Biology subjects

Gumber, D.

Publications and source records attributed to Gumber, D..

3 recordsLinked to original sources

bioRxiv2023

Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting

Chimeric antigen receptor (CAR) T cell therapeutic responses are hampered by limited T cell trafficking, persistence, and durable anti-tumor activity in solid tumor microenvironments. However, these challenges can be largely overcome by relatively unconstrained synthetic engineering strategies, which are being harnessed to improve solid tumor CAR T cell therapies. Here, we describe fully optimized CAR T cells targeting tumor-associated glycoprotein-72 (TAG72) for the treatment of solid tumors, identifying the CD28 transmembrane domain upstream of the 4-1BB co-stimulatory domain as a driver of potent anti-tumor activity and IFN{gamma} secretion. These findings have culminated into a phase 1 trial evaluating safety, feasibility, and bioactivity of TAG72-CAR T cells for the treatment of patients with advanced ovarian cancer (NCT05225363). Preclinically, we found that CAR T cell-mediated IFN{gamma} production facilitated by IL-12 signaling was required for tumor cell killing, which was recapitulated by expressing an optimized membrane-bound IL-12 (mbIL12) molecule on CAR T cells. Critically, mbIL12 cell surface expression and downstream signaling was induced and sustained only following CAR T cell activation. CAR T cells with mbIL12 demonstrated improved antigen-dependent T cell proliferation and potent cytotoxicity in recursive tumor cell killing assays in vitro and showed robust in vivo anti-tumor efficacy in human xenograft models of ovarian cancer peritoneal metastasis. Further, locoregional administration of TAG72-CAR T cells with antigen-dependent IL-12 signaling promoted durable anti-tumor responses against both regional and systemic disease in mice and was associated with improved systemic T cell persistence. Our study features a clinically-applicable strategy to improve the overall efficacy of locoregionally-delivered CAR T cells engineered with antigen-dependent immune-modulating cytokines in targeting both regional and systemic disease.

cancer biology↗

bioRxiv2022

Selective IL13Rα2-Targeted Functionality of IL13-Ligand CARs is Enhanced by Inclusion of 4-1BB Co-Stimulation

ABSTRACTChimeric antigen receptor (CAR) T cell immunotherapy is emerging as a powerful strategy for cancer therapy; however, an important safety consideration is the potential for off-tumor recognition of normal tissue. This is particularly important as ligand-based CARs are optimized for clinical translation. Our group has developed and clinically translated an IL13(E12Y) ligand- based CAR targeting the cancer antigen IL13R2 for treatment of glioblastoma (GBM). There remains limited understanding of how IL13-ligand CAR design impacts the activity and selectivity for the intended tumor-associated target IL13R2 versus the more ubiquitous unintended target IL13R1. In this study, we functionally compared IL13(E12Y)-CARs incorporating different intracellular signaling domains, including first-generation CD3{zeta}- containing CARs (IL13{zeta}), second-generation 4-1BB- (CD137) or CD28-containing CARs (IL13- BB{zeta} or IL13-28{zeta}), and third-generation CARs containing both 4-1BB and CD28 (IL13-28BB{zeta}). In vitro co-culture assays at high tumor burden establish that 2nd generation IL13-BB{zeta} or IL13- 28{zeta} outperform first-generation IL13{zeta} and 3rd generation IL13-28BB{zeta} CAR designs, with IL13- BB{zeta} providing superior CAR proliferation and in vivo anti-tumor potency in human xenograft mouse models. IL13-28{zeta} displayed a lower threshold for antigen recognition, resulting in higher off-target IL13R1 reactivity both in vitro and in vivo. Syngeneic mouse models of GBM also demonstrate safety and anti-tumor potency of murine IL13-BB{zeta} CAR T cells delivered systemically after lymphodepletion. These findings support the use of IL13-BB{zeta} CARs for greater selective recognition of IL13R2 over IL13R1, higher proliferative potential, and superior anti-tumor responsiveness. This study exemplifies the potential of modulating factors outside the antigen targeting domain of a CAR to improve selective tumor recognition..

immunology↗

bioRxiv2020

Selective activation of FZD7 promotes mesendodermal differentiation of human pluripotent stem cells.

WNT proteins are secreted symmetry breaking signals that interact with cell surface receptors of the FZD family to regulate a multitude of developmental processes. Studying selectivity between WNTs and FZDs has been hampered by the paucity of purified WNT proteins and by their apparent non-selective interactions with the FZD receptors. Here we describe an engineered protein, called F7L6, comprised of antibody-derived single chain variable fragments that selectively binds to human FZD7 and the co-receptor LRP6. F7L6 potently activates WNT/{beta}-catenin signaling in a manner similar to Wnt3a. In contrast to Wnt3a, F7L6 engages only FZD7 and none of the other FZD proteins. Treatment of human pluripotent stem (hPS) cells with F7L6 initiates transcriptional programs similar to those observed during primitive streak formation and subsequent gastrulation in the mammalian embryo. This demonstrates that selective engagement and activation of FZD7 signaling is sufficient to promote mesendodermal differentiation of hPS cells.

developmental biology↗