scholarly journals Rapid video-based deep learning of cognate versus non-cognate T cell-dendritic cell interactions

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Priya N. Anandakumaran ◽  
Abigail G. Ayers ◽  
Pawel Muranski ◽  
Remi J. Creusot ◽  
Samuel K. Sia

AbstractIdentification of cognate interactions between antigen-specific T cells and dendritic cells (DCs) is essential to understanding immunity and tolerance, and for developing therapies for cancer and autoimmune diseases. Conventional techniques for selecting antigen-specific T cells are time-consuming and limited to pre-defined antigenic peptide sequences. Here, we demonstrate the ability to use deep learning to rapidly classify videos of antigen-specific CD8+ T cells. The trained model distinguishes distinct interaction dynamics (in motility and morphology) between cognate and non-cognate T cells and DCs over 20 to 80 min. The model classified high affinity antigen-specific CD8+ T cells from OT-I mice with an area under the curve (AUC) of 0.91, and generalized well to other types of high and low affinity CD8+ T cells. The classification accuracy achieved by the model was consistently higher than simple image analysis techniques, and conventional metrics used to differentiate between cognate and non-cognate T cells, such as speed. Also, we demonstrated that experimental addition of anti-CD40 antibodies improved model prediction. Overall, this method demonstrates the potential of video-based deep learning to rapidly classify cognate T cell-DC interactions, which may also be potentially integrated into high-throughput methods for selecting antigen-specific T cells in the future.

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A763-A763
Author(s):  
Remko Schotte ◽  
Julien Villaudy ◽  
Martijn Kedde ◽  
Wouter Pos ◽  
Daniel Go ◽  
...  

BackgroundAdaptive immunity to cancer cells forms a crucial part of cancer immunotherapy. Recently, the importance of tumor B-cell signatures were shown to correlate with melanoma survival. We investigated whether tumor-targeting antibodies could be isolated from a patient that cured (now 13 years tumor-free) metastatic melanoma following adoptive transfer of ex vivo expanded autologous T cells.MethodsPatient‘s peripheral blood B cells were isolated and tested for the presence of tumor-reactive B cells using AIMM’s immmortalisation technology. Antibody AT1412 was identified by virtue of its differential binding to melanoma cells as compared to healthy melanocytes. AT1412 binds the tetraspanin CD9, a broadly expressed protein involved in multiple cellular activities in cancer and induces ADCC and ADCP by effector cells.ResultsSpontaneous immune rejection of tumors was observed in human immune system (HIS) mouse models implanted with CD9 genetically-disrupted A375 melanoma (A375-CD9KO) tumor cells, while A375wt cells were not cleared. Most notably, no tumor rejection of A375-CD9KO tumors was observed in NSG mice, indicating that blockade of CD9 makes tumor cells susceptible to immune rejection.CD9 has been described to regulate integrin signaling, e.g. LFA-1, VLA-4, VCAM-1 and ICAM-1. AT1412 was shown to modulate CD9 function by enhancing adhesion and transmigration of T cells to endothelial (HUVEC) cells. AT1412 was most potently enhancing transendothelial T-cell migration, in contrast to a high affinity version of AT1412 or other high affinity anti-CD9 reference antibodies (e.g. ALB6). Enhanced immune cell infiltration is also observed in immunodeficient mice harbouring a human immune system (HIS). AT1412 strongly enhanced CD8 T-cell and macrophage infiltration resulting in tumor rejection (A375 melanoma). PD-1 checkpoint blockade is further sustaining this effect. In a second melanoma model carrying a PD-1 resistant and highly aggressive tumor (SK-MEL5) AT1412 together with nivolumab was inducing full tumor rejection, while either one of the antibodies alone did not.ConclusionsThe safety of AT1412 has been assessed in preclinical development and is well tolerated up to 10 mg/kg (highest dose tested) by non human primates. AT1412 demonstrated a half-life of 8.5 days, supporting 2–3 weekly administration in humans. Besides transient thrombocytopenia no other pathological deviations were observed. No effect on coagulation parameters, bruising or bleeding were observed macro- or microscopically. The thrombocytopenia is reversible, and its recovery accelerated in those animals developing anti-drug antibodies. First in Human clinical study is planned to start early 2021.Ethics ApprovalStudy protocols were approved by the Medical Ethical Committee of the Leiden University Medical Center (Leiden, Netherlands).ConsentBlood was obtained after written informed consent by the patient.


1988 ◽  
Vol 167 (2) ◽  
pp. 612-622 ◽  
Author(s):  
P Bacha ◽  
D P Williams ◽  
C Waters ◽  
J M Williams ◽  
J R Murphy ◽  
...  

The IL-2 toxin-mediated inhibition of protein synthesis in high affinity IL-2-R-positive murine and human T cell lines has been examined. Both excess free IL-2 and mAb to the Tac epitope of the p55 subunit of IL-2-R are shown to block the action of IL-2 toxin; whereas, agents that interact with other receptors or antigens on the T cell surface have no effect. We show that IL-2 toxin, like diphtheria toxin, must pass through an acidic vesicle in order to intoxicate target T cells. Finally, we demonstrate that the IL-2 toxin-mediated inhibition of protein synthesis in both human and murine T cells that bear the high affinity IL-2-R is due to the classic diphtheria toxin fragment A-catalyzed ADP ribosylation of elongation factor 2.


2020 ◽  
Vol 5 (51) ◽  
pp. eabb5590 ◽  
Author(s):  
Heather M. Ren ◽  
Elizabeth M. Kolawole ◽  
Mingqiang Ren ◽  
Ge Jin ◽  
Colleen S. Netherby-Winslow ◽  
...  

Development of tissue-resident memory (TRM) CD8 T cells depends on CD4 T cells. In polyomavirus central nervous system infection, brain CXCR5hi PD-1hi CD4 T cells produce interleukin-21 (IL-21), and CD8 T cells lacking IL-21 receptors (IL21R−/−) fail to become bTRM. IL-21+ CD4 T cells exhibit elevated T cell receptor (TCR) affinity and higher TCR density. IL21R−/− brain CD8 T cells do not express CD103, depend on vascular CD8 T cells for maintenance, are antigen recall defective, and lack TRM core signature genes. CD4 T cell–deficient and IL21R−/− brain CD8 T cells show similar deficiencies in expression of genes for oxidative metabolism, and intrathecal delivery of IL-21 to CD4 T cell–depleted mice restores expression of electron transport genes in CD8 T cells to wild-type levels. Thus, high-affinity CXCR5hi PD-1hi CD4 T cells in the brain produce IL-21, which drives CD8 bTRM differentiation in response to a persistent viral infection.


2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A49.1-A49
Author(s):  
MAJ de Rooij ◽  
DM van der Steen ◽  
D Remst ◽  
A Wouters ◽  
M van der Meent ◽  
...  

BackgroundCancer Testis Antigens (CTAs) are highly expressed in multiple different tumor types, but silent in normal tissue, except the testis. This tumor-restricted expression pattern makes them an ideal target for adoptive T-cell therapy. However, the responsiveness in clinical setting may be hampered because high-affinity T cells against self-antigens presented in the context of self-HLA are deleted in the thymus by negative selection. In this study, we aim to identify high-affinity T cell receptors (TCRs) specific for CTAs from the allogeneic-HLA repertoire.Materials and MethodsIn this study, HLA class I binding peptides derived from different CTA genes were identified by HLA-peptide elution experiments and subsequent mass spectrometric analysis. From the identified peptides HLA tetramers were generated to isolate peptide specific CD8+ T cells from healthy allogeneic donors. Efficacy and safety of the TCRs was determined by various different stimulation assays. The most potent TCRs were sequenced, analyzed and transduced into peripheral CD8+ and CD4+ T cells to confirm CTA specific cytokine production and cytotoxicity.ResultsMAGE and CTAG peptides were eluted from multiple myelomas, EBV-transformed lymphoblastic cells, acute myeloid leukemia and ovarium carcinomas. We selected TCRs recognizing 3 different MAGE-A1 peptides in the context of HLA-A*02:01, HLA-A*03:01 and HLA-B*07:02. Furthermore, we selected TCRs specific for MAGE-A3 in the context of HLA-B*35:01 and HLA-A*01:01; TCRs specific for MAGE-A9 in the context of HLA-A*01:01 and TCRs specific for CTAG1 in the context of HLA-A*02:01. The selected T-cell clones demonstrated efficient recognition of MAGE-A1, MAGE-A3 or CTAG1 positive multiple myeloma and solid tumor cell lines without detectable cross-reactivity.ConclusionsWe identified multiple different TCRs from the allogeneic-HLA repertoire specific for CTA genes. These TCRs demonstrate efficient recognition and killing of CTA positive multiple myeloma and solid tumor cell lines and did not show any cross-reactivity. The peptides recognized by the TCRs are presented in different HLA alleles. Since, 71% of the world population contains one of these HLA-alleles, a large percentage suffering from a MAGE or CTAG positive tumor could potentially be treated with the identified TCRs by TCR-gene therapy.Disclosure InformationM.A.J. de Rooij: None. D.M. van der Steen: None. D. Remst: None. A. Wouters: None. M. van der Meent: None. R.S. Hagedoorn: None. M.G.D. Kester: None. P.A. van Veelen: None. F.J.H. Falkenburg: None. M.H.M. Heemskerk: None.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4226-4226
Author(s):  
Hakim Echchannaoui ◽  
Jutta Petschenka ◽  
Edite Antunes ◽  
Matthias Theobald

Abstract Abstract 4226 Several studies have demonstrated the clinical efficacy of adoptive T cell therapy for targeting cancer. Using HLA-A2.1 transgenic mice, we have demonstrated the feasibility of T-cell receptor (TCR) gene transfer into T cells to circumvent self-tolerance to the widely expressed human p53(264–272) tumor-associated antigen and developed approaches to generate high-affinity CD8-independent TCR. A safety concern of TCR gene transfer is the pairing of endogenous and introduced TCR chains resulting in the potential generation of self-reactive T cells (off-target autoimmunity). Several strategies to favor matched TCR chains pairing and thus enhancing TCR cell surface expression, including optimization of TCR encoding nucleotide sequences, introduction of an additional inter-chain disulfide bond between the TCR α and β chain constant domains, coexpression of both TCR α and β encoding-genes using self-cleaving 2A virus peptide-based retroviral vectors have been applied. However, adoptive transfer of mouse T cells transduced with modified p53-specific TCRs into p53-deficient humanized (A2Kb) mice was inducing lethal autoimmunity due to the formation of self-reactive TCRs infiltrating vital organs, such as spleen, liver and bone marrow. Therefore, an optimized single chain (sc) p53-specific TCR was engineered to avoid the formation of mismatched TCR heterodimers. The safety and therapeutic efficiency of this approach were evaluated in humanized mouse models of adoptive T cell transfer and successfully demonstrated that optimized p53-specific scTCR-redirected T cells (i) do not induce OFF-target autoimmunity and (ii) mediate antitumor reactivity. Importantly, because the expression of p53 antigen on normal tissues raises the concern of potential on-target toxicity, we performed adoptive T cell transfer experiments in humanized mice expressing the Human p53 protein (Hupki mice) and did not observe any sign of TCR gene transfer-mediated GvHD in this model. In conclusion, these mouse studies suggest that the optimized p53(264–272)-specific scTCR could represent a safe and efficient approach for TCR-based gene therapy. Disclosures: No relevant conflicts of interest to declare.


1998 ◽  
Vol 188 (10) ◽  
pp. 1867-1874 ◽  
Author(s):  
Gayle M. Davey ◽  
Sonya L. Schober ◽  
Bart T. Endrizzi ◽  
Angela K. Dutcher ◽  
Stephen C. Jameson ◽  
...  

During T cell development, thymocytes which are tolerant to self-peptides but reactive to foreign peptides are selected. The current model for thymocyte selection proposes that self-peptide–major histocompatibility complex (MHC) complexes that bind the T cell receptor with low affinity will promote positive selection while those with high affinity will result in negative selection. Upon thymocyte maturation, such low affinity self-peptide–MHC ligands no longer provoke a response, but foreign peptides can incidentally be high affinity ligands and can therefore stimulate T cells. For this model to work, thymocytes must be more sensitive to ligand than mature T cells. Contrary to this expectation, several groups have shown that thymocytes are less responsive than mature T cells to anti-T cell receptor for antigen (TCR)/CD3 mAb stimulation. Additionally, the lower TCR levels on thymocytes, compared with T cells, would potentially correlate with decreased thymocyte sensitivity. Here we compared preselection thymocytes and mature T cells for early activation events in response to peptide–MHC ligands. Remarkably, the preselection thymocytes were more responsive than mature T cells when stimulated with low affinity peptide variants, while both populations responded equally well to the antigenic peptide. This directly demonstrates the increased sensitivity of thymocytes compared with T cells for TCR engagement by peptide–MHC complexes.


Urban Science ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 78 ◽  
Author(s):  
Deepank Verma ◽  
Arnab Jana ◽  
Krithi Ramamritham

The assessments on human perception of urban spaces are essential for the management and upkeep of surroundings. A large part of the previous studies is dedicated towards the visual appreciation and judgement of various physical features present in the surroundings. Visual qualities of the environment stimulate feelings of safety, pleasure, and belongingness. Scaling such assessments to cover city boundaries necessitates the assistance of state-of-the-art computer vision techniques. We developed a mobile-based application to collect visual datasets in the form of street-level imagery with the help of volunteers. We further utilised the potential of deep learning-based image analysis techniques in gaining insights into such datasets. In addition, we explained our findings with the help of environment variables which are related to individual satisfaction and wellbeing.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Tianzhu Tao ◽  
Lulong Bo ◽  
Teng Li ◽  
Longbao Shi ◽  
Hui Zhang ◽  
...  

Background. B7 family members and ligands have been identified as critical checkpoints in orchestrating the immune response during sepsis. V-domain Ig suppressor of T cell activation (VISTA) is a new inhibitory immune checkpoint involved in restraining T cell response. Previous studies demonstrated that VISTA engagement on T cells and myeloid cells could transmit inhibitory signals, resulting in reduced activation and function. The current study was designed to determine the potential therapeutic effects of a high-affinity anti-VISTA antibody (clone MH5A) in a murine model of sepsis. Methods. Polymicrobial sepsis was induced in male C57BL/6 mice via cecal ligation and puncture. Expression profiles of VISTA on T lymphocytes and macrophage were examined at 24 and 72 h postsurgery. The effects of anti-VISTA mAb on the 7-day survival, lymphocyte apoptosis, cytokine expression, bacterial burden, and vital organ damage were determined. Furthermore, the effects of anti-VISTA mAb on CD3+ T cell apoptosis and macrophage activation were determined in vitro. Results. VISTA was substantially expressed on T cells and macrophages in sham-operated mice; septic peritonitis did not induce significant changes in the expression profiles. Treatment with MH5A improved the survival of septic mice, accompanied by reduced lymphocyte apoptosis, decreased cytokine expression, and enhanced bacterial clearance. Engagement of VISTA receptor with MH5A mitigated CD3+ T cell apoptosis cultured from CLP mice and suppressed LPS-induced cytokine production by macrophage in vitro. Conclusion. The present study identified VISTA as a novel immune checkpoint in the regulation of T cell and macrophage response during sepsis. Modulation of the VISTA pathway might offer a promising opportunity in the immunotherapy for sepsis.


2020 ◽  
Vol 8 (2) ◽  
pp. e000896
Author(s):  
Talia Velasco-Hernandez ◽  
Samanta Romina Zanetti ◽  
Heleia Roca-Ho ◽  
Francisco Gutierrez-Aguera ◽  
Paolo Petazzi ◽  
...  

BackgroundThere are few therapeutic options available for patients with B-cell acute lymphoblastic leukemia (B-ALL) relapsing as CD19– either after chemotherapy or CD19-targeted immunotherapies. CD22-chimeric antigen receptor (CAR) T cells represent an attractive addition to CD19-CAR T cell therapy because they will target both CD22+CD19– B-ALL relapses and CD19– preleukemic cells. However, the immune escape mechanisms from CD22-CAR T cells, and the potential contribution of the epitope binding of the anti-CD22 single-chain variable fragment (scFv) remain understudied.MethodsHere, we have developed and comprehensively characterized a novel CD22-CAR (clone hCD22.7) targeting a membrane-distal CD22 epitope and tested its cytotoxic effects against B-ALL cells both in in vitro and in vivo assays.ResultsConformational epitope mapping, cross-blocking, and molecular docking assays revealed that the hCD22.7 scFv is a high-affinity binding antibody which specifically binds to the ESTKDGKVP sequence, located in the Ig-like V-type domain, the most distal domain of CD22. We observed efficient killing of B-ALL cells in vitro, although the kinetics were dependent on the level of CD22 expression. Importantly, we show an efficient in vivo control of patients with B-ALL derived xenografts with diverse aggressiveness, coupled to long-term hCD22.7-CAR T cell persistence. Remaining leukemic cells at sacrifice maintained full expression of CD22, ruling out CAR pressure-mediated antigen loss. Finally, the immunogenicity capacity of this hCD22.7-scFv was very similar to that of other CD22 scFv previously used in adoptive T cell therapy.ConclusionsWe report a novel, high-affinity hCD22.7 scFv which targets a membrane-distal epitope of CD22. 4-1BB-based hCD22.7-CAR T cells efficiently eliminate clinically relevant B- CD22high and CD22low ALL primary samples in vitro and in vivo. Our study supports the clinical translation of this hCD22.7-CAR as either single or tandem CD22–CD19-CAR for both naive and anti-CD19-resistant patients with B-ALL.


2019 ◽  
Vol 12 (604) ◽  
pp. eaaw8151 ◽  
Author(s):  
Adam H. Courtney ◽  
Alexey A. Shvets ◽  
Wen Lu ◽  
Gloria Griffante ◽  
Marianne Mollenauer ◽  
...  

T cells require the protein tyrosine phosphatase CD45 to detect and respond to antigen because it activates the Src family kinase Lck, which phosphorylates the T cell antigen receptor (TCR) complex. CD45 activates Lck by opposing the negative regulatory kinase Csk. Paradoxically, CD45 has also been implicated in suppressing TCR signaling by dephosphorylating the same signaling motifs within the TCR complex upon which Lck acts. We sought to reconcile these observations using chemical and genetic perturbations of the Csk/CD45 regulatory axis incorporated with computational analyses. Specifically, we titrated the activities of Csk and CD45 and assessed their influence on Lck activation, TCR-associated ζ-chain phosphorylation, and more downstream signaling events. Acute inhibition of Csk revealed that CD45 suppressed ζ-chain phosphorylation and was necessary for a regulatable pool of active Lck, thereby interconnecting the activating and suppressive roles of CD45 that tune antigen discrimination. CD45 suppressed signaling events that were antigen independent or induced by low-affinity antigen but not those initiated by high-affinity antigen. Together, our findings reveal that CD45 acts as a signaling “gatekeeper,” enabling graded signaling outputs while filtering weak or spurious signaling events.


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