1
|
Pircher H, Pinschewer DD, Boehm T. MHC I tetramer staining tends to overestimate the number of functionally relevant self-reactive CD8 T cells in the preimmune repertoire. Eur J Immunol 2023; 53:e2350402. [PMID: 37179469 DOI: 10.1002/eji.202350402] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/19/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023]
Abstract
Previous studies that used peptide-MHC (pMHC) tetramers (tet) to identify self-specific T cells have questioned the effectiveness of thymic-negative selection. Here, we used pMHCI tet to enumerate CD8 T cells specific for the immunodominant gp33 epitope of lymphocytic choriomeningitis virus glycoprotein (GP) in mice transgenically engineered to express high levels of GP as a self-antigen in the thymus. In GP-transgenic mice (GP+ ), monoclonal P14 TCR+ CD8 T cells that express a GP-specific TCR could not be detected by gp33/Db -tet staining, indicative of their complete intrathymic deletion. By contrast, in the same GP+ mice, substantial numbers of polyclonal CD8 T cells identifiable by gp33/Db -tet were present. The gp33-tet staining profiles of polyclonal T cells from GP+ and GP-negative (GP- ) mice were overlapping, but mean fluorescence intensities were ∼15% lower in cells from GP+ mice. Remarkably, the gp33-tet+ T cells in GP+ mice failed to clonally expand after lymphocytic choriomeningitis virus infection, whereas those of GP- mice did so. In Nur77GFP -reporter mice, dose-dependent responses to gp33 peptide-induced TCR stimulation revealed that gp33-tet+ T cells with high ligand sensitivity are lacking in GP+ mice. Hence, pMHCI tet staining identifies self-specific CD8 T cells but tends to overestimate the number of truly self-reactive cells.
Collapse
Affiliation(s)
- Hanspeter Pircher
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Daniel D Pinschewer
- Division of Experimental Virology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Thomas Boehm
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
- Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| |
Collapse
|
2
|
Groeneveldt C, Kinderman P, van Stigt Thans JJC, Labrie C, Griffioen L, Sluijter M, van den Wollenberg DJM, Hoeben RC, den Haan JMM, van der Burg SH, van Hall T, van Montfoort N. Preinduced reovirus-specific T-cell immunity enhances the anticancer efficacy of reovirus therapy. J Immunother Cancer 2022; 10:jitc-2021-004464. [PMID: 35853671 PMCID: PMC9301813 DOI: 10.1136/jitc-2021-004464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2022] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Many solid tumors do not respond to immunotherapy due to their immunologically cold tumor microenvironment (TME). We and others found that oncolytic viruses (OVs), including reovirus type 3 Dearing, can enhance the efficacy of immunotherapy by recruiting CD8+ T cells to the TME. A significant part of the incoming CD8+ T cells is directed toward reovirus itself, which may be detrimental to the efficacy of OVs. However, here we aim to exploit these incoming virus-specific T cells as anticancer effector cells. METHODS We performed an in-depth characterization of the reovirus-induced T-cell response in immune-competent mice bearing pancreatic KPC3 tumors. The immunodominant CD8+ T-cell epitope of reovirus was identified using epitope prediction algorithms and peptide arrays, and the quantity and quality of reovirus-specific T cells after reovirus administration were assessed using high-dimensional flow cytometry. A synthetic long peptide (SLP)-based vaccination strategy was designed to enhance the intratumoral frequency of reovirus-specific CD8+ T cells. RESULTS Reovirus administration did not induce tumor-specific T cells but rather induced high frequencies of reovirus-specific CD8+ T cells directed to the immunodominant epitope. Priming of reovirus-specific T cells required a low-frequent population of cross-presenting dendritic cells which was absent in Batf3-/- mice. While intratumoral and intravenous reovirus administration induced equal systemic frequencies of reovirus-specific T cells, reovirus-specific T cells were highly enriched in the TME exclusively after intratumoral administration. Here, they displayed characteristics of potent effector cells with high expression of KLRG1, suggesting they may be responsive against local reovirus-infected cells. To exploit these reovirus-specific T cells as anticancer effector cells, we designed an SLP-based vaccination strategy to induce a strong T-cell response before virotherapy. These high frequencies of circulating reovirus-specific T cells were reactivated on intratumoral reovirus administration and significantly delayed tumor growth. CONCLUSIONS These findings provide proof of concept that OV-specific T cells, despite not being tumor-specific, can be exploited as potent effector cells for anticancer treatment when primed before virotherapy. This is an attractive strategy for low-immunogenic tumors lacking tumor-specific T cells.
Collapse
Affiliation(s)
- Christianne Groeneveldt
- Medical Oncology, Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Priscilla Kinderman
- Medical Oncology, Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Camilla Labrie
- Medical Oncology, Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Lisa Griffioen
- Medical Oncology, Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Marjolein Sluijter
- Medical Oncology, Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Rob C Hoeben
- Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Joke M M den Haan
- Molecular Cell Biology and Immunlogy, Amsterdam UMC - Location VUMC, Amsterdam, The Netherlands
| | - Sjoerd H van der Burg
- Medical Oncology, Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Thorbald van Hall
- Medical Oncology, Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Nadine van Montfoort
- Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|