Expression of HLA class II molecules on thyrocytes is a characteristic feature of autoimmune thyroid disease and may lead the thyroid cells to present autoantigens to CD4(+) T lymphocytes. Since HLA-DM is a critical molecule in class II-restricted antigen processing and presentation, we assessed the expression of HLA-DMB, -invariant chain (Ii), class II transactivator (CIITA) and DRA in an untransformed, pure thyrocyte strain HTV-59A. Here we report that both HLA-DMB mRNA and the protein are expressed in thyrocytes and that CIITA expression is enhanced by interferon-gamma (IFN-gamma) treatment and occurs before DMB, Ii and DRA up-regulation, suggesting CIITA expression is a requirement for antigen processing in thyrocytes. These results indicate that thyrocytes are capable of antigen processing and possibly antigen presentation to T cells.
HLA-DMB expression by thyrocytes: indication of the antigen-processing and possible presenting capability of thyroid cells
CURCIO, Francesco;AMBESI IMPIOMBATO, Francesco Saverio;
1999-01-01
Abstract
Expression of HLA class II molecules on thyrocytes is a characteristic feature of autoimmune thyroid disease and may lead the thyroid cells to present autoantigens to CD4(+) T lymphocytes. Since HLA-DM is a critical molecule in class II-restricted antigen processing and presentation, we assessed the expression of HLA-DMB, -invariant chain (Ii), class II transactivator (CIITA) and DRA in an untransformed, pure thyrocyte strain HTV-59A. Here we report that both HLA-DMB mRNA and the protein are expressed in thyrocytes and that CIITA expression is enhanced by interferon-gamma (IFN-gamma) treatment and occurs before DMB, Ii and DRA up-regulation, suggesting CIITA expression is a requirement for antigen processing in thyrocytes. These results indicate that thyrocytes are capable of antigen processing and possibly antigen presentation to T cells.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
