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Biology subjects

Kester, M. G.

Publications and source records attributed to Kester, M. G..

2 recordsLinked to original sources

Temperature-based MHC class-I multimer peptide exchange for human HLA-A, B and C

T cell recognition of specific antigens presented by major histocompatibility complexes class-I (MHC-I) can play an important role during immune responses against pathogens and cancer cells. Detection of T cell immunity is based on assessing the presence of antigen-specific cytotoxic CD8+ T cells using MHC class-I (MHC-I) multimer technology. Previously we have designed conditional peptides for HLA-A*02:01, H-2Kb and HLA-E that form stable peptide-MHC-I-complexes at low temperatures and dissociate when exposed to a defined elevated temperature. The resulting conditional MHC-I complex can easily and without additional handling be exchanged with a peptide of interest, allowing to exchange peptides in a ready-to-use multimer and a high-throughput manner. Here we present data that this peptide-exchange technology is a general applicable, ready-to-use and fast approach to load many different peptides in MHC-I multimers for alleles of the HLA-A, HLA-B and HLA-C loci. We describe the development of conditional peptides for HLA-A*03:01, HLA-A*11:01, HLA-B*07:02 and HLA-C*07:02 that only form stable peptide-MHC-I complexes at low temperatures, allowing peptide exchange at higher defined temperature. We document the ease and flexibility of this technology by monitoring CD8+ T cell responses to virus-specific peptide-MHC complexes in patients. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/630039v2_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@1a48592org.highwire.dtl.DTLVardef@3d5f24org.highwire.dtl.DTLVardef@13160b7org.highwire.dtl.DTLVardef@c4bb19_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIT cell immunity relies on antigen-specific CD8+ T cells recognizing peptide MHC-I complexes. C_LIO_LIEstablishing temperature-based peptide exchange across multiple HLA alleles, resulting in a robust, easy, and fast system to generate peptide MHC-I complexes. C_LIO_LITemperature-based MHC class-I multimer demonstrate applicability across major MHC-I gene families for monitoring CD8+ T cell responses. C_LIO_LIEasy high-throughput peptide exchange potential, enhancing clinical utility of MHC multimer technology. C_LI

immunology↗

SARS-CoV-2-specific CD4+ and CD8+ T cell responses can originate from cross-reactive CMV-specific T cells

Detection of SARS-coronavirus-2 (SARS-CoV-2) specific CD4+ and CD8+ T cells in SARS-CoV-2-unexposed donors has been explained by the presence of T cells primed by other coronaviruses. However, based on the relative high frequency and prevalence of cross-reactive T cells, we hypothesized CMV may induce these cross-reactive T cells. Stimulation of pre-pandemic cryo-preserved PBMCs with SARS-CoV-2 peptides revealed that frequencies of SARS-CoV-2-specific T cells were higher in CMV-seropositive donors. Characterization of these T cells demonstrated that membrane-specific CD4+ and spike-specific CD8+ T cells originate from cross-reactive CMV-specific T cells. Spike-specific CD8+ T cells recognize SARS-CoV-2 spike peptide FVSNGTHWF (FVS) and dissimilar CMV pp65 peptide IPSINVHHY (IPS) presented by HLA-B*35:01. These dual IPS/FVS-reactive CD8+ T cells were found in multiple donors as well as severe COVID-19 patients and shared a common T cell receptor (TCR), illustrating that IPS/FVS-cross-reactivity is caused by a public TCR. In conclusion, CMV-specific T cells cross-react with SARS-CoV-2, despite low sequence homology between the two viruses, and may contribute to the pre-existing immunity against SARS-CoV-2.

immunology↗