Quantitative but Not Qualitative Variation in MHC Class II Alters CD4 Interaction and Influences T Cell Repertoire Formation

1997 ◽  
Vol 177 (1) ◽  
pp. 49-61
Author(s):  
Sheryl L. Fuller-Espie ◽  
Geraldine A. Murphy ◽  
Sara J. Brett ◽  
Robert I. Lechler
1998 ◽  
Vol 187 (11) ◽  
pp. 1871-1883 ◽  
Author(s):  
Laurent Gapin ◽  
Yoshinori Fukui ◽  
Jean Kanellopoulos ◽  
Tetsuro Sano ◽  
Armanda Casrouge ◽  
...  

The positive selection of CD4+ T cells requires the expression of major histocompatibility complex (MHC) class II molecules in the thymus, but the role of self-peptides complexed to class II molecules is still a matter of debate. Recently, it was observed that transgenic mice expressing a single peptide–MHC class II complex positively select significant numbers of diverse CD4+ T cells in the thymus. However, the number of selected T cell specificities has not been evaluated so far. Here, we have sequenced 700 junctional complementarity determining regions 3 (CDR3) from T cell receptors (TCRs) carrying Vβ11-Jβ1.1 or Vβ12-Jβ1.1 rearrangements. We found that a single peptide–MHC class II complex positively selects at least 105 different Vβ rearrangements. Our data yield a first evaluation of the size of the T cell repertoire. In addition, they provide evidence that the single Eα52-68–I-Ab complex skews the amino acid frequency in the TCR CDR3 loop of positively selected T cells. A detailed analysis of CDR3 sequences indicates that a fraction of the β chain repertoire bears the imprint of the selecting self-peptide.


1995 ◽  
Vol 182 (5) ◽  
pp. 1481-1491 ◽  
Author(s):  
E V Fedoseyeva ◽  
R C Tam ◽  
P L Orr ◽  
M R Garovoy ◽  
G Benichou

Self-proteins are regularly processed for presentation to autoreactive T cells in association with both class I and class II major histocompatibility complex (MHC) molecules. The presentation of self-peptides plays a crucial role in the acquisition of T cell repertoire during thymic selection. We previously reported that the self-MHC class I peptide Ld 61-80 was immunogenic in syngeneic B10.A mice (H-2a). We showed that despite its high affinity for self-MHC class II molecules, Ld 61-80 peptide failed to induce elimination of autoreactive CD4+ T cells, presumably due to incomplete processing and presentation in the B10.A's developing thymus (cryptic-self peptide). In this report, we showed that the cryptic phenotype was not an intrinsic property of the self-peptide Ld 61-80 since it was found to be naturally presented and subsequently tolerogenic in BALB/c mice (H-2d) (dominant self-peptide). In addition, the self-peptide Ld 61-80 was found to be immunogenic in different H-2a mice while it was invariably tolerogenic in H-2d mice regardless of their background genes. We observed that Ld 61-80 bound equally well to H-2d and H-2k MHC class II molecules. Also, no correlation was found between the quantity of self-Ld protein and the tolerogenicity of Ld 61-80. Surprisingly, Ld 61-80 was not naturally presented in (H-2d x H-2a) F1 mice, indicating that the H-2a MHC locus contained a gene that impaired the presentation of the self-peptide. Analyses of T cell responses to the self-peptide in several H-2 recombinant mice revealed that the presentation of Ld 61-80 was controlled by genes that mapped to a 170-kb portion of the MHC class II region. This study shows that (a) endogenously processed self-peptides presented by MHC class II molecules are involved in shaping the CD4+ T cell repertoire in the thymus; (b) The selection of self-peptides for presentation by MHC class II molecules to nascent autoreactive T cells is influenced by nonstructural MHC genes that map to a 170-kb portion of the MHC class II region; and (c) the MHC locus of H-2a mice encodes factors that prevent or abrogate the presentation by MHC class II molecules of the self-peptide Ld 61-80. These findings may have important implications for understanding the molecular mechanisms involved in T cell repertoire acquisition and self-tolerance induction.


1996 ◽  
Vol 47 (1-2) ◽  
pp. 107
Author(s):  
Zoltan A. Nagy ◽  
Damir Vidovic' ◽  
Natalie Boulanger ◽  
Jeanmarie Guenot ◽  
Kouichi Ito ◽  
...  

Author(s):  
Marja van Eggermond ◽  
Marijke Lambert ◽  
Françoise Mascart ◽  
Etienne Dupont ◽  
Peter van den Elsen

Immunology ◽  
2012 ◽  
Vol 137 (3) ◽  
pp. 226-238 ◽  
Author(s):  
Luise U Weigand ◽  
Xiaoling Liang ◽  
Sabine Schmied ◽  
Sabine Mall ◽  
Richard Klar ◽  
...  

Blood ◽  
2001 ◽  
Vol 98 (3) ◽  
pp. 868-876 ◽  
Author(s):  
Yuji Miura ◽  
Christopher J. Thoburn ◽  
Emilie C. Bright ◽  
Matthias Sommer ◽  
Susan Lefell ◽  
...  

Abstract Administration of cyclosporine A (CsA) after autologous stem cell transplantation elicits an autoimmune syndrome with pathology similar to graft-versus-host disease (GVHD). This syndrome, termed autologous GVHD, is associated with the appearance of autoreactive T cells directed at major histocompatibility class (MHC) class II antigens. In the rat model of autologous GVHD, clonal analysis reveals that the effector T cells are highly conserved and recognize a peptide from the invariant chain peptide presented by MHC class II. Although human autologous GVHD effector T cells share a similar phenotypic specificity, clonality of the response in humans has not been determined. To examine the human effector T-cell response, the T-cell repertoire of peripheral blood lymphocytes was assessed by complementarity-determining region 3 (CDR3) size distribution analysis and T-cell clonotype analysis in 26 patients treated with CsA after transplantation. Autologous GVHD developed in 3 of 4 patients with human leukocyte antigen (HLA)-DRB1*0701, and clonal expansions of β-chain variable region (BV)16+ T cells were shared. Clonal expansions within BV15+ and BV22+ T cells were also detected in 4 of 6 patients with HLA-DRB1*1501 and in 3 of 4 patients with HLA-DRB1*0401, respectively. Sequencing of BV16 cDNA for which the CDR3 size pattern exhibited apparent clone predominance revealed an identical CDR3 peptide sequence in 2 different patients, one with HLA-DRB1*0701 and the other with HLA-DRB1*1502. These findings indicate that the discrete antigen-driven expansion of T cells is involved in autologous GVHD.


2001 ◽  
Vol 8 (3-4) ◽  
pp. 279-290 ◽  
Author(s):  
P. Ströbel ◽  
M. Helmreich ◽  
H. Kalbacher ◽  
H. K. Müller-Hermelink ◽  
A. Marx

The major histocompatibility complex (MHC) class II is involved both in thymocyte maturation and peptide presentation and might thus play a key role in the pathogenesis of paraneoplastic myasthenia gravis (MG) in thymomas. To further investigate this issue, we analyzed and scored the expression of epithelial class II expression in 35 thymomas (medullary, MDT; mixed, MXT; cortical and well differentiated thymic carcinoma, CT / WDTC) and correlated it with the histological tumor subtype, prevalence of MG and thymocyte maturation, which was analyzed by flow cytometry and RT-PCR. Our results show that both MHC class II expression and thymocyte maturation are highly dependent on the histological tumor subtype. CT / WDTC retain features of the normal outer thymic cortex, namely substantial MHC class II expression together with normal early thymocyte maturation until late phases of positive selection, but disturbed terminal thymopoiesis. By contrast, MDT and MXT retain features of the normal inner cortex and the medulla with low to absent class II expression and highly abnormal early thymocyte maturation including impaired positive selection, while terminal T cell maturation in MXT appeared undisturbed. There was no correlation between MHC class II expression and MG status for a given tumor subtype. In conclusion, our results provide evidence for a different histogenesis of cortical thymomas and well differentiated carcinomas on the one hand and mixed and medullary thymomas on the other.Decreased expression levels of MHC class II, although of crucial importance for abnormal intratumorous maturation, are not sufficient to explain the emergence of paraneoplastic MG.


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