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Project description:Immunotherapy using checkpoint-blocking antibodies against PD-1 has produced impressive results in a wide range of cancers. However, the response remains heterogeneous among patients. We used noninvasive immuno-positron emission tomography (PET), using 89Zr-labeled PEGylated single-domain antibody fragments (nanobodies or VHHs), to explore the dynamics and distribution of intratumoral CD8+ T cells and CD11b+ myeloid cells in response to anti-PD-1 treatment in the MC38 colorectal mouse adenocarcinoma model. Responding and nonresponding tumors showed consistent differences in the distribution of CD8+ and CD11b+ cells. Anti-PD-1 treatment mobilized CD8+ T cells from the tumor periphery to a more central location. Only those tumors fully infiltrated by CD8+ T cells went on to complete resolution. All tumors contained CD11b+ myeloid cells from the outset of treatment, with later recruitment of additional CD11b+ cells. As tumors grew, the distribution of intratumoral CD11b+ cells became more heterogeneous. Shrinkage of tumors in responders correlated with an increase in the CD11b+ population in the center of the tumors. The changes in distribution of CD8+ and CD11b+ cells, as assessed by PET, served as biomarkers to gauge the efficacy of anti-PD-1 treatment. Single-cell RNA sequencing of RNA from intratumoral CD45+ cells showed that CD11b+ cells in responders and nonresponders were markedly different. The responders exhibited a dominant population of macrophages with an M1-like signature, while the CD45+ population in the nonresponders displayed an M2-like transcriptional signature. Thus, by using immuno-PET and single-cell RNA sequencing, we show that anti-PD-1 treatment not only affects interactions of CD8+ T cells with the tumor but also impacts the intratumoral myeloid compartment.
| S-EPMC6708368 | biostudies-literature
Project description:Immunotherapy using checkpoint-blocking antibodies against PD-1 has produced impressive results in a wide range of cancers. However, the response remains heterogeneous among patients. We used noninvasive immuno-positron emission tomography (PET), using 89Zr-labeled PEGylated single-domain antibody fragments (nanobodies or VHHs), to explore the dynamics and distribution of intratumoral CD8+ T cells and CD11b+ myeloid cells in response to anti-PD-1 treatment in the MC38 colorectal mouse adenocarcinoma model. Responding and nonresponding tumors showed consistent differences in the distribution of CD8+ and CD11b+ cells. Anti-PD-1 treatment mobilized CD8+ T cells from the tumor periphery to a more central location. Only those tumors fully infiltrated by CD8+ T cells went on to complete resolution. All tumors contained CD11b+ myeloid cells from the outset of treatment, with later recruitment of additional CD11b+ cells. As tumors grew, the distribution of intratumoral CD11b+ cells became more heterogeneous. Shrinkage of tumors in responders correlated with an increase in the CD11b+ population in the center of the tumors. The changes in distribution of CD8+ and CD11b+ cells, as assessed by PET, served as biomarkers to gauge the efficacy of anti-PD-1 treatment. Single-cell RNA sequencing of RNA from intratumoral CD45+ cells showed that CD11b+ cells in responders and nonresponders were markedly different. The responders exhibited a dominant population of macrophages with an M1-like signature, while the CD45+ population in the nonresponders displayed an M2-like transcriptional signature. Thus, by using immuno-PET and single-cell RNA sequencing, we show that anti-PD-1 treatment not only affects interactions of CD8+ T cells with the tumor but also impacts the intratumoral myeloid compartment.
2019-08-21 | GSE136125 | GEO
Project description:Immunotherapy using checkpoint-blocking antibodies against PD-1 has produced impressive results in a wide range of cancers. However, the response remains heterogeneous among patients. We used noninvasive immuno-positron emission tomography (PET), using 89Zr-labeled PEGylated single-domain antibody fragments (nanobodies or VHHs), to explore the dynamics and distribution of intratumoral CD8+ T cells and CD11b+ myeloid cells in response to anti-PD-1 treatment in the MC38 colorectal mouse adenocarcinoma model. Responding and nonresponding tumors showed consistent differences in the distribution of CD8+ and CD11b+ cells. Anti-PD-1 treatment mobilized CD8+ T cells from the tumor periphery to a more central location. Only those tumors fully infiltrated by CD8+ T cells went on to complete resolution. All tumors contained CD11b+ myeloid cells from the outset of treatment, with later recruitment of additional CD11b+ cells. As tumors grew, the distribution of intratumoral CD11b+ cells became more heterogeneous. Shrinkage of tumors in responders correlated with an increase in the CD11b+ population in the center of the tumors. The changes in distribution of CD8+ and CD11b+ cells, as assessed by PET, served as biomarkers to gauge the efficacy of anti-PD-1 treatment. Single-cell RNA sequencing of RNA from intratumoral CD45+ cells showed that CD11b+ cells in responders and nonresponders were markedly different. The responders exhibited a dominant population of macrophages with an M1-like signature, while the CD45+ population in the nonresponders displayed an M2-like transcriptional signature. Thus, by using immuno-PET and single-cell RNA sequencing, we show that anti-PD-1 treatment not only affects interactions of CD8+ T cells with the tumor but also impacts the intratumoral myeloid compartment.
2019-08-21 | GSE136121 | GEO
Project description:Immuno-PET identifies the myeloid compartment as a key contributor to the outcome of the anti-tumor response under PD-1 blockade
| PRJNA561345 | ENA
Project description:Immuno-PET identifies the myeloid compartment as a key contributor to the outcome of the anti-tumor response under PD-1 blockade [scRNA-seq]
| PRJNA561347 | ENA
Project description:Immuno-PET identifies the myeloid compartment as a key contributor to the outcome of the anti-tumor response under PD-1 blockade [bulk RNA-seq]
| PRJNA561346 | ENA
Project description:BackgroundPrevious studies have shown that functional systemic immunity is required for the efficacy of PD-1/PD-L1 blockade immunotherapies in cancer. Hence, systemic reprogramming of immunosuppressive dysfunctional myeloid cells could overcome resistance to cancer immunotherapy.MethodsReprogramming of tumour-associated myeloid cells with oleuropein was studied by quantitative differential proteomics, phenotypic and functional assays in mice and lung cancer patients. Combinations of oleuropein and two different delivery methods of anti-PD-1 antibodies were tested in colorectal cancer tumour models and in immunotherapy-resistant lung cancer models.ResultsOleuropein treatment reprogrammed monocytic and granulocytic myeloid-derived suppressor cells, and tumour-associated macrophages towards differentiation of immunostimulatory subsets. Oleuropein regulated major differentiation programmes associated to immune modulation in myeloid cells, which potentiated T cell responses and PD-1 blockade. PD-1 antibodies were delivered by two different strategies, either systemically or expressed within tumours using a self-amplifying RNA vector. Combination anti-PD-1 therapies with oleuropein increased tumour infiltration by immunostimulatory dendritic cells in draining lymph nodes, leading to systemic antitumour T cell responses. Potent therapeutic activities were achieved in colon cancer and lung cancer models resistant to immunotherapies, even leading to complete tumour regression.DiscussionOleuropein significantly improves the outcome of PD-1/PD-L1 blockade immunotherapy strategies by reprogramming myeloid cells.
| S-EPMC10912768 | biostudies-literature
Project description:The rapid ascension of immune checkpoint blockade treatments has placed an emphasis on the need for viable, robust, and noninvasive imaging methods for immune checkpoint proteins, which could be of diagnostic value. Immunoconjugate-based positron emission tomography (immuno-PET) allows for sensitive and quantitative imaging of target levels and has promising potential for the noninvasive evaluation of immune checkpoint proteins. However, the advancement of immuno-PET is currently limited by available imaging tools, which heavily rely on full-length IgGs with Fc-mediated effects and are heterogeneous mixtures upon random conjugation with chelators for imaging. Herein, we have developed a site-specific αPD-L1 Fab conjugate with the chelator 1,4,7-triazacyclononane- N, N', N″-triacetic acid (NOTA), enabling radiolabeling for PET imaging, using the amber suppression-mediated genetic incorporation of unnatural amino acid (UAA), p-azidophenylalanine. This Fab conjugate is homogeneous and demonstrated tight binding toward the PD-L1 antigen in vitro. The radiolabeled version, 64Cu-NOTA-αPD-L1, has been employed in PET imaging to allow for effective visualization and mapping of the biodistribution of PD-L1 in two normal mouse models, including the capturing of different PD-L1 expression levels in the spleens of the different mouse types. Follow-up in vivo blocking studies and ex vivo fluorescent staining further validated specific tissue uptakes of the imaging agent. This approach illustrates the utility of UAA-based site-specific Fab conjugation as a general strategy for making sensitive PET imaging probes, which could facilitate the elucidation of the roles of a wide variety of immune checkpoint proteins in immunotherapy.
| S-EPMC6521698 | biostudies-literature
Project description:Immune checkpoints, such as programmed death-ligand 1 (PD-L1), limit T-cell function and tumor cells use this ligand to escape the anti-tumor immune response. Treatments with monoclonal antibodies blocking these checkpoints have shown long-lasting responses, but only in a subset of patients. This study aims to develop a Nanobody (Nb)-based probe in order to assess human PD-L1 (hPD-L1) expression using positron emission tomography imaging, and to compare the influence of two different radiolabeling strategies, since the Nb has a lysine in its complementarity determining region (CDR), which may impact its affinity upon functionalization. The Nb has been conjugated with the NOTA chelator site-specifically via the Sortase-A enzyme or randomly on its lysines. [68Ga]Ga-NOTA-(hPD-L1) Nbs were obtained in >95% radiochemical purity. In vivo tumor targeting studies at 1 h 20 post-injection revealed specific tumor uptake of 1.89 ± 0.40%IA/g for the site-specific conjugate, 1.77 ± 0.29%IA/g for the random conjugate, no nonspecific organ targeting, and excretion via the kidneys and bladder. Both strategies allowed for easily obtaining 68Ga-labeled hPD-L1 Nbs in high yields. The two conjugates were stable and showed excellent in vivo targeting. Moreover, we proved that the random lysine-conjugation is a valid strategy for clinical translation of the hPD-L1 Nb, despite the lysine present in the CDR.
| S-EPMC7599876 | biostudies-literature
Project description:Myeloid-derived suppressor cells (MDSCs) are immature monocytes and granulocytes that impede immune-mediated clearance of malignant cells by multiple mechanisms, including the formation of immunosuppressive reactive oxygen species (ROS) via the myeloid cell NADPH oxidase (NOX2). Histamine dihydrochloride (HDC), a NOX2 inhibitor, exerts anti-cancer efficacy in experimental tumor models but the detailed mechanisms are insufficiently understood. To determine effects of HDC on the MDSC compartment we utilized three murine cancer models known to entail accumulation of MDSC, i.e. EL-4 lymphoma, MC-38 colorectal carcinoma, and 4T1 mammary carcinoma. In vivo treatment with HDC delayed EL-4 and 4T1 tumor growth and reduced the ROS formation by intratumoral MDSCs. HDC treatment of EL-4 bearing mice also reduced the accumulation of intratumoral MDSCs and reduced MDSC-induced suppression of T cells ex vivo. Experiments using GR1-depleted and Nox2 knock out mice supported that the anti-tumor efficacy of HDC required presence of NOX2+ GR1+ cells in vivo. In addition, treatment with HDC enhanced the anti-tumor efficacy of programmed cell death receptor 1 (PD-1) and PD-1 ligand checkpoint blockade in EL-4- and MC-38-bearing mice. Immunomodulatory effects of a HDC-containing regimen on MDSCs were further analyzed in a phase IV trial (Re:Mission Trial, ClinicalTrials.gov; NCT01347996) where patients with acute myeloid leukemia received HDC in conjunction with low-dose IL-2 (HDC/IL-2) for relapse prevention. Peripheral CD14+HLA-DR-/low MDSCs (M-MDSCs) were reduced during cycles of HDC/IL-2 therapy and a pronounced reduction of M-MDSCs during HDC/IL-2 treatment heralded favorable clinical outcome. We propose that anti-tumor properties of HDC may comprise the targeting of MDSCs.
| S-EPMC6394491 | biostudies-literature