V-domain immunoglobulin suppressor of T cell activation (VISTA) is a recently discovered immune checkpoint ligand that functions to suppress T cell activity. The therapeutic potential of activating this immune checkpoint pathway to reduce inflammatory responses remains untapped, largely due to the inability to derive agonists targeting its unknown receptor. A dimeric construct of the IgV domain of VISTA (VISTA-Fc) was shown to suppress the activation of T cells in vitro. However, this effect required its immobilization on a solid surface, suggesting that VISTA-Fc may display limited efficacy as a VISTA-receptor agonist in vivo. Herein, we have designed a stable pentameric VISTA construct (VISTA.COMP) by genetically fusing its IgV domain to the pentamerization domain from the cartilage oligomeric matrix protein (COMP). In contrast to VISTA-Fc, VISTA.COMP does not require immobilization to inhibit the proliferation of CD4+ T cells undergoing polyclonal activation. Furthermore, we show that VISTA.COMP, but not VISTA-Fc, functions as an immunosuppressive agonist in vivo capable of prolonging the survival of skin allografts in a mouse transplant model as well as rescuing mice from acute concanavalin-A–induced hepatitis. Collectively, we believe our data demonstrate that VISTA.COMP is a checkpoint receptor agonist and the first agent to our knowledge targeting the putative VISTA-receptor to suppress T cell–mediated immune responses.
Aaron Prodeus, Aws Abdul-Wahid, Amanda Sparkes, Nicholas W. Fischer, Marzena Cydzik, Nicholas Chiang, Mays Alwash, Alessandra Ferzoco, Nathalie Vacaresse, Michael Julius, Reginald M. Gorczysnki, Jean Gariépy
This file is in Adobe Acrobat (PDF) format. If you have not installed and configured the Adobe Acrobat Reader on your system.
PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.
Many versions of the free Acrobat Reader do not allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users: Right-click on the Download link and choose the option that says something like "Save Link As...". Mac users should hold the mouse button down on the link to get these same options.