Elimination of a Human T-cell Region in Staphylokinase by T-cell Screening and Computer Modeling

SummaryStaphylokinase is a potent highly fibrin-selective thrombolytic agent, but it induces a humoral immune response in most treated patients. Staphylokinase-specific T-lymphocytes can be found in normal healthy individuals, from whom a large panel of staphylokinasespecific T-cells were cloned. The staphylokinase amino acid sequence 71-87 was widely recognized, as it induced proliferation of T-cell clones isolated from 90% of the donors. Computer modeling of this area, threaded as 11-mer peptides within the peptide-binding groove of the major HLA-DR alleles, indicated two putative partially overlapping binding sequences. The region-(71-87)-specific T-cell clones recognized either one or the other minimal peptide, confirming that both sequences could be functional T-cell epitopes. Furthermore, to guide the mutagenesis to eliminate T-cell reactivity, the contribution of each residue to the HLA-DR-anchoring and T-cell receptor exposure was evaluated for both binding motifs. Computer calculations combined with functional assays resulted in the design of staphylokinasevariants, including 2 to 4 amino acid substitutions in the region 71-87. These variants were no longer recognized by the region-(71-87)specific T-cell clones, and importantly no new staphylokinase-variantspecific cellular immune response could be measured.

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Thyrotropin-Receptor and Thyroid Peroxidase-Specific T Cell Clones and Their Cytokine Profile in Autoimmune Thyroid Disease1

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.82.11.4336 ◽

1997 ◽

Vol 82 (11) ◽

pp. 3655-3663

Author(s):

Maria Elena Fisfalen ◽

Ellen M. Palmer ◽

Gijs A. van Seventer ◽

Keyoumars Soltani ◽

Yoshikuni Sawai ◽

...

Keyword(s):

Amino Acid ◽

T Cell ◽

Thyroid Tissue ◽

Cytokine Profile ◽

Thyroid Peroxidase ◽

Amino Acid Residues ◽

T Cell Epitopes ◽

T Cell Clones ◽

Cell Clones ◽

Ifn Γ

We studied the cytokine profile and the immune responses to thyroid antigens of specific T cell clones (TCC) isolated from patients with Hashimoto’s thyroiditis (HT) and Graves’ disease (GD). Antigen-specific TCC were reactive to thyroid peroxidase (TPO), thyroglobulin (Tg) or human recombinant TSH-receptor extracellular domain (TSH-R), and/or their respective peptides. Of the 43 clones derived from HT patients, 65% were reactive to TPO, and 59% of the 32 clones derived from GD patients were reactive to TSH-R. TPO epitopes 100–119 and 625–644 were recognized by 75% of HT-derived clones, whereas TSH-R epitopes 158–176, 207–222, and 343–362/357–376 were recognized by 85% of GD-derived TCC. The TCC were classified according to their cytokine profile into T helper cell (Th)0 [secreting interleukin (IL)-4, IL-5, interferon (IFN)-γ], Th1 (secreting IFN-γ) and Th2 (secreting IL-4 and/or IL-5). Tumor necrosis factor-β and IL-10 were produced by all subsets. The specific TCC were predominantly Th1-like cells in HT, and were Th0- and Th1-like cells in GD. Fifty three percent of Th0 clones were derived from GD patients and were reactive to TSH-R, whereas 50% of Th1 clones were derived from HT patients and were reactive to TPO or Tg. Most Th2 clones (82%) were reactive to TPO and were established from peripheral blood. All these clones produced IL-5, and 64% produced IL-4 and IL-10. Interestingly, IFN-γ was highly produced by TPO- or Tg-specific clones established from HT thyroid tissue. These results confirm at the clonal level our previous studies regarding T cell epitopes on TPO and TSH-R molecules and support the concept that immunodominant T cell epitopes are located on amino acid residues 100–119 and 625–644 of TPO in HT and amino acid residues 158–176, 207–222 and 343–362/357–376 of TSH-R in GD. Our studies also demonstrate that thyroid-specific T cells can be classified into Th0, Th1, and Th2 subsets. TPO- or Tg-specific clones with Th1 phenotype appear to be involved in the pathogenesis of HT, mediating thyroid tissue destruction, whereas TSH-R clones with Th0 phenotype may induce thyroid-stimulating autoantibodies in GD.

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T cell epitopes on the 36K and 65K Mycobacterium leprae antigens defined by human T cell clones

European Journal of Immunology ◽

10.1002/eji.1830180604 ◽

1988 ◽

Vol 18 (6) ◽

pp. 849-854 ◽

Cited By ~ 17

Author(s):

Wim C. A.Van Schooten ◽

Tom H. M. Ottenhoff ◽

Paul R. Klatser ◽

Jelle Thole ◽

René R. P.De Vries ◽

...

Keyword(s):

T Cell ◽

Mycobacterium Leprae ◽

T Cell Epitopes ◽

T Cell Clones ◽

Human T Cell ◽

Cell Clones

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Heterogeneity of HLA-DR haplotypes as detected by human T cell clones primed against DR1 through DR8

Human Immunology ◽

10.1016/0198-8859(85)90365-9 ◽

1985 ◽

Vol 12 (2) ◽

pp. 101-102

Keyword(s):

T Cell ◽

T Cell Clones ◽

Human T Cell ◽

Hla Dr ◽

Cell Clones

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Mapping of Specific and Promiscuous HLA-DR-Restricted T-Cell Epitopes on the Plasmodium falciparum 27-Kilodalton Sexual Stage-Specific Antigen

Infection and Immunity ◽

10.1128/iai.66.8.3579-3590.1998 ◽

1998 ◽

Vol 66 (8) ◽

pp. 3579-3590 ◽

Cited By ~ 9

Author(s):

Carmen E. Contreras ◽

Isabelle N. Ploton ◽

Robert F. Siliciano ◽

Christopher L. Karp ◽

Raphael Viscidi ◽

...

Keyword(s):

Plasmodium Falciparum ◽

T Cell ◽

Specific Antigen ◽

Cytokine Profile ◽

T Cell Epitopes ◽

Sexual Stage ◽

T Cell Clones ◽

Hla Dr ◽

Cell Clones ◽

Ifn Γ

ABSTRACT We have characterized HLA-DR-restricted T-cell epitopes on the 27-kDa protein (Pfg27), a sexual stage-specific antigen, of the human malaria parasite Plasmodium falciparum in subjects with a history of malaria. Pfg27, expressed early in the sexual stages, is recognized by monoclonal antibodies capable of reducing the infectivity of gametocytes in mosquitoes. By using 16 Pfg27-specific CD4+-T-cell clones derived from three donors, seven different T-cell epitopes were identified. Among them, P11 (amino acids 191 to 210 of the Pfg27 sequence, IDVVDSYIIKPIPALPVTPD) was found to contain a previously described binding motif for multiple HLA-DR allotypes. Indeed, P11 was found to be promiscuous in that it could be recognized by T cells in the context of at least five different HLA-DR molecules. The cytokine profile of the clones was mixed. Seven of nine T-cell clones exhibited a Th0-like cytokine profile, producing high levels of gamma interferon (IFN-γ) and interleukin-4 (IL-4) upon stimulation with specific peptides and mitogens. The other two clones had a Th1-like cytokine profile with high expression of IFN-γ and no IL-4. Identification of a promiscuous epitope in Pfg27 could play a significant role in the design of a subunit vaccine for suppressing malaria transmission.

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Antigenic Properties and Processing Requirements of 65-Kilodalton Mannoprotein, a Major Antigen Target of Anti-Candida Human T-Cell Response, as Disclosed by Specific Human T-Cell Clones

Infection and Immunity ◽

10.1128/iai.69.6.3728-3736.2001 ◽

2001 ◽

Vol 69 (6) ◽

pp. 3728-3736 ◽

Cited By ~ 38

Author(s):

Roberto Nisini ◽

Giulia Romagnoli ◽

Maria Jesus Gomez ◽

Roberto La Valle ◽

Antonella Torosantucci ◽

...

Keyword(s):

T Cell ◽

Cell Response ◽

T Cell Response ◽

Interleukin 4 ◽

Cell Mediated Immunity ◽

T Cell Epitopes ◽

T Cell Clones ◽

Human T Cell ◽

Cell Clones ◽

Antigenic Properties

ABSTRACT T-cell-mediated immunity is known to play a central role in the host response to Candida albicans. T-cell clones are useful tools for the exact identification of fungal T-cell epitopes and the processing requirements of C. albicans antigens. We isolated human T-cell clones from an HLA-DRB1*1101 healthy donor by using an antigenic extract (MP-F2) of the fungus. Specific clones were T-cell receptor α/β and CD4+/CD8−and showed a T-helper type 1 cytokine profile (production of gamma interferon and not interleukin-4). The large majority of these clones recognized both the natural (highly glycosylated) and the recombinant (nonglycosylated) 65-kDa mannoprotein (MP65), an MP-F2 minor constituent that was confirmed to be an immunodominant antigen of the human T-cell response. Surprisingly, most of the clones recognized two synthetic peptides of different MP65 regions. However, the peptides shared the amino acid motif IXSXIXXL, which may be envisaged as a motif sequence representing the minimal epitope recognized by these clones. Three clones recognized natural and pronase-treated MP65 but did not detect nonglycosylated, recombinant MP65 or the peptides, suggesting a possible role for polysaccharides in T-cell recognition ofC. albicans. Finally, lymphoblastoid B-cell lines were efficient antigen-presenting cells (APC) for recombinant MP65 and peptides but failed to present natural, glycosylated antigens, suggesting that nonprofessional APC might be defective in processing highly glycosylated yeast proteins. In conclusion, this study provides the first characterization of C. albicans-specific human T-cell clones and provides new clues for the definition of the cellular immune response against C. albicans.

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