In an effort to identify immunoregulatory molecules on dendritic cells (DC), we generated and screened for mAbs capable of modulating the T cell stimulatory function of DC. A particularly interesting mAb was mAb DF272. It recognizes monocyte-derived DC, but not blood monocytes or lymphocytes, and has profound immunomodulatory effects on DC. Treatment of DC with intact IgG or Fab of mAb DF272 enhanced their T cell stimulatory capacity. This effect on DC was accompanied by neither an up-regulation of costimulatory molecules such as @entity7938 ( @entity7938 ), @entity2937 ( @entity2937 ), and MHC class II molecules nor by an induction of cytokine production, including IL-1, @entity310 , @entity688 , and IL-12. Moreover, the well-established inhibitory function of @entity688 -treated DC could be reverted with mAb DF272. Even T cells, anergized because of stimulation with @entity688 -treated DC, could be reactivated and induced to proliferate upon stimulation with mAb DF272-treated DC. Furthermore, mAb DF272-treated DC favored the induction of a type-1 cytokine response in T cells and inhibited @entity688 production. By using a retrovirus-based cDNA expression library generated from DC, we cloned and sequenced the mAb DF272-defined @entity15392 and could demonstrate that it is identical with @entity4634 ), a recently identified new member of the B7 family of costimulatory molecules. Our results thus demonstrate that the mAb DF272-defined surface molecule B7-H1 represents a unique receptor structure on DC that might play a role in the induction and maintenance of T cell anergy.

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@entity4634 :: ('29126', 'Gene') :: ['B7-H1 (programmed death-1 ligand'] @entity2937 :: ('942', 'Gene') :: ['CD86', 'B7.2'] @entity310 :: ('7124', 'Gene') :: ['TNF-alpha'] @entity7938 :: ('941', 'Gene') :: ['CD80', 'B7.1'] @entity15392 :: ('57126', 'Gene') :: ['cell surface receptor'] @entity688 :: ('3586', 'Gene') :: ['IL-10']
@entity4634 :: (29126,Gene) :: ['B7-H1 (programmed death-1 ligand']
