Search

Exhausted CD8 T (T ex ) cells in chronic viral infection and cancer have sustained co-expression of inhibitory receptors (IRs). T ex cells can be reinvigorated by blocking IRs, such as PD-1, but synergistic reinvigoration and enhanced disease control can be achieved by co-targeting multiple IRs including PD-1 and LAG-3. To dissect the molecular changes intrinsic when these IR pathways are disrupted, we investigated the impact of loss of PD-1 and/or LAG-3 on T ex cells during chronic infection. These analyses revealed distinct roles of PD-1 and LAG-3 in regulating T ex cell proliferation and effector functions, respectively. Moreover, these studies identified an essential role for LAG-3 in sustaining TOX and T ex cell durability as well as a LAG-3-dependent circuit that generated a CD94/NKG2 + subset of T ex cells with enhanced cytotoxicity mediated by recognition of the stress ligand Qa-1b, with similar observations in humans. These analyses disentangle the non-redundant mechanisms of PD-1 and LAG-3 and their synergy in regulating T ex cells., Competing Interests: Declaration of interests E.J.W. is a member of the Parker Institute for Cancer Immunotherapy which supported this study. E.J.W. is an advisor for Arsenal Bioscience, Coherus, Danger Bio, Janssen, New Limit, Marengo, Pluto Immunotherapeutics, Prox Biosciences, Related Sciences, Santa Ana Bio, and Synthekine. E.J.W. is a founder of and holds stock in Arsenal Biosciences. A.H.S. has patents/pending royalties on the PD-1 pathway from Roche and Novartis and has research funding from IOME, AbbVie, and Taiwan Bio. A.H.S. serves as an advisor for Selecta, Elpiscience, Monopteros, Bicara, Fibrogen, IOME, Bioentre, Corner Therapeutics, Alixia, GlaxoSmithKline, Amgen, and Janssen. D.A.A.V. has patents covering LAG-3, with others pending. D.A.A.V. is a co-founder and stockholder for Novasenta, Tizona, and Trishula; a stockholder for Oncorus and Werewolf; and has patents licensed to Bristol Myers Squibb (BMS) and Novasenta. D.A.A.V. is a scientific advisor for Tizona, Werewolf, F-Star, Bicara, Apeximmune, and T7/Imreg Bio and is a consultant for BMS, Incyte, Regeneron, Ono Pharma, Peptone, and Avidity Partners. D.A.A.V. receives research funding from BMS and Novasenta. O.K. holds stock in Arsenal Biosciences and is an employee of Orange Grove Bio. A.C.H. consults for Immunai and received research funding from BMS and Merck. J.R.G. consults for Arsenal Biosciences., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Macrophages play a pivotal role in tumor immunity. We report that reprogramming of macrophages to tumor-associated macrophages (TAMs) promotes the secretion of exosomes. Mechanistically, increased exosome secretion is driven by MADD, which is phosphorylated by Akt upon TAM induction and activates Rab27a. TAM exosomes carry high levels of programmed death-ligand 1 (PD-L1) and potently suppress the proliferation and function of CD8 + T cells. Analysis of patient melanoma tissues indicates that TAM exosomes contribute significantly to CD8 + T cell suppression. Single-cell RNA sequencing analysis showed that exosome-related genes are highly expressed in macrophages in melanoma; TAM-specific RAB27A expression inversely correlates with CD8 + T cell infiltration. In a murine melanoma model, lipid nanoparticle delivery of small interfering RNAs (siRNAs) targeting macrophage RAB27A led to better T cell activation and sensitized tumors to anti-programmed cell death protein 1 (PD-1) treatment. Our study demonstrates tumors use TAM exosomes to combat CD8 T cells and suggests targeting TAM exosomes as a potential strategy to improve immunotherapies., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to "humanize" ovarian cancer patient-derived xenograft (PDX) models by autologous transfer of patient-matched tumor infiltrating lymphocytes (TILs) to evaluate immunotherapies., Methods: Orthotopic high-grade serous ovarian cancer (HGSOC) PDX models were established from three patient donors. Models were molecularly and histologically validated by immunohistochemistry. TILs were expanded from donor tumors using a rapid expansion protocol. Ex vivo TIL and tumor co-cultures were performed to validate TIL reactivity against patient-matched autologous tumor cells. Expression of TIL activation markers and cytokine secretion was quantitated by flow cytometry and ELISA. As proof of concept, the efficacy of anti-PD-1 monotherapy was tested in autologous TIL/tumor HGSOC PDX models., Results: Evaluation of T-cell activation in autologous TIL/tumor co-cultures resulted in an increase in HLA-dependent IFNγ production and T-cell activation. In response to increased IFNγ production, tumor cell expression of PD-L1 was increased. Addition of anti-PD-1 antibody to TIL/tumor co-cultures increased autologous tumor lysis in a CCNE1 amplified model. Orthotopic HGSOC PDX models from parallel patient-matched tumors maintained their original morphology and molecular marker profile. Autologous tumor-reactive TIL administration in patient-matched PDX models resulted in reduced tumor burden and increased survival, in groups that also received anti-PD-1 therapy., Conclusions: This study validates a novel, clinically relevant model system for in vivo testing of immunomodulating therapeutic strategies for ovarian cancer, and provides a unique platform for assessing patient-specific T-cell response to immunotherapy., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The recent success of immune checkpoint blockade in melanoma and lung adenocarcinoma has galvanized the field of immuno-oncology as well as revealed the limitations of current treatments, as the majority of patients do not respond to immunotherapy. Development of accurate preclinical models to quickly identify novel and effective therapeutic combinations are critical to address this unmet clinical need. Pancreatic ductal adenocarcinoma (PDA) is a canonical example of an immune checkpoint blockade resistant tumor with only 2% of patients responding to immunotherapy. The genetically engineered Kras G12D+/- ;Trp53 R172H+/- ;Pdx-1 Cre (KPC) mouse model of PDA recapitulates human disease and is a valuable tool for assessing therapies for immunotherapy resistant in the preclinical setting, but time to tumor onset is highly variable. Surgical orthotopic tumor implantation models of PDA maintain the immunobiological hallmarks of the KPC tissue-specific tumor microenvironment (TME) but require a time-intensive procedure and introduce aberrant inflammation. Here, we use an ultrasound-guided orthotopic tumor implantation model (UG-OTIM) to non-invasively inject KPC-derived PDA cell lines directly into the mouse pancreas. UG-OTIM tumors grow in the endogenous tissue site, faithfully recapitulate histological features of the PDA TME, and reach enrollment-sized tumors for preclinical studies by four weeks after injection with minimal seeding on the peritoneal wall. The UG-OTIM system described here is a rapid and reproducible tumor model that may allow for high throughput analysis of novel therapeutic combinations in the murine PDA TME.