Expression of ICAM-1, B7.1 and TPO on human thyrocytes induced by IFN-alpha.

OBJECTIVE

To detect expression of intercellular adhesion molecule-1 (ICAM-1), B7.1 and thyroid peroxidase (TPO) on thyrocyte and study the possible mechanism of interferon-alpha (IFN-alpha) in the pathogenesis of autoimmune thyroid disease (AITD).

METHODS

Thyrocytes were cultured from 6 normal persons. Antigen expression on thyrocytes induced by cytokines was examined using immunofluorescence staining with flow cytometer.

RESULTS

IFN-alpha significantly stimulated the expression of ICAM-1, B7.1 and TPO, as compared with those of control group. IFN-gamma markedly enhanced the expression of HLA-DR and ICAM-1, but not B7.1. Prolactin (PRL) resulted in increased expression of ICAM-1, B7.1, as well as overexpression of TPO, which is more significant than that stimulated by IFN-alpha.

CONCLUSIONS

Thyroid autoimmunity induced by IFN-alpha is associated with the expression of ICAM-1, B7.1 and TPO. IFN-gamma could not induce the expression of B7.1, therefore it is not an initiator in AITD. In addition, we should pay more attention to PRL which possibly plays an important role in the initiation and perpetuation of postpartum thyroiditis.