Abstract
Recent data have suggested that in psoriasis, the T-infiltrating cells could be submitted to regulatory pathways, possibly through natural killer receptors. HLA-G binds to different natural killer receptors and is able to inhibit T-cell functions. Because this molecule is induced by interferon-gamma, a major cytokine in psoriasis, we asked whether HLA-G and its receptor might be expressed in this disease. Specific RNAs for HLA-G1 and HLA-G5 were consistently found in lesional skin specimens, soluble HLA-G5 transcripts being found only in psoriasis. HLA-G protein was found in all psoriatic sections, but never in normal skin controls. Double labeling demonstrated that HLA-G-positive cells were CD68(+), CD11c(+) macrophages. The NKR ILT2 was also present in psoriatic skin, the T CD4(+)-infiltrating cells expressing indeed ILT2. The demonstration of HLA-G and ILT2 expression in psoriatic skin suggests that this pathway may act as an inhibitory feed back aimed to down-regulate the deleterious effects of T-cell infiltrate in this disease.
MeSH terms
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Alternative Splicing
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Antigens, CD / metabolism
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Antigens, Differentiation, Myelomonocytic / metabolism
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CD4-Positive T-Lymphocytes / metabolism
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Female
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HLA Antigens / genetics
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HLA Antigens / metabolism*
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HLA Antigens / physiology
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HLA-G Antigens
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Histocompatibility Antigens Class I / genetics
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Histocompatibility Antigens Class I / metabolism*
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Histocompatibility Antigens Class I / physiology
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Humans
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Integrin alphaXbeta2 / metabolism
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Leukocyte Immunoglobulin-like Receptor B1
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Lymphocytes, Tumor-Infiltrating / physiology
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Macrophages / metabolism
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Psoriasis / metabolism*
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Psoriasis / pathology
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Psoriasis / physiopathology
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Receptors, Immunologic / metabolism*
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Receptors, Immunologic / physiology
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Reference Values
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Skin / metabolism*
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Skin / pathology
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T-Lymphocytes / physiology
Substances
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Antigens, CD
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Antigens, Differentiation, Myelomonocytic
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CD68 antigen, human
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HLA Antigens
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HLA-G Antigens
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Histocompatibility Antigens Class I
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Integrin alphaXbeta2
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LILRB1 protein, human
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Leukocyte Immunoglobulin-like Receptor B1
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NKTR protein, human
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RNA, Messenger
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Receptors, Immunologic