Human thymic epithelial cells express functional HLA-DP molecules.
HLA-DP molecules function as restriction elements in the presentation of foreign antigens to T cells by antigen presenting cells and certain HLA-DP molecules confer susceptibility to autoimmune disease. Because HLA molecules play an essential role in thymic selection and elimination of autoreactive T lymphocytes, we examined whether human thymic epithelial cells (TEC) expressed HLA-DP molecules. We present evidence that TEC obtained from short time culture express low but significant levels of HLA-DP molecules. The expression of HLA-DP molecules was comparable to or higher than the expression of HLA-DQ but lower than that of HLA-DR. Upon IFN-gamma treatment, HLA-DP expression was strongly upregulated. Since HLA-DQ and DR expression was upregulated in parallel, the hierarchy between MHC class II isotypes remained unchanged following interferon treatment. TEC elicited significant proliferation of HLA-DP allospecific primed lymphocyte typing (PLT) CD4 T cell lines. IFN-gamma treatment strongly upregulated the HLA-DP allospecific PLT responses whereas other PLT responses remained largely unchanged. In conclusion, these data indicate that human thymus epithelial cells express significant levels of functional HLA-DP molecules.
Jørgensen
A
A
Institute of Medical Anatomy, University of Copenhagen, Denmark.
Röpke
C
C
Nielsen
M
M
Madsen
H
H
Svejgaard
A
A
Odum
N
N
D002675:Child, Preschool; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D006682:HLA-DP Antigens / Q000276:immunology* / Q000502:physiology; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000494:pharmacology; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology
D006682:HLA-DP Antigens; D007371:Interferon-gamma