Class II Hla-Dr Antigens on Non-Autoimmune Human Thyroid Cells Stimulate Autologous T Cells with High Suppressor Activity
作者:
LahatN.,
SheinfeldM.,
SobelE.,
BaronE.,
KraiemZ.,
期刊:
Autoimmunity
(Taylor Available online 1990)
卷期:
Volume 8,
issue 2
页码: 125-133
ISSN:0891-6934
年代: 1990
DOI:10.3109/08916939008995730
出版商: Taylor&Francis
关键词: Thyroid HLA-DR;Suppressor T cells
数据来源: Taylor
摘要:
Human autoimmune thyroid cells“spontaneously”express MHC-class II antigens. These antigens have been assumed to trigger thyroid-specific helper T cell clones, leading in turn to the expansion of thyroid autoantibody-secreting B cells. Thyroid cells derived from non-autoimmune subjects do not express MHC-class antigens, but these can be readily induced with -γ-interferon. We have addressed the issue of whether it is sufficient for normal thyroid cells to bear class II antigens in order to trigger autologous T cells. We found that non-autoimmune thyrocytes expressing DR antigens fail to stimulate autologous resting T cells. However, proliferative activity and interleukin-2 secretion were observed when fresh T cells were first triggered by autologous non-T cells and then incubated with thyrocytes. More CDgthan CD4, cells proliferated in the T:thyrocyte cultures, but CD4cells were necessary for the proliferation and interleukin-2 secretion. Addition of antibodies to thyroglobulin or to DR antigens inhibited T cell proliferation and interleukin-2 secretion, thus pointing to T cell recognition of both thyroid-specific and DR antigens. Evaluation of the function of the thyroid stimulated T cells revealed very potent suppressor but negligible helper and cytotoxic activities. It would seem, therefore, that DR-restricted T cell activation by autologous antigen on non-autoimmune thyroid cells does occur, but since it results in enhanced suppression, its nature seems protective, thus leading to maintenance of immunological self-tolerance.
点击下载:
PDF (830KB)
返 回