Selection of intraepithelial lymphocytes with CD8 alpha/alpha co-receptors by self-antigen in the murine gut.
AUTOR(ES)
Rocha, B
RESUMO
We have studied T-cell receptor (TCR) and alpha/alpha CD8 expression in thymus-independent intraepithelial lymphocytes (TI IELs) from the gut of mice bearing transgenic (TG) TCR alpha beta specific for the male antigen, presented by H-2Db class I major histocompatibility complex (MHC) molecules. In contrast to TCR+ alpha beta cells differentiating in the thymus (from CD4+CD8+ precursors to CD4+CD8- or CD4-CD8+ progeny), TI IELs are not deleted by self-antigens, nor are they positively selected in the absence of the specific peptide. On the contrary, recognition of the antigen in the context of self-MHC is required for selection and granular differentiation of CD8+ TI IELs. Our results also show that, in contrast to the thymus, expression of the beta TG does not block expression of endogenous TCR gamma delta genes in TI IELs. The size of this gut IEL subpopulation and its difference in mechanisms of repertoire selection demonstrate the existence of a major extrathymic pathway of T-cell differentiation, the role of which remains to be elucidated.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=49286Documentos Relacionados
- The role of charge and multiple faces of the CD8 alpha/alpha homodimer in binding to major histocompatibility complex class I molecules: support for a bivalent model.
- Inducible costimulator-dependent IL-10 production by regulatory T cells specific for self-antigen
- Posttraumatic therapeutic vaccination with modified myelin self-antigen prevents complete paralysis while avoiding autoimmune disease
- Synergism in the activation of human CD8 T cells by cross-linking the T-cell receptor complex with the CD8 differentiation antigen.
- Conjugation of a self-antigen to papillomavirus-like particles allows for efficient induction of protective autoantibodies