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 ◽  
...  

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.

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  

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.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 631
Author(s):  
Jie Wang ◽  
Katarzyna Urbanska ◽  
Prannda Sharma ◽  
Reza Nejati ◽  
Lauren Shaw ◽  
...  

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.


Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2965-2972 ◽  
Author(s):  
Y Kusunoki ◽  
Y Hirai ◽  
S Kyoizumi ◽  
M Akiyama

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.


2002 ◽  
Vol 22 (15) ◽  
pp. 5419-5433 ◽  
Author(s):  
Susanne M. A. Lens ◽  
Takao Kataoka ◽  
Karen A. Fortner ◽  
Antoine Tinel ◽  
Isabel Ferrero ◽  
...  

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.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 962-962 ◽  
Author(s):  
Ksenia Bezverbnaya ◽  
Vivian Lau ◽  
Craig Aarts ◽  
Galina Denisova ◽  
Arya Afsahi ◽  
...  

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ioana Sandu ◽  
Dario Cerletti ◽  
Manfred Claassen ◽  
Annette Oxenius

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.


2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A6.2-A7
Author(s):  
LA King ◽  
R Lameris ◽  
RC Roovers ◽  
P Parren ◽  
TD de Gruijl ◽  
...  

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.


2003 ◽  
Vol 198 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Lucy S.K. Walker ◽  
Anna Chodos ◽  
Mark Eggena ◽  
Hans Dooms ◽  
Abul K. Abbas

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.


2021 ◽  
Vol 9 (3) ◽  
pp. e002035
Author(s):  
Kathrin Davari ◽  
Tristan Holland ◽  
Laura Prassmayer ◽  
Giulia Longinotti ◽  
Kenneth P Ganley ◽  
...  

BackgroundThe cancer-testis antigen MAGE-A4 is an attractive target for T-cell-based immunotherapy, especially for indications with unmet clinical need like non-small cell lung or triple-negative breast cancer.MethodsAn unbiased CD137-based sorting approach was first used to identify an immunogenic MAGE-A4-derived epitope (GVYDGREHTV) that was properly processed and presented on human leukocyte antigen (HLA)-A2 molecules encoded by the HLA-A*02:01 allele. To isolate high-avidity T cells via subsequent multimer sorting, an in vitro priming approach using HLA-A2-negative donors was conducted to bypass central tolerance to this self-antigen. Pre-clinical parameters of safety and activity were assessed in a comprehensive set of in vitro and in vivo studies.ResultsA MAGE-A4-reactive, HLA-A2-restricted T-cell receptor (TCR) was isolated from primed T cells of an HLA-A2-negative donor. The respective TCR-T-cell (TCR-T) product bbT485 was demonstrated pre-clinically to have a favorable safety profile and superior in vivo potency compared with TCR-Ts expressing a TCR derived from a tolerized T-cell repertoire to self-antigens. This natural high-avidity TCR was found to be CD8 co-receptor independent, allowing effector functions to be elicited in transgenic CD4+ T helper cells. These CD4+ TCR-Ts supported an anti-tumor response by direct killing of MAGE-A4-positive tumor cells and upregulated hallmarks associated with helper function, such as CD154 expression and release of key cytokines on tumor-specific stimulation.ConclusionThe extensive pre-clinical assessment of safety and in vivo potency of bbT485 provide the basis for its use in TCR-T immunotherapy studies. The ability of this non-mutated high-avidity, co-receptor-independent TCR to activate CD8+ and CD4+ T cells could potentially provide enhanced cellular responses in the clinical setting through the induction of functionally diverse T-cell subsets that goes beyond what is currently tested in the clinic.


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