Preparation and functional properties of monoclonal antibodies to human, mouse and rat OX-2

We have prepared mouse and rat hybridomas to a 43-kDa molecule expressed in the thymus, on a subpopulation of dendritic cells, and in the brain, in ma mmalian tissue derived from mouse, rat and human. Using CHO cells transient ly transfected with adenovirus vector(s) expressing a cDNA construct for th e relevant OX-2 gene, we show these monoclonal antibodies (Mabs) detect a m olecule encoded by this construct (rat OX-2 (rOX-2), mouse OX-2 (mOX-2) and human OX-2 (huOX-2), respectively). Furthermore, at least some of the anti -rat Mabs detect determinants expressed on the murine OX-2 molecule, as we predicted in an earlier publication. Previous studies have implied that thi s molecule might serve an important role in regulation of cell signaling fo r cytokine production. Using one-way mixed leukocyte reactions we show that when cells are cultured in the presence of the species-specific Mab, cytok ine production becomes polarized 'away from' type-2 cytokine production, wi th preferentially increased expression of type-1 cytokine production. (C) 1 999 Elsevier Science B.V. All rights reserved.