scholarly journals O7 A bispecific VHH approach to leverage the potent and widely applicable tumor cytolytic capacity of Vγ9Vδ2 T cells

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A6.2-A7
Author(s):  
LA King ◽  
R Lameris ◽  
RC Roovers ◽  
P Parren ◽  
TD de Gruijl ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
T Cells ◽  
T Cell ◽  
Xenograft Model ◽  
Cell Receptor ◽  
Target Cells ◽  
Mouse Xenograft Model ◽  
Vγ9vδ2 T Cells

Vγ9Vδ2-T cells include a unique and potent subset of T cells which play an important role in tumor defense. Vγ9Vδ2-T cells recognize and can lyse butyrophilin 3A1-expressing target cells with elevated levels of non-peptide phosphoantigens (pAg), induced by cell stress or malignancy. To date, Vγ9Vδ2-T cell based cancer immunotherapeutic approaches were well tolerated and in some cases capable of inducing relevant clinical responses. In an effort to improve the efficacy and consistency of Vγ9Vδ2-T cell based cancer immunotherapy, we designed a bispecific VHH that binds to both Vγ9Vδ2-T cells and EGFR expressed by tumor cells and results in the target-specific activation of Vγ9Vδ2-T cells and subsequent lysis of colorectal cancer cell lines and primary colorectal cancer samples both in vitro and in an in vivo mouse xenograft model. Of note, tumor cell lysis was independent of mutations in KRAS and BRAF that are known to impair the efficacy of clinically registered anti-EGFR monoclonal antibodies as well as common Vγ9Vδ2-T cell receptor sequence variations. In combination with the conserved monomorphic nature of the Vγ9Vδ2-TCR and the facile replacement of the tumor-specific VHH, this immunotherapeutic approach can in principle be applied to a large group of cancer types.Disclosure InformationL.A. King: None. R. Lameris: None. R.C. Roovers: None. P. Parren: None. T.D. de Gruijl: None. H.J. van der Vliet: None.

scholarly journals Single-cell transcriptomics identifies multiple pathways underlying antitumor function of TCR- and CD8αβ-engineered human CD4+ T cells

2020 ◽  
Vol 6 (27) ◽  
pp. eaaz7809 ◽  
Author(s):  
Jan A. Rath ◽  
Gagan Bajwa ◽  
Benoit Carreres ◽  
Elisabeth Hoyer ◽  
Isabelle Gruber ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Cell Function ◽  
Xenograft Model ◽  
Cell Receptor ◽  
Target Cells ◽  
Antigen Specificity ◽  
Molecular Features ◽  
Mouse Xenograft Model

Transgenic coexpression of a class I–restricted tumor antigen–specific T cell receptor (TCR) and CD8αβ (TCR8) redirects antigen specificity of CD4+ T cells. Reinforcement of biophysical properties and early TCR signaling explain how redirected CD4+ T cells recognize target cells, but the transcriptional basis for their acquired antitumor function remains elusive. We, therefore, interrogated redirected human CD4+ and CD8+ T cells by single-cell RNA sequencing and characterized them experimentally in bulk and single-cell assays and a mouse xenograft model. TCR8 expression enhanced CD8+ T cell function and preserved less differentiated CD4+ and CD8+ T cells after tumor challenge. TCR8+CD4+ T cells were most potent by activating multiple transcriptional programs associated with enhanced antitumor function. We found sustained activation of cytotoxicity, costimulation, oxidative phosphorylation– and proliferation-related genes, and simultaneously reduced differentiation and exhaustion. Our study identifies molecular features of TCR8 expression that can guide the development of enhanced immunotherapies.

scholarly journals Exhausted CD8+ T cells exhibit low and strongly inhibited TCR signaling during chronic LCMV infection

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ioana Sandu ◽  
Dario Cerletti ◽  
Manfred Claassen ◽  
Annette Oxenius
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Viral Infections ◽  
Cell Receptor ◽  
Target Cells ◽  
Tcr Signaling ◽  
And Function

Abstract Chronic viral infections are often associated with impaired CD8+ T cell function, referred to as exhaustion. Although the molecular and cellular circuits involved in CD8+ T cell exhaustion are well defined, with sustained presence of antigen being one important parameter, how much T cell receptor (TCR) signaling is actually ongoing in vivo during established chronic infection is unclear. Here, we characterize the in vivo TCR signaling of virus-specific exhausted CD8+ T cells in a mouse model, leveraging TCR signaling reporter mice in combination with transcriptomics. In vivo signaling in exhausted cells is low, in contrast to their in vitro signaling potential, and despite antigen being abundantly present. Both checkpoint blockade and adoptive transfer of naïve target cells increase TCR signaling, demonstrating that engagement of co-inhibitory receptors curtails CD8+ T cell signaling and function in vivo.

scholarly journals T Cells Expressing Engager and Costimulatory Molecules for the Immunotherapy of CD19+ Malignancies

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2433-2433
Author(s):  
Mireya Paulina Velasquez ◽  
Kota Iwahori ◽  
David L Torres ◽  
Sunitha Kakarla ◽  
Caroline Arber ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Xenograft Model ◽  
Retroviral Vector ◽  
Effector Function ◽  
Target Cells ◽  
Antitumor Effects

Abstract Background: Immunotherapy with anti-CD19/anti-CD3 bispecific engager molecules has shown promise in clinical studies for CD19+ malignancies. However engager molecules have short half-lives and do not accumulate at tumor sites. In addition, co-delivery of other immunostimulatory molecules to enhance antitumor effects is difficult to achieve. We have recently shown that T cells can be genetically modified to secrete bispecific engager molecules (ENG-T cells). ENG-T cells are activated by tumor cells in an antigen-dependent manner, redirect bystander T cells to tumor cells, and have antitumor activity in preclinical models. We now wanted to explore if additional genetic modifications of ENG-T cells can enhance their effector function in vitro and in vivo. Since bispecific engager molecules do not provide co-stimulation, we focused on the provision of co-stimulatory signals by coexpressing CD80 and CD137L on the cell surface of ENG-T cells. Thus, the aim of the study was to compare the effector function of CD19-specific T-cell engagers (CD19-ENG T cells) and CD19-ENG T cells co-expressing CD80 and 41BBL (CD19-ENG/Costim T cells). Methods: CD19-ENG T cells were generated by transducing T cells with a retroviral vector encoding a CD19-specific T-cell engager and mOrange separated by an IRES (SFG.CD19-ENG-I-mO), and CD19-ENG/Costim T cells were generated by double transducing T cells with SFG.CD19-ENG-I-mO and a 2nd retroviral vector encoding 41BBL and CD80 separated by an IRES. The effector function of ENG T-cells was evaluated in vitro and in a leukemia xenograft model. Results: After single or double transduction 60-80% of T cells were positive for mOrange, and ~80% of CD19-ENG/Costim T cells were positive for CD80 and 30-40% positive for 41BBL. In coculture assays CD19-ENG and CD19-ENG/Costim T cells recognized CD19+ lymphoma (Daudi, Raji) and acute leukemia (BV173) cells as judged by IFN-g secretion in contrast to negative controls. While CD19+ target cells that express CD80 and CD86 (Daudi and Raji) induced robust IL2 production of CD19-ENG and CD19-ENG/Costim T cells, CD19-ENG/Costim T cells produced significantly higher levels of IL2 in comparison to CD19-ENG T cells after stimulation with CD19+/CD80-/CD86- negative target cells (BV173). Cytokine production was antigen dependent since ENG and ENG/Costim T cells specific for an irrelevant antigen (EphA2) did not produce cytokines. Specificity was confirmed in cytotoxicity assays. In transwell assays containing inserts preventing T-cell migration, only ENG T cells redirected bystander T cells in the bottom well to CD19+ tumor cells. To assess in vivo anti-tumor activity of CD19-ENG T cells and CD19-ENG/Costim T cells we used the BV173/NSG mouse xenograft model in which BV173 cells are genetically modified with firefly luciferase (ffLuc-BV173) to allow for serial bioluminescence imaging. While therapy with CD19-ENG T cells on day 7 post ffLuc-BV173 injection resulted in the cure of all mice, when therapy was delayed to day 14, only 1/10 mice was alive on day 80. In contrast therapy of mice on day 14 with CD19-ENG/Costim T cells resulted in long-term survival of 7/10 mice. Control T cells (EphA2-ENG T cells or EphA2-ENG/Costim T cells) had no antitumor effects. Conclusions: We have generated CD19-ENG T cells and CD19-ENG/Costim T cells with the ability to direct bystander T cells to CD19+ malignancies. Both ENG T-cell populations had potent antitumor activity in a preclinical ALL model, and provision of costimulation further enhanced antitumor effects. Genetically modifying T cells to express engager molecules and additional molecules to enhance their effector function may present a promising alternative to current CD19-targeted immunotherapies. Disclosures Velasquez: Celgene, Bluebird bio: Other. Iwahori:Celgene, Bluebird bio: Other. Kakarla:Celgene, Bluebird bio: Other. Song:Celgene, Bluebird bio: Other. Gottschalk:Celgene, Bluebird bio: Other.

scholarly journals 203 A membrane-tethered IL-15/IL-15 receptor fusion protein enhances the persistence and efficacy of CD70-targeted TRuC-T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A214-A214
Author(s):  
Jian Ding ◽  
Lindsay Webb ◽  
Troy Patterson ◽  
Michelle Fleury ◽  
Adam Zieba ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Hematological Malignancies ◽  
Cell Receptor ◽  
Target Cells ◽  
Cell Therapies ◽  
Anti Tumor Activity

BackgroundAdoptive cell therapies have shown great promise in hematological malignancies. To realize the potential of T cell therapies in solid tumors, we have developed T cell receptor fusion construct (TRuC®) T cells, which are equipped with an engineered T cell receptor that utilizes all TCR signaling subunits and recognizes tumor-associated antigens independent of HLA. Previously, we have described the discovery and preclinical efficacy of fratricide-resistant TRuC-T cells targeting CD70, a tumor antigen overexpressed in various solid and hematological malignancies. As a strategy to enhance T cell effector function and persistence in the hostile tumor microenvironment, we engineered anti-CD70 TRuC-T cells to co-express a membrane-bound IL15Ra-IL15 fusion protein (IL-15fu). IL-15 is a common ? chain cytokine that promotes the differentiation, maintenance, and effector function of memory CD8+ T cell subsets and confers resistance to IL-2-mediated activation induced cell death (AICD).MethodsT cells were activated by CD3/CD28 stimulation and lentivirally transduced with a T2A-containing bicistronic vector encoding the anti-CD70 CD3?-TRuC and the IL-15fu proteins; the cells were further expanded for 9 days in media containing IL-7/IL-15. Surface co-expression of the TRuC and IL-15fu proteins and the T cell memory phenotype was assessed by flow cytometry. In vitro persistence was tested in a repeated stimulation assay in which T cells were challenged by addition of fresh CD70+ target cells every four days with longitudinal assessment of T-cell expansion, phenotype, cytokine production, and cytotoxicity. In vivo, the antitumor efficacy of the anti-CD70 TRuC/IL-15fu T cells was evaluated in MHC class I/II deficient NSG mice bearing human tumor xenografts.ResultsThe anti-CD70 TRuC and IL-15fu proteins showed high transduction efficiency and robust co-expression on the surface of T cells. The IL-15fu significantly increased the proportion of naïve cells within the TRuC-T cell product, most dramatically in the CD8+ subset. In vitro, TRuC-T cells bearing the IL-15fu showed greatly enhanced expansion and persistence upon repeated stimulation with CD70+ target cells. Moreover, the IL-15fu enhanced T-cell survival and persistence under unstimulated, cytokine-free conditions. In vivo, the anti-tumor activity of CD70-targeted TRuC-T cells was significantly improved by IL-15fu in multiple tumor models and was associated with enhanced intratumoral T-cell accumulation and a preferential expansion of CD8+ T cells.ConclusionsThe addition of the IL-15fu improved the phenotype, persistence, and anti-tumor activity of CD70-targeted TRuC-T cells, potentially increasing the likelihood of clinical benefit in patients with CD70 overexpressing solid and liquid cancers.Ethics ApprovalAll animal studies were conducted by TCR2 Therapeutics staff at the Charles River Laboratories CRADL facility under a protocol approved by the Charles River Laboratories Institutional Animal Care and Use Committee.

scholarly journals Oncogenic lncRNA ZNF561-AS1 is essential for colorectal cancer proliferation and survival through regulation of miR-26a-3p/miR-128-5p-SRSF6 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zizhen Si ◽  
Lei Yu ◽  
Haoyu Jing ◽  
Lun Wu ◽  
Xidi Wang
Keyword(s):  
Colorectal Cancer ◽  
Rna Binding ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Cancer Proliferation ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model

Abstract Background Long non-coding RNAs (lncRNA) are reported to influence colorectal cancer (CRC) progression. Currently, the functions of the lncRNA ZNF561 antisense RNA 1 (ZNF561-AS1) in CRC are unknown. Methods ZNF561-AS1 and SRSF6 expression in CRC patient samples and CRC cell lines was evaluated through TCGA database analysis, western blot along with real-time PCR. SRSF6 expression in CRC cells was also examined upon ZNF561-AS1 depletion or overexpression. Interaction between miR-26a-3p, miR-128-5p, ZNF561-AS1, and SRSF6 was examined by dual luciferase reporter assay, as well as RNA binding protein immunoprecipitation (RIP) assay. Small interfering RNA (siRNA) mediated knockdown experiments were performed to assess the role of ZNF561-AS1 and SRSF6 in the proliferative actives and apoptosis rate of CRC cells. A mouse xenograft model was employed to assess tumor growth upon ZNF561-AS1 knockdown and SRSF6 rescue. Results We find that ZNF561-AS1 and SRSF6 were upregulated in CRC patient tissues. ZNF561-AS1 expression was reduced in tissues from treated CRC patients but upregulated in CRC tissues from relapsed patients. SRSF6 expression was suppressed and enhanced by ZNF561-AS1 depletion and overexpression, respectively. Mechanistically, ZNF561-AS1 regulated SRSF6 expression by sponging miR-26a-3p and miR-128-5p. ZNF561-AS1-miR-26a-3p/miR-128-5p-SRSF6 axis was required for CRC proliferation and survival. ZNF561-AS1 knockdown suppressed CRC cell proliferation and triggered apoptosis. ZNF561-AS1 depletion suppressed the growth of tumors in a model of a nude mouse xenograft. Similar observations were made upon SRSF6 depletion. SRSF6 overexpression reversed the inhibitory activities of ZNF561-AS1 in vivo, as well as in vitro. Conclusion In summary, we find that ZNF561-AS1 promotes CRC progression via the miR-26a-3p/miR-128-5p-SRSF6 axis. This study reveals new perspectives into the role of ZNF561-AS1 in CRC.

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 Single-cell RNA sequencing reveals distinct cellular factors for response to immunotherapy targeting CD73 and PD-1 in colorectal cancer

2021 ◽  
Vol 9 (7) ◽  
pp. e002503
Author(s):  
Miok Kim ◽  
Yong Ki Min ◽  
Jinho Jang ◽  
Hyejin Park ◽  
Semin Lee ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Clinical Trials ◽  
T Cells ◽  
T Cell ◽  
In Vivo Models ◽  
Single Cell Rna Sequencing ◽  
Tcr Diversity ◽  
Cancer Immunotherapies

BackgroundAlthough cancer immunotherapy is one of the most effective advanced-stage cancer therapies, no clinically approved cancer immunotherapies currently exist for colorectal cancer (CRC). Recently, programmed cell death protein 1 (PD-1) blockade has exhibited clinical benefits according to ongoing clinical trials. However, ongoing clinical trials for cancer immunotherapies are focused on PD-1 signaling inhibitors such as pembrolizumab, nivolumab, and atezolizumab. In this study, we focused on revealing the distinct response mechanism for the potent CD73 ectoenzyme selective inhibitor AB680 as a promising drug candidate that functions by blocking tumorigenic ATP/adenosine signaling in comparison to current therapeutics that block PD-1 to assess the value of this drug as a novel immunotherapy for CRC.MethodsTo understand the distinct mechanism of AB680 in comparison to that of a neutralizing antibody against murine PD-1 used as a PD-1 blocker, we performed single-cell RNA sequencing of CD45+ tumor-infiltrating lymphocytes from untreated controls (n=3) and from AB680-treated (n=3) and PD-1-blockade-treated murine CRC in vivo models. We also used flow cytometry, Azoxymethane (AOM)/Dextran Sulfate Sodium (DSS) models, and in vitro functional assays to validate our new findings.ResultsWe initially observed that the expressions of Nt5e (a gene for CD73) and Entpd1 (a gene for CD39) affect T cell receptor (TCR) diversity and transcriptional profiles of T cells, thus suggesting their critical roles in T cell exhaustion within tumor. Importantly, PD-1 blockade significantly increased the TCR diversity of Entpd1-negative T cells and Pdcd1-positive T cells. Additionally, we determined that AB680 improved the anticancer functions of immunosuppressed cells such as Treg and exhausted T cells, while the PD-1 blocker quantitatively reduced Malat1high Treg and M2 macrophages. We also verified that PD-1 blockade induced Treg depletion in AOM/DSS CRC in vivo models, and we confirmed that AB680 treatment caused increased activation of CD8+ T cells using an in vitro T cell assay.ConclusionsThe intratumoral immunomodulation of CD73 inhibition is distinct from PD-1 inhibition and exhibits potential as a novel anticancer immunotherapy for CRC, possibly through a synergistic effect when combined with PD-1 blocker treatments. This study may contribute to the ongoing development of anticancer immunotherapies targeting refractory CRC.

scholarly journals Modulation of the CCR5 Receptor/Ligand Axis by Seminal Plasma and the Utility of In Vitro versus In Vivo Models

2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Jennifer A. Juno ◽  
Kathleen M. Wragg ◽  
Anne B. Kristensen ◽  
Wen Shi Lee ◽  
Kevin J. Selva ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Seminal Plasma ◽  
Target Cells ◽  
Ccr5 Expression ◽  
Ccr5 Receptor ◽  
The Impact ◽  
Hiv 1

ABSTRACT Sexual HIV-1 transmission occurs primarily in the presence of semen. Although data from macaque studies suggest that CCR5+ CD4+ T cells are initial targets for HIV-1 infection, the impact of semen on T cell CCR5 expression and ligand production remains inconclusive. To determine if semen modulates the lymphocyte CCR5 receptor/ligand axis, primary human T cell CCR5 expression and natural killer (NK) cell anti-HIV-1 antibody-dependent beta chemokine production was assessed following seminal plasma (SP) exposure. Purified T cells produce sufficient quantities of RANTES to result in a significant decline in CCR5bright T cell frequency following 16 h of SP exposure (P = 0.03). Meanwhile, NK cells retain the capacity to produce limited amounts of MIP-1α/MIP-1β in response to anti-HIV-1 antibody-dependent stimulation (median, 9.5% MIP-1α+ and/or MIP-1β+), despite the immunosuppressive nature of SP. Although these in vitro experiments suggest that SP-induced CCR5 ligand production results in the loss of surface CCR5 expression on CD4+ T cells, the in vivo implications are unclear. We therefore vaginally exposed five pigtail macaques to SP and found that such exposure resulted in an increase in CCR5+ HIV-1 target cells in three of the animals. The in vivo data support a growing body of evidence suggesting that semen exposure recruits target cells to the vagina that are highly susceptible to HIV-1 infection, which has important implications for HIV-1 transmission and vaccine design. IMPORTANCE The majority of HIV-1 vaccine studies do not take into consideration the impact that semen exposure might have on the mucosal immune system. In this study, we demonstrate that seminal plasma (SP) exposure can alter CCR5 expression on T cells. Importantly, in vitro studies of T cells in culture cannot replicate the conditions under which immune cells might be recruited to the genital mucosa in vivo, leading to potentially erroneous conclusions about the impact of semen on mucosal HIV-1 susceptibility.

Anatomic location and T-cell stimulatory functions of mouse dendritic cell subsets defined by CD4 and CD8 expression

Blood ◽  
2002 ◽  
Vol 99 (6) ◽  
pp. 2084-2093 ◽  
Author(s):  
Alexander D. McLellan ◽  
Michaela Kapp ◽  
Andreas Eggert ◽  
Christian Linden ◽  
Ursula Bommhardt ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Antigen Expression ◽  
Cell Receptor ◽  
In Vitro Assays ◽  
Peptide Complexes ◽  
Marginal Zones

Abstract Mouse spleen contains CD4+, CD8α+, and CD4−/CD8α− dendritic cells (DCs) in a 2:1:1 ratio. An analysis of 70 surface and cytoplasmic antigens revealed several differences in antigen expression between the 3 subsets. Notably, the Birbeck granule–associated Langerin antigen, as well as CD103 (the mouse homologue of the rat DC marker OX62), were specifically expressed by the CD8α+ DC subset. All DC types were apparent in the T-cell areas as well as in the splenic marginal zones and showed similar migratory capacity in collagen lattices. The 3 DC subtypes stimulated allogeneic CD4+ T cells comparably. However, CD8α+ DCs were very weak stimulators of resting or activated allogeneic CD8+ T cells, even at high stimulator-to-responder ratios, although this defect could be overcome under optimal DC/T cell ratios and peptide concentrations using CD8+ F5 T-cell receptor (TCR)–transgenic T cells. CD8α− or CD8α+DCs presented alloantigens with the same efficiency for lysis by cytotoxic T lymphocytes (CTLs), and their turnover rate of class I–peptide complexes was similar, thus neither an inability to present, nor rapid loss of antigenic complexes from CD8α DCs was responsible for the low allostimulatory capacity of CD8α+ DCs in vitro. Surprisingly, both CD8α+ DCs and CD4−/CD8− DCs efficiently primed minor histocompatibility (H-Y male antigen) cytotoxicity following intravenous injection, whereas CD4+ DCs were weak inducers of CTLs. Thus, the inability of CD8α+ DCs to stimulate CD8+ T cells is limited to certain in vitro assays that must lack certain enhancing signals present during in vivo interaction between CD8α+ DCs and CD8+ T cells.

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.

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