Not sure if it will be an agonist, but anti-CD279 antibodies are available. http://www.ebioscience.com/antigens/c/cd251-cd300/cd279-pd-1-antibodies-proteins-kits.htm?limit=50®ulatory_status=21&gclid=COX35rvegcACFU82aQodxTsAtg
I'm curious why you wouldn't use PD-L1 or PD-L2, which are the normal agonists. Certain tumor cell lines express them. Without any idea what your intent is, it's hard to say more. You can buy or make them. http://www.acrobiosystems.com/A290-CD274--B7-H1-Molecule.html Sells PD-L1.
antagonist mAb for this target are available. because therapeutic antibody had been developed. we have ever made several antibodies.if you can test the agonist activity , we can provide some IgG protein for the assay. my email is [email protected]