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Nelson, M. H.

Publications and source records attributed to Nelson, M. H..

3 recordsLinked to original sources

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↗

Identification of human CD4+ T cell populations with distinct antitumor activity

How naturally arising human CD4+ T helper subsets impact tumor immunity is unknown. We reported that human CD4+CD26high T cells elicit potent immunity against solid tumor malignancies. As CD26high T cells secrete type-17 cytokines and have been categorized as Th17 cells, we posited these helper populations would possess similar molecular properties. Herein, we reveal that CD26high T cells are epigenetically and transcriptionally distinct from Th17 cells. Of clinical significance, CD26high T cells engineered with a chimeric antigen receptor (CAR) ablated large human tumors to a greater extent than enriched Th17, Th1, or Th2 cells. Moreover, CD26high T cells mediated curative responses in mice, even when redirected with a suboptimal CAR and without the aid of CD8+ CAR T cells. CD26high T cells co-secreted effector cytokines at heightened levels and robustly persisted. Collectively, our work reveals the potential of human CD4+ T cell populations to improve durability of solid tumor therapies.

immunology↗

PI3Kδ inhibition supports memory T cells with enhanced antitumor fitness

Phosphatidylinositol-3-kinase p110{delta} (PI3K{delta}) inhibition by Idelalisib (CAL-101) in hematological malignancies directly induces apoptosis in cancer cells and disrupts immunological tolerance by depleting regulatory T cells (Tregs). Yet, little is known about the direct impact of PI3K{delta} blockade on effector T cells from CAL-101 therapy. Herein, we demonstrate a direct effect of p110{delta} inactivation via CAL-101 on murine and human CD8+ T cells that promotes a strong undifferentiated memory phenotype (elevated CD62L/CCR7, CD127 and Tcf7). These CAL-101 T cells also persisted longer after transfer and exerted stronger antitumor immunity compared to traditionally expanded CD8+ T cells in two solid tumor models. Thus, this report describes a novel direct enhancement of CD8+ T cell memory by a p110{delta} inhibitor that leads to markedly improved tumor regression. This finding has significant implications to improve outcomes from next generation cancer immunotherapies.\n\nHighlightsO_LIIn vitro blockade of PI3K p110{delta} with CAL-101 endows antitumor T cells with a stronger memory phenotype than those treated with AKTi\nC_LIO_LIThe strong memory phenotype of CAL-101 treated cells translates into improved survival of mice bearing aggressive tumors after adoptive transfer of these T cells\nC_LIO_LIHuman CAR engineered T cells treated with CAL-101 possess an enhanced memory phenotype and robust antitumor efficacy\nC_LIO_LIThe antitumor efficacy of CAL-101 primed T cells is not mediated by high CD62L or CD127 expression, but is likely driven by their stem memory phenotype\nC_LI\n\neTOC BlurbBowers et al report a novel function of PI3K blockade using the p110{delta} subunit inhibitor CAL-101 to induce memory and antitumor potency in CD8+ T cells. Ex vivo treatment of T cells with CAL-101 leads to improved antitumor control and subject survival in both murine transgenic T cell and human CAR T cell models.

cancer biology↗