scholarly journals Citrullinated Epitopes Identified on Tumour MHC Class II by Peptide Elution Stimulate Both Regulatory and Th1 Responses and Require Careful Selection for Optimal Anti-Tumour Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Peter Symonds ◽  
Ana Marcu ◽  
Katherine W. Cook ◽  
Rachael L. Metheringham ◽  
Lindy G. Durrant ◽  
...  
Keyword(s):  
Mhc Class Ii ◽  
Tumour Response ◽  
Class Ii ◽  
Combination Vaccine ◽  
High Dose ◽  
Immune Recognition ◽  
Tumour Therapy ◽  
Arginine Residues ◽  
Selection For ◽  
Combined Vaccine

BackgroundSomatic mutations or post-translational modifications of proteins result in changes that enable immune recognition. One such post-translational modification is citrullination, the conversion of arginine residues to citrulline. Citrullinated peptides are presented on MHC class II (MHCII) via autophagy which is upregulated by cellular stresses such as tumourigenesis.MethodsPeptides were eluted from B16 melanoma expressing HLA-DP4 and analysed by mass spectrometry to profile the presented citrullinated repertoire. Initially, seven of the identified citrullinated peptides were used in combination to vaccinate HLA-DP4 transgenic mice. Immune responses were characterised from the combination and individual vaccines by ex vivo cytokine ELISpot assay and assessed for tumour therapy.ResultsThe combination vaccine induced only weak anti-tumour therapy in the B16cDP4 melanoma model. Immune phenotyping revealed a dominant IFNγ response to citrullinated matrix metalloproteinase-21 peptide (citMMP21) and an IL-10 response to cytochrome p450 peptide (citCp450). Exclusion of the IL-10 inducing citCp450 peptide from the combined vaccine failed to recover a strong anti-tumour response. Single peptide immunisation confirmed the IFNγ response from citMMP21 and the IL-10 response from citCp450 but also showed that citrullinated Glutamate receptor ionotropic (citGRI) peptide stimulated a low avidity IFNγ response. Interestingly, both citMMP21 and citGRI peptides individually, stimulated strong anti-tumour responses that were significantly better than the combined vaccine. In line with the citGRI T cell avidity, it required high dose immunisation to induce an anti-tumour response. This suggests that as the peptides within the combined vaccine had similar binding affinities to MHC-II the combination vaccine may have resulted in lower presentation of each epitope and weak anti-tumour immunity.ConclusionWe demonstrate that tumours present citrullinated peptides that can stimulate Th1 and regulatory responses and that competition likely exists between similar affinity peptides. Characterisation of responses from epitopes identified by peptide elution are necessary to optimise selection for tumour therapy.

C-Type Lectin Receptor Mediated Immune Recognition of ADAMTS13 Promotes HLA-DRB1*11 Dependent Presentation of CUB1-2 Derived Peptides by Dendritic Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 196-196
Author(s):  
Nicoletta Sorvillo ◽  
Simon D van Haren ◽  
Wouter Pos ◽  
Eszter Herczenik ◽  
Rob Fijnheer ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Antigen Presenting Cells ◽  
Class Ii ◽  
Immune Recognition ◽  
Dependent Manner ◽  
Sirna Silencing ◽  
Antigen Presenting

Abstract Abstract 196 ADAMTS13 is a plasma metalloproteinase that regulates platelet adhesion and aggregation by virtue of its ability to process newly released ultra-large von Willebrand factor (VWF) multimers on the surface of endothelial cells. Autoantibodies directed against ADAMTS13 prohibit the processing of VWF multimers initiating a rare and life-threatening disorder called acquired thrombotic thrombocytopenic purpura (TTP). HLA-DRB1*11 has recently been identified as a risk factor for acquired TTP. This finding implies that formation of autoantibodies towards ADAMTS13 depends on appropriate presentation of ADAMTS13 derived peptides to CD4+ T-cells by antigen presenting cells. Here, we investigate endocytosis of recombinant ADAMTS13 by immature monocyte-derived dendritic cells (iDCs) using flow cytometry and confocal microscopy. Upon incubation of fluorescently labeled-rADAMTS13 with DCs, a time- and concentration dependent uptake of ADAMTS13 was observed. Endocytosis of ADAMTS13 was completely blocked upon addition of EGTA and mannan. We subsequently explored involvement of C-type lectins (CLRs) in the uptake of ADAMTS13 using specific blocking antibodies and siRNA silencing. We found that ADAMTS13 endocytosis was significantly decreased in cells treated with a monoclonal antibody directed towards macrophage mannose receptor (MR). Furthermore siRNA silencing of MR reduced the uptake of ADAMTS13 by dendritic cells. In vitro binding studies revealed that ADAMTS13 interacts with the carbohydrate recognition domains of MR. These data show that ADAMTS13 is internalized by iDCs in a MR-dependent manner. Antigen presenting cells continuously process endogenous and exogenous antigens into small peptides that are loaded on MHC class I or MHC class II for presentation to T lymphocytes. We have recently developed a method to analyze HLA-DR-presented peptide repertoires of dendritic cells pulsed with antigen (van Haren et al., 2011). Here, we addressed which ADAMTS13-derived peptides were presented on MHC class II alleles of a panel of both HLA-DRB1*11 positive and negative donors. Compared to previous studies with model antigens only a limited number of ADAMTS13-derived peptides were presented on MHC class II. Inspection of peptide-profiles obtained from DRB1*11 positive individuals revealed that two antigenic “core” peptides derived from the CUB1-2 domains of ADAMTS13 were presented by a DR11-positive donor. In addition to these immuno-dominant peptides several other peptides were also presented although with a markedly reduced efficiency. Our findings show that DRB1*11 expressing antigen presenting cells preferentially present antigenic “core” peptides derived from the CUB1-2 domains of ADAMTS13. We hypothesize that functional presentation of these peptides on HLA-DRB1*11 contributes to the onset of acquired TTP by stimulating low affinity self-reactive CD4+ T cells that have escaped negative selection in the thymus. Disclosures: No relevant conflicts of interest to declare.

scholarly journals HLA-DO as the Optimizer of Epitope Selection for MHC Class II Antigen Presentation

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e71228 ◽  
Author(s):  
Yuri O. Poluektov ◽  
AeRyon Kim ◽  
Isamu Z. Hartman ◽  
Scheherazade Sadegh-Nasseri
Keyword(s):  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Selection For ◽  
Class Ii Antigen ◽  
Epitope Selection ◽  
Mhc Class Ii Antigen

scholarly journals Role of chain pairing for the production of functional soluble IA major histocompatibility complex class II molecules.

1996 ◽  
Vol 183 (5) ◽  
pp. 2087-2095 ◽  
Author(s):  
C A Scott ◽  
K C Garcia ◽  
F R Carbone ◽  
I A Wilson ◽  
L Teyton
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Leucine Zipper ◽  
Cell Receptor ◽  
Class Ii ◽  
Immune Recognition ◽  
Major Histocompatibility ◽  
Extracellular Medium ◽  
Histocompatibility Complex ◽  
Low Efficiency

Structural studies of cellular receptor molecules involved in immune recognition require the production of large quantities of the extracellular domains of these glycoproteins. The murine major histocompatibility complex (MHC) class II-restricted response has been extensively studied by functional means, but the engineering and purification of the native, empty form of the most-studied murine MHC class II molecule, IA, has been difficult to achieve. IA molecules, which are the murine equivalent of human histocompatibility leukocyte antigen-DQ molecules, have a low efficiency of chain pairing, which results in poor transport to the cell surface and in the appearance of mixed isotype pairs. We have engineered soluble IA molecules whose pairing has been forced by the addition of leucine zipper peptide dimers at their COOH-terminus. The molecules are secreted "empty" into the extracellular medium and can be loaded with single peptide after purification. These IA molecules have been expressed in milligram quantity for crystallization as well as for activation of T cells and measurement of MHC class II-T cell receptor interactions.

scholarly journals CD56+-T-Cell Responses to Bacterial Superantigens and Immune Recognition of Attenuated Vaccines

2003 ◽  
Vol 10 (6) ◽  
pp. 1065-1073 ◽  
Author(s):  
Kamal U. Saikh ◽  
Beverly Dyas ◽  
Teri Kissner ◽  
Robert G. Ulrich
Keyword(s):  
T Cells ◽  
T Cell ◽  
Natural Killer ◽  
Mhc Class Ii ◽  
Nkt Cells ◽  
Class Ii ◽  
Immune Recognition ◽  
Cell Surface Glycoprotein ◽  
Bacterial Superantigens ◽  
Mhc Class Ii Molecules

ABSTRACT Natural killer T (NKT) cells, coexpressing natural killer (NK) and T-cell receptors (TCR), are associated with immunity to viruses, tumors, and parasites. A well-characterized subclass of these NKT cells expresses biased TCR and recognizes glycolipids such as α-galactoceramide, which is found naturally only in marine sponges and presented by the cell surface glycoprotein CD1d. However, a larger number of T cells present in human blood coexpress the NK marker CD56 and unbiased TCR and do not appear to require CD1 for antigen presentation. Observing high frequencies of CD4 and CD8 coreceptor expression in human CD56+ T cells, we examined the potential role of major histocompatibility complex (MHC) class II molecules in the activation of these cells. Activation of mononuclear cells with bacterial superantigens presented by MHC class II molecules resulted in increased frequency of CD56+ T cells. Primarily, CD4+ cells within the CD56+-T-cell population responded to the bacterial superantigens, and cytokine expression profiles were Th1-like. Further, increased levels of T cells expressing CD56 were observed in mononuclear cell cultures responding to a Staphylococcus aureus vaccine or tetanus toxoid. Collectively, our data suggest that a significant number of CD56+ T cells recognize pathogen-associated ligands in association with MHC class II molecules.

scholarly journals Footprints of antigen processing boost MHC class II natural ligand binding predictions

2018 ◽  
Author(s):  
Carolina Barra ◽  
Bruno Alvarez ◽  
Massimo Andreatta ◽  
Søren Buus ◽  
Morten Nielsen
Keyword(s):  
Binding Affinity ◽  
Mhc Class Ii ◽  
Antigen Processing ◽  
Prediction Models ◽  
Class Ii ◽  
Immune Recognition ◽  
Peptide Fragments ◽  
Mhc Ii ◽  
Natural Ligand

AbstractMajor Histocompatibility complex class II (MHC-II) molecules present peptide fragments to T cells for immune recognition. Current predictors for peptide:MHC-II binding are trained on binding affinity data, generatedin-vitroand therefore lacking information about antigen processing. For the first time, we here describe prediction models of peptide:MHC-II binding trained directly on naturally eluted peptides, and show that these, in addition to peptide binding to the MHC, incorporate identifiable rules of antigen processing. In fact, we observed detectable signals of protease cleavage at defined positions of the peptides. We also hypothesize a role of the length of the terminal ligand protrusions for trimming the peptide to the epitope presented. The results of integrating binding affinity and eluted ligand data in a combined model demonstrate improved performance for the prediction of MHC-II ligands, and foreshadow a new generation of improved peptide:MHC-II prediction tools of considerable importance for understanding and manipulating immune responses.

Sign in / Sign up

Export Citation Format

Share Document