scholarly journals Bordetella pertussis Proteins Dominating the Major Histocompatibility Complex Class II-Presented Epitope Repertoire in Human Monocyte-Derived Dendritic Cells

2014 ◽  
Vol 21 (5) ◽  
pp. 641-650 ◽  
Author(s):  
Rachel M. Stenger ◽  
Hugo D. Meiring ◽  
Betsy Kuipers ◽  
Martien Poelen ◽  
Jacqueline A. M. van Gaans-van den Brink ◽  
...  

ABSTRACTKnowledge of naturally processedBordetella pertussis-specific T cell epitopes may help to increase our understanding of the basis of cell-mediated immune mechanisms to control this reemerging pathogen. Here, we elucidate for the first time the dominant major histocompatibility complex (MHC) class II-presentedB. pertussisCD4+T cell epitopes, expressed on human monocyte-derived dendritic cells (MDDC) after the processing of whole bacterial cells by use of a platform of immunoproteomics technology. Pertussis epitopes identified in the context of HLA-DR molecules were derived from two envelope proteins, i.e., putative periplasmic protein (PPP) and putative peptidoglycan-associated lipoprotein (PAL), and from two cytosolic proteins, i.e., 10-kDa chaperonin groES protein (groES) and adenylosuccinate synthetase (ASS). No epitopes were detectable from known virulence factors. CD4+T cell responsiveness in healthy adults against peptide pools representing epitope regions or full proteins confirmed the immunogenicity of PAL, PPP, groES, and ASS. Elevated lymphoproliferative activity to PPP, groES, and ASS in subjects within a year after the diagnosis of symptomatic pertussis suggested immunogenic exposure to these proteins during clinical infection. The PAL-, PPP-, groES-, and ASS-specific responses were associated with secretion of functional Th1 (tumor necrosis factor alpha [TNF-α] and gamma interferon [IFN-γ]) and Th2 (interleukin 5 [IL-5] and IL-13) cytokines. Relative paucity in the naturalB. pertussisepitope display of MDDC, not dominated by epitopes from known protective antigens, can interfere with the effectiveness of immune recognition ofB. pertussis. A more complete understanding of hallmarks inB. pertussis-specific immunity may advance the design of novel immunological assays and prevention strategies.

1998 ◽  
Vol 188 (5) ◽  
pp. 819-831 ◽  
Author(s):  
Danielle Lankar ◽  
Volker Briken ◽  
Kristin Adler ◽  
Peter Weiser ◽  
Sylvanie Cassard ◽  
...  

Stimulation of CD4+ helper T lymphocytes by antigen-presenting cells requires the degradation of exogenous antigens into antigenic peptides which associate with major histocompatibility complex (MHC) class II molecules in endosomal or lysosomal compartments. B lymphocytes mediate efficient antigen presentation first by capturing soluble antigens through clonally distributed antigen receptors (BCRs), composed of membrane immunoglobulin (Ig) associated with Ig-α/Ig-β heterodimers which, second, target antigens to MHC class II–containing compartments. We report that antigen internalization and antigen targeting through the BCR or its Ig-α–associated subunit to newly synthesized class II lead to the presentation of a large spectrum of T cell epitopes, including some cryptic T cell epitopes. To further characterize the intracellular mechanisms of BCR-mediated antigen presentation, we used two complementary experimental approaches: mutational analysis of the Ig-α cytoplasmic tail, and overexpression in B cells of dominant negative syk mutants. Thus, we found that the syk tyrosine kinase, an effector of the BCR signal transduction pathway, is involved in the presentation of peptide– MHC class II complexes through antigen targeting by BCR subunits.


1997 ◽  
Vol 186 (8) ◽  
pp. 1223-1232 ◽  
Author(s):  
Thomas Brocker

Thymic T cell development is controlled by T cell receptor (TCR)–major histocompatibility complex (MHC) interactions, whereas a further dependence of peripheral mature T cells on TCR–MHC contact has not been described so far. To study this question, CD4 T cell survival was surveyed in mice lacking MHC class II expression and in mice expressing MHC class II exclusively on dendritic cells. Since neither of these mice positively select CD4 T cells in the thymus, they were grafted with MHC class II–positive embryonic thymic tissue, which had been depleted of bone marrow derived cells. Although the thymus grafts in both hosts were repopulated with host origin thymocytes of identical phenotype and numbers, an accumulation of CD4+ T cells in peripheral lymphoid organs could only be observed in mice expressing MHC class II on dendritic cells, but not in mice that were completely MHC class II deficient. As assessed by histology, the accumulating peripheral CD4 T cells were found to be in close contact with MHC class II+ dendritic cells, suggesting that CD4 T cells need peripheral MHC class II expression for survival and that class II+ dendritic cells might play an important role for the longevity of CD4 T cells.


2000 ◽  
Vol 68 (1) ◽  
pp. 247-256 ◽  
Author(s):  
Radim Osička ◽  
Adriana Osičková ◽  
Tümay Basar ◽  
Pierre Guermonprez ◽  
Marie Rojas ◽  
...  

ABSTRACT Bordetella pertussis adenylate cyclase (AC) toxin-hemolysin (ACT-Hly) can penetrate a variety of eukaryotic cells. Recombinant AC toxoids have therefore been recently used for delivery of CD8+ T-cell epitopes into antigen-presenting cells in vivo and for induction of protective antiviral, as well as therapeutic antitumor cytotoxic T-cell responses. We have explored the carrier potential of the ACT molecule by insertional mutagenesis scanning for new permissive sites, at which integration of two- to nine-residue-long peptides does not interfere with membrane interaction and translocation of ACT. A model CD8+ T-cell epitope of ovalbumin was incorporated at 10 of these permissive sites along the toxin molecule, and the capacity of ACT constructs to penetrate into cell cytosol and deliver the epitope into the major histocompatibility complex (MHC) class I antigen processing and presentation pathway was examined. While all six constructs bearing the epitope within the Hly portion of ACT failed to deliver the epitope to the MHC class I molecules, all four toxoids with inserts within different permissive sites in the AC domain efficiently delivered the epitope into this cytosolic pathway, giving rise to stimulation of a specific CD8+ T-cell hybridoma. The results suggest that, in contrast to the AC domain, the hemolysin moiety of ACT does not reach the cytosolic entry of the MHC class I pathway.


1997 ◽  
Vol 185 (6) ◽  
pp. 1013-1022 ◽  
Author(s):  
Leonard C. Harrison ◽  
Margo C. Honeyman ◽  
Sylvie Trembleau ◽  
Silvia Gregori ◽  
Fabio Gallazzi ◽  
...  

The class II major histocompatibility complex molecule I-Ag7 is strongly linked to the development of spontaneous insulin-dependent diabetes mellitus (IDDM) in non obese diabetic mice and to the induction of experimental allergic encephalomyelitis in Biozzi AB/H mice. Structurally, it resembles the HLA-DQ molecules associated with human IDDM, in having a non-Asp residue at position 57 in its β chain. To identify the requirements for peptide binding to I-Ag7 and thereby potentially pathogenic T cell epitopes, we analyzed a known I-Ag7-restricted T cell epitope, hen egg white lysozyme (HEL) amino acids 9–27. NH2- and COOH-terminal truncations demonstrated that the minimal epitope for activation of the T cell hybridoma 2D12.1 was M12-R21 and the minimum sequence for direct binding to purified I-Ag7 M12-Y20/ K13-R21. Alanine (A) scanning revealed two primary anchors for binding at relative positions (p) 6 (L) and 9 (Y) in the HEL epitope. The critical role of both anchors was demonstrated by incorporating L and Y in poly(A) backbones at the same relative positions as in the HEL epitope. Well-tolerated, weakly tolerated, and nontolerated residues were identified by analyzing the binding of peptides containing multiple substitutions at individual positions. Optimally, p6 was a large, hydrophobic residue (L, I, V, M), whereas p9 was aromatic and hydrophobic (Y or F) or positively charged (K, R). Specific residues were not tolerated at these and some other positions. A motif for binding to I-Ag7 deduced from analysis of the model HEL epitope was present in 27/30 (90%) of peptides reported to be I-Ag7–restricted T cell epitopes or eluted from I-Ag7. Scanning a set of overlapping peptides encompassing human proinsulin revealed the motif in 6/6 good binders (sensitivity = 100%) and 4/13 weak or non-binders (specificity = 70%). This motif should facilitate identification of autoantigenic epitopes relevant to the pathogenesis and immunotherapy of IDDM.


Author(s):  
Wahiba Ezzemani ◽  
Marc P. Windisch ◽  
Anass Kettani ◽  
Haya Altawalah ◽  
Jalal Nourlil ◽  
...  

Background: Globally, the recent outbreak of Zika virus (ZIKV) in Brazil, Asia Pacific, and other countries highlighted the unmet medical needs. Currently, there are neither effective vaccines nor therapeutics available to prevent or treat ZIKV infection. Objective: In this study, we aimed to design an epitope-based vaccine for ZIKV using an in silico approach to predict and analyze B- and T-cell epitopes. Methods: The prediction of the most antigenic epitopes has targeted the capsid and the envelope proteins as well as nonstructural proteins NS5 and NS3 using immune-informatics tools PROTPARAM, CFSSP, PSIPRED, and Vaxijen v2.0. B and T-cell epitopes were predicted using ABCpred, IEDB, TepiTool, and their toxicity were evaluated using ToxinPred. The 3-dimensional epitope structures were generated by PEP-FOLD. Energy minimization was performed using Swiss-Pdb Viewer, and molecular docking was conducted using PatchDock and FireDock server. Results: As a result, we predicted 307 epitopes of MHCI (major histocompatibility complex class I) and 102 epitopes of MHCII (major histocompatibility complex class II). Based on immunogenicity and antigenicity scores, we identified the four most antigenic MHC I epitopes: MVLAILAFLR (HLA-A*68 :01), ETLHGTVTV (HLA-A*68 :02), DENHPYRTW (HLA-B*44 :02),QEGVFHTMW (HLA-B*44 :03) and TASGRVIEEW (HLA-B*58:01), and MHC II epitopes: IIKKFKKDLAAMLRI (HLA-DRB3*02 :02), ENSKMMLELDPPFGD (HLA-DRB3*01:01), HAETWFFDENHPYRT (HLA-DRB3*01:01), TDGVYRVMTRRLLGS (HLA-DRB1*11 :01), and DGCWYGMEIRPRKEP (HLA-DRB5*01:01). Conclusion : This study provides novel potential B cell and T cell epitopes to fight Zika virus infections and may prompt further development of vaccines against ZIKV and other emerging infectious diseases. However, further investigations for protective immune response by in vitro and in vivo studies to ratify the immunogenicity, safety of the predicted structure, and ultimately the vaccine properties to prevent ZIKV infections are warranted.


2003 ◽  
Vol 14 (8) ◽  
pp. 3378-3388 ◽  
Author(s):  
Nicole N. van der Wel ◽  
Masahiko Sugita ◽  
Donna M. Fluitsma ◽  
Xaiochun Cao ◽  
Gerty Schreibelt ◽  
...  

The maturation of dendritic cells is accompanied by the redistribution of major histocompatibility complex (MHC) class II molecules from the lysosomal MHC class II compartment to the plasma membrane to mediate presentation of peptide antigens. Besides MHC molecules, dendritic cells also express CD1 molecules that mediate presentation of lipid antigens. Herein, we show that in human monocyte-derived dendritic cells, unlike MHC class II, the steady-state distribution of lysosomal CD1b and CD1c isoforms was unperturbed in response to lipopolysaccharide-induced maturation. However, the lysosomes in these cells underwent a dramatic reorganization into electron dense tubules with altered lysosomal protein composition. These structures matured into novel and morphologically unique compartments, here termed mature dendritic cell lysosomes (MDL). Furthermore, we show that upon activation mature dendritic cells do not lose their ability of efficient clathrin-mediated endocytosis as demonstrated for CD1b and transferrin receptor molecules. Thus, the constitutive endocytosis of CD1b molecules and the differential sorting of MHC class II from lysosomes separate peptide- and lipid antigen-presenting molecules during dendritic cell maturation.


2010 ◽  
Vol 78 (7) ◽  
pp. 2956-2965 ◽  
Author(s):  
Marlena M. Westcott ◽  
Curtis J. Henry ◽  
Jacqueline E. Amis ◽  
Elizabeth M. Hiltbold

ABSTRACT Dendritic cells (DC) provide a suboptimal niche for the growth of Listeria monocytogenes, a facultative intracellular bacterial pathogen of immunocompromised and pregnant hosts. This is due in part to a failure of large numbers of bacteria to escape to the cytosol, an essential step in the intracellular life cycle that is mediated by listeriolysin O (LLO). Here, we demonstrate that wild-type bacteria that failed to enter the cytosol of bone marrow-derived DC were retained in a LAMP2+ compartment. An isogenic L. monocytogenes strain that produces an LLO protein with reduced pore-forming activity had a severe escape and growth phenotype in DC. Few mutant bacteria entered the cytosol in the first 2 h and were instead found in LAMP2+, major histocompatibility complex class II+ (MHC-II+) H2-DM vesicles characteristic of MHC-II antigen loading compartments (MIIC). In contrast, the mutant had a minor phenotype in bone marrow-derived macrophages (BMM) despite the reduced LLO activity. In the first hour, DC phagosomes acidified to a pH that was, on average, half a point higher than that of BMM phagosomes. Unlike BMM, L. monocytogenes growth in DC was minimal after 5 h, and consequently, DC remained viable and matured late in infection. Taken together, the data are consistent with a model in which phagosomal maturation events associated with the acquisition of MHC-II molecules present a suboptimal environment for L. monocytogenes escape to the DC cytosol, possibly by limiting the activity of LLO. This, in combination with an undefined mechanism that controls bacterial growth late in infection, promotes DC survival during the critical maturation response.


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