Central tolerance spares the private high-avidity CD4(+) T-cell repertoire specific for an islet antigen in NOD mice.
Eur J Immunol
; 45(7): 1946-56, 2015 Jul.
Article
em En
| MEDLINE
| ID: mdl-25884569
ABSTRACT
Although central tolerance induces the deletion of most autoreactive T cells, some autoreactive T cells escape thymic censorship. Whether potentially harmful autoreactive T cells present distinct TCRαß features remains unclear. Here, we analyzed the TCRαß repertoire of CD4(+) T cells specific for the S100ß protein, an islet antigen associated with type 1 diabetes. We found that diabetes-resistant NOD mice deficient for thymus specific serine protease (TSSP), a protease that impairs class II antigen presentation by thymic stromal cells, were hyporesponsive to the immunodominant S100ß1-15 epitope, as compared to wild-type NOD mice, due to intrathymic negative selection. In both TSSP-deficient and wild-type NOD mice, the TCRαß repertoire of S100ß-specific CD4(+) T cells though diverse showed a specific bias for dominant TCRα rearrangements with limited CDR3α diversity. These dominant TCRα chains were public since they were found in all mice. They were of intermediate- to low-avidity. In contrast, high-avidity T cells expressed unique TCRs specific to each individual (private TCRs) and were only found in wild-type NOD mice. Hence, in NOD mice, the autoreactive CD4(+) T-cell compartment has two major components, a dominant and public low-avidity TCRα repertoire and a private high-avidity CD4(+) T-cell repertoire; the latter is deleted by re-enforced negative selection.
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Base de dados:
MEDLINE
Assunto principal:
Linfócitos T CD4-Positivos
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Ilhotas Pancreáticas
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Receptores de Antígenos de Linfócitos T alfa-beta
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Tolerância Central
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Subunidade beta da Proteína Ligante de Cálcio S100
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article