PubMed · 7367279
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M Schwob. 1980-02-16. [Autoimmune diseases].. https://pubmed.ncbi.nlm.nih.gov/7367279/
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Naturally occurring CD25(+)CD4(+) regulatory T cells are engaged in the maintenance of immunological self-tolerance and down-regulation of various immune responses. Recent studies with mice showed that Foxp3, which encodes the transcription factor Scurfin, is a master regulatory gene for the development and function of CD25(+)CD4(+) regulatory T cells. Here we examined the role of FOXP3 in human CD25(+)CD4(+) regulatory T cells. The FOXP3 gene and its protein product were preferentially expressed in peripheral CD25(+)CD4(+) T cells, in particular CD25(+)CD45RO(+)CD4(+) T cells in normal individuals and, interestingly, in some human T cell leukemia virus type 1-infected T cell lines, which constitutively express CD25. TCR stimulation of CD25(-)CD45RO(-)CD4(+) naive T cells failed to elicit FOXP3 expression at the gene or protein level. Ex vivo retroviral gene transfer of FOXP3, on the other hand, converted peripheral CD25(-)CD45RO(-)CD4(+) naive T cells into a regulatory T cell phenotype similar to CD25(+)CD4(+) regulatory T cells. For example, FOXP3-transduced T cells exhibited impaired proliferation and production of cytokines including IL-2 and IL-10 upon TCR stimulation, up-regulated the expression of regulatory T cell-associated molecules such as CD25 and CTL-associated antigen-4 and suppressed in vitro proliferation of other T cells in a cell-cell contact-dependent manner. Thus, human FOXP3 is a crucial regulatory gene for the development and function of CD25(+)CD4(+) regulatory T cells, and can be used as their reliable marker. Furthermore, regulatory T cells de novo produced from normal naive T cells by FOXP3 transduction can be instrumental for treatment of autoimmune/inflammatory diseases and negative control of various immune responses.
BACKGROUND: The demonstration of tissue-bound immunoreactants by direct immunofluorescence microscopy (DIF) is a valuable parameter in the diagnosis of various autoimmune and immunecomplex-mediated skin diseases. For preservation of tissue-bound immunoreactants, biopsies are usually fresh-frozen in liquid nitrogen or transported in Michel's fixative. But even optimally preserved tissue specimens are no guarantee for the correct diagnosis by DIF, especially when weak to moderate IgG fluorescence of the epidermal basement membrane zone is involved. In such cases false negative results are easily obtained due to the relatively high dermal "background" fluorescence produced by polyclonal anti-human IgG fluorescein conjugates. METHODS: In the present study we have compared the use of normal saline (0.9% NaCl) with liquid nitrogen and Michel's fixative as transport medium for skin biopsies. From 25 patients with an autoimmune skin disease (pemphigus, pemphigoid, lupus erythematosus and vasculitis) four matched skin biopsies were obtained and transported in either saline for 24 and 48 hours, liquid nitrogen, or Michel's fixative for 48 hours. RESULTS: Direct IF microscopy showed significant reduction of background fluorescence (p < 0.01) and relatively enhanced desired specific (IgG, IgA) staining in biopsies transported in saline. A conclusive or tentative IF diagnosis was reached in 92% after 24 h saline, 83% after 48 h saline, 68% after freezing in liquid nitrogen, and 62% after 48 h Michel's medium (n = 25). CONCLUSIONS: We conclude that transporting biopsies without freezing in normal saline for 24 hours is an adequate and attractive method for routine IF diagnosis in autoimmune and immune complex-mediated dermatoses. The superior results with saline incubation are explained by washing away of IgG background in dermis and epidermis.
Summary Hepatitis C virus infection is often associated with extra-hepatic manifestations, secondary to the elicitation of autoimmune reactions, generalized deposition of immune complexes and lymphoproliferative disorders. The most clearly established associations are those linking chronic hepatitis C with mixed cryoglobulinaemia (and the related glomerulonephritis and cutaneous vasculitis), as well as with the presence of autoantibodies. Less well-documented disorders include non-Hodgkin's lymphoma, thrombocytopenia, sialadenitis, thyroid disease, lichen planus, porphyria cutanea tarda, rheumatoid disorders and neurological disorders. Extra-hepatic manifestations are most frequent in patients of female sex, advanced age, long-lasting infection and cirrhosis. Optimal treatment strategies should be based on the predominant manifestation of the disease. In the case of autoimmune disorders not clearly attributable to the viral infection, corticosteroids may be the most effective option. Interferon-alpha alone or in combination with ribavirin may be indicated for those disorders related to immune complex deposition, such as mixed cryoglobulinaemia, although relapses of extra-hepatic signs often occur on discontinuation of treatment. In some cases, interferon-alpha may induce or exacerbate some extra-hepatic manifestations.