Blockade of the CD28/B7 and CD40/CD40L costimulatory pathways does not ameliorate chronic rejection in a mouse aortic allograft model of direct antigen presentationJ.L Tang; J.E Woodward; V Subbotin; A.J Logar; H Sun; L.A Valdivia; A.T Schaefer; L.B Zottola; R Peach; J.J Fung; A.S Rao · 2001