Expression and regulation of @entity5823 ligand and @entity5823 in @entity1 XXXX cell lines.

@entity1 @entity981 @entity706 @entity39 @entity5 @entity2936 @entity2109 @entity4621 @entity5823 @entity4209 @entity32998 @entity1893 @entity978
The @entity5823 antigen was originally described as a specific surface marker for @entity978 . Recent work established @entity5823 as a member of the @entity5 @entity39 factor/nerve growth factor receptor superfamily whose ligand ( @entity4209 ) has also been cloned and expressed; @entity4209 is active as membrane-bound type II glycoprotein. Here, @entity4209 mRNA expression was studied in a panel of 102 continuous @entity1 @entity706 cell lines and was found only in four @entity2109 , one Burkit-type @entity981 and one @entity1893 ( @entity1893 ) cell line. The product of @entity4209 mRNA is expressed as a membrane protein on the surface of these malignant B-cell lines. Treatment of these cell lines with soluble @entity32998 , @entity4621 or staphylococcus aureus Cowan antigen resulted in the enhancement of cell surface @entity4209 protein expression. @entity4209 mRNA was not detected in normal unstimulated peripheral blood (PB) monocytes, monocyte-derived macrophages, or T-cells, but was detected in primary granulocytes; exposure to activating reagents induced and upregulated @entity4209 transcription in these different PB populations. While @entity2936 and @entity4209 surface protein expression on PB monocytes could be enhanced or induced by treatment with gamma-interferon, these cells remained negative for @entity5823 , both at the mRNA and at the protein level. Similarly, PB monocyte-derived macrophages and granulocytes remained negative for @entity5823 mRNA and protein expression, regardless of stimulation. Only activated T-cells expressed @entity5823 mRNA and surface protein. @entity4209 -transfected cells and cells constitutively expressing @entity4209 delivered a similar stimulus for proliferation of the @entity5823 + @entity978 ( @entity978 )-derived cell line HDLM-2, but inhibited proliferation of the @entity5823 + large cell @entity706 cell line KARPAS-299. These data provide strong evidence for the involvement in growth regulation of recombinant and natural @entity4209 through its interaction with the @entity5823 receptor. Collectively, these data suggest that the @entity4209 - @entity5823 interaction has potent biological activity and might play a critical role in the immune response and pathogenesis of @entity978 and some @entity1893 , in particular @entity2109 .
