scholarly journals Stromal remodeling regulates dendritic cell abundance and activity in the tumor microenvironment

2021 ◽  
Author(s):  
Athanasios Papadas ◽  
Gauri Deb ◽  
Adam Officer ◽  
Alexander Cicala ◽  
Chelsea Hope ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cell Fate ◽  
Cd8 T Cells ◽  
Tumor Stroma ◽  
Lymphoid Cells ◽  
Adult Tissue ◽  
Tumor Seeding ◽  
Embryonic Morphogenesis ◽  
Necessary And Sufficient

Stimulatory dendritic cells (SDC), enriched within Batf3-DC (cDC1), engage in productive interactions with CD8+ effectors along tumor-stroma boundaries. The paradoxical accumulation of poised cross-presenting Batf3-DC within stromal sheets, distal to tumoral nests, is unlikely to simply reflect passive exclusion away from immunosuppressive tumor cores. Drawing parallels with embryonic morphogenesis, we hypothesized that invasive margin stromal remodeling may generate developmentally conserved cell-fate cues that regulate Batf3-DC behavior. We find that CD8+ T-cells massively infiltrate tumor matrices undergoing proteoglycan versican (VCAN) proteolysis, an essential organ-sculpting modification in development and adult tissue-plane forging. VCAN proteolysis releases a bioactive fragment (matrikine), versikine, that is necessary and sufficient for Batf3-DC accumulation. Versikine does not influence tumor-seeding pre-DC differentiation; rather, it orchestrates a distinctive activation program conferring exquisite sensitivity to DNA-sensing, coupled with survival support from atypical innate lymphoid cells. Thus, homeostatic signals from stroma invasion regulate SDC survival and activity to promote T-cell inflammation.

scholarly journals Antigen-dependent competition shapes the local repertoire of tissue-resident memory CD8+ T cells

2016 ◽  
Vol 213 (13) ◽  
pp. 3075-3086 ◽  
Author(s):  
Andreas Muschaweckh ◽  
Veit R. Buchholz ◽  
Anne Fellenzer ◽  
Christian Hessel ◽  
Paul-Albert König ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Fate ◽  
Cd8 T Cells ◽  
Immune Surveillance ◽  
Cell Formation ◽  
Memory Cd8 T Cells ◽  
Tcr Signals ◽  
Necessary And Sufficient ◽  
Resident Memory T Cells ◽  
Cross Competition

Tissue-resident memory CD8+ T cells (TRM) constitute a major component of the immune-surveillance system in nonlymphoid organs. Local, noncognate factors are both necessary and sufficient to support the programming of TRM cell fate in tissue-infiltrating T cells. Recent evidence suggests that TCR signals received in infected nonlymphoid tissues additionally contribute to TRM cell formation. Here, we asked how antigen-dependent pathways influence the generation of skin-resident memory T cells that arise from a polyclonal repertoire of cells induced by infection with an antigenically complex virus and recombinant vaccine vector. We found that CD8+ T cells of different specificities underwent antigen-dependent competition in the infected tissue, which shaped the composition of the local pool of TRM cells. This local cross-competition was active for T cells recognizing antigens that are coexpressed by infected cells. In contrast, TRM cell development remained largely undisturbed by the presence of potential competitors when antigens expressed in the same tissue were segregated through infection with antigenically distinct viral quasispecies. Functionally, local cross-competition might serve as a gatekeeping mechanism to regulate access to the resident memory niche and to fine-tune the local repertoire of antiviral TRM cells.

scholarly journals 453 Novel combination immunotherapy for boosting and priming immune responses in pancreatic cancer: strong anti-tumour effects with interleukin-15 and CD40 agonist treatment

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A480-A480
Author(s):  
Jonas Van Audenaerde ◽  
Elly Marcq ◽  
Bianca von Scheidt ◽  
Ashleigh Davey ◽  
Amanda Oliver ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
T Cells ◽  
Dendritic Cells ◽  
Natural Killer ◽  
Mouse Models ◽  
Cd8 T Cells ◽  
Tumour Growth ◽  
Immune Memory ◽  
Combination Immunotherapy ◽  
Interleukin 15

BackgroundWith the poorest 5-year survival of all cancers, improving treatment for pancreatic cancer is one of the biggest challenges in cancer research. In this era of combination immunotherapies, we sought to explore the potential of combining both priming and activation of the immune system. To achieve this, we combined a CD40 agonist with interleukin-15 and tested its potential in pancreatic cancer.MethodsTwo different mouse models of pancreatic cancer were used to assess the potential of this combination regimen. Therefore, effects on tumour growth kinetics and survival were charted. Differential effects on immune signatures was investigated using RNA sequencing. Functional immune subset involvement was tested using different immune depletion experiments and multicolour flow cytometry in different relevant immune sites. Immune memory was checked using re-challenge experiments.ResultsWe demonstrated profound reduction in tumour growth and increased survival of mice with the majority of mice being cured when both agents were combined, including an unprecedented dose reduction of CD40 agonist without losing any efficacy (fig 1). RNA sequencing analysis showed involvement of natural killer cell and T cell mediated anti-tumour responses and the importance of antigen-presenting cell pathways. This combination resulted in enhanced infiltration of tumours by both cytotoxic T cells and natural killer cells, as well as a striking increase in the ratio of CD8+ T cells over T regulatory cells. We also observed a significant increase in numbers of dendritic cells in tumour draining lymph nodes, particularly CD103+ dendritic cells with cross-presentation potential. A critical role for CD8+ T cells and involvement of natural killer cells in the anti-tumour effect was highlighted. Importantly, strong immune memory was established, with an increase in memory CD8+ T cells only when both interleukin-15 and the CD40 agonist were combined.Abstract 453 Figure 1Tumour kinetics and survival in Panc02 (left) and KPC (right) pancreatic cancer mouse modelsConclusionsWe demonstrated profound synergistic anti-tumour effects upon combination of CD40 agonist and interleukin-15 treatment in mouse models of pancreatic cancer. This preclinical data supports initiation of a first-in-human clinical trial with this combination immunotherapy strategy in pancreatic cancer.

scholarly journals Atypical lymphoid cells circulating in blood in COVID-19 infection: morphology, immunophenotype and prognosis value

2020 ◽  
pp. jclinpath-2020-207087
Author(s):  
Anna Merino ◽  
Alexandru Vlagea ◽  
Angel Molina ◽  
Natalia Egri ◽  
Javier Laguna ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Automatic System ◽  
Lymphoid Cells ◽  
Effector Memory ◽  
Laboratory Findings ◽  
Deep Blue ◽  
Sensitivity Specificity ◽  
Reactive Lymphocytes ◽  
D Dimer

AimsAtypical lymphocytes circulating in blood have been reported in COVID-19 patients. This study aims to (1) analyse if patients with reactive lymphocytes (COVID-19 RL) show clinical or biological characteristics related to outcome; (2) develop an automatic system to recognise them in an objective way and (3) study their immunophenotype.MethodsClinical and laboratory findings in 36 COVID-19 patients were compared between those showing COVID-19 RL in blood (18) and those without (18). Blood samples were analysed in Advia2120i and stained with May Grünwald-Giemsa. Digital images were acquired in CellaVisionDM96. Convolutional neural networks (CNNs) were used to accurately recognise COVID-19 RL. Immunophenotypic study was performed throughflow cytometry.ResultsNeutrophils, D-dimer, procalcitonin, glomerular filtration rate and total protein values were higher in patients without COVID-19 RL (p<0.05) and four of these patients died. Haemoglobin and lymphocyte counts were higher (p<0.02) and no patients died in the group showing COVID-19 RL. COVID-19 RL showed a distinct deep blue cytoplasm with nucleus mostly in eccentric position. Through two sequential CNNs, they were automatically distinguished from normal lymphocytes and classical RL with sensitivity, specificity and overall accuracy values of 90.5%, 99.4% and 98.7%, respectively. Immunophenotypic analysis revealed COVID-19 RL are mostly activated effector memory CD4 and CD8 T cells.ConclusionWe found that COVID-19 RL are related to a better evolution and prognosis. They can be detected by morphology in the smear review, being the computerised approach proposed useful to enhance a more objective recognition. Their presence suggests an abundant production of virus-specific T cells, thus explaining the better outcome of patients showing these cells circulating in blood.

scholarly journals Cellular cytotoxicity is a form of immunogenic cell death

2020 ◽  
Vol 8 (1) ◽  
pp. e000325 ◽  
Author(s):  
Luna Minute ◽  
Alvaro Teijeira ◽  
Alfonso R Sanchez-Paulete ◽  
Maria C Ochoa ◽  
Maite Alvarez ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Dendritic Cells ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Immunogenic Cell Death ◽  
Cell Debris ◽  
Tumor Cell Death ◽  
Mhc Multimer

BackgroundThe immune response to cancer is often conceptualized with the cancer immunity cycle. An essential step in this interpretation is that antigens released by dying tumors are presented by dendritic cells to naive or memory T cells in the tumor-draining lymph nodes. Whether tumor cell death resulting from cytotoxicity, as mediated by T cells or natural killer (NK) lymphocytes, is actually immunogenic currently remains unknown.MethodsIn this study, tumor cells were killed by antigen-specific T-cell receptor (TCR) transgenic CD8 T cells or activated NK cells. Immunogenic cell death was studied analyzing the membrane exposure of calreticulin and the release of high mobility group box 1 (HMGB1) by the dying tumor cells. Furthermore, the potential immunogenicity of the tumor cell debris was evaluated in immunocompetent mice challenged with an unrelated tumor sharing only one tumor-associated antigen and by class I major histocompatibility complex (MHC)-multimer stainings. Mice deficient inBatf3,Ifnar1andSting1were used to study mechanistic requirements.ResultsWe observe in cocultures of tumor cells and effector cytotoxic cells, the presence of markers of immunogenic cell death such as calreticulin exposure and soluble HMGB1 protein. Ovalbumin (OVA)-transfected MC38 colon cancer cells, exogenously pulsed to present the gp100 epitope are killed in culture by mouse gp100-specific TCR transgenic CD8 T cells. Immunization of mice with the resulting destroyed cells induces epitope spreading as observed by detection of OVA-specific T cells by MHC multimer staining and rejection of OVA+EG7 lymphoma cells. Similar results were observed in mice immunized with cell debris generated by NK-cell mediated cytotoxicity. Mice deficient inBatf3-dependent dendritic cells (conventional dendritic cells type 1, cDC1) fail to develop an anti-OVA response when immunized with tumor cells killed by cytotoxic lymphocytes. In line with this, cultured cDC1 dendritic cells uptake and can readily cross-present antigen from cytotoxicity-killed tumor cells to cognate CD8+T lymphocytes.ConclusionThese results support that an ongoing cytotoxic antitumor immune response can lead to immunogenic tumor cell death.

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