy ◽  
Amit Jairaman ◽  
Jonathan Skupsky ◽  
Angel Zavala ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Tracking ◽  
Cell Types ◽  
Cell Receptor ◽  
Receptor Activation ◽  
Specific Cell ◽  
Transgenic Expression ◽  
Reporter Mouse

Calcium is an essential cellular messenger that regulates numerous functions in living organisms. Here, we describe development and characterization of ‘Salsa6f’, a fusion of GCaMP6f and tdTomato optimized for cell tracking while monitoring cytosolic Ca2+, and a transgenic Ca2+ reporter mouse with Salsa6f targeted to the Rosa26 locus for Cre-dependent expression in specific cell types. The development and function of T cells was unaffected in Cd4-Salsa6f mice. We describe Ca2+ signals reported by Salsa6f during T cell receptor activation in naive T cells, helper Th17 T cells and regulatory T cells, and Ca2+ signals mediated in T cells by an activator of mechanosensitive Piezo1 channels. Transgenic expression of Salsa6f enables ratiometric imaging of Ca2+ signals in complex tissue environments found in vivo. Two-photon imaging of migrating T cells in the steady-state lymph node revealed both cell-wide and localized sub-cellular Ca2+ transients (‘sparkles’) as cells migrate.

scholarly journals T Cell Calcium Dynamics Visualized in a Ratiometric tdTomato-GCaMP6f Transgenic Reporter Mouse

2017 ◽  
Author(s):  
Tobias X. Dong ◽  
Shivashankar Othy ◽  
Amit Jairaman ◽  
Jonathan Skupsky ◽  
Angel Zavala ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Tracking ◽  
Cell Types ◽  
Cell Receptor ◽  
Functional Expression ◽  
Specific Cell ◽  
Transgenic Expression ◽  
Reporter Mouse

AbstractCalcium is an essential cellular messenger that regulates numerous functions in living organisms. Here we describe development and characterization of “Salsa6f”, a fusion of GCaMP6f and tdTomato optimized for cell tracking while monitoring cytosolic Ca2+, and a transgenic Ca2+ reporter mouse with Salsa6f floxed and targeted to the Rosa26 locus for expression in specific cell types. Using CD4-Cre-Salsa6f mice, we report normal development and function of T cells expressing Salsa6f and demonstrate Ca2+ signaling dynamics during T cell receptor engagement in naïve T cells, helper Th17 T cells and regulatory T cells. Salsa6f expression also revealed functional expression of mechanosensitive Piezo1 channels in T cells. Transgenic expression of Salsa6f enables ratiometric imaging of Ca2+ signals in complex tissue environments found in vivo. Deep tissue two-photon imaging of T cells in the steady-state lymph node revealed a highly localized Ca2+ signaling behavior (“sparkles”) as cells migrate.

scholarly journals T Cells Engineered with a Novel Chimeric Receptor Demonstrate Durable In Vivo Efficacy Against Disseminated Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 962-962 ◽  
Author(s):  
Ksenia Bezverbnaya ◽  
Vivian Lau ◽  
Craig Aarts ◽  
Galina Denisova ◽  
Arya Afsahi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Inhibitory Effect ◽  
In Vivo Efficacy ◽  
Engineered T Cells

Abstract Despite recent therapeutic developments, multiple myeloma remains an incurable plasma cell malignancy. Poor prognosis for myeloma patients relapsing post-transplant calls for the need for novel treatment options. Immunotherapy with engineered T cells has proven highly efficacious against B-cell cancers, and early-phase clinical trials suggest that multiple myeloma is susceptible to this form of therapy. We designed a new chimeric T cell receptor, T cell antigen coupler (TAC), which relies upon activation through endogenous T cell receptor complex, thus allowing engineered T cells to auto-regulate their activity (Helsen et al, Nat. Comm., 2018). Using published single-chain antibody fragments (scFvs) C11D5.3 and J22.9-xi, we generated B cell maturation antigen (BCMA)-specific TAC receptors for targeting multiple myeloma. Primary human T cells were transduced with lentiviral vectors carrying different BCMA TAC constructs and assessed for in vitro functionality via cytokine production, cytotoxicity, and proliferation assays. In vivo efficacy and T cell tracking were performed in an established orthotopic xenograft mouse model based on a BCMA-positive KMS-11 cell line. C11D5.3 and J22.9-xi TAC T cells demonstrated comparable in vitro performance with both types of cultures efficiently killing BCMA-expressing targets, producing IFN-γ, TNF-α, and IL-2 cytokines, and undergoing multiple rounds of proliferation. In vivo, TAC T cells carrying either scFv were capable of curing mice bearing disseminated myeloma; however, the TAC T cells carrying J22.9-xi scFv were more potent on a per-cell basis (Figure 1A, top panel). Mice in remission 3 months post-treatment with a single dose of 106 TAC-positive T cells showed evidence of sustained anti-tumor protection upon rechallenge with a fresh dose of 106 KMS-11 tumor cells (Figure 1B). Mice treated with low-dose J22.9-xi T cells were more resistant to rechallenge than mice treated with a comparable dose of C11D5.3 TAC T cells. Tracking of the TAC T cells in vivo revealed that the J22.9-xi TAC T cells expanded to a much larger extent than the C11D5.3 TAC T cells (Figure 1A, bottom panel), indicating that there were likely more J22.9-xi TAC T cells present at the time of tumor rechallenge. To understand whether biological aspects of BCMA may influence the proliferative response of the TAC T cells, we explored the influence of APRIL, the soluble ligand for BCMA, on TAC T cell proliferation in vitro. Strikingly, despite comparable proliferation of both TAC T cell populations following stimulation with KMS-11 tumor cells in the absence of APRIL in vitro, the presence of APRIL had a strong inhibitory effect on proliferation of C11D5.3 TAC T cells and only a modest inhibitory effect on J22.9-xi TAC T cells. Our preclinical findings support further development of TAC T cells for the treatment of multiple myeloma and underscore the importance of T cell expansion in determining the therapeutic activity of engineered T cells. This work further reveals a novel observation that the natural ligand of BCMA can impair the therapeutic impact of T cells engineered with chimeric receptors directed against BCMA and provide a basis for advancing BCMA-specific TAC T cells into the clinic. Disclosures Denisova: Triumvira Immunologics: Patents & Royalties. Afsahi:Triumvira Immunologics: Patents & Royalties. Helsen:Triumvira Immunologics: Employment, Patents & Royalties. Bramson:Triumvira Immunologics: Employment, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

scholarly journals Antigen-dependent Proliferation of CD4+ CD25+ Regulatory T Cells In Vivo

2003 ◽  
Vol 198 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Lucy S.K. Walker ◽  
Anna Chodos ◽  
Mark Eggena ◽  
Hans Dooms ◽  
Abul K. Abbas
Keyword(s):  
T Cells ◽  
Population Dynamics ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Tissue Antigen ◽  
Treg Population

The failure of CD25+ regulatory T cells (Tregs) to proliferate after T cell receptor (TCR) stimulation in vitro has lead to their classification as naturally anergic. Here we use Tregs expressing a transgenic TCR to show that despite anergy in vitro, Tregs proliferate in response to immunization in vivo. Tregs also proliferate and accumulate locally in response to transgenically expressed tissue antigen whereas their CD25− counterparts are depleted at such sites. Collectively, these data suggest that the anergic state that characterizes CD25+ Tregs in vitro may not accurately reflect their responsiveness in vivo. These observations support a model in which Treg population dynamics are shaped by the local antigenic environment.

scholarly journals INHIBITION OF SPECIFIC CELL-MEDIATED CYTOTOXICITY BY ANTI-T-CELL RECEPTOR ANTIBODY

1974 ◽  
Vol 139 (4) ◽  
pp. 888-901 ◽  
Author(s):  
Arthur K. Kimura
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Specific Cell ◽  
In Vitro Immunization ◽  
Effector Cells ◽  
Mouse Cells ◽  
Different Strains

The present study describes a method for the production of a specific anti-T-cell receptor antiserum, and characteristics of its ability to block specific cell-mediated cytotoxicity in vitro. Immunization and antiserum adsorption procedures were designed to select for idiotypic differences in the recognition units of C3H lymphocytes immune to two different strains of mouse cells, such that the reactivity of only one population of effector cells is inhibited by this antiserum. Both in vivo and in vitro sensitized effector T cells are subject to this inhibition. That the site of the antiserum blockade is clearly on the effector cell and not on the target cell is demonstrated.

Sign in / Sign up

Export Citation Format

Share Document