VISTA.COMP — an engineered checkpoint receptor agonist that potently suppresses T cell–mediated immune responses
Aaron Prodeus, … , Reginald M. Gorczysnki, Jean Gariépy
Aaron Prodeus, … , Reginald M. Gorczysnki, Jean Gariépy
Published September 21, 2017
Citation Information: JCI Insight. 2017;2(18):e94308. https://doi.org/10.1172/jci.insight.94308.
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Research Article Immunology Therapeutics

VISTA.COMP — an engineered checkpoint receptor agonist that potently suppresses T cell–mediated immune responses

Abstract

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.

Authors

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

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Figure 1

Pentameric VISTA.COMP suppresses T cell activation and proliferation as a soluble ligand in vitro.

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Pentameric VISTA.COMP suppresses T cell activation and proliferation as ...
(A) CFSE-labeled purified murine CD4+ T cells were activated by plate-bound anti-CD3 antibody (2.5 μg/ml) in the presence (blue) or absence (red) of immobilized (left) or soluble (right) VISTA-Fc (10 μg/ml) for 48 hours. VISTA-Fc suppresses the proliferation of CD4+ T cells when immobilized but not when added as a soluble ligand in the culture media. (B) Recombinant VISTA.COMP was expressed as described in the Methods, and the purity and pentameric status was confirmed by SDS-PAGE and Western blot in the presence or absence of a reducing agent (DTT). Reduced VISTA.COMP migrates as a single band approximately 50 kDa, while the disulfide-stabilized pentamer has an apparent mass of 250 kDa. (C) Proliferation assay of CD4+ T cells undergoing activation in the presence of coated (9 μg/ml, left) or soluble (12 μg/ml, right) VISTA.COMP (blue) or COMP (red). Soluble VISTA.COMP suppresses T cell expansion (top, forward scatter [FSC] and side scatter [SSC] profiles) and proliferation (bottom, CFSE dilution). Culture medium was harvested from CD4+ T cells 48 and 72 hours after anti-CD3 activation in the presence of COMP or VISTA.COMP (10 μg/ml), and IL-2 (D) and IFN-γ (E) secretion was quantified by ELISA. In addition to proliferation, VISTA.COMP was found to significantly suppress IL-2 and IFN-γ secretion from T cells (data represent mean ± SEM, ***P < 0.005 relative to COMP control by Student’s t test, n = 3). All data shown are representative of at least 3 independent experiments.