An immortalized cell line with features of XXXX follicular dendritic cells. Antigen and cytokine expression analysis.

@entity1 @entity650 @entity4666 @entity1356 @entity19 @entity39 @entity8790 @entity6977 @entity1582 @entity1192 @entity2772 @entity7527 @entity1199 @entity3646 @entity688 @entity2841
@entity8790 ( @entity8790 ) are specialized cells residing primarily within lymphoid follicles. They bind immunocomplexes and play an important role in the presentation of antigen to follicular B cells. Isolation of @entity8790 for in vitro studies, however, is difficult because they constitute only about 1% of the cells in lymphoid tissue and form tight clusters entrapping lymphocytes within their dendritic processes. The monoclonal antibody (mAb) Ki-M4, which is highly restricted in its binding to @entity8790 , is used to identify these cells. In order to establish a new immortalized cell line with features of @entity8790 , we applied a modified procedure to isolate and enrich @entity8790 from @entity1 tonsils and fused them with the @entity1582 cell line SP2/0-Ag14. The new hybrid cell line, designated @entity8790 -H1, is of both @entity19 lymphoid and @entity1 @entity8790 origin. @entity8790 -H1 was found to have unlimited growth potential and to consistently express the Ki-M4 antigen and other surface antigens of @entity1 @entity8790 . Semiquantitative reverse-transcribed polymerase chain reaction (RT-PCR) of enriched @entity8790 and @entity8790 -H1 revealed the same highly restricted cytokine/mRNA profile for both, with detectable levels of @entity1192 and surface @entity7527 and a lack of mRNA for @entity1356 , @entity1199 , @entity2772 , @entity3646 , @entity6977 , @entity4666 , @entity688 , interferon-gamma, tumor @entity39 factor-alpha, transforming growth factor-beta and @entity2841 . Additionally a weak but constant @entity650 mRNA expression was found in the cell line @entity8790 -H1 by RT-PCR. In situ hybridization experiments in tonsils revealed @entity650 transcripts in cells with a staining pattern characteristic of a dendritic cell only in a few germinal centers. To our knowledge, @entity8790 -H1 is the first cell line that constantly expresses surface antigens and a cytokine profile characteristic of @entity8790 . It is, therefore, well suited for studying the biology of @entity8790 and the functional relationship between @entity8790 and normal or neoplastic lymphatic cells.
