801 PRIME™ IL-15 (RPTR-147): Preliminary clinical results and biomarker analysis from a first-in-human Phase 1 study of IL-15 loaded peripherally-derived autologous T cell therapy in solid tumor patients

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A850-A850
Author(s):  
Erika Hamilton ◽  
Sarah Nikiforow ◽  
Philip Bardwell ◽  
Christine McInnis ◽  
Jeffrey Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Metastatic Disease ◽  
Cd8 T Cells ◽  
Dose Escalation ◽  
Phase 1 ◽  
T Cell Clones ◽  
Cell Product ◽  
Cell Clones ◽  
Biomarker Analysis

BackgroundRPTR-147 is a novel autologous non-genetically modified multi-clonal T cell product loaded with an IL15-Fc nanogel. The product was derived from rare peripherally-derived anti-tumor T cell clones that were primed against a multi-antigen cassette containing tumor associated antigens (TAA), known to be over-expressed in specific tumor types. We describe preliminary results from the ongoing first-in-human Phase 1 trial.MethodsAutologous anti-TAA T cells are generated with a proprietary dendritic cell priming process and then loaded with an IL15-Fc nanogel. TAAs used in cassette: PRAME, NY-ESO-1, SSX2, Survivin and WT1. Thawed RPTR-147 is delivered by infusion. Pre- and post-treatment biopsies were collected for biomarker analysis by immunohistochemistry (IHC) and transcriptome sequencing. Serial blood collections were obtained for measuring IL-15 pharmacokinetics and pharmacodynamic parameters including plasma cytokine levels and immunophenotyping by flow cytometry. T cell receptor sequencing (TCRSeq) was used to characterize the T cell repertoire from manufactured T cell product and the patient‘s blood.ResultsInterim clinical and biomarker data from 17 patients with advanced metastatic disease refractory to SOC who received monthly infusions of 20-360 million cells/m², were reviewed (table 1). There were no dose-limiting toxicities and no evidence of cytokine-release syndrome. The 360M/m² dose contained 3X more IL15-Fc than the MTD of systemically administered IL15-Fc,1 but produced less than a tenth of the systemic exposure to free IL15-Fc. Currently, 360M cells/m² is considered safe and well-tolerated. Further dose escalation is planned.Matched evaluable biopsies were obtained in 7 patients. Tumor-infiltrating T cell lymphocytes was observed in 5 cases for CD8 T cells and 4 cases for CD4 T cells. A dose dependent increase in both inflammatory cytokines and NK & CD8+ T cells was observed, consistent with expected MOA and PK. TCRSeq analysis demonstrated that product specific T cell clones could be tracked in both patient‘s blood and tumor over time. Further analysis to decode the specificity of those cells and demonstrate that tumor antigen specific T cells can be found in patient‘s blood and tumor biopsies is ongoing.Of the 17 patients who received RPTR-147 infusions 10 were noted to have stable disease (SD) and in 4 patients SD lasted > 6 months.Abstract 801 Table 1Summary of PatientsTumor types for the 17 patients with advanced metastatic disease included in this clinical trial (NCT0381568)ConclusionsInterim results with RPTR-147 have shown it to be well-tolerated and have a favorable safety profile. Dose-escalation is proceeding. Ongoing biomarker analysis will inform future clinical strategies in matching patients to an optimized PRIME IL-15 T cell product.Trial RegistrationNCT03815682Ethics ApprovalThe study was approved by local institutional IRBs after acceptance of the IND by the FDA.ConsentWritten informed consent was obtained from the patient for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.ReferenceRomee R, Cooley S, Berrien-Elliott MM, et al. First-in-human phase 1 clinical study of the IL-15 superagonist complex ALT-803 to treat relapse after transplantation. Blood 2018;131(23):2515-2527.

Development of a Nonhuman Primate Model for Analysis of the Adoptive Transfer of Antigen-Specific T Cell Clones.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 770-770
Author(s):  
Carolina Berger ◽  
Michael Jensen ◽  
Stanley R. Riddell
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Adoptive Transfer ◽  
Cell Transfer ◽  
Primate Model ◽  
T Cell Clones ◽  
Cell Clones

Abstract In principle, the adoptive transfer of T cell clones specific for antigens expressed by pathogens or malignant cells could be therapeutically effective and allow precise control of the specificity, function, and magnitude of T cell immunity. However, the infusion of large numbers of cultured T cells or T cell clones in clinical trials has frequently failed to eradicate tumors or provide long-term control of infection. This may be due in part to the acquisition of an effector phenotype by the T cells during in vitro culture, which reduces their ability to survive in vivo and establish an immune response of sufficient magnitude for sustained efficacy. Several approaches including the administration of cytokines such as IL15, or lymphodepletion prior to cell transfer might promote the establishment of T cell memory after T cell transfer. To facilitate the rational development of clinical trials of T cell therapy, we have employed a nonhuman primate model of adoptive T cell transfer in which culture conditions and cell doses identical to those in human studies are utilized, and designed strategies to permit rigorous analysis of the persistence, function, phenotype, and migration of transferred cells. CD8+ CTL specific for macaque CMV were detected using an overlapping peptide panel and cytokine flow cytometry, isolated as individual T cell clones by limiting dilution, and propagated to large numbers in vitro. The T cell clones were transduced to express an intracellular truncated CD19 (ΔCD19) surface marker to allow tracking and functional assessment of T cells in vivo, and enriched by immunomagnetic selection to high purity (>98%) prior to transfer. The persistence of transferred ΔCD19+ T cells in the blood and their migration to the bone marrow and lymph nodes was determined by flow cytometry after staining with anti CD19, CD8, and CD3 antibodies. The infusion of ΔCD19+CD8+ CTL (3 x 108/kg) was safe and the cells remained detectable in vivo for >5 months. ΔCD19+CD8+ T cells were easily detected in the blood 1 day after transfer at a level of 2.7% of CD8+ T cells and gradually declined over 56 days to a stable population of 0.15–0.2% of CD8+ T cells. At the time of transfer the ΔCD19+CD8+ T cells had an effector phenotype (CD62L− CD127−), but gradually converted to a CD62L+CD127+ memory phenotype in vivo. The infused T cells were found at high levels in lymph node and bone marrow at day 14 after transfer (1.4% and 2.5%, respectively) and the cells at these sites were predominantly CD62L+. The ΔCD19+CD62L+ T cells lacked direct lytic function and expressed low levels of granzyme B, consistent with memory T cells. Sorting of these cells from post-transfer PBMC showed that in vitro activation restored lytic activity. The transferred ΔCD19+CD62L+ T cells in post-infusion PBMC produced IFNγ and TNFα comparable to endogenous CMV-specific CD8+ CTL. These results demonstrate that a subset (5–10%) of transferred CD8+ CTL clones can persist long-term as functional memory T cells. The macaque CD8+ T cell clones are responsive to IL15 in vitro and a safe regimen for administering IL15 to macaques that boosts endogenous T cells has been identified. Studies are now in progress to determine if IL15 can enhance the efficiency with which effector and memory CD8+ T cell responses can be augmented after adoptive transfer of T cell clones.

HLA Class II Upregulation During An Ongoing Viral Infection Can Lead to HLA-DP Directed Graft-Versus-Host Disease After HLA-DPB1 Mismatched CD4+ Donor Lymphocyte Infusion

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3062-3062 ◽  
Author(s):  
Sanja Stevanovic ◽  
Cornelis A.M. van Bergen ◽  
Simone A.P. van Luxemburg-Heijs ◽  
Jessica C. Harskamp ◽  
C.J.M. Halkes ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Hematopoietic Cells ◽  
Class Ii ◽  
Hla Class Ii ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
T Cell Clones ◽  
Cell Clones

Abstract Abstract 3062 T cell depletion of the graft in allogeneic hematopoietic stem cell transplantation (alloSCT) prevents the occurrence of severe acute Graft-versus-Host Disease (GvHD), but also impairs post-transplant anti-tumor and anti-viral immunity. Early intervention with donor lymphocyte infusion (DLI) after alloSCT may prevent relapse of the malignancy and improve immune reconstitution, but can be associated with reintroduction of GvHD. Since under non-inflammatory conditions HLA class II molecules are predominantly expressed on hematopoietic cells, DLI consisting of only CD4+ T cells can selectively target residual patient (pt) HLA class II + hematopoietic cells without inducing severe GvHD. However, recently in two pts with acute myeloid leukemia we observed severe GvHD after prophylactic CD4+ DLI following a 10/10 HLA allele matched, but HLA-DPB1 mismatched unrelated donor alloSCT. Both pts received a T cell depleted SCT after a non-myeloablative conditioning regimen, resulting in mixed chimerism (>97 % donor) at 3 months after alloSCT, and no GvHD. A single infusion of 0.5*106 purified CD4+ T cells/kg was administered 3.5 months after alloSCT, resulting in a decreasing pt chimerism coinciding with grade 1 skin GvHD, followed by grade 3–4 colonic GvHD 3–8 weeks later. Both pts were successfully treated with immune suppression and are in complete remission (CR) more than one year later. During the clinical immune responses high percentages of activated CD4+ (30–74 %) and CD8+ T cells (9–56 %) were demonstrated in peripheral blood (PB). Using cell sorting, we clonally isolated 777 and 289 CD4+, and 204 and 34 CD8+ T cell clones from pts 1 and 2, respectively, and tested these clones for recognition of multiple pt and donor derived target cells using IFNg ELISA. None of the CD8+ clones were alloreactive. In contrast, 3 and 8 % of the CD4+ T cell clones from pts 1 and 2, respectively, recognized various pt hematopoietic cells, but not donor cells, indicating alloreactivity. Retroviral transduction of donor EBV-LCL with pt HLA-DPB1 alleles identified specific recognition of the mismatched alleles for 2 and 7 % of all CD4+ T cell clones isolated, respectively. The remaining alloreactive CD4+ T cell clones showed a hematopoiesis-restricted minor histocompatibility antigen recognition pattern, since they failed to recognize pt skin fibroblasts pretreated with IFNg to upregulate HLA class II expression. In contrast, the majority of HLA-DPB1 specific CD4+ T cell clones recognized pt IFNg treated skin fibroblasts, indicating a direct role as mediators of GvHD after HLA-DPB1 mismatched CD4+ DLI. Since both pts were in CR, but mixed chimeric at the time of CD4+ DLI, we hypothesized that residual pt HLA-DP+ hematopoietic cells after alloSCT may have served as antigen presenting cells (APC) to induce the HLA-DPB1 specific CD4+ T cell response. Lineage specific chimerism analysis of PB samples prior to CD4+ DLI showed complete donor chimerism in the B cell and myeloid compartments, whereas predominantly pt chimerism (89–100% pt) was demonstrated in the T cell compartment. Flowcytometric analysis showed that 5–25 % of the pt CD4+ and CD8+ T cells were activated and expressed HLA-DP. CMV tetramer analysis demonstrated that 31 % of CD8+ T cells from pt 1 and 10 % from pt 2 were CMV specific, which had expanded as a consequence of CMV reactivation. We hypothesize that the HLA-DPB1 specific CD4+ T cell response has been induced by upregulated HLA-DP expression on activated pt T cells due to preexisting CMV infection, and/or by residual pt derived skin-resident APC, resulting in limited skin GvHD. We demonstrated CMV infection in a colon biopsy at the time of colonic GvHD, suggesting that local production of cytokines by pt derived CMV specific T cells may have upregulated HLA class II expression on non-hematopoietic cells and enhanced the HLA-DPB1 specific CD4+ T cell response, resulting in exacerbation of GvHD. In conclusion, we show in two pts that GvHD after prophylactic CD4+ DLI administered early after HLA-DPB1 mismatched T cell depleted alloSCT was caused by alloreactive CD4+ T cells directed against pt mismatched HLA-DPB1 alleles. Our results suggest that the presence of active viral infections inducing immune responses by residual pt T cells at the time of prophylactic HLA class II mismatched CD4+ DLI increases the likelihood of development of GvHD by influencing HLA class II expression on pt hematopoietic and non-hematopoietic cells. Disclosures: No relevant conflicts of interest to declare.

ROR1 Specific T Cell Clones from Healthy Individuals Show Common T Cell Receptor Motifs

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3364-3364
Author(s):  
Falk Heidenreich ◽  
Elke Ruecker-Braun ◽  
Juliane S. Stickel ◽  
Anne Eugster ◽  
Denise Kühn ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cell Receptor ◽  
T Cell Clones ◽  
Cell Clones

Abstract Background Immunotherapy for CLL with new antibodies or T-cells with modified TCR relies on attractive targets. ROR1 is such a promising target since it is highly overexpressed in CLL. Chimeric antigen receptor engineered T cells and antibodies directed against the extracellular part of ROR1 have already been developed and tested in vitro or in animal models, but still there is no MHC-class I presented peptide serving as target structure for CD8+ T cells (with or without a genetically modified T cell receptor) available. Aim The aim of this study was (1) to identify an immunogenic MHC-class I presented ROR1 peptide, (2) to generate respective ROR1 peptide specific CD8+ T cell clones, and (3) to analyze the nucleotide sequence of the CDR3 region of the expressed alpha and beta T cell receptor chain. Results In mass spectrometric-based analyses of the HLA-ligandome a HLA-B*07 presented ROR1 peptide was identified in primary CLL cells of two patients. Six T cell clones specific for this particular ROR1-peptide were generated from single CD8+ T cells from 2 healthy individuals with 3 T cell clones generated from each donor. Functionality and specificity of those T cell clones were tested in cytotoxicity assays. All 6 dextramer+ CD8+ T cell clones lysed peptide loaded and HLA-B*07+ transduced K562 cells (kindly provided by Lorenz Jahn, [Jahn et al., Blood, 2015 Feb 5;125(6):949-58]). Two selected clones (XD8 and XB6) were tested for their cytotoxic potential against 2 ROR1+ HLA-B*07+ tumor cell lines (with the ROR1 peptide identified by mass spectrometry for both of them) and against 2 primary CLL cell samples. Tested clones showed a significant lysis of the respective target cells. CDR3 regions of the alpha and beta T cell receptor chain were sequenced on a single cell level. The CDR3 alpha region from each of the 3 ROR1 specific T cell clones from donor A showed some similarities to T cell clones derived from donor B (Table 1). Conclusion For the first time a MHC-class I presented ROR1 peptide antigen is reported. ROR1 positive CLL cells can be targeted by specific HLA-B*07 restricted CTLs. Respective CD8+ T cell clones with anti-leukemic activity from 2 donors share some amino acid motifs of the CDR3 alpha and beta regions. In conclusion, this information provides the possibility of generating ROR1 specific CD8+ T cells with genetically modified T cell receptors for immunotherapy and for tracking those cells after administration with next generation sequencing in peripheral blood samples of patients. Furthermore, data suggest the existence of public TCR motifs in leukemia antigen specific CTLs, which needs to be proven in follow-up experiments with larger cohorts of donors and patients. Finally, the presented strategy to identify leukemia specific peptide antigens for CD8+ T cells might be an attractive method for similar projects. Table 1 Amino acid sequences of CDR3 alpha and beta regions of the TCR of ROR1 specific CD8+ T cell clones. When comparing two clones, matching amino acids are depicted in red. The aromatic amino acids phenylalanine (F) and tyrosine (Y) are shown in blue when situated at the same position. Gaps inserted during the sequence alignment process are indicated by a hyphen '-'. Table 1. Amino acid sequences of CDR3 alpha and beta regions of the TCR of ROR1 specific CD8+ T cell clones. When comparing two clones, matching amino acids are depicted in red. The aromatic amino acids phenylalanine (F) and tyrosine (Y) are shown in blue when situated at the same position. Gaps inserted during the sequence alignment process are indicated by a hyphen '-'. Disclosures Middeke: Sanofi: Honoraria. Schetelig:Sanofi: Honoraria.

scholarly journals Functional Characterization and Modulation of Cytokine Production by CD8+ T Cells from Human Immunodeficiency Virus-Infected Individuals

Blood ◽  
1997 ◽  
Vol 89 (10) ◽  
pp. 3672-3681 ◽  
Author(s):  
Enrico Maggi ◽  
Roberto Manetti ◽  
Francesco Annunziato ◽  
Lorenzo Cosmi ◽  
Maria Grazia Giudizi ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Clones ◽  
Cell Clones ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Hiv Seropositive

CD8+ T-cell clones were generated from peripheral blood mononuclear cells (PBMC) of three human immunodeficiency virus (HIV)-seronegative individuals and six HIV-seropositive individuals and assessed for their cytokine secretion profile, cytolytic potential, and chemokine production. While the great majority of CD8+ T-cell clones generated from HIV-seronegative individuals produced interferon (IFN)-γ, but not interleukin-4 (IL-4), that is a type 1 cytotoxic (Tc1) profile, high numbers of CD8+ T-cell clones generated from HIV-seropositive individuals produced IL-4 in addition to IFN-γ or IL-4 alone, thus showing a type 0 cytotoxic (Tc0)- or a type 2 cytotoxic (Tc2) profile, respectively. Tc0/Tc2 cells displayed lower cytolytic activity than Tc1 cells, including a reduced ability to lyse autologous targets pulsed with HIV or HIV peptides. By contrast, the production of chemokines RANTES and macrophage inflammatory protein-1α was comparable in Tc1, Tc0, and Tc2 clones irrespective of whether they were derived from HIV-seronegative or HIV-seropositive individuals. When CD8+ T-cell clones were generated from PBMC cultures of HIV-seronegative individuals conditioned with IL-4 plus an anti–IL-12 antibody (Ab), a shift towards the Tc0/Tc2-like profile was observed. Conversely, the addition to PBMC cultures of IL-12 plus an anti – IL-4 Ab shifted the differentiation of CD8+ T cells from HIV-infected individuals towards the Tc1-like profile, whereas IL-12 or anti–IL-4 Ab alone had a lower Tc1-promoting effect. Irradiated PBMC from HIV-infected individuals, used as feeder cells, shifted the differentiation of CD8+ T cells from a healthy HIV-seronegative individual towards the Tc0/Tc2-like profile. On the other hand, a shift towards the Tc1-like profile was noted in CD8+ T-cell clones generated from the skin specimens of two HIV-seropositive patients with Kaposi's sarcoma, successfully treated with IFN-α, in comparison to CD8+ clones generated from the same skin areas before treatment. The IFN-α–induced Tc1 shift could be prevented by the incubation of skin-infiltrating CD8+ T cells with IL-4 before cloning. Taken together, these data indicate that both defective production of IL-12 and abnormal IL-4 production in bulk PBMC populations of HIV-infected individuals may contribute to the development of high numbers of CD8+ T-cell clones showing a Tc0/Tc2-like phenotype and reduced cytolytic potential against HIV itself. They also suggest that the cytokine profile of CD8+ T-cell clones can be modulated by cytokines (or anticytokine Ab) both in vitro and in vivo.

Ex Vivo Expansion of Donor-Derived Anti-Tumor T Cells for CLL-Specific Adoptive Immunotherapy

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 978-978
Author(s):  
Masayasu Naito ◽  
Ursula Hainz ◽  
Kristen Stevenson ◽  
Anselmo Alonso ◽  
Ken-ichi Matsuoka ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Fold Change ◽  
Nih3t3 Cells ◽  
T Cell Clones ◽  
Cell Clones ◽  
Average Fold Change

Abstract Abstract 978 Although chronic lymphocytic leukemia (CLL) is sensitive to graft-versus-leukemia (GVL) effects, strategies to enhance donor-derived tumor immunity are needed to prevent relapse and improve outcomes after allogeneic hematopoietic stem cell transplantation (HSCT). Post-transplant infusion of mature donor T cells specific for recipient CLL cells could provide an effective treatment approach personalized to the individual tumor. However, unmanipulated CLL cells are weak antigen presenting cells (APCs), expressing low levels of costimulatory molecules, and therefore only poorly stimulate the expansion of tumor-reactive T cells. To overcome this barrier, we evaluated a novel formulation of human recombinant CD40L, a molecule known to enhance the immunostimulatory capacity of normal and malignant B cells. This formulation of CD40L (designated CD40L-Tri) was designed with the extracellular domain of CD40L connected by a long flexible linker to a leucine zipper for trimerization and an octahistidine motif for purification. We compared the immunostimulatory activity of CD40L-Tri with a murine fibroblast cell line that was engineered to express human CD40L (tCD40L/NIH3T3). In 3 of 3 cases, CD40L-Tri (at 0.5, 1, and 2 mg/ml) significantly expanded normal CD19+ B cells over 14 days by an average fold change of 21.5, 27.0 and 29.5, respectively (all p<0.05). We further observed that exposure of normal CD19+ B cells to CD40L-Tri (at 2mg/ml, n=3) resulted in significantly increased expression of the costimulatory molecules CD80, CD83 and CD86 at 48 hours by an average fold change of 28.7, 24, and 169.9, respectively(all p<0.05), which was comparable to the average fold change of tCD40L/NIH3T3 (24.7, 21.8, and 144.9, respectively, all p<0.05). In three separate experiments, thymidine incorporation assays revealed that exposure of normal B cells to CD40L-Tri consistently generated APCs with high capacity to stimulate allogeneic CD4+ and CD8+ T cells, at comparable levels to tCD40L/NIH3T3 cells. Consistent with these results, CD40L-Tri-activated B cells could be used to present pulsed peptide to specifically expand T cells specific for the influenza peptide M1 from a normal HLA-A2+ volunteer. Together, these studies confirmed that CD40L-Tri has potent immune-stimulatory effects on B cells, and can be utilized to expand human T cells without the risk of expansion of xenoantigen-specific T cells incurred through the use of conventional tCD40L/NIH3T3 cells. To evaluate the ability of CD40L-Tri to facilitate the expansion of CLL-specific T cells, we examined T cell responses against 4 cryopreserved CLL tumors for which cryopreserved HLA-matched normal donor cells were available. Donor CD8+ T cells were subjected to four weekly in vitro stimulations with CD40L-Tri-activated recipient CLL-B cells in the presence of IL-7, IL-12, and IL-15. In 3 of 4 cases, donor CD8+ T cells with specificity against recipient tumor were expanded. These CTL were not reactive with recipient-derived fibroblasts or PHA blasts, suggesting that T cell reactivity was tumor- rather than allo-specific. CD8+ CLL-reactive T cells secreted IFNg by Elispot and were cytotoxic to recipient CLL cells. Reactivity was blocked in the presence of MHC class I blocking antibody (W6/32). Cloning of CLL-reactive T cells from 2 patients resulted in the isolation of up to 8 tumor-reactive T cell clones each, that were confirmed to have tumor-specific and MHC class I-restricted reactivity. These T cell clones were also reactive against other CLL cells that shared at least one HLA molecule with original donor/recipient, suggesting that these CTL clones recognize common CLL antigens. Our results demonstrate that the combination of CD40L-Tri-activation of CLL cells and supportive cytokines can reliably generate CLL-specific T cells from HLA-matched donors. Our ongoing studies focus on the identification of CLL antigens recognized by these T cells, which may serve to identify useful immunogens for CLL immunotherapy. These studies suggest a potentially effective strategy for adoptive T cell therapy to enhance GVL after allogeneic HSCT in patients with CLL and possibly other mature B cell malignancies. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Major Histocompatibility Complex–independent Recognition of a Distinctive Pollen Antigen, Most Likely a Carbohydrate, by Human CD8+ α/β T Cells

1997 ◽  
Vol 186 (6) ◽  
pp. 899-908 ◽  
Author(s):  
Silvia Corinti ◽  
Raffaele De Palma ◽  
Angelo Fontana ◽  
Maria Cristina Gagliardi ◽  
Carlo Pini ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Response ◽  
Major Histocompatibility ◽  
T Cell Clones ◽  
Histocompatibility Complex ◽  
Cell Clones

We have isolated CD8+ α/β T cells from the blood of atopic and healthy individuals which recognize a nonpeptide antigen present in an allergenic extract from Parietaria judaica pollen. This antigen appears to be a carbohydrate because it is resistant to proteinase K and alkaline digestion, is hydrophilic, and is sensitive to trifluoromethane-sulphonic and periodic acids. In addition, on a reverse-phase high performance liquid chromatography column the antigen recognized by CD8+ T cells separates in a fraction which contains &gt;80% hexoses (glucose and galactose) and undetectable amounts of proteins. Presentation of this putative carbohydrate antigen (PjCHOAg) to CD8+ T cell clones is dependent on live antigen presenting cells (APCs) pulsed for &gt;1 h at 37°C, suggesting that the antigen has to be internalized and possibly processed. Indeed, fixed APCs or APCs pulsed at 15°C were both unable to induce T cell response. Remarkably, PjCHOAg presentation is independent of the expression of classical major histocompatibility complex (MHC) molecules or CD1. CD8+ T cells stimulated by PjCHOAg-pulsed APCs undergo a sustained [Ca2+]i increase and downregulate their T cell antigen receptors (TCRs) in an antigen dose– and time-dependent fashion, similar to T cells stimulated by conventional ligands. Analysis of TCR Vβ transcripts shows that six independent PjCHOAg-specific T cell clones carry the Vβ8 segment with a conserved motif in the CDR3 region, indicating a structural requirement for recognition of this antigen. Finally, after activation, the CD8+ clones from the atopic patient express CD40L and produce high levels of interleukins 4 and 5, suggesting that the clones may have undergone a Th2-like polarization in vivo. These results reveal a new class of antigens which triggers T cells in an MHC-independent way, and these antigens appear to be carbohydrates. We suggest that this type of antigen may play a role in the immune response in vivo.

scholarly journals Regional and clonal T cell dynamics at single cell resolution in immune checkpoint blockade

2021 ◽  
Author(s):  
Joy A. Pai ◽  
Andrew Chow ◽  
Jennifer Sauter ◽  
Marissa Mattar ◽  
Hira Rizvi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Cd8 T Cell ◽  
Immune Checkpoint Blockade ◽  
Rna Seq ◽  
Cell Dynamics ◽  
T Cell Clones ◽  
Cell Clones

Paired T cell receptor and RNA single cell sequencing (scTCR/RNA-seq) has allowed for enhanced resolution of clonal T cell dynamics in cancer. Here, we report a scTCR/RNA-seq dataset of 162,062 single T cells from 31 tissue regions, including tumor, adjacent normal tissues, and lymph nodes (LN), from three patients who underwent resections for progressing lung cancers after immune checkpoint blockade (ICB). We found marked regional heterogeneity in tumor persistence that was associated with heterogeneity in CD4 and CD8 T cell phenotypes; regions with persistent cancer cells were enriched for follicular helper CD4 T cells (TFH), regulatory T cells (Treg), and exhausted CD8 T cells. Clonal analysis demonstrated that highly-expanded T cell clones were predominantly of the CD8 subtype, were ubiquitously present across all sampled regions, found in the peripheral circulation, and expressed gene signatures of 'large' and 'dual-expanded' clones that have been predictive of response to ICB. Longitudinal tracking of CD8 T cell clones in the peripheral blood revealed that the persistence of ubiquitous CD8 T cell clones, as well as phenotypically distinct clones with tumor-reactive features, correlated with systemic tumor control. Finally, tracking CD8 T cell clones across tissues revealed the presence of TCF-1+ precursor exhausted CD8 T cells in tumor draining LNs that were clonally linked to expanded exhausted CD8 T cells in tumors. Altogether, this comprehensive scTCR/RNA-seq dataset with regional, longitudinal, and clonal resolution provides fundamental insights into the tissue distribution, persistence, and differentiation trajectories of ICB-responsive T cells that underlie clinical responses to ICB.

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