Abstract: The present invention provides a newly identified CD28 family member that functions as lymphocyte inhibitory receptor termed pG6b, which is expressed on T cells. Methods and compositions for modulating pG6b-mediated negative signaling and interfering with the interaction of its counter-receptor for therapeutic, diagnostic, and research purposes are also provided.

Abstract: The present invention provides a newly identified B7 receptor, zB7R1 that functions as lymphocyte inhibitory receptor, which is a PD-1-like molecule and is expressed on T cells. The present invention also provides the discovery of zB7R1's ability to bind to CD155. Methods and compositions for modulating zB7R1-mediated negative signaling and interfering with the interaction of its counter-receptor for therapeutic, diagnostic and research purposes are also provided.

Abstract: The invention provides pHHLA2 co-receptor polypeptides and functional fragments, antibodies to same, isolated polynucleotides encoding same, vectors containing the polynucleotides, cells containing the vectors. Methods of making and using these co-stimulatory pHHLA2 co-receptors molecules are also disclosed.

Abstract: Novel methods of using isolated polypeptides, isolated polynucleotides encoding the polypeptides, and related compositions are disclosed for pNKp30 protein. The methods involved modulating the proliferation of T-cells in vitro and in vivo and modulation of immune response. The present invention also includes methods for producing pNKp30, including soluble molecules, uses therefor and antibodies thereto.