20 results on '"Rammensee, Hans-Georg"'
Search Results
2. Novel ACE2 fusion protein with adapting activity against SARS-CoV-2 variants in vitro
- Author
-
Zekri, Latifa, primary, Ruetalo, Natalia, additional, Christie, Mary, additional, Walker, Carolin, additional, Manz, Timo, additional, Rammensee, Hans-Georg, additional, Salih, Helmut R., additional, Schindler, Michael, additional, and Jung, Gundram, additional
- Published
- 2023
- Full Text
- View/download PDF
3. Staining of activated ß2-integrins in combination with CD137 and CD154 for sensitive identification of functional antigen-specific CD4+ and CD8+ T cells
- Author
-
Schöllhorn, Anna, primary, Maia, Ana, additional, Kimmerle, Felix, additional, Born, Jan, additional, Rammensee, Hans-Georg, additional, Dimitrov, Stoyan, additional, and Gouttefangeas, Cécile, additional
- Published
- 2023
- Full Text
- View/download PDF
4. Staining of activated ß2-integrins in combination with CD137 and CD154 for sensitive identification of functional antigen-specific CD4+ and CD8+ T cells.
- Author
-
Schöllhorn, Anna, Maia, Ana, Kimmerle, Felix, Born, Jan, Rammensee, Hans-Georg, Dimitrov, Stoyan, and Gouttefangeas, Cécile
- Subjects
T cells ,COVID-19 vaccines ,SIGNAL-to-noise ratio ,MONOCLONAL antibodies ,CELL survival - Abstract
Common flow cytometry-based methods used for functional assessment of antigen-specific T cells rely on de novo expression of intracellular cytokines or cell surface activation induced markers. They come with some limitations such as complex experimental setting, loss of cell viability and often high unspecific background which impairs assay sensitivity. We have previously shown that staining of activated ß
2 -integrins either with multimers of their ligand ICAM-1 or with a monoclonal antibody can serve as a functional marker detectable on T cells after minutes (CD8+ ) or few hours (CD4+ ) of activation. Here, we present a simple method for detection of activated ß2-integrins in combination with established cell surface activation induced markers. We observed that activated ß2-integrins were still detectable after 14 hours of stimulation, allowing their detection together with CD137 and CD154. Combinatorial gating of cells expressing activated ß2-integrins and CD137 or CD154 reduced background in unstimulated samples, increasing the signal-to-noise ratio and allowing improved assessment of low-frequency T cell responses. Extracellular staining of these markers highly correlated with production of intracellular cytokines IL-2, TNF or IFNg in CD4+ and CD8+ T cells. As an exemplary application, SARS-CoV-2 spike-specific T cell responses were assessed in individuals after COVID-19 vaccination. This method should be useful for epitope discovery projects and for the simultaneous monitoring of lowfrequency antigen-specific CD4+ and CD8+ T cell responses in various physiological situations. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
5. Integrin Activation Enables Sensitive Detection of Functional CD4+ and CD8+ T Cells: Application to Characterize SARS-CoV-2 Immunity
- Author
-
Schöllhorn, Anna, Schuhmacher, Juliane, Besedovsky, Luciana, Fendel, Rolf, Jensen, Anja T R, Stevanović, Stefan, Lange, Tanja, Rammensee, Hans-Georg, Born, Jan, Gouttefangeas, Cécile, and Dimitrov, Stoyan
- Subjects
Immunology ,Immunology and Allergy ,Cd4+ T Cells ,Cd8+ T Cells ,Sars-cov-2 ,Antigen Specificity ,Integrin Activation - Abstract
We have previously shown that conformational change in the β2-integrin is a very early activation marker that can be detected with fluorescent multimers of its ligand intercellular adhesion molecule (ICAM)-1 for rapid assessment of antigen-specific CD8+ T cells. In this study, we describe a modified protocol of this assay for sensitive detection of functional antigen-specific CD4+ T cells using a monoclonal antibody (clone m24 Ab) specific for the open, high-affinity conformation of the β2-integrin. The kinetics of β2-integrin activation was different on CD4+ and CD8+ T cells (several hours vs. few minutes, respectively); however, m24 Ab readily stained both cell types 4-6 h after antigen stimulation. With this protocol, we were able to monitor ex vivo effector and memory CD4+ and CD8+ T cells specific for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cytomegalovirus (CMV), Epstein-Barr virus (EBV), and hepatitis B virus (HBV) in whole blood or cryopreserved peripheral blood mononuclear cells (PBMCs) of infected or vaccinated individuals. By costaining β2-integrin with m24 and CD154 Abs, we assessed extremely low frequencies of polyfunctional CD4+ T cell responses. The novel assay used in this study allows very sensitive and simultaneous screening of both CD4+ and CD8+ T cell reactivities, with versatile applicability in clinical and vaccination studies.
- Published
- 2021
- Full Text
- View/download PDF
6. Immunopeptidomics-Guided Warehouse Design for Peptide-Based Immunotherapy in Chronic Lymphocytic Leukemia
- Author
-
Nelde, Annika, primary, Maringer, Yacine, additional, Bilich, Tatjana, additional, Salih, Helmut R., additional, Roerden, Malte, additional, Heitmann, Jonas S., additional, Marcu, Ana, additional, Bauer, Jens, additional, Neidert, Marian C., additional, Denzlinger, Claudio, additional, Illerhaus, Gerald, additional, Aulitzky, Walter Erich, additional, Rammensee, Hans-Georg, additional, and Walz, Juliane S., additional
- Published
- 2021
- Full Text
- View/download PDF
7. Broad and Efficient Activation of Memory CD4+ T Cells by Novel HAdV- and HCMV-Derived Peptide Pools
- Author
-
Höttler, Alexander, primary, März, Léo, additional, Lübke, Maren, additional, Rammensee, Hans-Georg, additional, and Stevanović, Stefan, additional
- Published
- 2021
- Full Text
- View/download PDF
8. Deoxyribonuclease 1-Mediated Clearance of Circulating Chromatin Prevents From Immune Cell Activation and Pro-inflammatory Cytokine Production, a Phenomenon Amplified by Low Trap1 Activity: Consequences for Systemic Lupus Erythematosus
- Author
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Felux, Jasmin, primary, Erbacher, Annika, additional, Breckler, Magali, additional, Hervé, Roxane, additional, Lemeiter, Delphine, additional, Mannherz, Hans Georg, additional, Napirei, Markus, additional, Rammensee, Hans-Georg, additional, and Decker, Patrice, additional
- Published
- 2021
- Full Text
- View/download PDF
9. Deoxyribonuclease 1-Mediated Clearance of Circulating Chromatin Prevents From Immune Cell Activation and Pro-inflammatory Cytokine Production, a Phenomenon Amplified by Low Trap1 Activity: Consequences for Systemic Lupus Erythematosus
- Author
-
Felux, Jasmin, Erbacher, Annika, Breckler, Magali, Hervé, Roxane, Lemeiter, Delphine, Mannherz, Hans Georg, Napirei, Markus, Rammensee, Hans-Georg, and Decker, Patrice
- Subjects
Mice, Knockout ,Immunology ,autoimmunity ,DNase1 ,Gene Expression ,clearance ,lupus ,Chromatin ,TRAP1 ,Mice ,inflammation ,Leukocytes ,Animals ,Cytokines ,Deoxyribonuclease I ,Lupus Erythematosus, Systemic ,HSP90 Heat-Shock Proteins ,Inflammation Mediators ,extracellular chromatin ,Extracellular Space ,Spleen ,Original Research - Abstract
Increased concentrations of circulating chromatin, especially oligo-nucleosomes, are observed in sepsis, cancer and some inflammatory autoimmune diseases like systemic lupus erythematosus (SLE). In SLE, circulating nucleosomes mainly result from increased apoptosis and decreased clearance of apoptotic cells. Once released, nucleosomes behave both as an autoantigen and as a damage-associated molecular pattern (DAMP) by activating several immune cells, especially pro-inflammatory cells. Deoxyribonuclease 1 (DNase1) is a major serum nuclease whose activity is decreased in mouse and human lupus. Likewise, the mitochondrial chaperone tumor necrosis factor (TNF) receptor-associated protein-1 (Trap1) protects against oxidative stress, which is increased in SLE. Here, using wild type, DNase1-deficient and DNase1/Trap1-deficient mice, we demonstrate that DNase1 is a major serum nuclease involved in chromatin degradation, especially when the plasminogen system is activated. In vitro degradation assays show that chromatin digestion is strongly impaired in serum from DNase1/Trap1-deficient mice as compared to wild type mice. In vivo, after injection of purified chromatin, clearance of circulating chromatin is delayed in DNase1/Trap1-deficient mice in comparison to wild type mice. Since defective chromatin clearance may lead to chromatin deposition in tissues and subsequent immune cell activation, spleen cells were stimulated in vitro with chromatin. Splenocytes were activated by chromatin, as shown by interleukin (IL)-12 secretion and CD69 up-regulation. Moreover, cell activation was exacerbated when Trap1 is deficient. Importantly, we also show that cytokines involved in lupus pathogenesis down-regulate Trap1 expression in splenocytes. Therefore, combined low activities of both DNase1 and Trap1 lead to an impaired degradation of chromatin in vitro, delayed chromatin clearance in vivo and enhanced activation of immune cells. This situation may be encountered especially, but not exclusively, in SLE by the negative action of cytokines on Trap1 expression.
- Published
- 2020
10. A Non-interventional Clinical Trial Assessing Immune Responses After Radiofrequency Ablation of Liver Metastases From Colorectal Cancer
- Author
-
Löffler, Markus W., primary, Nussbaum, Bianca, additional, Jäger, Günter, additional, Jurmeister, Philipp S., additional, Budczies, Jan, additional, Pereira, Philippe L., additional, Clasen, Stephan, additional, Kowalewski, Daniel J., additional, Mühlenbruch, Lena, additional, Königsrainer, Ingmar, additional, Beckert, Stefan, additional, Ladurner, Ruth, additional, Wagner, Silvia, additional, Bullinger, Florian, additional, Gross, Thorben H., additional, Schroeder, Christopher, additional, Sipos, Bence, additional, Königsrainer, Alfred, additional, Stevanović, Stefan, additional, Denkert, Carsten, additional, Rammensee, Hans-Georg, additional, Gouttefangeas, Cécile, additional, and Haen, Sebastian P., additional
- Published
- 2019
- Full Text
- View/download PDF
11. Broad and Efficient Activation of Memory CD4+ T Cells by Novel HAdV- and HCMV-Derived Peptide Pools.
- Author
-
Höttler, Alexander, März, Léo, Lübke, Maren, Rammensee, Hans-Georg, and Stevanović, Stefan
- Subjects
MONONUCLEAR leukocytes ,T cells ,ANTIGENS ,VIRAL antigens ,STEM cell transplantation ,T cell receptors ,VIRAL proteins ,MEMORY - Abstract
Reactivation of Human Cytomegalovirus (HCMV) and Human Adenovirus (HAdV) in immunocompromised patients following stem cell transplantation (SCT) or solid organ transplantation (SOT) is associated with high morbidity and mortality. The adoptive transfer of virus-specific CD8
+ and CD4+ T cells has been shown to re-establish the antiviral T-cell response and improve clinical outcome. The viral load in immunocompromised patients can efficiently be reduced solely by the infusion of virus-specific CD4+ T cells. The identification of CD4+ T-cell epitopes has mainly focused on a limited number of viral proteins that were characterized as immunodominant. Here, we used in silico prediction to determine promiscuous CD4+ T-cell epitopes from the entire proteomes of HCMV and HAdV. Immunogenicity testing with enzyme-linked immuno spot (ELISpot) assays and intracellular cytokine staining (ICS) revealed numerous novel CD4+ T-cell epitopes derived from a broad spectrum of viral antigens. We identified 17 novel HCMV-derived and seven novel HAdV-derived CD4+ T-cell epitopes that were recognized by > 50% of the assessed peripheral blood mononuclear cell (PBMC) samples. The newly identified epitopes were pooled with previously published, retested epitopes to stimulate virus-specific memory T cells in PBMCs from numerous randomly selected blood donors. Our peptide pools induced strong IFNγ secretion in 46 out of 48 (HCMV) and 31 out of 31 (HAdV) PBMC cultures. In conclusion, we applied an efficient method to screen large viral proteomes for promiscuous CD4+ T-cell epitopes to improve the detection and isolation of virus-specific T cells in a clinical setting. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
12. Integrin Activation Enables Sensitive Detection of Functional CD4+ and CD8+ T Cells: Application to Characterize SARS-CoV-2 Immunity.
- Author
-
Schöllhorn, Anna, Schuhmacher, Juliane, Besedovsky, Luciana, Fendel, Rolf, Jensen, Anja T. R., Stevanović, Stefan, Lange, Tanja, Rammensee, Hans-Georg, Born, Jan, Gouttefangeas, Cécile, and Dimitrov, Stoyan
- Subjects
MONONUCLEAR leukocytes ,T cells ,CELL adhesion molecules ,SARS-CoV-2 ,INTEGRINS - Abstract
We have previously shown that conformational change in the β
2 -integrin is a very early activation marker that can be detected with fluorescent multimers of its ligand intercellular adhesion molecule (ICAM)-1 for rapid assessment of antigen-specific CD8+ T cells. In this study, we describe a modified protocol of this assay for sensitive detection of functional antigen-specific CD4+ T cells using a monoclonal antibody (clone m24 Ab) specific for the open, high-affinity conformation of the β2 -integrin. The kinetics of β2 -integrin activation was different on CD4+ and CD8+ T cells (several hours vs. few minutes, respectively); however, m24 Ab readily stained both cell types 4–6 h after antigen stimulation. With this protocol, we were able to monitor ex vivo effector and memory CD4+ and CD8+ T cells specific for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cytomegalovirus (CMV), Epstein–Barr virus (EBV), and hepatitis B virus (HBV) in whole blood or cryopreserved peripheral blood mononuclear cells (PBMCs) of infected or vaccinated individuals. By costaining β2 -integrin with m24 and CD154 Abs, we assessed extremely low frequencies of polyfunctional CD4+ T cell responses. The novel assay used in this study allows very sensitive and simultaneous screening of both CD4+ and CD8+ T cell reactivities, with versatile applicability in clinical and vaccination studies. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
13. A Simple and Rapid Method for Quality Control of Major Histocompatibility Complex–Peptide Monomers by Flow Cytometry
- Author
-
Chandran, P. Anoop, primary, Heidu, Sonja, additional, Zelba, Henning, additional, Schmid-Horch, Barbara, additional, Rammensee, Hans-Georg, additional, Pascolo, Steve, additional, and Gouttefangeas, Cécile, additional
- Published
- 2017
- Full Text
- View/download PDF
14. Human Peripheral CD4+ Vδ1+ γδT Cells Can Develop into αβT Cells
- Author
-
Ziegler, Hendrik, Welker, Christian, Sterk, Marco, Haarer, Jan, Rammensee, Hans-Georg, Handgretinger, Rupert, and Schilbach, Karin
- Subjects
δβ heterodimer ,extrathymic T-cell development ,inflammation ,Immunology ,extrathymic T-cell progenitor ,hematopoietic progenitor cell ,T-cell development ,Original Research ,Vδ1+ γδT cells - Abstract
The lifelong generation of αβT cells enables us to continuously build immunity against pathogens and malignancies despite the loss of thymic function with age. Homeostatic proliferation of post-thymic naïve and memory T cells and their transition into effector and long-lived memory cells balance the decreasing output of naïve T cells, and recent research suggests that also αβT-cell development independent from the thymus may occur. However, the sites and mechanisms of extrathymic T-cell development are not yet understood in detail. γδT cells represent a small fraction of the overall T-cell pool, and are endowed with tremendous phenotypic and functional plasticity. γδT cells that express the Vδ1 gene segment are a minor population in human peripheral blood but predominate in epithelial (and inflamed) tissues. Here, we characterize a CD4(+) peripheral Vδ1(+) γδT-cell subpopulation that expresses stem-cell and progenitor markers and is able to develop into functional αβT cells ex vivo in a simple culture system and in vivo. The route taken by this process resembles thymic T-cell development. However, it involves the re-organization of the Vδ1(+) γδTCR into the αβTCR as a consequence of TCR-γ chain downregulation and the expression of surface Vδ1(+)Vβ(+) TCR components, which we believe function as surrogate pre-TCR. This transdifferentiation process is readily detectable in vivo in inflamed tissue. Our study provides a conceptual framework for extrathymic T-cell development and opens up a new vista in immunology that requires adaptive immune responses in infection, autoimmunity, and cancer to be reconsidered.
- Published
- 2014
15. Human peripheral Vd1+ ?d T cells can develop into a� T cells
- Author
-
Handgretinger Rupert, Ziegler Hendrik, Sterk Marko, Rammensee Hans-Georg, Schilbach Karin, and Haarer Jan
- Subjects
Immunology ,Immunology and Allergy ,Biology ,Molecular biology ,Peripheral - Published
- 2013
16. Human Peripheral CD4+ Vδ1+ γδT Cells Can Develop into αβT Cells
- Author
-
Ziegler, Hendrik, primary, Welker, Christian, additional, Sterk, Marco, additional, Haarer, Jan, additional, Rammensee, Hans-Georg, additional, Handgretinger, Rupert, additional, and Schilbach, Karin, additional
- Published
- 2014
- Full Text
- View/download PDF
17. Human peripheral CD4+ Vδ1+ γδT cells can develop into αβT cells.
- Author
-
Ziegler, Hendrik, Welker, Christian, Sterk, Marco, Haarer, Jan, Rammensee, Hans-Georg, Handgretinger, Rupert, Schilbach, Karin, Schönbach, Christian, and Kaye, Jonathan
- Subjects
T cells ,HOMEOSTASIS ,IMMUNE response ,THYMUS ,PROGENITOR cells - Abstract
The lifelong generation of αβT cells enables us to continuously build immunity against pathogens and malignancies despite the loss of thymic function with age. Homeostatic proliferation of post-thymic naïve and memory T cells and their transition into effector and long-lived memory cells balance the decreasing output of naïveT cells, and recent research suggests that also αβT-cell development independent from the thymus may occur. However, the sites and mechanisms of extrathymic T-cell development are not yet understood in detail. γδT cells represent a small fraction of the overall T-cell pool, and are endowed with tremendous phenotypic and functional plasticity. γδT cells that express the Vδ1 gene segment are a minor population in human peripheral blood but predominate in epithelial (and inflamed) tissues. Here, we characterize a CD4
+ peripheral Vδ1+ γδT-cell subpopulation that expresses stem-cell and progenitor markers and is able to develop into functional abT cells ex vivo in a simple culture system and in vivo. The route taken by this process resembles thymic T-cell development. However, it involves the re-organization of the Vδ1+ γδTCR into the abTCR as a consequence ofTCR-γ chain downregulation and the expression of surfaceVδ1+ Vβ+ TCR components, whichwe believe function as surrogate pre-TCR.This transdifferentiation process is readily detectable in vivo in inflamed tissue. Our study provides a conceptual framework for extrathymicT-cell development and opens up a new vista in immunology that requires adaptive immune responses in infection, autoimmunity, and cancer to be reconsidered. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
18. Multi-omics analysis of overexpressed tumor-associated proteins: gene expression, immunopeptide presentation, and antibody response in oropharyngeal squamous cell carcinoma, with a focus on cancer-testis antigens.
- Author
-
Abou Kors T, Meier M, Mühlenbruch L, Betzler AC, Oliveri F, Bens M, Thomas J, Kraus JM, Doescher J, von Witzleben A, Hofmann L, Ezic J, Huber D, Benckendorff J, Barth TFE, Greve J, Schuler PJ, Brunner C, Blackburn JM, Hoffmann TK, Ottensmeier C, Kestler HA, Rammensee HG, Walz JS, and Laban S
- Subjects
- Humans, Male, Female, Middle Aged, Antigen Presentation immunology, Aged, Gene Expression Regulation, Neoplastic, Antibody Formation genetics, Antibody Formation immunology, Adult, Squamous Cell Carcinoma of Head and Neck immunology, Squamous Cell Carcinoma of Head and Neck genetics, Exome Sequencing, Multiomics, Oropharyngeal Neoplasms immunology, Oropharyngeal Neoplasms genetics, Antigens, Neoplasm immunology, Antigens, Neoplasm genetics
- Abstract
Introduction: The human leukocyte antigen complex (HLA) is essential for inducing specific immune responses to cancer by presenting tumor-associated peptides (TAP) to T cells. Overexpressed tumor associated antigens, mainly cancer-testis antigens (CTA), are outlined as essential targets for immunotherapy in oropharyngeal squamous cell carcinoma (OPSCC). This study assessed the degree to which presentation, gene expression, and antibody response (AR) of TAP, mainly CTA, are correlated in OPSCC patients to evaluate their potential as immunotherapy targets., Materials and Methods: Snap-frozen tumor (N
Ligand/RNA =40), healthy mucosa (NRNA =6), and healthy tonsils (NLigand =5) samples were obtained. RNA-Seq was performed using Illumina HiSeq 2500/NovaSeq 6000 and whole exome sequencing (WES) utilizing NextSeq500. HLA ligands were isolated from tumor tissue using immunoaffinity purification, UHPLC, and analyzed by tandem MS. Antibodies were measured in serum (NAb =27) utilizing the KREX™ CT262 protein array. Data analysis focused on 312 proteins (KREX™ CT262 panel + overexpressed self-proteins)., Results: 183 and 94 of HLA class I and II TAP were identified by comparative profiling with healthy tonsils. Genes from 26 TAP were overexpressed in tumors compared to healthy mucosa (LFC>1; FDR<0.05). Low concordance (r=0.25; p<0.0001) was found between upregulated mRNA and class I TAP. The specific mode of correlation of TAP was found to be dependent on clinical parameters. A lack of correlation was observed both between mRNA and class II TAP, as well as between class II tumor-unique TAP (TAP-U) presentation and antibody response (AR) levels., Discussion: This study demonstrates that focusing exclusively on gene transcript levels fails to capture the full extent of TAP presentation in OPSCC. Furthermore, our findings reveal that although CTA are presented at relatively low levels, a few CTA TAP-U show potential as targets for immunotherapy., Competing Interests: SL: Advisory Boards: Merck Sharp & Dohme MSD, Bristol Myers Squibb BMS, Sanofi Genzyme, Astra Zeneca AZ. Honoraria: MSD, BMS. Travel reimbursement: Merck Serono, Astra Zeneca. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Abou Kors, Meier, Mühlenbruch, Betzler, Oliveri, Bens, Thomas, Kraus, Doescher, von Witzleben, Hofmann, Ezic, Huber, Benckendorff, Barth, Greve, Schuler, Brunner, Blackburn, Hoffmann, Ottensmeier, Kestler, Rammensee, Walz and Laban.)- Published
- 2024
- Full Text
- View/download PDF
19. Staining of activated ß 2 -integrins in combination with CD137 and CD154 for sensitive identification of functional antigen-specific CD4 + and CD8 + T cells.
- Author
-
Schöllhorn A, Maia A, Kimmerle F, Born J, Rammensee HG, Dimitrov S, and Gouttefangeas C
- Subjects
- Humans, CD4-Positive T-Lymphocytes, Integrins metabolism, COVID-19 Vaccines metabolism, SARS-CoV-2, Antigens metabolism, CD40 Ligand, Cytokines metabolism, CD8-Positive T-Lymphocytes, COVID-19 metabolism
- Abstract
Common flow cytometry-based methods used for functional assessment of antigen-specific T cells rely on de novo expression of intracellular cytokines or cell surface activation induced markers. They come with some limitations such as complex experimental setting, loss of cell viability and often high unspecific background which impairs assay sensitivity. We have previously shown that staining of activated ß
2 -integrins either with multimers of their ligand ICAM-1 or with a monoclonal antibody can serve as a functional marker detectable on T cells after minutes (CD8+ ) or few hours (CD4+ ) of activation. Here, we present a simple method for detection of activated ß2 -integrins in combination with established cell surface activation induced markers. We observed that activated ß2 -integrins were still detectable after 14 hours of stimulation, allowing their detection together with CD137 and CD154. Combinatorial gating of cells expressing activated ß2 -integrins and CD137 or CD154 reduced background in unstimulated samples, increasing the signal-to-noise ratio and allowing improved assessment of low-frequency T cell responses. Extracellular staining of these markers highly correlated with production of intracellular cytokines IL-2, TNF or IFNγ in CD4+ and CD8+ T cells. As an exemplary application, SARS-CoV-2 spike-specific T cell responses were assessed in individuals after COVID-19 vaccination. This method should be useful for epitope discovery projects and for the simultaneous monitoring of low-frequency antigen-specific CD4+ and CD8+ T cell responses in various physiological situations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Schöllhorn, Maia, Kimmerle, Born, Rammensee, Dimitrov and Gouttefangeas.)- Published
- 2023
- Full Text
- View/download PDF
20. Broad and Efficient Activation of Memory CD4 + T Cells by Novel HAdV- and HCMV-Derived Peptide Pools.
- Author
-
Höttler A, März L, Lübke M, Rammensee HG, and Stevanović S
- Subjects
- Antigens, Viral immunology, Humans, Memory T Cells immunology, Adenoviruses, Human immunology, CD4-Positive T-Lymphocytes immunology, Cytomegalovirus immunology, Epitope Mapping methods, Epitopes, T-Lymphocyte immunology
- Abstract
Reactivation of Human Cytomegalovirus (HCMV) and Human Adenovirus (HAdV) in immunocompromised patients following stem cell transplantation (SCT) or solid organ transplantation (SOT) is associated with high morbidity and mortality. The adoptive transfer of virus-specific CD8
+ and CD4+ T cells has been shown to re-establish the antiviral T-cell response and improve clinical outcome. The viral load in immunocompromised patients can efficiently be reduced solely by the infusion of virus-specific CD4+ T cells. The identification of CD4+ T-cell epitopes has mainly focused on a limited number of viral proteins that were characterized as immunodominant. Here, we used in silico prediction to determine promiscuous CD4+ T-cell epitopes from the entire proteomes of HCMV and HAdV. Immunogenicity testing with enzyme-linked immuno spot (ELISpot) assays and intracellular cytokine staining (ICS) revealed numerous novel CD4+ T-cell epitopes derived from a broad spectrum of viral antigens. We identified 17 novel HCMV-derived and seven novel HAdV-derived CD4+ T-cell epitopes that were recognized by > 50% of the assessed peripheral blood mononuclear cell (PBMC) samples. The newly identified epitopes were pooled with previously published, retested epitopes to stimulate virus-specific memory T cells in PBMCs from numerous randomly selected blood donors. Our peptide pools induced strong IFNγ secretion in 46 out of 48 (HCMV) and 31 out of 31 (HAdV) PBMC cultures. In conclusion, we applied an efficient method to screen large viral proteomes for promiscuous CD4+ T-cell epitopes to improve the detection and isolation of virus-specific T cells in a clinical setting., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Höttler, März, Lübke, Rammensee and Stevanović.)- Published
- 2021
- Full Text
- View/download PDF
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