CD1c restricts responses of mycobacteria-specific T cells. Evidence for antigen presentation by a second member of the human CD1 family.
J Immunol
; 157(7): 2795-803, 1996 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-8816382
ABSTRACT
Previous studies suggest that CD1 is a family of Ag-presenting molecules distantly related to those encoded by the MHC. However, of the four known human CD1 proteins, only CD1b has been shown to restrict Ag-specific T cell responses. In this study, we have shown that a second member of the human CD1 family, CD1c, could also mediate Ag presentation to T cells. Three T cell lines recognizing mycobacterial Ags in a CD1c-restricted manner were isolated from normal donor blood. These T cells were MHC unrestricted, and their recognition of Ag was independent of the products of the transporter associated with Ag presentation-1/2 and DMA/B genes that are generally required for Ag presentation by MHC-encoded Ag-presenting molecules. Furthermore, unlike MHC-restricted responses to peptides, the CD1c-restricted T cell lines recognized protease-resistant mycobacterial lipid Ags. These T cell lines also showed significant cytotoxicity toward CD1c-expressing target cells even in the absence of mycobacterial Ags, which was shown by clonal analysis to be mediated by a subpopulation of T cells directly reactive to CD1c molecules. Our findings establish the ability of a second member of the CD1 family to restrict responses of Ag-specific T cells, and thus support the general hypothesis that the CD1 family comprises a third lineage of Ag-presenting molecules that presents a novel class of foreign and self Ags to MHC-unrestricted T cells.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Subpopulações de Linfócitos T
/
Apresentação de Antígeno
/
Antígenos CD1
/
Mycobacterium tuberculosis
Limite:
Humans
Idioma:
En
Revista:
J Immunol
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Estados Unidos