Immune Characters and Plasticity of the Sentinel Lymph Node in Colorectal Cancer Patients

Purpose. This study is aimed at immunologically characterizing sentinel lymph nodes (SNs) in colorectal cancer (CRC) patients and identifying changes in immunological phenotype and function of SNs isolated from the tumor immunosuppressive microenvironment. Methods. A total of 53 pairs of matched SNs and non-SNs (NSNs) were collected by using a lymph node tracer dye. Flow cytometry was performed to detect the immunophenotype of T cells as well as the expression of activation and inhibitory markers. Differential expression and distribution of characteristic immune cell markers were analyzed by multiplex immunohistochemistry (mIHC). Transcriptomics analysis was conducted to compare the differences in the expression of immune-related genes among lymph nodes. The ex vivo culture of lymph nodes was carried out to examine changes in immunological phenotypes and functions. Results. Compared with NSNs, SNs harbored a significantly higher percentage of regulatory T cells (Tregs) but a lower proportion of MoMDSCs. As indicated in the mIHC assays, Tregs, T follicular helper (Tfh) cells, and M2 macrophages were mainly distributed in cortical areas, germinal centers, and subcapsular sinus areas, respectively, while significantly higher numbers of Tregs and Tfh cells were detected in SNs as compared to NSNs. Moreover, GSEA revealed that T cell activation genes and CD8+ T cell exhaustion-related genes are enriched in SNs and NSNs, respectively. The ex vivo culture led to an increase in the proportion of CD4+ cells, while activating T cells in SNs. In addition, SNs displayed a higher increase in the expression of cytokines IFN-γ, TNF-α, and sFas than NSNs. Conclusion. SNs are shown to be in an immune active state in vivo, while highly expressing inhibitory cytokines and suppressive markers. The ex vivo culture enhanced antitumor immunological function of SN-T cells, providing a starting material for adoptive cell therapy for CRC.

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BCL6 Inhibitor-Mediated Downregulation of Phosphorylated SAMHD1 and T Cell Activation Are Associated with Decreased HIV Infection and Reactivation

Journal of Virology ◽

10.1128/jvi.01073-18 ◽

2018 ◽

Vol 93 (2) ◽

Cited By ~ 2

Author(s):

Yanhui Cai ◽

Mohamed Abdel-Mohsen ◽

Costin Tomescu ◽

Fengtian Xue ◽

Guoxin Wu ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Hiv Infection ◽

T Cell Activation ◽

Cell Activation ◽

Ex Vivo ◽

B Cell Lymphoma ◽

Lymphoid Tissues ◽

Tfh Cells ◽

Hiv 1

ABSTRACT Clearance of HIV-infected germinal center (GC) CD4+ follicular helper T cells (Tfh) after combination antiretroviral therapy (ART) is essential to an HIV cure. Blocking B cell lymphoma 6 (BCL6; the master transcription factor for Tfh cells) represses HIV infection of tonsillar CD4+ Tfh ex vivo, reduces GC formation, and limits immune activation in vivo. We assessed the anti-HIV activity of a novel BCL6 inhibitor, FX1, in Tfh/non-Tfh CD4+ T cells and its impact on T cell activation and SAMHD1 phosphorylation (Thr592). FX1 repressed HIV-1 infection of peripheral CD4+ T cells and tonsillar Tfh/non-Tfh CD4+ T cells (P < 0.05) and total elongated and multispliced HIV-1 RNA production during the first round of viral life cycle (P < 0.01). Using purified circulating CD4+ T cells from uninfected donors, we demonstrate that FX1 treatment resulted in downregulation pSAMHD1 expression (P < 0.05) and T cell activation (HLA-DR, CD25, and Ki67; P < 0.01) ex vivo corresponding with inhibition of HIV-1 and HIV-2 replication. Ex vivo HIV-1 reactivation using purified peripheral CD4+ T cells from HIV-infected ART-suppressed donors was also blocked by FX1 treatment (P < 0.01). Our results indicate that BCL6 function contributes to Tfh/non-Tfh CD4+ T cell activation and cellular susceptibility to HIV infection. BCL6 inhibition represents a novel therapeutic strategy to potentiate HIV suppression in Tfh/non-Tfh CD4+ T cells without reactivation of latent virus. IMPORTANCE The expansion and accumulation of HIV-infected BCL6+ Tfh CD4+ T cells are thought to contribute to the persistence of viral reservoirs in infected subjects undergoing ART. Two mechanisms have been raised for the preferential retention of HIV within Tfh CD4+ T cells: (i) antiretroviral drugs have limited tissue distribution, resulting in insufficient tissue concentration and lower efficacy in controlling HIV replication in lymphoid tissues, and (ii) cytotoxic CD8+ T cells within lymphoid tissues express low levels of chemokine receptor (CXCR5), thus limiting their ability to enter the GCs to control/eliminate HIV-infected Tfh cells. Our results indicate that the BCL6 inhibitor FX1 can not only repress HIV infection of tonsillar Tfh ex vivo but also suppress HIV infection and reactivation in primary, non-Tfh CD4+ T cells. Our study provides a rationale for targeting BCL6 protein to extend ART-mediated reduction of persistent HIV and/or support strategies toward HIV remission beyond ART cessation.

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157 Lymph node targeted boosting with cognate amphiphile-peptide vaccines enhances TCR-T Cell therapy to eradicate solid tumors

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.157 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A167-A167

Author(s):

Dylan Drakes ◽

Abdulraouf Abbas ◽

Jacqueline Shields ◽

Peter DeMuth

Keyword(s):

T Cells ◽

Lymph Node ◽

T Cell ◽

Lymph Nodes ◽

T Cell Activation ◽

Cell Activation ◽

Cytokine Secretion ◽

T Cell Therapy ◽

Cell Therapies

BackgroundClinical results from TCR-T Cell therapies demonstrate anti-tumor efficacy, although therapeutic benefits remain transient due to suboptimal T Cell functional persistence and tumor infiltration alongside antigen escape mechanisms.1 2 3 4 5 Amphiphile (AMP) vaccines improve lymph node targeting of cancer immunogens, stimulating an enhanced endogenous anti-tumor response.6 7 We describe an approach to generate robust and durable anti-tumor responses by combining AMP lymphatic targeting with TCR-T Cell therapy. AMP cognate peptides traffic to lymph nodes and improve TCR-T Cell activation, persistence, and function compared to soluble (SOL) peptide vaccination or TCR-T Cells alone, inducing a superior anti-tumor effect.MethodsC57BL/6J mice were subcutaneously implanted with B16F10 10 days prior to transduced pmel-1 T cell transfer or 75 days after T cell treatment for rechallenge experiments. Tumor-bearing mice received 5 doses, 2x/week of AMP-GP100/AMP-CpG, SOL-GP100/SOL-CpG, or PBS by tail-base vaccination. Caliper measurements determined tumor progression and overall survival. TCR-T Cell persistence was assessed bi-weekly through retro-orbital bleeds. Tumors and lymph nodes from treated mice were excised and analyzed by Nanostring for differential gene expression and flow cytometry for TCR-T Cell functional persistence and T cell epitope spread. Human T Cells (HTCs) and Dendritic Cells (DCs) were isolated from autologous PBMCs, transduced with KRAS-specific TCRs, and cultured with AMP-KRAS-peptide pulsed DCs before assaying T Cell boosting.ResultsWe demonstrate that AMP vaccination expands tumor specific TCR-T Cells in vivo up to 46-fold while enhancing the activation, cytokine secretion, and pro-inflammatory gene expression of tumor-infiltrating TCR-T Cells. Endogenous tumor-infiltrating T cells from AMP vaccinated mice produced up to 17-fold greater cytokine secretion following re-stimulation with non-targeted tumor epitopes. These results correspond to the eradication of established B16F10 tumors and a resistance to secondary tumor challenge in cured mice. Providing clinical relevance, HTCs transduced with KRAS-specific TCRs and boosted with AMP-KRAS-peptide pulsed DCs exhibited enhanced T cell activation, Th1 cytokine secretion, and cytolytic capacity compared to HTCs exposed to unlabeled DCs.ConclusionsAMP vaccination delivers cognate peptides to lymph nodes providing in vivo activation of tumor-specific TCR-T Cells which amplifies anti-tumor potency of such adoptively transferred cells. AMP vaccination significantly enhanced TCR-T Cell anti-tumor response and led to durable cures of solid tumors in an established, syngeneic tumor model. Additionally, AMP-peptide pulsed autologous DCs enhanced the function of clinically relevant KRAS-specific TCR-T cells in vitro. Taken together, these studies provide direct rationale and evidence for the combination of AMP vaccination with TCR-T Cell therapies to augment clinical responses.ReferencesRobbins PF, Morgan RA, Feldman SA, Yang JC, Sherry RM, Dudley ME, Wunderlich JR, Nahvi AV, Helman LJ, Mackall CL, et al. Tumor regression in patients with metastatic synovial cell sarcoma and melanoma using genetically engineered lymphocytes reactive with NY-ESO-1. J Clin Oncol 2011;29:917–924. doi: 10.1200/JCO.2010.32.2537.Rapoport AP, Stadtmauer EA, Binder-Scholl GK, Goloubeva O, Vogl DT, Lacey SF, Badros AZ, Garfall A, Weiss B, Finklestein J, et al. NY-ESO-1-specific TCR-engineered T cells mediate sustained antigen-specific antitumor effects in myeloma. Nat Med 2015;21:914–921. doi: 10.1038/nm.3910.Doran SL, Stevanovic S, Adhikary S, Gartner JJ, Jia L, Kwong MLM, Faquin WC, Hewitt SM, Sherry RM, Yang JC, et al. T-Cell Receptor Gene Therapy for Human Papillomavirus-Associated Epithelial Cancers: A First-in-Human, Phase I/II Study. J Clin Oncol 2019;37:2759–2768. doi: 10.1200/JCO.18.02424.Chandran SS, Klebanoff CA. T cell receptor-based cancer immunotherapy: Emerging efficacy and pathways of resistance. Immunol Rev 2019;290:127–147. doi: 10.1111/imr.12772.D’Angelo SP, Melchiori L, Merchant MS, Bernstein D, Glod J, Kaplan R, Grupp S, Tap WD, Chagin K, Binder GK, et al. Antitumor Activity Associated with Prolonged Persistence of Adoptively Transferred NY-ESO-1 (c259)T Cells in Synovial Sarcoma. Cancer Discov 2018;8:944–957. doi: 10.1158/2159-8290.CD-17-1417.H Liu, KD Moynihan, Y Zheng, GL Szeto, AV Li, B Huang, DS Van Egeren, C Park, DJ Irvine. Structure-based programming of lymph-node targeting in molecular vaccines. Nature 2014;507: 519–522. doi: 10.1038/nature12978.KD Moynihan, CF Opel, GL Szeto, A Tzeng, EF Zhu, JM Engreitz, RT Williams, K Rakhra, MH Zhang, AM Rothschilds, S Kumari, RL Kelly, BH Kwan, W Abraham, K Hu, NK Mehta, MJ Kauke, H Suh, JR Cochran, DA Lauffenburger, KD Wittrup, DJ Irvine. Eradication of large established tumors in mice by combination immunotherapy that engages innate and adaptive immune responses. Nat Med 2016; 22: 1402–1410. doi: 10.1038/nm.4200.

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764 Expansion with IL-15 increases cytotoxicity of Vγ9Vδ2 T cells and is associated with higher levels of cytotoxic molecules and T-bet

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0764 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A812-A812

Author(s):

Pia Aehnlich ◽

Per Thor Straten ◽

Ana Micaela Carnaz Simoes ◽

Signe Skadborg ◽

Gitte Olofsson

Keyword(s):

T Cells ◽

T Cell ◽

Cell Expansion ◽

Ex Vivo ◽

Adoptive Cell Therapy ◽

Hematological Cancers ◽

Cytotoxic Molecules ◽

Vγ9vδ2 T Cells ◽

T Cell Expansion

BackgroundAdoptive cell therapy (ACT) is an approved treatment option for certain hematological cancers and has also shown success for some solid cancers. Still, benefit and eligibility do not extend to all patients. ACT with Vγ9Vδ2 T cells is a promising approach to overcome this hurdle.MethodsIn this study, we explored the effect of different cytokine conditions on the expansion of Vγ9Vδ2 T cells in vitro.ResultsWe could show that Vγ9Vδ2 T cell expansion is feasible with two different cytokine conditions: (a) 1000U/ml interleukin (IL)-2 and (b) 100U/ml IL-2+100U/ml IL-15. We did not observe differences in expansion rate or Vγ9Vδ2 T cell purity between the conditions; however, IL-2/IL-15-expanded Vγ9Vδ2 T cells displayed enhanced cytotoxicity against tumor cells, also in hypoxia. While this increase in killing capacity was not reflected in phenotype, we demonstrated that IL-2/IL-15-expanded Vγ9Vδ2 T cells harbor increased amounts of perforin, granzyme B and granulysin in a resting state and release more upon activation. IL-2/IL-15-expanded Vγ9Vδ2 T cells also showed higher levels of transcription factor T-bet, which could indicate that T-bet and cytotoxic molecule levels confer the increased cytotoxicity.ConclusionsThese results advocate the inclusion of IL-15 into ex vivo Vγ9Vδ2 T cell expansion protocols in future clinical studies.

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A Randomized Phase II Trial of Idiotype Vaccination and Adoptive Autologous T-Cell Transfer in Multiple Myeloma patients

Blood ◽

10.1182/blood.2020008493 ◽

2021 ◽

Author(s):

Muzaffar H Qazilbash ◽

Neeraj Y Saini ◽

Cha Soung-chul ◽

Zhe Wang ◽

Edward Stadtmauer ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Phase Ii ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Phase Ii Trial ◽

Ex Vivo ◽

Vaccine Strategy ◽

Randomized Phase Ii

We hypothesized that combining adoptively transferred autologous T cells with a cancer vaccine strategy would enhance therapeutic efficacy by adding anti-myeloma idiotype-keyhole limpet hemocyanin (Id-KLH) vaccine to vaccine-specific co-stimulated T cells. In this randomized, phase II trial, eligible patients received either the control (KLH only) or Id-KLH vaccine, an auto-transplant, vaccine-specific co-stimulated T-cells expanded ex-vivo, and two booster doses of the assigned vaccine. In 36 patients (20 in KLH, 16 in Id-KLH) enrolled, no dose-limiting toxicity was seen in either arm. At last evaluation, 6 (30%) and 8 (50%) had achieved complete remission in KLH-only and Id-KLH, respectively (p=0.22) and no difference in 3-year progression-free survival was observed (59% and 56%, respectively; p=0.32). In a 594 Nanostring nCounter gene panel analyzed for immune reconstitution (IR), compared with KLH-only patients, there was a greater change in IR genes in T-cells in Id-KLH patients relative to baseline. Specifically, upregulation of genes associated with activation, induction of effector function, and generation of memory CD8+ T cells after Id-KLH, but not after KLH control vaccination, was observed. Similarly, responding patients across both arms were associated with upregulation of genes associated with T-cell activation. At baseline, all patients had greater expression of CD8+ T-cell exhaustion markers. These changes were associated with functional Id-specific immune responses in a subset of Id-KLH patients analyzed. In conclusion, in this combination immunotherapy approach, we observed a significantly more robust IR in CD4+ and CD8+ T cells in the Id-KLH arm, supporting further investigation of vaccine and adoptive immunotherapy strategies.

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Inconsistent Reversal of HIV-1 Latency Ex Vivo by Antigens of HIV-1, CMV, and Other Infectious Agents

10.21203/rs.3.rs-35386/v1 ◽

2020 ◽

Author(s):

Thomas Vollbrecht ◽

Aaron O. Angerstein ◽

Bryson Menke ◽

Nikesh M. Kumar ◽

Michelli Faria Oliveira ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Ex Vivo ◽

Latent Reservoir ◽

Antigen Specificity ◽

Pcr Assay ◽

Hiv 1

Abstract BackgroundA reservoir of replication-competent but latent virus is the main obstacle to a cure for HIV-infection. Much of this reservoir resides in memory CD4 T cells. We hypothesized that these cells can be reactivated with antigens from HIV and other common pathogens to reverse latency. ResultsWe obtained mononuclear cells from the peripheral blood of antiretroviral-treated patients with suppressed viremia. We tested pools of peptides and proteins derived from HIV and from other pathogens including CMV for their ability to reverse latency ex vivo by activation of memory responses. We assessed activation of the CD4 T cells by measuring the up-regulation of cell-surface CD69. We assessed HIV-expression using two assays: a real-time PCR assay for virion-associated viral RNA and a droplet digital PCR assay for cell-associated, multiply spliced viral mRNA. Reversal of latency occurred in a minority of cells from some participants, but no single antigen induced HIV-expression ex vivo consistently. When reversal of latency was induced by a specific peptide pool or protein, the extent was proportionally greater than that of T cell activation. ConclusionsIn this group of patients in whom antiretroviral therapy was started during chronic infection, the latent reservoir does not appear to consistently reside in CD4 T cells of a predominant antigen-specificity. Peptide-antigens reversed HIV-latency ex vivo with modest and variable activity. When latency was reversed by specific peptides or proteins, it was proportionally greater than the extent of T cell activation, suggesting partial enrichment of the latent reservoir in cells of specific antigen-reactivity.

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Double Strike Approach for Tumor Attack: Engineering T Cells Using a CD40L:CD28 Chimeric Co-Stimulatory Switch Protein for Enhanced Tumor Targeting in Adoptive Cell Therapy

Frontiers in Immunology ◽

10.3389/fimmu.2021.750478 ◽

2021 ◽

Vol 12 ◽

Author(s):

Luis Felipe Olguín-Contreras ◽

Anna N. Mendler ◽

Grzegorz Popowicz ◽

Bin Hu ◽

Elfriede Noessner

Keyword(s):

T Cells ◽

T Cell ◽

Solid Tumors ◽

Tumor Cells ◽

T Cell Activation ◽

Intracellular Signaling ◽

Adoptive Cell Therapy ◽

Tumor Rejection ◽

Target Cells ◽

Type I

Activation of co-stimulatory pathways in cytotoxic T lymphocytes expressing chimeric antigen receptors (CARs) have proven to boost effector activity, tumor rejection and long-term T cell persistence. When using antigen-specific T cell receptors (TCR) instead of CARs, the lack of co-stimulatory signals hampers robust antitumoral response, hence limiting clinical efficacy. In solid tumors, tumor stroma poses an additional hurdle through hindrance of infiltration and active inhibition. Our project aimed at generating chimeric co-stimulatory switch proteins (CSP) consisting of intracellular co-stimulatory domains (ICD) fused to extracellular protein domains (ECD) for which ligands are expressed in solid tumors. The ECD of CD40L was selected for combination with the ICD from the CD28 protein. With this approach, it was expected to not only provide co-stimulation and strengthen the TCR signaling, but also, through the CD40L ECD, facilitate the activation of tumor-resident antigen-presenting cells (APCs), modulate activation of tumor endothelium and induce TCR-MHC independent apoptotic effect on tumor cells. Since CD28 and CD40L belong to different classes of transmembrane proteins (type I and type II, respectively), creating a chimeric protein presented a structural and functional challenge. We present solutions to this challenge describing different CSP formats that were successfully expressed in human T cells along with an antigen-specific TCR. The level of surface expression of the CSPs depended on their distinct design and the state of T cell activation. In particular, CSPs were upregulated by TCR stimulation and downregulated following interaction with CD40 on target cells. Ligation of the CSP in the context of TCR-stimulation modulated intracellular signaling cascades and led to improved TCR-induced cytokine secretion and cytotoxicity. Moreover, the CD40L ECD exhibited activity as evidenced by effective maturation and activation of B cells and DCs. CD40L:CD28 CSPs are a new type of switch proteins designed to exert dual beneficial antitumor effect by acting directly on the gene-modified T cells and simultaneously on tumor cells and tumor-supporting cells of the TME. The observed effects suggest that they constitute a promising tool to be included in the engineering process of T cells to endow them with complementary features for improved performance in the tumor milieu.

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Advances in Adoptive Cell Therapy Using Induced Pluripotent Stem Cell-Derived T Cells

Frontiers in Immunology ◽

10.3389/fimmu.2021.759558 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ratchapong Netsrithong ◽

Methichit Wattanapanitch

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

Cell Biology ◽

Ex Vivo ◽

Adoptive Cell Therapy ◽

Basic Knowledge ◽

Car T Cells ◽

Car T ◽

Induced Pluripotent

Adoptive cell therapy (ACT) using chimeric antigen receptor (CAR) T cells holds impressive clinical outcomes especially in patients who are refractory to other kinds of therapy. However, many challenges hinder its clinical applications. For example, patients who undergo chemotherapy usually have an insufficient number of autologous T cells due to lymphopenia. Long-term ex vivo expansion can result in T cell exhaustion, which reduces the effector function. There is also a batch-to-batch variation during the manufacturing process, making it difficult to standardize and validate the cell products. In addition, the process is labor-intensive and costly. Generation of universal off-the-shelf CAR T cells, which can be broadly given to any patient, prepared in advance and ready to use, would be ideal and more cost-effective. Human induced pluripotent stem cells (iPSCs) provide a renewable source of cells that can be genetically engineered and differentiated into immune cells with enhanced anti-tumor cytotoxicity. This review describes basic knowledge of T cell biology, applications in ACT, the use of iPSCs as a new source of T cells and current differentiation strategies used to generate T cells as well as recent advances in genome engineering to produce next-generation off-the-shelf T cells with improved effector functions. We also discuss challenges in the field and future perspectives toward the final universal off-the-shelf immunotherapeutic products.

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Intravenous Arginine Administration Benefits CD4+ T-Cell Homeostasis and Attenuates Liver Inflammation in Mice with Polymicrobial Sepsis

Nutrients ◽

10.3390/nu12041047 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1047

Author(s):

Chiu-Li Yeh ◽

Sharon Angela Tanuseputero ◽

Jin-Ming Wu ◽

Yi-Ru Tseng ◽

Po-Jen Yang ◽

...

Keyword(s):

T Cells ◽

Single Dose ◽

Lymph Node ◽

T Cell ◽

Lymph Nodes ◽

Cd4 T Cells ◽

Cd4 T Cell ◽

Liver Inflammation ◽

Aortic Lymph Node ◽

Inos Inhibitor

This study investigated the effects of a single dose of arginine (Arg) administration at the beginning of sepsis on CD4+ T-cell regulation and liver inflammation in C57BL/6J mice. Mice were divided into normal control (NC), sham (SH), sepsis saline (SS), and sepsis Arg (SA) groups. An inducible nitric oxide (NO) synthase (iNOS) inhibitor was administered to additional sepsis groups to evaluate the role of NO during sepsis. Sepsis was induced using cecal ligation and puncture (CLP). The SS and SA groups received saline or Arg (300 mg/kg body weight) via tail vein 1 h after CLP. Mice were euthanized at 12 and 24 h post-CLP. Blood, para-aortic lymph nodes, and liver tissues were collected for further measurement. The findings showed that sepsis resulted in decreases in blood and para-aortic lymph node CD4+ T-cell percentages, whereas percentages of interleukin (IL)-4- and IL-17-expressing CD4+ T cells were upregulated. Compared to the SS group, Arg administration resulted in maintained circulating and para-aortic lymph node CD4+ T cells, an increased Th1/Th2 ratio, and a reduced Th17/Treg ratio post-CLP. In addition, levels of plasma liver injury markers and expression of inflammatory genes in liver decreased. These results suggest that a single dose of Arg administered after CLP increased Arg availability, sustained CD4+ T-cell populations, elicited more-balanced Th1/Th2/Th17/Treg polarization in the circulation and the para-aortic lymph nodes, and attenuated liver inflammation in sepsis. The favorable effects of Arg were abrogated when an iNOS inhibitor was administered, which indicated that NO may be participated in regulating the homeostasis of Th/Treg cells and subsequent liver inflammation during sepsis.

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Superresolution imaging reveals nanometer- and micrometer-scale spatial distributions of T-cell receptors in lymph nodes

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1512331113 ◽

2016 ◽

Vol 113 (26) ◽

pp. 7201-7206 ◽

Cited By ~ 41

Author(s):

Ying S. Hu ◽

Hu Cang ◽

Björn F. Lillemeier

Keyword(s):

T Cells ◽

Plasma Membrane ◽

T Cell ◽

Lymph Nodes ◽

T Cell Activation ◽

T Cell Receptors ◽

Cell Activation ◽

Cell Receptors ◽

Micrometer Scale

T cells become activated when T-cell receptors (TCRs) recognize agonist peptides bound to major histocompatibility complex molecules on antigen-presenting cells. T-cell activation critically relies on the spatiotemporal arrangements of TCRs on the plasma membrane. However, the molecular organizations of TCRs on lymph node-resident T cells have not yet been determined, owing to the diffraction limit of light. Here we visualized nanometer- and micrometer-scale TCR distributions in lymph nodes by light sheet direct stochastic optical reconstruction microscopy (dSTORM) and structured illumination microscopy (SIM). This dSTORM and SIM approach provides the first evidence, to our knowledge, of multiscale reorganization of TCRs during in vivo immune responses. We observed nanometer-scale plasma membrane domains, known as protein islands, on naïve T cells. These protein islands were enriched within micrometer-sized surface areas that we call territories. In vivo T-cell activation caused the TCR territories to contract, leading to the coalescence of protein islands and formation of stable TCR microclusters.

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Tumor masses support naive T cell infiltration, activation, and differentiation into effectors

Journal of Experimental Medicine ◽

10.1084/jem.20092454 ◽

2010 ◽

Vol 207 (8) ◽

pp. 1791-1804 ◽

Cited By ~ 134

Author(s):

Elizabeth D. Thompson ◽

Hilda L. Enriquez ◽

Yang-Xin Fu ◽

Victor H. Engelhard

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Adoptive Transfer ◽

Cell Activation ◽

Ex Vivo ◽

Tumor Infiltrating Lymphocytes ◽

T Cell Infiltration

Studies of T cell responses to tumors have focused on the draining lymph node (LN) as the site of activation. We examined the tumor mass as a potential site of activation after adoptive transfer of naive tumor-specific CD8 T cells. Activated CD8 T cells were present in tumors within 24 h of adoptive transfer and proliferation of these cells was also evident 4–5 d later in mice treated with FTY720 to prevent infiltration of cells activated in LNs. To confirm that activation of these T cells occurred in the tumor and not the tumor-draining LNs, we used mice lacking LNs. Activated and proliferating tumor-infiltrating lymphocytes were evident in these mice 24 h and 4 d after naive cell transfer. T cells activated within tumors acquired effector function that was evident both ex vivo and in vivo. Both cross-presenting antigen presenting cells within the tumor and tumor cells directly presenting antigen activated these functional CD8 effectors. We conclude that tumors support the infiltration, activation, and effector differentiation of naive CD8 T cells, despite the presence of immunosuppressive mechanisms. Thus, targeting of T cell activation to tumors may present a tool in the development of cancer immunotherapy.

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