The brain has a limited capacity to self-protect against protein aggregate-associated pathology, and mounting evidence supports a role for phagocytic glia in this process. We have established a Drosophila model to investigate the role of phagocytic glia in clearance of neuronal mutant huntingtin (Htt) aggregates associated with Huntington disease. We find that glia regulate steady-state numbers of Htt aggregates expressed in neurons through a clearance mechanism that requires the glial scavenger receptor Draper and downstream phagocytic machinery. Remarkably, some of these engulfed neuronal Htt aggregates effect prion-like conversion of soluble, wild-type Htt in the glial cytoplasm. We provide genetic evidence that this conversion depends strictly on the Draper signaling pathway, unveiling a previously unanticipated role for phagocytosis in transfer of pathogenic protein aggregates in an intact brain. These results suggest a potential mechanism by which phagocytic glia contribute to both protein aggregate-related neuroprotection and pathogenesis in neurodegenerative disease.

Pancreatic ductal adenocarcinoma (PDA) is a lethal cancer resistant to immunotherapy. We create a PDA mouse model and show that neoantigen expression is required for intratumoral T cell accumulation and response to immune checkpoint blockade. By generating a peptide:MHC tetramer, we identify that PDA induces rapid intratumoral, and progressive systemic, tumor-specific T cell exhaustion. Monotherapy PD-1 or PD-L1 blockade enhances systemic T cell expansion and induces objective responses that require systemic T cells. However, tumor escape variants defective in IFNg-inducible Tap1 and MHC class I cell surface expression ultimately emerge. Combination PD-1 + PD-L1 blockade synergizes therapeutically by increasing intratumoral KLRG1+Lag3ÀTNFa+ tumor-specific T cells and generating memory T cells capable of expanding to spontaneous tumor recurrence, thereby prolonging animal survival. Our studies support that PD-1 and PD-L1 are relevant immune checkpoints in PDA and identify a combination for clinical testing in those patients with neoantigenspecific T cells.

Pancreatic cancer is a particularly lethal malignancy and resists immunotherapy. Here, using a preclinical pancreatic cancer murine model, we demonstrate a progressive decrease in IFNγ and Granzyme B and a concomitant increase in Tox and IL-10 in intratumoral tumor-specific T cells. Intratumoral myeloid cells produced elevated IL-27, a cytokine that correlates with poor patient outcome. Abrogating IL-27 signaling significantly decreased intratumoral Tox+ T cells and delayed tumor growth yet was not curative. Agonistic αCD40 decreased intratumoral IL-27producing myeloid cells, decreased IL-10-producing intratumoral T cells, and promoted intratumoral Klrg1+Gzmb+ short-lived effector T cells. Combination agonistic αCD40+αPD-L1 cured 63% of tumor-bearing animals, promoted rejection following tumor re-challenge and correlated with a 2-log increase in pancreas-residing tumor-specific T cells. Interfering with Ifngr1 expression in non-tumor/host cells abrogated agonistic αCD40+αPD-L1 efficacy. In contrast, interfering with non-tumor/host cell Tnfrsf1a led to cure in 100% of animals following agonistic αCD40+αPD-L1 and promoted the formation of circulating central memory T cells rather than

Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy resistant to therapies, including immune-checkpoint blockade. We investigated two distinct strategies to modulate tumor-associated macrophages (TAM) to enhance cellular therapy targeting mesothelin in an autochthonous PDA mouse model. Administration of an antibody to colonystimulating factor (anti-Csf1R) depleted Ly6C low protumorigenic TAMs and significantly enhanced endogenous T-cell intratumoral accumulation. Despite increasing the number of endogenous T cells at the tumor site, as previously reported, TAM depletion had only minimal impact on intratumoral accumulation and persistence of T cells engineered to express a murine mesothelin-specific T-cell receptor (TCR). TAM depletion interfered with the antitumor activity of the infused T cells in PDA, evidenced by reduced tumor cell apoptosis. In contrast, TAM programming with agonistic anti-CD40 increased both Ly6C high TAMs and the intratumoral accumulation and longevity of TCR-engineered T cells. Anti-CD40 significantly increased the frequency and number of proliferating and granzyme B þ engineered T cells, and increased tumor cell apoptosis. However, anti-CD40 failed to rescue intratumoral engineered T-cell IFNg production. Thus, although functional modulation, rather than TAM depletion, enhanced the longevity of engineered T cells and increased tumor cell apoptosis, ultimately, anti-CD40 modulation was insufficient to rescue key effector defects in tumor-reactive T cells. This study highlights critical distinctions between how endogenous T cells that evolve in vivo, and engineered T cells with previously acquired effector activity, respond to modifications of the tumor microenvironment.

NSAIDs given prophylactically or within 30 days of flare onset may shorten neuropsychiatric symptom duration in patients with new-onset and relapsing/remitting PANS and PANDAS. A randomized placebo-control clinical trial of NSAIDs in PANS is warranted to formally assess treatment efficacy.

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IMS has patents on T cell receptors (62758397, 62808248), serves on the scientific advisory boards of Luminary Therapeutics and Immunogenesis, and has sponsored research projects with Genocea and Small Business Innovation Research grants.

T lymphocytes are capable of specific recognition and elimination of target cells. Physiological antigen recognition is mediated by the T cell receptor (TCR), which is an alpha beta heterodimer comprising the products of randomly rearranged V, D, and J genes. The exquisite specificity and functionality of T cells can be leveraged for cancer therapy: specifically, the adoptive transfer of T cells that express tumor-reactive TCRs can induce regression of solid tumors in patients with advanced cancer. However, the isolation and expression of a tumor antigen-specific TCRs is a highly involved process that requires identifying an immunogenic epitope, ensuring human cells are of the correct haplotype, performing a laborious T cell expansion process, and carrying out downstream TCR sequencing and cloning. Recent advances in single-cell sequencing have begun to streamline this process. This protocol synthesizes and expands upon methodologies to generate, isolate, and engineer human T cells with tumor-reactive TCRs for adoptive cell therapy. Though this process is perhaps more arduous than the alternative strategy of using chimeric antigen receptors (CARs) for engineering, the ability to target intracellular proteins using TCRs substantially increases the types of antigens that can be safely targeted.