The expression of CD80 was limited in some APCs and not found in

The expression of CD80 was limited in some APCs and not found in cholangiocarcinoma cells. Consequently, cholangiocarcinoma cells expressing HLA-DR, but lacking costimulatory molecules (CD80 and CD86) were found in 54% of cases. These cancer cells could act as nonprofessional APCs, possibly generating IL-10–producing Treg cells (anergy T cells), and then an IL-10–predominant cytokine milieu could cause the induction of IgG4-positive cells.5, 6 In these phenotypic cases, the number of IgG4-positive cells Antifection chemical infiltrating carcinoma tissue was higher than in HLA-DR–negative cases and both HLA-DR– and CD86-positive

cases, confirming this speculation. Cells positive for both HLA-DR and CD86 are suggested to play the role of professional APCs, as it was reported that MHC-II–positive thyroid epithelial cells could present antigens to T cells and activate autoreactive T cells.25, 26 Although further study is needed to clarify the functional mechanism of these cholangiocarcinoma cells as APCs, this study demonstrated that HLA-DR– and CD86-positive cancer cells were not associated with IgG4 reactions in cholangiocarcinoma tissue. As to pathogenesis of IgG4 reactions in IgG4-related diseases,

the participation of CD4+CD25+Foxp3+ Treg cells, click here which are capable of producing IL-10, has been speculated.27 Foxp3 is thought to be the master transcription factor of Treg cells and, until recently, Foxp3 expression was thought to be restricted to the T cell lineage. However, immunohistochemistry and flow cytometric analysis demonstrated that some carcinoma tissues and cultured cancer cell lines expressed Foxp3.7-10 Immunohistochemistry using the antibody recognizing the N

terminus, but not the C terminus, of Foxp3-highlighted cholangiocarcinoma tissue in 39% of cases as well as see more Treg cell morphology, suggesting the presence of the splicing variant of Foxp3 in cholangiocarcinoma cells. Molecular analysis using a cholangiocarcinoma cell line demonstrated that the cells expressed mRNA of Foxp3, but lack Exon 3. This type of splicing variant has already been reported in a melanoma cell line and created a novel amino acid caused by a frame shift at the C terminus.9 This is why the antibody recognizing the C terminus of Foxp3 could not detect the variant of Foxp3 found in cholangiocarcinoma tissue. Although a functional analysis of this variant as a transcription factor is necessary, it has already been reported that Foxp3 expression is closely correlated with the expression of IL-10 in all Foxp3-positive cell lines.10 The present study, using a cholangiocarcinoma cell line, also demonstrated that cells express mRNA of IL-10 as well as Foxp3. Moreover, the IL-10 protein was detected in the culture medium by ELISA at a concentration of 7.8-15.

Leave a Reply

Your email address will not be published. Required fields are marked *

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>