scholarly journals CD1c bypasses lysosomes to present a lipopeptide antigen with 12 amino acids

2009 ◽  
Vol 206 (6) ◽  
pp. 1409-1422 ◽  
Author(s):  
Ildiko Van Rhijn ◽  
David C. Young ◽  
Annemieke De Jong ◽  
Jenny Vazquez ◽  
Tan-Yun Cheng ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
Protease Inhibitors ◽  
Antigen Processing ◽  
Evolutionary Conservation ◽  
Peptide Sequence ◽  
Intact Cells ◽  
Cell Responses ◽  
Human T Cells ◽  
Peptide Length

The recent discovery of dideoxymycobactin (DDM) as a ligand for CD1a demonstrates how a nonribosomal lipopeptide antigen is presented to T cells. DDM contains an unusual acylation motif and a peptide sequence present only in mycobacteria, but its discovery raises the possibility that ribosomally produced viral or mammalian proteins that commonly undergo lipidation might also function as antigens. To test this, we measured T cell responses to synthetic acylpeptides that mimic lipoproteins produced by cells and viruses. CD1c presented an N-acyl glycine dodecamer peptide (lipo-12) to human T cells, and the response was specific for the acyl linkage as well as the peptide length and sequence. Thus, CD1c represents the second member of the CD1 family to present lipopeptides. lipo-12 was efficiently recognized when presented by intact cells, and unlike DDM, it was inactivated by proteases and augmented by protease inhibitors. Although lysosomes often promote antigen presentation by CD1, rerouting CD1c to lysosomes by mutating CD1 tail sequences caused reduction in lipo-12 presentation. Thus, although certain antigens require antigen processing in lysosomes, others are destroyed there, providing a hypothesis for the evolutionary conservation of large CD1 families containing isoforms that survey early endosomal pathways.

scholarly journals CD1c tetramers detect ex vivo T cell responses to processed phosphomycoketide antigens

2013 ◽  
Vol 210 (4) ◽  
pp. 729-741 ◽  
Author(s):  
Dalam Ly ◽  
Anne G. Kasmar ◽  
Tan-Yun Cheng ◽  
Annemieke de Jong ◽  
Shouxiong Huang ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
Antigen Processing ◽  
Polyketide Synthase ◽  
Ex Vivo ◽  
Bacterial Antigen ◽  
Cell Responses ◽  
Human T Cells ◽  
Branching Patterns ◽  
Human Dendritic Cells

CD1c is expressed with high density on human dendritic cells (DCs) and B cells, yet its antigen presentation functions are the least well understood among CD1 family members. Using a CD1c-reactive T cell line (DN6) to complete an organism-wide survey of M. tuberculosis lipids, we identified C32 phosphomycoketide (PM) as a previously unknown molecule and a CD1c-presented antigen. CD1c binding and presentation of mycoketide antigens absolutely required the unusual, mycobacteria-specific lipid branching patterns introduced by polyketide synthase 12 (pks12). Unexpectedly, one TCR responded to diversely glycosylated and unglycosylated forms of mycoketide when presented by DCs and B cells. Yet cell-free systems showed that recognition was mediated only by the deglycosylated phosphoantigen. These studies identify antigen processing of a natural bacterial antigen in the human CD1c system, indicating that cells act on glycolipids to generate a highly simplified neoepitope composed of a sugar-free phosphate anion. Using knowledge of this processed antigen, we generated human CD1c tetramers, and demonstrate that CD1c–PM complexes stain T cell receptors (TCRs), providing direct evidence for a ternary interaction among CD1c-lipid-TCR. Furthermore, PM-loaded CD1c tetramers detect fresh human T cells from peripheral blood, demonstrating a polyclonal response to PM antigens in humans ex vivo.

130 Immunogenic potential of chimeric antigen receptor (CAR)-engineered T cells expressing inducible nuclease-deactivated SpCas9 (dCas9)

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A143-A143
Author(s):  
Dharmeshkumar Patel ◽  
Dharmeshkumar Patel ◽  
Angshumala Goswami ◽  
Vitaly Balan ◽  
Zhifen Yang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Peptide Sequence ◽  
T Cell Epitopes ◽  
Cell Responses ◽  
Car T Cells ◽  
Car T

BackgroundThe application of CRISPR-Cas9 for personalized medicine is potentially revolutionary for the treatment of several diseases including cancer. However, the bacterial origin of the Cas9 protein raises concerns about immunogenicity. Recent ELISA-based assays detected antibodies against Cas9 from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in 5–10% of sera from 343 normal healthy individuals.1,2 SpCas9-specific memory CD8 T cell responses were not demonstrated in those individuals. To date, there are no conclusive studies assessing whether CRISPR-Cas9-modified CAR-T could raise CD8 T cell-mediated immunogenicity in humans. Refuge CAR-T cell platform employs an inducible, non-gene editing, nuclease deactivated Cas9 (dCas9) to modulate gene expression in response to external stimuli such as antigen-dependent CAR signaling to suppress PD-1 expression.MethodsIn the present study, we analyzed two putative HLA-A*02:01 and two HLA-B*07:02-associated SpCas9 T cell epitopes. The candidate epitopes were derived from a prediction algorithm that incorporates T cell receptor contact residue hydrophobicity and HLA binding affinity. We engaged in-vitro sensitization (IVS) assay to identify immunogenic potential of dCas9 peptides.ResultsAutologous IVS assay of T cells in two healthy donor PBMCs identified CD8-T cell responses after two rounds of stimulation against only one HLA-A*02:01-associated Cas9 peptide (sequence NLIALSLGL) P1– while the other candidate epitopes did not elicit any response. Dextramer analysis demonstrated that 15% of CD8+ T cells were specific for P1 and ~11% of CD8+ cells produced INFG upon challenge with P1-loaded T2 cells.ConclusionsOur in-vitro sensitization assay was able to demonstrate that dCas9 epitope P1 is immunogenic and may elicit adaptive immune response against gene edited CAR-T cells. Endogenous processing and presentation of P1 and other putative epitopes by Refuge CAR-T cells are currently being analyzed.AcknowledgementsRefuge Biotechnologies Inc. Menlo Park, California, 94025Trial RegistrationN/AEthics ApprovalN/AConsentN/AReferencesSimhadri VL, McGill J, McMahon S, Wang J, Jiang H, Sauna ZE. Prevalence of Pre-existing Antibodies to CRISPR-Associated Nuclease Cas9 in the USA Population. Mol Ther Methods Clin Dev 2018;10:105–112. Published 2018 Jun 15. doi:10.1016/j.omtm.2018.06.006Ferdosi SR, Ewaisha R, Moghadam F, et al. Multifunctional CRISPR-Cas9 with engineered immunosilenced human T cell epitopes. Nat Commun2019;10(1):1842. Published 2019 Apr 23. doi:10.1038/s41467-019-09693-x

scholarly journals LAT1 Is a Critical Transporter of Essential Amino Acids for Immune Reactions in Activated Human T Cells

2013 ◽  
Vol 191 (8) ◽  
pp. 4080-4085 ◽  
Author(s):  
Keitaro Hayashi ◽  
Promsuk Jutabha ◽  
Hitoshi Endou ◽  
Hironori Sagara ◽  
Naohiko Anzai
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
Essential Amino Acids ◽  
Immune Reactions ◽  
Human T Cells

scholarly journals RNA-seq of Human T-Cells After Hematopoietic Stem Cell Transplantation Identifies Linc00402 as a Novel Regulator of T-Cell Alloimmunity

2020 ◽  
Author(s):  
Daniel Peltier ◽  
Molly Radosevich ◽  
Guoqing Hou ◽  
Cynthia Zajac ◽  
Katherine Oravecz-Wilson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Solid Organ Transplantation ◽  
Solid Organ ◽  
Hematopoietic Stem ◽  
Cell Responses ◽  
Human T Cells ◽  
Allogeneic Stimulation

ABSTRACTMechanisms governing allogeneic T-cell responses after allogeneic hematopoietic stem cell (HSC) and solid organ transplantation are incompletely understood. Long non-coding RNAs (lncRNA) do not code for, but control gene expression with tissue specificity. However, their role in T-cell alloimmunity is unknown. We performed RNA-seq on donor T-cells from HSCT patients and found that increasing strength of allogeneic stimulation caused greater differential expression of lncRNAs. The differential expression was validated in an independent patient cohort, and also following ex vivo allogeneic stimulation of healthy human T-cells. Linc00402, a novel, conserved lncRNA, was identified as the most differentially expressed and was enriched 88 fold in human T-cells. Mechanistically, it was mainly located in the cytoplasm, and its expression was rapidly reduced following T-cell activation. Consistent with this, tacrolimus preserved the expression of Linc00402 following T-cell activation, and lower levels of Linc00402 were found in patients who subsequently went on to develop acute graft versus host disease (GVHD). The dysregulated expression of Linc00402 was also validated in murine T-cells, both in vitro and in vivo. Functional studies using multiple modalities to deplete Linc00402 in both mouse and human T-cells, demonstrated a critical role for Linc00402 in the T-cell proliferative response to an allogeneic stimulus but not a non-specific anti-CD3/CD28 stimulus. Thus, our studies identified Linc00402 as a novel, conserved regulator of allogeneic T-cell function. Because of its T-cell specific expression and its impact on allogeneic T-cell responses, targeting Linc00402 may improve outcomes after allogeneic HSC and solid organ transplantation.One sentence summaryLncRNAs are differentially expressed by allogeneic antigen-stimulated T-cells, and the novel lncRNA, Linc00402, is a specific regulator of mouse and human allogeneic T-cells.

scholarly journals The Homology Modeling and Docking Investigation of Human Cathepsin B

2020 ◽  
Vol 10 (1) ◽  
pp. 26687
Author(s):  
Afshin Khara ◽  
Ehsan Jahangirian ◽  
Hossein Tarrahimofrad
Keyword(s):  
Amino Acids ◽  
Protease Inhibitors ◽  
Cystatin C ◽  
Active Site ◽  
Cathepsin B ◽  
Antigen Processing ◽  
3D Structure ◽  
Cysteine Proteases ◽  
Docking Studies ◽  
Alternative Methods

Background: Cathepsin B comprises a group of lysosomal cysteine proteases belonging to the Papain family; it has an intracellular function in the process of protein catabolism, antigen processing in the immune response, and Alzheimer’s disease. In cancers, cathepsin B interferes with autophagy and intracellular catabolism, and breaks down extracellular matrix, decreases protease inhibitors expression, and ultimately helps to accelerate metastasis, tumor malignancy, and reduce immune resistance. Methods: In this study, the 3D structure of cathepsin B was constructed using modeler and Iterative Threading ASSEmbly Refinement (I-TASSER), based on similarity to the crystallographic model of procathepsin B (1PBH). Then, the predicted cathepsin B model was evaluated using PROCHECK and PROSA for quality and reliability. Molecular studies suggested that the amino acids cysteine 108, histidine 189, and histidine 190 form the envelope of the active site of cathepsin B. The docking studies of cathepsin B was performed with protease inhibitors cystatin C, E-64 and leupeptin. Results: The lowest binding energy was related to the cathepsin B-E-64 complex. Accordingly, it was found that E64 interacts with the amino acid cysteine 108 of the active site of cathepsin B. Leupeptin made 2 hydrogen bonds with cathepsin B, but none with the active site of cathepsin amino acids. Cystatin C established a hydrogen bond with the arginine 18 of cathepsin B and made electrostatic bonds with aspartate 148 of cathepsin B. Conclusion: Therefore, the bioinformatics and docking studies of cathepsin B with its inhibitors could be used as reliable identification, treatment, and alternative methods for selecting the inhibitors and controllers of cancer progression.

MPLA-coated hepatitis B virus surface antigen (HBsAg) nanocapsules induce vigorous T cell responses in cord blood derived human T cells

2016 ◽  
Vol 12 (8) ◽  
pp. 2383-2394 ◽  
Author(s):  
Anette Pietrzak-Nguyen ◽  
Keti Piradashvili ◽  
Michael Fichter ◽  
Leah Pretsch ◽  
Fred Zepp ◽  
...  
Keyword(s):  
T Cells ◽  
Hepatitis B Virus ◽  
T Cell ◽  
Hepatitis B ◽  
Cord Blood ◽  
Surface Antigen ◽  
Virus Surface ◽  
Cell Responses ◽  
Human T Cells ◽  
B Virus

scholarly journals Bee venom processes human skin lipids for presentation by CD1a

2015 ◽  
Vol 212 (2) ◽  
pp. 149-163 ◽  
Author(s):  
Elvire A. Bourgeois ◽  
Sumithra Subramaniam ◽  
Tan-Yun Cheng ◽  
Annemieke De Jong ◽  
Emilie Layre ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Human Skin ◽  
Skin Barrier ◽  
Bee Venom ◽  
Host Immune Responses ◽  
Cell Responses ◽  
Human T Cells ◽  
Patient Studies

Venoms frequently co-opt host immune responses, so study of their mode of action can provide insight into novel inflammatory pathways. Using bee and wasp venom responses as a model system, we investigated whether venoms contain CD1-presented antigens. Here, we show that venoms activate human T cells via CD1a proteins. Whereas CD1 proteins typically present lipids, chromatographic separation of venoms unexpectedly showed that stimulatory factors partition into protein-containing fractions. This finding was explained by demonstrating that bee venom–derived phospholipase A2 (PLA2) activates T cells through generation of small neoantigens, such as free fatty acids and lysophospholipids, from common phosphodiacylglycerides. Patient studies showed that injected PLA2 generates lysophospholipids within human skin in vivo, and polyclonal T cell responses are dependent on CD1a protein and PLA2. These findings support a previously unknown skin immune response based on T cell recognition of CD1a proteins and lipid neoantigen generated in vivo by phospholipases. The findings have implications for skin barrier sensing by T cells and mechanisms underlying phospholipase-dependent inflammatory skin disease.

scholarly journals Cross-presenting human    T cells induce robust CD8+    T cell responses

2009 ◽  
Vol 106 (7) ◽  
pp. 2307-2312 ◽  
Author(s):  
M. Brandes ◽  
K. Willimann ◽  
G. Bioley ◽  
N. Levy ◽  
M. Eberl ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Human T Cells

scholarly journals Human T cells employ conserved AU-rich elements to fine-tune IFN-γ production

2019 ◽  
Author(s):  
Julian J. Freen-van Heeren ◽  
Branka Popović ◽  
Aurélie Guislain ◽  
Monika C. Wolkers
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Activated T Cells ◽  
Cell Responses ◽  
Human T Cells ◽  
Engineered T Cells ◽  
Ifn Γ ◽  
Post Transcriptional Regulation ◽  
Fine Tune

ABSTRACTLong-lasting CD8+ T cell responses are critical in combatting infections and tumors. The pro-inflammatory cytokine IFN-γ is a key effector molecule herein. We recently showed that in murine T cells, the production of IFN-γ is tightly regulated through AU-rich elements (AREs) that are located in the 3’ Untranslated Region (UTR). Loss of AREs resulted in prolonged cytokine production in activated T cells and boosted anti-tumoral T cell responses. Here, we investigated whether these findings can be translated to primary human T cells. Utilizing CRISPR-Cas9 technology, we deleted the ARE region from the IFNG 3’UTR in peripheral blood-derived human T cells. Loss of AREs stabilized the IFNG mRNA in T cells and supported a higher proportion of sustained IFN-γ protein-producing T cells. Importantly, this was also true for tumor antigen-specific T cells. MART-1 TCR engineered T cells that were gene-edited for ARE-deletion showed increased percentages of IFN-γ producing MART-1-specific ARE-Del T cells in response to MART-1 expressing tumor cells. Combined, our study reveals that ARE-mediated post-transcriptional regulation is highly conserved between murine and human T cells. Furthermore, generating antigen-specific ARE-Del T cells is feasible, a feature that could potentially be exploited for therapeutical purposes.

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