scholarly journals Vβ1+ Jβ1.1+/Vα2+ Jα49+ CD4+ T Cells Mediate Resistance against Infection with Blastomyces dermatitidis

2006 ◽  
Vol 75 (1) ◽  
pp. 193-200 ◽  
Author(s):  
Marcel Wüthrich ◽  
Hanna I. Filutowicz ◽  
Holly L. Allen ◽  
George S. Deepe ◽  
Bruce S. Klein
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Receptor ◽  
Blastomyces Dermatitidis ◽  
T Cell Clones ◽  
Interleukin 5 ◽  
Protective Antigens ◽  
Cell Clones ◽  
A Cell ◽  
Ifn Γ

ABSTRACT Immunization with a cell wall/membrane (CW/M) and yeast cytosol extract (YCE) crude antigen from Blastomyces dermatitidis confers T-cell-mediated resistance against lethal experimental infection in mice. We isolated and characterized T cells that recognize components of these protective antigens and mediate protection. CD4+ T-cell clones elicited with CW/M antigen adoptively transferred protective immunity when they expressed a Vα2+ Jα49+/Vβ1+ Jβ1.1+ heterodimeric T-cell receptor (TCR) and produced high levels of gamma interferon (IFN-γ). In contrast, Vβ8.1/8.2+ CD4+ T-cell clones that were reactive against CW/M and YCE antigens and produced little or no IFN-γ either failed to mediate protection or exacerbated the infection depending on the level of interleukin-5 expression. Thus, the outgrowth of protective T-cell clones against immunodominant antigens of B. dermatitidis is biased by a combination of the TCR repertoire and Th1 cytokine production.

scholarly journals An Ex Vivo Study of T Lymphocytes Recovered from the Lungs of I/St Mice Infected with and Susceptible toMycobacterium tuberculosis

1998 ◽  
Vol 66 (10) ◽  
pp. 4981-4988 ◽  
Author(s):  
Irina Lyadova ◽  
Vladimir Yeremeev ◽  
Konstantin Majorov ◽  
Boris Nikonenko ◽  
Sergei Khaidukov ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Antimycobacterial Activity ◽  
Enzymatic Digestion ◽  
Interleukin 4 ◽  
T Cell Clones ◽  
Cell Clones ◽  
Ifn Γ

ABSTRACT I/St mice, previously characterized as susceptible toMycobacterium tuberculosis H37Rv, were given 103 or 105 CFU intravenously. At two time points postinoculation, the cell suspensions that resulted from enzymatic digestion of lungs were enumerated and further characterized phenotypically and functionally. Regarding the T-cell populations recovered at 2 and 5 weeks postinfection, two main results were obtained: (i) the population of CD44− CD45RB+cells disappeared within 2 weeks postinfection, while the number of CD44+ CD45RB−/low cells slowly increased between weeks 2 and 5; (ii) when cocultured with irradiated syngeneic splenocytes, these lung T cells proliferated in the presence of H37Rv sonicate. Using H37Rv sonicate and irradiated syngeneic splenocytes to reactivate lung T cells, we selected five CD3+CD4+ CD8− T-cell clones. In addition to the H37Rv sonicate, the five clones react to both a short-term culture filtrate and an affinity-purified 15- to 18-kDa mycobacterial molecule as assessed by the proliferative assay. However, there was a clear difference between T-cell clones with respect to cytokine (gamma interferon [IFN-γ] and interleukin-4 [IL-4] and IL-10) profiles: besides one Th1-like (IFN-γ+ IL-4−) clone and one Th0-like (IFN-γ+ IL-4+IL-10+) clone, three clones produced predominantly IL-10, with only marginal or no IL-4 and IFN-γ responses. Inhibition of mycobacterial growth by macrophages in the presence of T cells was studied in a coculture in vitro system. It was found that the capacity to enhance antimycobacterial activity of macrophages fully correlated with INF-γ production by individual T-cell clones following genetically restricted recognition of infected macrophages. The possible functional significance of cytokine diversity among T-cell clones is discussed.

scholarly journals Diversification of the antigen-specific T cell receptor repertoire after varicella zoster vaccination

2016 ◽  
Vol 8 (332) ◽  
pp. 332ra46-332ra46 ◽  
Author(s):  
Qian Qi ◽  
Mary M. Cavanagh ◽  
Sabine Le Saux ◽  
Hong NamKoong ◽  
Chulwoo Kim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Chronic Infection ◽  
Cell Receptor ◽  
Control Mechanisms ◽  
Cell Repertoire ◽  
T Cell Clones ◽  
Varicella Zoster ◽  
Cell Clones

Diversity and size of the antigen-specific T cell receptor (TCR) repertoire are two critical determinants for successful control of chronic infection. Varicella zoster virus (VZV) that establishes latency during childhood can escape control mechanisms, in particular with increasing age. We examined the TCR diversity of VZV-reactive CD4 T cells in individuals older than 50 years by studying three identical twin pairs and three unrelated individuals before and after vaccination with live attenuated VZV. Although all individuals had a small number of dominant T cell clones, the breadth of the VZV-specific repertoire differed markedly. A genetic influence was seen for the sharing of individual TCR sequences from antigen-reactive cells but not for repertoire richness or the selection of dominant clones. VZV vaccination favored the expansion of infrequent VZV antigen–reactive TCRs, including those from naïve T cells with lesser boosting of dominant T cell clones. Thus, vaccination does not reinforce the in vivo selection that occurred during chronic infection but leads to a diversification of the VZV-reactive T cell repertoire. However, a single-booster immunization seems insufficient to establish new clonal dominance. Our results suggest that repertoire analysis of antigen-specific TCRs can be an important readout to assess whether a vaccination was able to generate memory cells in clonal sizes that are necessary for immune protection.

scholarly journals Self-reactive human CD4 T cell clones form unusual immunological synapses

2012 ◽  
Vol 209 (2) ◽  
pp. 335-352 ◽  
Author(s):  
David A. Schubert ◽  
Susana Gordo ◽  
Joseph J. Sabatino ◽  
Santosh Vardhana ◽  
Etienne Gagnon ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Receptor ◽  
Tcr Signaling ◽  
T Cell Clones ◽  
Cell Clones ◽  
Immunological Synapses ◽  
High Degree ◽  
Self Antigen

Recognition of self–peptide-MHC (pMHC) complexes by CD4 T cells plays an important role in the pathogenesis of many autoimmune diseases. We analyzed formation of immunological synapses (IS) in self-reactive T cell clones from patients with multiple sclerosis and type 1 diabetes. All self-reactive T cells contained a large number of phosphorylated T cell receptor (TCR) microclusters, indicative of active TCR signaling. However, they showed little or no visible pMHC accumulation or transport of TCR–pMHC complexes into a central supramolecular activation cluster (cSMAC). In contrast, influenza-specific T cells accumulated large quantities of pMHC complexes in microclusters and a cSMAC, even when presented with 100-fold lower pMHC densities. The self-reactive T cells also maintained a high degree of motility, again in sharp contrast to virus-specific T cells. 2D affinity measurements of three of these self-reactive T cell clones demonstrated a normal off-rate but a slow on-rate of TCR binding to pMHC. These unusual IS features may facilitate escape from negative selection by self-reactive T cells encountering very small amounts of self-antigen in the thymus. However, these same features may enable acquisition of effector functions by self-reactive T cells encountering large amounts of self-antigen in the target organ of the autoimmune disease.

Diversity of HLA Class I and Class II Restricted Minor Histocompatibility Antigens in Graft-Versus-Leukemia Reactivity.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4084-4084
Author(s):  
Marieke Griffioen ◽  
M. Willy Honders ◽  
Anita N. Stumpf ◽  
Edith D. van der Meijden ◽  
Cornelis A.M. van Bergen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hematopoietic Cells ◽  
Cd4 T Cell ◽  
Cell Recognition ◽  
T Cell Clones ◽  
T Cell Recognition ◽  
Cell Clones ◽  
T Cell Clone ◽  
Ifn Γ

Abstract Abstract 4084 Poster Board III-1019 Donor lymphocyte infusion (DLI) can be an effective cellular immunotherapy for patients with hematological malignancies after HLA-matched allogeneic stem cell transplantation (alloSCT). The effect of DLI is mediated by donor derived T-cells recognizing minor histocompatibility antigens (mHags) encoded by single nucleotide polymorphisms (SNPs) on malignant cells of the recipient. Donor T-cells may also induce Graft-versus-Host Disease (GvHD) when directed against mHags with broad expression on non-malignant tissues. The aim of this study was to investigate the specificity and diversity of mHags recognized by T-cells in Graft-versus-Leukemia (GvL) reactivity. Activated (HLA-DR+) CD8+ and CD4+ T-cell clones were isolated from a patient successfully treated with DLI for relapsed chronic myeloid leukemia (CML) more than one year after HLA-matched alloSCT. GvL reactivity in this patient was accompanied with mild GvHD of the skin. Isolated T-cell clones were shown to recognize 13 different mHags. CD8+ T-cell clones were specific for HA-1 and HA-2 in HLA-A*0201, one unknown mHag in B*0801 and 4 unknown mHags in B*4001. CD4+ T-cell clones were specific for one unknown mHag in HLA-DQ and 5 unknown mHags in DR. By screening plasmid (class I) and bacteria (class II) cDNA libraries, we identified a mHag in HLA-DQ encoded by the PI4K2B gene (Griffioen et al., PNAS 2008), 4 mHags in HLA-DR encoded by the PTK2B, MR-1, LY75 and MTHFD1 genes (Stumpf et al., Blood 2009) and a mHag in B*4001 encoded by the TRIP10 gene. For the 3 T cell clones recognizing unknown mHags in B*4001, we performed Whole Genome Assocation scanning (WGAs). A panel of 60 EBV-LCL was retrovirally-transduced with B*4001 and tested for T-cell recognition. In parallel, genomic DNA was isolated and more than one million single nucleotide polymorphisms (SNPs) were determined by the Illumina beadchip array. Statistical analysis revealed significant association between T-cell recognition of EBV-LCL and the presence of coding SNPs in the SON DNA-binding protein and SWAP-70 genes. To get more insight into the role and potential use of the mHags in GvL reactivity and GvHD, all T-cell clones were analyzed in detail for reactivity against hematopoietic and non-hematopoietic cells. Hematopoietic cells included peripheral blood cells (monocytes, B-cells and T-cells), professional antigen presenting cells (APC) and leukemic cells (CML, ALL and AML). All CD8+ T-cell clones recognized (subsets of) peripheral blood cells as well as CML cells, except for the T-cell clone for TRIP10. Recognition of (subsets of) peripheral blood cells was also observed for all CD4+ T-cell clones, but CML cells were differentially recognized. CML cells were strongly recognized by the T-cell clones for MTHFD1 and the unknown mHag in HLA-DR, whereas no or low reactivity was observed for all other CD4+ T-cell clones. All CD8+ and CD4+ T-cell clones strongly recognized professional APC, including monocyte-derived dendritic cells and in vitro differentiated CML cells with APC phenotype. All T-cell clones were also capable of recognizing AML and ALL, except for the T-cell clone for TRIP10, which showed restricted recognition of AML-M4 and -M5 of monocytic origin. As non-hematopoietic cells, patient-derived fibroblasts were cultured with and without IFN-γ and tested for T-cell recognition. In the absence of IFN-γ, all T-cell clones failed to recognize fibroblasts, except for the T-cell clone for the unknown mHag in B*0801. After treatment with IFN-γ, additional reactivity was observed for the T-cell clones for SON DNA-binding protein and the unknown mHag in B*4001. Our data showed the specificity and diversity of mHags recognized by T-cells induced in a patient successfully treated with DLI for relapsed CML. The T-cell response was directed against 13 different mHags, of which 10 mHags in HLA class I and class II have now been identified by different techniques. Detailed analysis of T-cell recognition of hematopoietic and non-hematopoietic cells provides evidence that the mHags played different roles in the onset and execution of GvL and GvHD. Moreover, only one of the 10 identified mHags was expressed on fibroblasts after treatment with IFN-γ, indicating the characterization of mHags with potential relevance for T-cell based immunotherapy. Disclosures: No relevant conflicts of interest to declare.

ROR1 Specific T Cell Clones from Healthy Individuals Show Common T Cell Receptor Motifs

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3364-3364
Author(s):  
Falk Heidenreich ◽  
Elke Ruecker-Braun ◽  
Juliane S. Stickel ◽  
Anne Eugster ◽  
Denise Kühn ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
T Cell Receptor ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cell Receptor ◽  
T Cell Clones ◽  
Cell Clones

Abstract Background Immunotherapy for CLL with new antibodies or T-cells with modified TCR relies on attractive targets. ROR1 is such a promising target since it is highly overexpressed in CLL. Chimeric antigen receptor engineered T cells and antibodies directed against the extracellular part of ROR1 have already been developed and tested in vitro or in animal models, but still there is no MHC-class I presented peptide serving as target structure for CD8+ T cells (with or without a genetically modified T cell receptor) available. Aim The aim of this study was (1) to identify an immunogenic MHC-class I presented ROR1 peptide, (2) to generate respective ROR1 peptide specific CD8+ T cell clones, and (3) to analyze the nucleotide sequence of the CDR3 region of the expressed alpha and beta T cell receptor chain. Results In mass spectrometric-based analyses of the HLA-ligandome a HLA-B*07 presented ROR1 peptide was identified in primary CLL cells of two patients. Six T cell clones specific for this particular ROR1-peptide were generated from single CD8+ T cells from 2 healthy individuals with 3 T cell clones generated from each donor. Functionality and specificity of those T cell clones were tested in cytotoxicity assays. All 6 dextramer+ CD8+ T cell clones lysed peptide loaded and HLA-B*07+ transduced K562 cells (kindly provided by Lorenz Jahn, [Jahn et al., Blood, 2015 Feb 5;125(6):949-58]). Two selected clones (XD8 and XB6) were tested for their cytotoxic potential against 2 ROR1+ HLA-B*07+ tumor cell lines (with the ROR1 peptide identified by mass spectrometry for both of them) and against 2 primary CLL cell samples. Tested clones showed a significant lysis of the respective target cells. CDR3 regions of the alpha and beta T cell receptor chain were sequenced on a single cell level. The CDR3 alpha region from each of the 3 ROR1 specific T cell clones from donor A showed some similarities to T cell clones derived from donor B (Table 1). Conclusion For the first time a MHC-class I presented ROR1 peptide antigen is reported. ROR1 positive CLL cells can be targeted by specific HLA-B*07 restricted CTLs. Respective CD8+ T cell clones with anti-leukemic activity from 2 donors share some amino acid motifs of the CDR3 alpha and beta regions. In conclusion, this information provides the possibility of generating ROR1 specific CD8+ T cells with genetically modified T cell receptors for immunotherapy and for tracking those cells after administration with next generation sequencing in peripheral blood samples of patients. Furthermore, data suggest the existence of public TCR motifs in leukemia antigen specific CTLs, which needs to be proven in follow-up experiments with larger cohorts of donors and patients. Finally, the presented strategy to identify leukemia specific peptide antigens for CD8+ T cells might be an attractive method for similar projects. Table 1 Amino acid sequences of CDR3 alpha and beta regions of the TCR of ROR1 specific CD8+ T cell clones. When comparing two clones, matching amino acids are depicted in red. The aromatic amino acids phenylalanine (F) and tyrosine (Y) are shown in blue when situated at the same position. Gaps inserted during the sequence alignment process are indicated by a hyphen '-'. Table 1. Amino acid sequences of CDR3 alpha and beta regions of the TCR of ROR1 specific CD8+ T cell clones. When comparing two clones, matching amino acids are depicted in red. The aromatic amino acids phenylalanine (F) and tyrosine (Y) are shown in blue when situated at the same position. Gaps inserted during the sequence alignment process are indicated by a hyphen '-'. Disclosures Middeke: Sanofi: Honoraria. Schetelig:Sanofi: Honoraria.

scholarly journals Analysis of T cell receptor beta chains in Lewis rats with experimental allergic encephalomyelitis: conserved complementarity determining region 3.

1991 ◽  
Vol 174 (6) ◽  
pp. 1467-1476 ◽  
Author(s):  
D P Gold ◽  
H Offner ◽  
D Sun ◽  
S Wiley ◽  
A A Vandenbark ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cell Receptor ◽  
Fetal Life ◽  
Allergic Encephalomyelitis ◽  
T Cell Clones ◽  
Lewis Rats ◽  
Cell Clones ◽  
Complementarity Determining Region

This study explores the usage of T cell antigen receptor (TCR) beta chain elements in Lewis rats with experimentally induced allergic encephalomyelitis (EAE). TCRs from 15 different T cell clones and hybridomas derived from animals immunized with myelin basic protein (MBP), and all having specificity for the 21-mer encephalitogenic fragment MBP 68-88, utilized V beta 8.2. In addition, there was a marked conservation of the first two amino acid residues of the junctional complementarity determining region 3 (CDR3) associated with the V beta 8.2 receptors. 12 of 15 contained an aspartic acid followed by serine regardless of the associated J beta element. At the nucleotide level, this conservation of AspSer residues was accomplished with few or no nongermline-encoded nucleotide (N) additions. A similar pattern of AspSer usage and N region nucleotide additions was observed in a number of V beta 8.2 isolates derived from MBP-immunized lymph nodes. In contrast, V beta 8.2 polymerase chain reaction amplified isolates from Lewis T cells activated with concanavalin A or from lymph nodes of complete Freund's adjuvant-immunized animals showed no AspSer utilization (0/31) in the CDR3, and four to nine N region nucleotide additions. We conclude from this finding that AspSer residues in the CDR3, limited N region nucleotide additions, along with V beta 8.2 sequences, contribute to TCR specificity for MBP 68-88. This raises the possibility that encephalitogenic, disease-causing T cells either represent a population that derives from late fetal life or alternatively, that they are rare cells with this particular TCR phenotype contributed to the T cell pool throughout adulthood and are selected by antigen. In either case, the CDR3 AspSer sequences as well as V beta 8.2 sequences are candidates for the receptor target structures recognized by regulator T cells in recovery from and resistance to active EAE. In this respect, a preliminary analysis of TCR utilization in three T cell clones specific for MBP 68-88 isolated from animals recovered from active EAE indicates that while all three use V beta 8.2, only one contains AspSer in the CDR3.

scholarly journals Functional Characterization and Modulation of Cytokine Production by CD8+ T Cells from Human Immunodeficiency Virus-Infected Individuals

Blood ◽  
1997 ◽  
Vol 89 (10) ◽  
pp. 3672-3681 ◽  
Author(s):  
Enrico Maggi ◽  
Roberto Manetti ◽  
Francesco Annunziato ◽  
Lorenzo Cosmi ◽  
Maria Grazia Giudizi ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Clones ◽  
Cell Clones ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Hiv Seropositive

CD8+ T-cell clones were generated from peripheral blood mononuclear cells (PBMC) of three human immunodeficiency virus (HIV)-seronegative individuals and six HIV-seropositive individuals and assessed for their cytokine secretion profile, cytolytic potential, and chemokine production. While the great majority of CD8+ T-cell clones generated from HIV-seronegative individuals produced interferon (IFN)-γ, but not interleukin-4 (IL-4), that is a type 1 cytotoxic (Tc1) profile, high numbers of CD8+ T-cell clones generated from HIV-seropositive individuals produced IL-4 in addition to IFN-γ or IL-4 alone, thus showing a type 0 cytotoxic (Tc0)- or a type 2 cytotoxic (Tc2) profile, respectively. Tc0/Tc2 cells displayed lower cytolytic activity than Tc1 cells, including a reduced ability to lyse autologous targets pulsed with HIV or HIV peptides. By contrast, the production of chemokines RANTES and macrophage inflammatory protein-1α was comparable in Tc1, Tc0, and Tc2 clones irrespective of whether they were derived from HIV-seronegative or HIV-seropositive individuals. When CD8+ T-cell clones were generated from PBMC cultures of HIV-seronegative individuals conditioned with IL-4 plus an anti–IL-12 antibody (Ab), a shift towards the Tc0/Tc2-like profile was observed. Conversely, the addition to PBMC cultures of IL-12 plus an anti – IL-4 Ab shifted the differentiation of CD8+ T cells from HIV-infected individuals towards the Tc1-like profile, whereas IL-12 or anti–IL-4 Ab alone had a lower Tc1-promoting effect. Irradiated PBMC from HIV-infected individuals, used as feeder cells, shifted the differentiation of CD8+ T cells from a healthy HIV-seronegative individual towards the Tc0/Tc2-like profile. On the other hand, a shift towards the Tc1-like profile was noted in CD8+ T-cell clones generated from the skin specimens of two HIV-seropositive patients with Kaposi's sarcoma, successfully treated with IFN-α, in comparison to CD8+ clones generated from the same skin areas before treatment. The IFN-α–induced Tc1 shift could be prevented by the incubation of skin-infiltrating CD8+ T cells with IL-4 before cloning. Taken together, these data indicate that both defective production of IL-12 and abnormal IL-4 production in bulk PBMC populations of HIV-infected individuals may contribute to the development of high numbers of CD8+ T-cell clones showing a Tc0/Tc2-like phenotype and reduced cytolytic potential against HIV itself. They also suggest that the cytokine profile of CD8+ T-cell clones can be modulated by cytokines (or anticytokine Ab) both in vitro and in vivo.

scholarly journals Differential Functional Avidity of Dengue Virus-Specific T-Cell Clones for Variant Peptides Representing Heterologous and Previously Encountered Serotypes

2007 ◽  
Vol 81 (18) ◽  
pp. 10081-10091 ◽  
Author(s):  
Allison Imrie ◽  
Janet Meeks ◽  
Alexandra Gurary ◽  
Munkhzul Sukhbataar ◽  
Paul Kitsutani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dengue Virus ◽  
Severe Disease ◽  
T Cell Clones ◽  
Cell Responses ◽  
Cell Clones ◽  
Tnf Α ◽  
Dengue Virus Serotypes ◽  
Ifn Γ

ABSTRACT Proinflammatory cytokines secreted by memory CD8+ and CD4+ T cells are thought to play a direct role in the pathogenesis of dengue virus infection by increasing vascular permeability and thereby inducing the pathophysiologic events associated with dengue hemorrhagic fever and dengue shock syndrome. Severe disease is frequently observed in the setting of secondary infection with heterologous dengue virus serotypes, suggesting a role for cross-reactive memory T cells in the immunopathogenesis of severe disease. We used a large panel of well-characterized dengue virus-specific CD8+ T-cell clones isolated from Pacific Islanders previously infected with dengue virus 1 to examine effector memory function, focusing on a novel dominant HLA-B*5502-restricted NS5329-337 epitope, and assessed T-cell responses to stimulation with variant peptides representing heterologous serotypes. Variant peptides were differentially recognized by dengue virus 1-specific effector CD8+ cytotoxic T lymphocytes (CTL) in a heterogeneous and clone-specific manner, in which cytolytic function and cytokine secretion could be enhanced, diminished, or abrogated compared with cognate peptide stimulation. Dengue virus-specific CTL stimulated with cognate and variant peptides demonstrated a cytokine response hierarchy of gamma IFN (IFN-γ) > tumor necrosis factor alpha (TNF-α) > interleukin-2 (IL-2), and a subset of clones also produced IL-4 and IL-6. Individual clones demonstrated greater avidity for variant peptides representing heterologous serotypes, including serotypes previously encountered by the subject, and IFN-γ and TNF-α secretion was enhanced by stimulation with these heterologous peptides. Altered antiviral T-cell responses in response to stimulation with heterologous dengue virus serotypes have implications for control of virus replication and for disease pathogenesis.

scholarly journals Different Levels of T-Cell Receptor Triggering Induce Distinct Functions in Hepatitis B and Hepatitis C Virus-Specific Human CD4+ T-Cell Clones

2001 ◽  
Vol 75 (17) ◽  
pp. 7803-7810 ◽  
Author(s):  
Helmut M. Diepolder ◽  
Norbert H. Gruener ◽  
J. Tilman Gerlach ◽  
Maria-Christina Jung ◽  
Eddy A. Wierenga ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Specific Antigen ◽  
Cell Receptor ◽  
Receptor Internalization ◽  
Antigen Concentration ◽  
T Cell Clones ◽  
Cell Clones ◽  
Wide Range

ABSTRACT CD4+ T cells play a major role in the host defense against viruses and intracellular microbes. During the natural course of such an infection, specific CD4+ T cells are exposed to a wide range of antigen concentrations depending on the body compartment and the stage of disease. While epitope variants trigger only subsets of T-cell effector functions, the response of virus-specific CD4+ T cells to various concentrations of the wild-type antigen has not been systematically studied. We stimulated hepatitis B virus core- and hepatitis C virus NS3-specific CD4+ T-cell clones which had been isolated from patients with acute hepatitis during viral clearance with a wide range of specific antigen concentrations and determined the phenotypic changes and the induction of T-cell effector functions in relation to T-cell receptor internalization. A low antigen concentration induced the expression of T-cell activation markers and adhesion molecules in CD4+ T-cell clones in the absence of cytokine secretion and proliferation. The expression of CD25, HLA-DR, CD69, and intercellular cell adhesion molecule 1 increased as soon as T-cell receptor internalization became detectable. A 30- to 100-fold-higher antigen concentration, corresponding to the internalization of 20 to 30% of T-cell receptor molecules, however, was required for the induction of proliferation as well as for gamma interferon and interleukin-4 secretion. These data indicate that virus-specific CD4+ T cells can respond to specific antigen in a graded manner depending on the antigen concentration, which may have implications for a coordinate regulation of specific CD4+ T-cell responses.

Functional Characterization of Aspergillus Fumigatus Specific T-Cells Clones.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3223-3223
Author(s):  
Thomas Lehrnbecher ◽  
Ulrike Koehl ◽  
Emmanuel Roilides ◽  
Maria Simitsopoulou ◽  
Mitra Hanisch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Aspergillus Fumigatus ◽  
Functional Characterization ◽  
Cd4 Cells ◽  
Hematopoietic Stem ◽  
T Cell Clones ◽  
Th1 Response ◽  
Cell Clones ◽  
Ifn Γ

Abstract Invasive aspergillosis (IA) remains a major cause of morbidity and mortality in patients with hematological malignancies, in particular in patients who have undergone allogeneic hematopoietic stem cell transplantation (SCT). There is a growing body of evidence that T-cells play an important role in the immunological response to Aspergillus fumigatus. Using the Aspergillus fumigatus antigen extract EC SAB and the IFN-γ secretion assay (Miltenyi Biotec, Germany), we generated Aspergillus fumigatus specific T-cell clones by limiting dilution (n=4). Flow cytometry revealed a cell population of CD3+/CD4+ cells (mean±SEM, 98.2±1.2%). Functional assessment by ICC revealed that an average of 8.7% of these cells (range, 6.6%–18.5%) specifically secreted IFN-γ on stimulation with EC SAB, which supports the TH1 response of the generated cells to Aspergillus fumigatus antigens. The antigenic components of EC SAB are one or more proteins, since the addition of proteinase completely suppressed the stimulating effect of this preparation. The percentage of IFN-γ producing CD3+/CD4+ cells was less than 1% upon activation with antigen extracts from Aspergillus flavus, Aspergillus niger, Alternaria alternata, Mucor racemosus, Penicillium notatum and Candida albicans, indicating that the generated T-cell clones are specific for Aspergillus fumigatus. A strong proliferation of the generated Aspergillus fumigatus specific T-cells was seen after re-stimulation with EC SAB, whereas alloreactivity was reduced compared to CD4+ T-cells of the original fraction. Hyphal damage of Aspergillus fumigatus was assessed by means of an XTT assay. Polymorphonuclear leukocytes (PMNs) showed a similar hyphal damage when tested alone (mean±SEM, 14.2±2.1%), in combination with antigen presenting cells (APCs) (15.1±1.4%), or in combination with Aspergillus fumigatus specific T-cells (15.0±2.0%). A comparable hyphal damage was seen when Aspergillus fumigatus specific T-cells were co-incubated with APCs (14.2±1.7%). In contrast, the combination of APCs and Aspergillus fumigatus specific T-cells with PMNs resulted in a significantly higher hyphal damage compared to all other settings (23.3±2.8%; P<.0001). Interestingly, APCs alone or Aspergillus fumigatus specific T-cells alone showed a weak, but significant capacity to induce hyphal damage (7.4±1.1% and 11.3±1.8%, respectively). Before considering a clinical application, however, further studies need to focus on defining the optimal antigen(s) which reproducibly induce a TH1 response and elicit high antifungal activity, as well as to characterize the subpopulation of patients undergoing allogeneic SCT who ultimately benefit from either a prophylactic or a therapeutic adoptive transfer of Aspergillus fumigatus specific T-cells.

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