Increased Activation and Oligoclonality of Peripheral CD8+ T Cells in the Chronic Human Helminth Infection Alveolar Echinococcosis

ABSTRACT Alveolar echinococcosis (AE) in humans is a chronic disease characterized by slowly expanding liver lesions. Cellular immunity restricts the spreading of the extracellular pathogen, but functional contributions of CD4+ and CD8+ T cells are not defined. Here we studied ex vivo the phenotype and function of circulating T-cell subsets in AE patients by means of flow cytometry, T-cell receptor spectratyping, and lymphocyte proliferation. AE patients with parasitic lesions displayed a significant increase of activation of predominantly CD8+ T cells compared to healthy controls and AE patients without lesions. In vitro, proliferative T-cell responses to polyclonal stimulation with recall antigens and Echinococcus multilocularis vesicular fluid antigen were sustained during chronic persisting infection in all AE patients. Only in AE patients with parasitic lesions did T-cell receptor spectratyping reveal increased oligoclonality of CD8+ but not CD4+ T cells, suggesting a persistent antigenic drive for CD8+ T cells with subsequent proliferation of selected clonotypes. Thus, our data provide strong evidence for an active role of CD8+ T cells in AE.

Download Full-text

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

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.173 ◽

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.

Download Full-text

Development of a CD8 co-receptor independent T-cell receptor specific for tumor-associated antigen MAGE-A4 for next generation T-cell-based immunotherapy

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-002035 ◽

2021 ◽

Vol 9 (3) ◽

pp. e002035

Author(s):

Kathrin Davari ◽

Tristan Holland ◽

Laura Prassmayer ◽

Giulia Longinotti ◽

Kenneth P Ganley ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Receptor ◽

Cell Receptor ◽

T Cell Subsets ◽

In Vivo Studies ◽

High Avidity ◽

Cell Repertoire

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.

Download Full-text

Unbiased definition of a shared T-cell receptor motif enables population-based studies of tuberculosis

10.1101/123174 ◽

2017 ◽

Author(s):

W. S. DeWitt ◽

K. K. Quan ◽

D. Wilburn ◽

A. Sherwood ◽

M. Vignali ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Receptor ◽

Genetic Background ◽

Ex Vivo ◽

Cell Receptor ◽

Lipid Antigens ◽

Host Genetic ◽

Definition Of

ABSTRACTPeptide-specific T cells that are restricted by highly polymorphic major histocompatibility complex (MHC) proteins express diverse T-cell receptors (TCRs) that are rarely shared among unrelated individuals. T-cells can also recognize bacterial lipid antigens that bind the relatively non-polymorphic CD1 family of proteins. However, genetic variation in human CD1 genes and TCR diversity expressed by CD1-restricted T-cells have not been quantitatively determined. Here, we show that CD1B is nearly nucleotide-identical across all five continental ancestry groups, providing evidence for purifying selection during human evolution. We used CD1B tetramers loaded with a mycobacterial glycolipid antigen to isolate T-cells from four genetically unrelated South African adults and cataloged thousands of TCRs from in-vitro expanded T-cells using immunosequencing. We identified highly conserved motifs that were co-expressed as a functional heterodimer and significantly enriched among tetramer-positive T-cells sorted directly from peripheral blood. Finally, we show that frequencies of these TCR motifs are increased in the blood of patients with active tuberculosis compared to uninfected controls, a finding that is confirmed by ex-vivo frequencies of tetramer-positive T-cells determined by flow cytometry. These data provide a framework for unbiased definition of TCRs targeting lipid antigens, which can be tested for clinical associations independently of host genetic background.Brief SummaryWe used human genetics and immunosequencing to define a shared T-cell receptor motif that is specific for a mycobacterial lipid antigen and associated with tuberculosis independently of host genetic background.

Download Full-text

T cell receptor-mediated selection of functional rat CD8 T cells from defined immature thymocyte precursors in short-term suspension culture.

Journal of Experimental Medicine ◽

10.1084/jem.173.3.561 ◽

1991 ◽

Vol 173 (3) ◽

pp. 561-568 ◽

Cited By ~ 15

Author(s):

T Hünig ◽

R Mitnacht

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Receptor ◽

Cytotoxic T Lymphocyte ◽

Ex Vivo ◽

Interleukin 2 ◽

Cell Receptor ◽

Double Positive ◽

Homogeneous Population

Recent results have indicated that positive and negative repertoire selection act on the major population of CD4,8 double-positive (DP) thymocytes that express 5-10-fold less T cell receptor (TCR) than mature T cells (i.e., they are TCRlow). Since DP cells obtained ex vivo are heterogeneous with regard to their stage within thymic selection, a homogeneous population of virgin DP cells suitable for selection studies was generated in vitro from their immediate precursors, the CD8 single-positive (SP) immature blast cells. To mimic TCR-mediated selection signals, these virgin DP cells were then cultured for another 2 d in the presence of immobilized anti-TCR monoclonal antibodies with or without interleukin 2 (IL-2). Daily monitoring of recovery and phenotype showed that without TCR stimulation, the cells remained DP and became small, TCRlow cells that were lost with a half-life of 1 d, regardless of the presence of IL-2. TCR stimulation resulted in rapid downregulation of CD4 and CD8, maintenance of a larger cell size, and induction of the CD53 antigen that marks mature and CD4,8 double-negative rat thymocytes. In the absence of IL-2, viability decreased as rapidly as without TCR stimulation. Addition of IL-2 rescued TCR-stimulated virgin DP cells and prevented CD8 downregulation, so that 50-80% of input DP cells were recovered after 2 d as CD4-8+53+ cells. After release from modulation, these in vitro generated CD8 SP cells quantitatively upregulated the TCR to the TCRhigh phenotype and were readily induced to proliferate and exhibit cytotoxic T lymphocyte (CTL) activity in a polyclonal readout. Evidence is presented implicating an IL-2 receptor (IL-2R) not containing the p55 chain (i.e., most likely the p70 intermediate affinity IL-2R) in the TCR plus IL-2-driven in vitro differentiation of virgin DP cells towards the mature CD8 SP phenotype.

Download Full-text

161 Development of a CD8 co-receptor independent T cell receptor specific for tumor-associated antigen MAGE-A4 for next generation T cell-based immunotherapy

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0161 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A175-A175

Author(s):

Kathrin Davari ◽

Tristan Holland ◽

Laura Prassmayer ◽

Giulia Longinotti ◽

Kenneth Ganley ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Cells ◽

T Cell Receptor ◽

Cell Receptor ◽

Receptor Expression ◽

T Cell Subsets ◽

High Avidity

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 carcinoma or triple-negative breast cancer. Overcoming high tumor burden using adoptive transfer of T cells modified to express a transgenic T cell receptor (TCR) demands optimal recognition of the corresponding target on tumor cells by the TCR-modified T cells (TCR-Ts). Here we describe the isolation and pre-clinical characterization of high avidity TCR-Ts expressing a human leucocyte antigen (HLA)-A*02:01-restricted MAGE-A4-specific TCR that is fully functional in T cells irrespective of CD4 or CD8 co-receptor expression.MethodsAn unbiased CD137-based sorting approach was first used to identify an immunogenic MAGE-A4-derived candidate epitope that was properly processed and presented on 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 (allogeneic-HLA-restricted priming approach) 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 of the lead TCR candidate derived from a selected T cell clone.ResultsA TCR recognizing the MAGE-A4-derived decapeptide GVYDGREHTV was isolated from primed T cells of a non-tolerant HLA-A2-negative donor. The respective TCR-T cell product bbT485, expressing the lead TCR in T cells from healthy donors, was demonstrated pre-clinically to have a favorable safety profile and superior in vivo potency compared to TCR-Ts made using a TCR derived from an HLA-A2-positive donor bearing a tolerized T cell repertoire to self-antigens. The natural high avidity allogeneic (allo)-derived TCR was found to be CD8 co-receptor-independent, allowing effector functions to be elicited in transgenic CD4+ T helper cells. These CD4+ TCR-T cells not only supported an anti-tumor response by direct killing of MAGE-A4-positive tumor cells, but also upregulated hallmarks associated with helper function, such as CD154 expression and release of key cytokines upon tumor-specific stimulation.ConclusionsThe extensive pre-clinical assessment of safety and in vivo potency of this non-mutated high avidity, CD8 co-receptor-independent, MAGE-A4-specific HLA-A2 restricted TCR provide the basis for its use in clinical TCR-T immunotherapy studies. The ability of this co-receptor-independent TCR to activate all transduced T cells (irrespective of CD4 or CD8 expression) 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.

Download Full-text

T cell receptor zeta/CD3-p59fyn(T)-associated p120/130 binds to the SH2 domain of p59fyn(T).

Journal of Experimental Medicine ◽

10.1084/jem.178.6.2107 ◽

1993 ◽

Vol 178 (6) ◽

pp. 2107-2113 ◽

Cited By ~ 46

Author(s):

A J da Silva ◽

O Janssen ◽

C E Rudd

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Receptor ◽

T Cell Activation ◽

Intracellular Signaling ◽

Cell Activation ◽

Cell Receptor ◽

Sh2 Domain ◽

T Complex

Intracellular signaling from the T cell receptor (TCR)zeta/CD3 complex is likely to be mediated by associated protein tyrosine kinases such as p59fyn(T), ZAP-70, and the CD4:p56lck and CD8:p56lck coreceptors. The nature of the signaling cascade initiated by these kinases, their specificities, and downstream targets remain to be elucidated. The TCR-zeta/CD3:p59fyn(T) complex has previously been noted to coprecipitate a 120/130-kD doublet (p120/130). This intracellular protein of unknown identity associates directly with p59fyn(T) within the receptor complex. In this study, we have shown that this interaction with p120/130 is specifically mediated by the SH2 domain (not the fyn-SH3 domain) of p59fyn(T). Further, based on the results of in vitro kinase assays, p120/130 appears to be preferentially associated with p59fyn(T) in T cells, and not with p56lck. Antibody reprecipitation studies identified p120/130 as a previously described 130-kD substrate of pp60v-src whose function and structure is unknown. TCR-zeta/CD3 induced activation of T cells augmented the tyrosine phosphorylation of p120/130 in vivo as detected by antibody and GST:fyn-SH2 fusion proteins. p120/130 represents the first identified p59fyn(T):SH2 binding substrate in T cells, and as such is likely to play a key role in the early events of T cell activation.

Download Full-text

CD4+ T Cells from Glutamic Acid Decarboxylase (GAD)65-specific T Cell Receptor Transgenic Mice Are Not Diabetogenic and Can Delay Diabetes Transfer

Journal of Experimental Medicine ◽

10.1084/jem.20011845 ◽

2002 ◽

Vol 196 (4) ◽

pp. 481-492 ◽

Cited By ~ 62

Author(s):

Kristin V. Tarbell ◽

Mark Lee ◽

Erik Ranheim ◽

Cheng Chi Chao ◽

Maija Sanna ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Transgenic Mice ◽

T Cell Receptor ◽

Glutamic Acid Decarboxylase ◽

Cd4 T Cells ◽

Cell Receptor ◽

Acid Decarboxylase ◽

Gad 65

Glutamic acid decarboxylase (GAD)65 is an early and important antigen in both human diabetes mellitus and the nonobese diabetic (NOD) mouse. However, the exact role of GAD65-specific T cells in diabetes pathogenesis is unclear. T cell responses to GAD65 occur early in diabetes pathogenesis, yet only one GAD65-specific T cell clone of many identified can transfer diabetes. We have generated transgenic mice on the NOD background expressing a T cell receptor (TCR)-specific for peptide epitope 286–300 (p286) of GAD65. These mice have GAD65-specific CD4+ T cells, as shown by staining with an I-Ag7(p286) tetramer reagent. Lymphocytes from these TCR transgenic mice proliferate and make interferon γ, interleukin (IL)-2, tumor necrosis factor (TNF)-α, and IL-10 when stimulated in vitro with GAD65 peptide 286–300, yet these TCR transgenic animals do not spontaneously develop diabetes, and insulitis is virtually undetectable. Furthermore, in vitro activated CD4 T cells from GAD 286 TCR transgenic mice express higher levels of CTL-associated antigen (CTLA)-4 than nontransgenic littermates. CD4+ T cells, or p286-tetramer+CD4+ Tcells, from GAD65 286–300-specific TCR transgenic mice delay diabetes induced in NOD.scid mice by diabetic NOD spleen cells. This data suggests that GAD65 peptide 286–300-specific T cells have disease protective capacity and are not pathogenic.

Download Full-text

Enhancing and inhibitory motifs have coevolved to regulate CD4 activity

10.1101/2021.04.29.441928 ◽

2021 ◽

Author(s):

Mark S. Lee ◽

Peter J. Tuohy ◽

Caleb Kim ◽

Katrina Lichauco ◽

Heather L. Parrish ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Receptor ◽

Purifying Selection ◽

Cell Receptor ◽

Specific Information ◽

Transmembrane Receptors ◽

Peptide Antigens ◽

And Function ◽

Intracellular Domains

SUMMARYCD4+ T cells use T cell receptor (TCR)-CD3 complexes, and CD4, to respond to peptide antigens within MHCII molecules (pMHCII). We report here that, through ∼435 million years of evolution in jawed vertebrates, purifying selection has shaped motifs in the extracellular, transmembrane, and intracellular domains of eutherian CD4 that both enhance pMHCII responses and are coevolving with residues in an intracellular motif that inhibits pMHCII responses. Importantly, while CD4 interactions with the Src kinase, Lck, are classically viewed as the key determinant of CD4’s contribution to pMHCII responses, we found that without the inhibitory motif CD4-Lck interactions are not necessary for robust responses to pMHCII. In summary, motifs that mediate events on the outside and inside of CD4+ T cells coevolved to finetune the relay of pMHCII-specific information across the membrane. These results have implications for the evolution and function of complex transmembrane receptors and for biomimetic engineering.

Download Full-text

192 Pooled T cell receptor screening (POTS) provides unbiased, high-throughput method for TCR discovery

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.192 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A204-A204

Author(s):

Jack Reid ◽

Shihong Zhang ◽

Ariunaa Munkhbat ◽

Matyas Ecsedi ◽

Megan McAfee ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Single Cell ◽

T Cell Receptor ◽

High Throughput ◽

Ex Vivo ◽

Cell Receptor ◽

High Avidity ◽

Reporter System ◽

High Throughput Method

BackgroundT Cell Receptor (TCR)-T cell therapies have shown some promising results in cancer clinical trials, however the efficacy of treatment remains suboptimal. Outcomes could potentially be improved by utilizing highly functional TCRs for future trials. Current TCR discovery methods are relatively low throughput and rely on synthesis and screening of individual TCRs based on tetramer binding and peptide specificity, which is costly and labor intensive. We have developed and validated a pooled approach relying on directly cloned TCRs transduced into a fluorescent Jurkat reporter system (figure 1). This approach provides an unbiased, high-throughput method for TCR discovery.MethodsAs a model for POTS, T cells specific for a peptide derived adenovirus structural protein were sorted on tetramer and subjected to 10x single cell VDJ analysis. Pools of randomly paired TCR alpha and beta chains were cloned from the 10x cDNA into a lentiviral vector and transduced into a Jurkat reporter cells. Consecutive stimulations with cognate antigen followed by cell sorts were performed to enrich for functional TCRs. Full length TCRab pools were sequenced by Oxford Nanopore Technologies (ONT) and compared to a 10x dataset to find naturally paired TCRs.ResultsComparison between the ex vivo single cell VDJ sequencing and ONT sequencing of the transduced antigen specific TCRs showed more than 99% of the TCR pairs found in reporter positive Jurkat cells were naturally paired TCRs. The functionality of 8 TCR clonotypes discovered using POTS were compared and clone #2 showed the strongest response. Of the selected clonotypes, clone #2 showed a low frequency of 0.9% in the ex vivo single cell VDJ sequencing. After the first round of stimulation and sequencing, clone #2 takes up of 5% of all reporter-positive clones. The abundance of clone #2 further increased to 17% after another round of stimulation, sorting and sequencing, suggesting this method can retrieve and enrich for highly functional antigen specific TCRs.Abstract 192 Figure 1Outline of the POTS workflow.ConclusionsPOTS provides a high-throughput method for discovery of naturally paired, high-avidity T cell receptors. This method mitigates bias introduced by T cell differentiation state by screening TCRs in a clonal reporter system. Additionally, POTS allows for screening of low abundance clones when compared with traditional TCR discovery techniques. Pooled TCRs could also be screened in vivo with primary T cells in a mouse model to screen for the most functional and physiologically fit TCR for cancer treatment.

Download Full-text