Recent experimental studies have greatly clarified the function of cell surface molecules in the induction and modulation of T cell responses by @entity1358 ( @entity1358 ). However, the differences in ability to stimulate T cells evident for different types and subpopulations of the same @entity1358 , such as dendritic cell subsets, is less well understood. This report details an investigation of an antigen expressed on monocytes that is also expressed on a subset of @entity291 afferent lymph veiled cells (ALVC). A cDNA library derived from @entity291 monocytes was screened with monoclonal antibodies (mAb) for expression in COS-7 cells. Using separate mAb for screening, two cDNA were cloned, the sequences of which showed a single long open reading frame encoding a predicted type I glycoprotein of 506 @entity1522 that contained three immunoglobulin superfamily domains and a long 112- @entity535 cytoplasmic tail. We have termed this antigen @entity70496 , reflecting its myeloid and dendritic cell distribution. Analysis of the EMBL database revealed that the molecule is a member of the recently described family of signal regulatory proteins (SIRP). The outeremost Ig domain was of the adhesion/receptor I-type, suggesting that @entity70496 might bind to a ligand on another cell. Evidence for this was subsequently obtained by demonstrating that COS-7 cells transfected with @entity70496 cDNA bound @entity9214 T cells and this binding was blocked by specific mAb. The potential importance of this interaction was supported by the finding that the proliferation of resting memory @entity9214 T cells to ovalbumin-pulsed monocytes was significantly reduced in the presence of mAb to @entity70496 . A role for the molecule in the modulation of the monocyte/dendritic @entity1358 response is also predicted from the existence of multiple potential @entity669 phosphorylation sites in the cytoplasmic domain, including the presence of an immunoreceptor @entity669 -based inhibitory motif (ITIM) and the observation that the SIRP alpha family members have been shown to bind to SHP-1 and @entity70497 . Together these data indicate a possible functional importance for @entity70496 in the regulation of monocyte and dendritic cell function.

Cloning of two members of the SIRP alpha family of protein @entity669 phosphatase binding proteins in XXXX that are expressed on monocytes and a subpopulation of dendritic cells and which mediate binding to @entity9214 T cells.

@entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity70497 :: ('533590(Tax:9913)', 'Gene') :: ['SHP-2'] @entity1358 :: ('MESH:D002292', 'Disease') :: ['APC', 'antigen-presenting cells'] @entity669 :: ('CHEBI:18186', 'Chemical') :: ['tyrosine'] @entity9214 :: ('407098(Tax:9913)', 'Gene') :: ['CD4'] @entity70496 :: ('327666(Tax:9913)', 'Gene') :: ['MyD-1'] @entity291 :: ('9913', 'Species') :: ['cattle']
@entity291 :: (9913,Species) :: ['cattle']
