Biology subjects

Riley, J. L.

Publications and source records attributed to Riley, J. L..

5 recordsLinked to original sources

bioRxiv2026

An ancestral haplotype of P2RX5 yields a B-cell surface marker and a promising multi-lineage immunotherapy target

While CD19- and BCMA-directed immunotherapies have improved outcomes for B-lymphoid and plasma cell malignancies, frequent relapses with antigen loss/downregulation highlight the need for new targets. Here, using transcriptomic datasets and newly-developed monoclonal antibodies, we show that P2RX5, long considered a pseudogene in humans, encodes a stable protein in 80% of individuals of African descent carrying the ancestral haplotype. Like CD19, P2RX5 displays B-cell lineage-restricted expression in normal tissues. Unlike CD19, P2RX5 is expressed not only in B-cell neoplasms, but also in T-cell leukemia (T-ALL) and multiple myeloma (MM). We developed P2RX5-directed bispecific T-cell engagers and CAR T cells, which killed T-ALL cells with no evidence of T-cell fratricide. These agents were non-inferior to FDA-approved CD19- and BCMA-directed immunotherapeutics in cell culture and xenograft models of Burkitt lymphoma and MM, while maintaining potency against CD19- and BCMA-negative variants. Hence, P2RX5 is a unique multi-lineage target for frontline or salvage immunotherapy.

cancer biology↗

bioRxiv2024

Rab5 Overcomes CAR T Cell Dysfunction Induced by Tumor-Mediated CAR Capture

Continuous interaction between chimeric antigen receptor (CAR) T cell (CART) and tumors often result in CART dysfunction and tumor escape. We observed that tumors can take up CAR molecules, leaving CARTs without surface-expressed CARs and thus unable to kill tumors after prolonged exposure. Overexpression of Rab5 resulted in augmented clathrin-independent endocytosis, preventing loss of surface-expressed CARs, and enhanced CART activity. Interestingly, we observed membrane protrusions on the CART cell surface which disappeared after multiple tumor challenges. Rab5 maintained these protrusions after repeated tumor engagements and their presence correlated with effective tumor clearance, suggesting a link between endocytosis, membrane protrusions, and cytolytic activity. In vivo, Rab5-expressing CARTs demonstrated improved activity and were able to clear an otherwise refractory mesothelin-expressing solid cancer in humanized mice by maintaining CAR surface expression within the tumor. Thus, pairing Rab5 with CAR expression could improve the clinical efficacy of CART therapy. Highlights O_LI"CAR-jacking" occurs when surface CAR is internalized by target tumor cells. C_LIO_LIRab5 overexpression prevents "CAR-jacking" and enhances CART function. C_LIO_LIRab5 promotes CAR endocytic recycling and maintains membrane protrusions. C_LIO_LIRab5-expressing CARTs exhibit enhanced therapeutic efficacy against solid tumors. C_LI

immunology↗

bioRxiv2024

Gene-modified NK Cells Expressing CD64 and Pre-loaded with HIV-specific BNAbs Target Autologous HIV-1 Infected CD4+ T Cells by ADCC.

NK cells can efficiently mediate antibody-dependent cellular cytotoxicity (ADCC) of antibody coated target cells via the low-affinity Fc-receptor, CD16, but cannot retain antibodies over time. To increase antibody retention and facilitate targeted ADCC, we genetically modified human NK cells with the high-affinity Fc receptor, CD64, so that we could pre-load them with HIV-specific BNAbs and enhance their capacity to target HIV infected cells via ADCC. Purified NK cells from the peripheral blood of Control Donors or Persons Living with HIV (PLWH) were activated with IL-2/IL-15/IL-21 cytokines and transduced with a lentivirus encoding CD64. High levels of CD64 surface expression were maintained for multiple weeks on NK cells and CD64 transduced NK cells were similar to control NK cells with strong expression of CD56, CD16, NKG2A, NKp46, CD69, HLA-DR, CD38, and CD57. CD64 transduced NK cells exhibited significantly greater capacity to bind HIV-specific BNAbs in short-term antibody binding assay as well as retain the BNAbs over time (1 week antibody retention assay) compared to Control NK cells only expressing CD16. BNAb pre-loaded CD64 transduced NK cells showed a significantly enhanced capacity to mediate ADCC against autologous HIV-1 infected CD4+ primary T cells in both a short term 3 hour degranulation assay as well as a 24 hour HIV p24 HIV Elimination Assay when compared to control NK cells. A chimeric CD64 enhanced NK cell strategy (NK Enhancement Strategy, "NuKES") retaining bound HIV-specific antibody and targeted ADCC represents a novel autologous primary NK cell immuno-therapy strategy against HIV.

immunology↗

bioRxiv2022

Augmenting TCR signal strength and ICOS costimulation results in metabolically fit and therapeutically potent human CAR Th17 cell therapy

Adoptive cell transfer (ACT) therapy with IL-17 producing human T cells elicits potent antitumor activity in preclinical models. However, further refinement of this novel approach is needed to position it for clinical application. While activation signal strength differentially regulates IL-17 production by human CD4+ T cells, the degree to which TCR and co-stimulation signal strength impacts antitumor Th17 cell immunity remains poorly understood. We discovered that decreasing TCR/co-stimulation signal strength by incremental reduction of CD3/co-stimulation beads in a Th17 culture progressively diminished their effector memory phenotype but enhanced their polyfunctionality. Additional investigation revealed that Th17 cells stimulated with CD3/ICOS beads produced more IL-17A, IFN{gamma}, IL-2 and IL-22 than those stimulated with CD3/CD28 beads, regardless of signal strength. Th17 cells propagated with 30-fold fewer CD3/ICOS beads (weak signal strength, 1 bead per 10 T cells) were less reliant on glucose for growth compared to those stimulated with the standard, strong signal strength (3 beads per T cell). Further metabolomic analysis revealed Th17 cells weakly simulated with CD3/ICOS beads favored the central carbon pathway through increased gluconeogenesis for bioenergetics, marked by abundant intracellular phosphoenoylpyruvate (PEP). Importantly, Th17 cells weakly stimulated with CD3/ICOS beads and redirected with a chimeric antigen receptor (CAR) that recognizes mesothelin were more effective at clearing large human mesothelioma tumors when infused into mice than those manufactured using the standard FDA-approved protocols. Taken together, these data indicate Th17 ACT therapy can be improved by using fewer activation beads during T cell manufacturing, a finding that is both cost effective and directly translatable to patients.

immunology↗

bioRxiv2019

Discovery and Engineering of a Therapeutic Interfering Particle (TIP): a combination self-renewing antiviral

Population-level control of HIV-1 faces recognized challenges, including the evolution of viral resistance and adherence issues in resource-limited settings. It has long been proposed that viral deletion mutants that conditionally self-renew at the expense of the wild-type virus (i.e., Defective Interfering Particles, DIPs1) could constitute a long-term intervention that circumvents adherence challenges and has a high genetic barrier to resistance, echoing recent approaches2. Theories predict3, 4 that DIPs could be engineered into a therapy for HIV-1 (i.e., Therapeutic interfering particles or TIPs) provided they stably persist in patients (R0>1) by spreading to new cells during active infection (hence, a self-replenishing antiviral). To date, DIPs amenable to such engineering have remained elusive for HIV-1. Here we report the discovery of an HIV-1 DIP and its subsequent engineering into a TIP. The TIP interferes with HIV-1 replication at multiple stages of the viral lifecycle, including genome packaging, virion maturation, and reverse transcription, essentially acting as a combination antiviral. In humanized mice, the TIP suppressed HIV-1 replication by ten-fold and significantly protected CD4+ T cells from HIV-1 mediated depletion. These data provide proof-of-concept for a class of biologic with the potential to circumvent significant barriers to HIV-1 control.

synthetic biology↗