An IL-4 signalling axis in bone marrow drives pro-tumorigenic myelopoiesis

Myeloid cells are known to suppress antitumour immunity1. However, the molecular drivers of immunosuppressive myeloid cell states are not well defined. Here we used single-cell RNA sequencing of human and mouse non-small cell lung cancer (NSCLC) lesions, and found that in both species the type 2 cytokine interleukin-4 (IL-4) was predicted to be the primary driver of the tumour-infiltrating monocyte-derived macrophage phenotype. Using a panel of conditional knockout mice, we found that only deletion of the IL-4 receptor IL-4Rα in early myeloid progenitors in bone marrow reduced tumour burden, whereas deletion of IL-4Rα in downstream mature myeloid cells had no effect. Mechanistically, IL-4 derived from bone marrow basophils and eosinophils acted on granulocyte-monocyte progenitors to transcriptionally programme the development of immunosuppressive tumour-promoting myeloid cells. Consequentially, depletion of basophils profoundly reduced tumour burden and normalized myelopoiesis. We subsequently initiated a clinical trial of the IL-4Rα blocking antibody dupilumab2-5 given in conjunction with PD-1/PD-L1 checkpoint blockade in patients with relapsed or refractory NSCLC who had progressed on PD-1/PD-L1 blockade alone (ClinicalTrials.gov identifier NCT05013450 ). Dupilumab supplementation reduced circulating monocytes, expanded tumour-infiltrating CD8 T cells, and in one out of six patients, drove a near-complete clinical response two months after treatment. Our study defines a central role for IL-4 in controlling immunosuppressive myelopoiesis in cancer, identifies a novel combination therapy for immune checkpoint blockade in humans, and highlights cancer as a systemic malady that requires therapeutic strategies beyond the primary disease site.

Circulating senescent myeloid cells infiltrate the brain and cause neurodegeneration in histiocytic disorders

Neurodegenerative diseases (ND) are characterized by progressive loss of neuronal function. Mechanisms of ND pathogenesis are incompletely understood, hampering the development of effective therapies. Langerhans cell histiocytosis (LCH) is an inflammatory neoplastic disorder caused by hematopoietic progenitors expressing mitogen-activated protein kinase (MAPK)-activating mutations that differentiate into senescent myeloid cells that drive lesion formation. Some individuals with LCH subsequently develop progressive and incurable neurodegeneration (LCH-ND). Here, we showed that LCH-ND was caused by myeloid cells that were clonal with peripheral LCH cells. Circulating BRAFV600E+ myeloid cells caused the breakdown of the blood-brain barrier (BBB), enhancing migration into the brain parenchyma where they differentiated into senescent, inflammatory CD11a+ macrophages that accumulated in the brainstem and cerebellum. Blocking MAPK activity and senescence programs reduced peripheral inflammation, brain parenchymal infiltration, neuroinflammation, neuronal damage and improved neurological outcome in preclinical LCH-ND. MAPK activation and senescence programs in circulating myeloid cells represent targetable mechanisms of LCH-ND.

Circulating senescent myeloid cells drive blood brain barrier breakdown and neurodegeneration

Neurodegenerative diseases (ND) are characterized by progressive loss of neuronal function. Mechanisms of ND pathogenesis are incompletely understood, hampering the development of effective therapies. Langerhans cell histiocytosis (LCH) is an inflammatory neoplastic disorder caused by hematopoietic progenitors expressing MAPK activating mutations that differentiate into senescent myeloid cells that drive lesion formation. Some patients with LCH subsequently develop progressive and incurable neurodegeneration (LCH-ND). Here, we show that LCH-ND is caused by myeloid cells that are clonal with peripheral LCH cells. We discovered that circulating BRAF V600E + myeloid cells cause the breakdown of the blood-brain barrier (BBB), enhancing migration into the brain parenchyma where they differentiate into senescent, inflammatory CD11a + macrophages that accumulate in the brainstem and cerebellum. Blocking MAPK activity and senescence programs reduced parenchymal infiltration, neuroinflammation, neuronal damage and improved neurological outcome in preclinical LCH-ND. MAPK activation and senescence programs in circulating myeloid cells represent novel and targetable mechanisms of ND.

Intratumoral dendritic cell-CD4+ T helper cell niches enable CD8+ T cell differentiation following PD-1 blockade in hepatocellular carcinoma

Despite no apparent defects in T cell priming and recruitment to tumors, a large subset of T cell rich tumors fail to respond to immune checkpoint blockade (ICB). We leveraged a neoadjuvant anti-PD-1 trial in patients with hepatocellular carcinoma (HCC), as well as additional samples collected from patients treated off-label, to explore correlates of response to ICB within T cell-rich tumors. We show that ICB response correlated with the clonal expansion of intratumoral CXCL13+CH25H+IL-21+PD-1+CD4+ T helper cells ("CXCL13+ TH") and Granzyme K+ PD-1+ effector-like CD8+ T cells, whereas terminally exhausted CD39hiTOXhiPD-1hiCD8+ T cells dominated in nonresponders. CD4+ and CD8+ T cell clones that expanded post-treatment were found in pretreatment biopsies. Notably, PD-1+TCF-1+ (Progenitor-exhausted) CD8+ T cells shared clones mainly with effector-like cells in responders or terminally exhausted cells in nonresponders, suggesting that local CD8+ T cell differentiation occurs upon ICB. We found that these Progenitor CD8+ T cells interact with CXCL13+ TH within cellular triads around dendritic cells enriched in maturation and regulatory molecules, or "mregDC". These results suggest that discrete intratumoral niches that include mregDC and CXCL13+ TH control the differentiation of tumor-specific Progenitor exhasuted CD8+ T cells following ICB.

TREM2 macrophages drive NK cell paucity and dysfunction in lung cancer

Natural killer (NK) cells are commonly reduced in human tumors, enabling many to evade surveillance. Here, we sought to identify cues that alter NK cell activity in tumors. We found that, in human lung cancer, the presence of NK cells inversely correlated with that of monocyte-derived macrophages (mo-macs). In a murine model of lung adenocarcinoma, we show that engulfment of tumor debris by mo-macs triggers a pro-tumorigenic program governed by triggering receptor expressed on myeloid cells 2 (TREM2). Genetic deletion of Trem2 rescued NK cell accumulation and enabled an NK cell-mediated regression of lung tumors. TREM2+ mo-macs reduced NK cell activity by modulating interleukin (IL)-18/IL-18BP decoy interactions and IL-15 production. Notably, TREM2 blockade synergized with an NK cell-activating agent to further inhibit tumor growth. Altogether, our findings identify a new axis, in which TREM2+ mo-macs suppress NK cell accumulation and cytolytic activity. Dual targeting of macrophages and NK cells represents a new strategy to boost antitumor immunity.

Neoadjuvant cemiplimab for resectable hepatocellular carcinoma: a single-arm, open-label, phase 2 trial

BACKGROUND

Surgical resection of early stage hepatocellular carcinoma is standard clinical practice; however, most tumours recur despite surgery, and no perioperative intervention has shown a survival benefit. Neoadjuvant immunotherapy has induced pathological responses in multiple tumour types and might decrease the risk of postoperative recurrence in hepatocellular carcinoma. We aimed to evaluate the clinical activity of neoadjuvant cemiplimab (an anti-PD-1) in patients with resectable hepatocellular carcinoma.

METHODS

For this single-arm, open-label, phase 2 trial, patients with resectable hepatocellular carcinoma (stage Ib, II, and IIIb) were enrolled and received two cycles of neoadjuvant cemiplimab 350 mg intravenously every 3 weeks followed by surgical resection. Eligible patients were aged 18 years or older, had confirmed resectable hepatocellular carcinoma, an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate liver function. Patients were excluded if they had metastatic disease, if the surgery was not expected to be curative, if they had a known additional malignancy requiring active treatment, or if they required systemic steroid treatment or any other immunosuppressive therapy. After resection, patients received an additional eight cycles of cemiplimab 350 mg intravenously every 3 weeks in the adjuvant setting. The primary endpoint was significant tumour necrosis on pathological examination (defined as >70% necrosis of the resected tumour). Secondary endpoints included delay of surgery, the proportion of patients with an overall response, change in CD8+ T-cell density, and adverse events. Tumour necrosis and response were analysed in all patients who received at least one dose of cemiplimab and completed surgical resection; safety and other endpoints were analysed in the intention-to-treat population. Patients underwent pre-treatment biopsies and blood collection throughout treatment. This trial is registered with ClinicalTrials.gov (NCT03916627, Cohort B) and is ongoing.

FINDINGS

Between Aug 5, 2019, and Nov 25, 2020, 21 patients were enrolled. All patients received neoadjuvant cemiplimab, and 20 patients underwent successful resection. Of the 20 patients with resected tumours, four (20%) had significant tumour necrosis. Three (15%) of 20 patients had a partial response, and all other patients maintained stable disease. 20 (95%) patients had a treatment-emergent adverse event of any grade during the neoadjuvant treatment period. The most common adverse events of any grade were increased aspartate aminotransferase (in four patients), increased blood creatine phosphokinase (in three), constipation (in three), and fatigue (in three). Seven patients had grade 3 adverse events, including increased blood creatine phosphokinase (in two patients) and hypoalbuminaemia (in one). No grade 4 or 5 events were observed. One patient developed pneumonitis, which led to a delay in surgery by 2 weeks.

INTERPRETATION

This report is, to our knowledge, the largest clinical trial of a neoadjuvant anti-PD-1 monotherapy reported to date in hepatocellular carcinoma. The observed pathological responses to cemiplimab in this cohort support the design of larger trials to identify the optimal treatment duration and definitively establish the clinical benefit of preoperative PD-1 blockade in patients with hepatocellular carcinoma.

FUNDING

Regeneron Pharmaceuticals.

Single-cell analysis of human non-small cell lung cancer lesions refines tumor classification and patient stratification

Immunotherapy is a mainstay of non-small cell lung cancer (NSCLC) management. While tumor mutational burden (TMB) correlates with response to immunotherapy, little is known about the relationship between the baseline immune response and tumor genotype. Using single-cell RNA sequencing, we profiled 361,929 cells from 35 early-stage NSCLC lesions. We identified a cellular module consisting of PDCD1⁺CXCL13⁺ activated T cells, IgG⁺ plasma cells, and SPP1⁺ macrophages, referred to as the lung cancer activation module (LCAM^hi). We confirmed LCAM^hi enrichment in multiple NSCLC cohorts, and paired CITE-seq established an antibody panel to identify LCAM^hi lesions. LCAM presence was found to be independent of overall immune cell content and correlated with TMB, cancer testis antigens, and TP53 mutations. High baseline LCAM scores correlated with enhanced NSCLC response to immunotherapy even in patients with above median TMB, suggesting that immune cell composition, while correlated with TMB, may be a nonredundant biomarker of response to immunotherapy.

685 Characterization of molecular and spatial diversity of macrophages in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) has a dismal prognosis, and though checkpoint blocking antibodies have significantly improved patient outcome, many patients remain left out, highlighting the need to identify additional immune target to enhance therapeutic immunity. Macrophages (MF) are an abundant and heterogeneous population in the tumor microenvironment (TME), and are associated with a poor prognosis in multiple tumor types, including HCC, however, their molecular and functional diversity is still poorly understood.

Methods

We analyzed the molecular and spatial organization patterns of immune cells within the TME and adjacent tissue of 26 resected HCC lesions using single-cell RNA sequencing and multiplex immunohistochemistry (IHC).

Results

We found that Kupffer cells, the self-renewing tissue-resident macrophages in liver tissue, are lacking from the TME, which is dominated by monocyte-derived macrophages. ScRNAseq followed by high-resolution clustering identified distinct MF molecular programs within the monocyte-derived macrophage compartment. One MF subset expressed a shared signature with monocytes including FCN1, S100A8 and T cell activation genes like CXCL9 and IL32. Conversely, one subset of MF expressed FOLR2, SEPP1 and genes of the complement (C1Qs), a program shared with KC in the adjacent tissue, and include another intratumoral subset enriched for the expression of TREM2 and GPNMB. Guided by these results, we are developing an IHC antibody panel that allows to visualize distinct MF localization in the TME. Intratumoral MF interface with, and potentially regulate, the T cell compartment within the TME. We are analyzing HCC tumor lesions in our treatment-naïve cohort and in patients treated with neoadjuvant anti-PD-1 therapy (NCT03916627) to study co-localization and direct interaction of MF and T cells using physically-interacting cell sequencing (PICseq). This analysis enables us to identify MF with direct cell-cell contact with T cells, and our preliminary analysis demonstrates an enrichment in MF with an immunosuppressive phenotype. We are also using spatial transcriptomic to map molecular programs of MF in the TME, that we will corroborated with additional patients.

Conclusions

Taken together, our data provide a new understanding of intratumoral MF diversity and highlight the presence of specific immunoregulatory MF programs unique to tumor lesions, with subsets of these MF found to be directly interacting with T cells, potentially modulating anti-tumor responsiveness. Our analysis of resected tumor from anti-PD-1 treated patients, will allow us to correlate MF programs, and direct T cell interaction, with clinical response, and will inform therapeutic trials targeting specific MF populations so as to improve clinical efficacy of cancer immunotherapy.

Trial Registration

NCT03916627

Ethics Approval

Samples of tumor and non-involved liver were obtained from surgical specimens of patients undergoing resection at Mount Sinai Hospital (New York, NY) after obtaining informed consent in accordance with a protocol reviewed and approved by the Institutional Review Board at the Icahn School of Medicine at Mount Sinai (RUTH Human Subjects Electronic Submission System 18–00407 and 20–04150) and in collaboration with the Biorepository and Department of Pathology.

Abstract 64: Characterization of molecular and spatial diversity of macrophages in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a dismal prognosis, and though checkpoint blocking antibodies have significantly improved patient outcome, many patients remain left out highlighting the need to identify additional immune target to enhance therapeutic immunity. Macrophages (MΦ) are an abundant and heterogeneous population in the tumor microenvironment (TME), and are associated with a poor prognosis in multiple tumor types, including HCC, however, their molecular and functional diversity is still poorly understood. We analyzed the molecular and spatial organization patterns of immune cells within the TME and adjacent tissue of 23 resected HCC lesions using single-cell RNA sequencing and multiplex immunohistochemistry (IHC). Strikingly, we found that Kupffer cells (KC), the self-renewing tissue-resident macrophages in liver tissue, are lacking from the TME, which is dominated by monocyte-derived macrophages. ScRNAseq followed by high-resolution clustering identified distinct MΦ molecular programs within the monocyte-derived macrophage compartment. One MΦ subset expressed a shared signature with monocytes including FCN1 and S100A8 in addition to T cell activation genes like CXCL9 and IL32. Conversely, one subset of MΦ expressed FOLR2, SEPP1 and genes of the complement (C1Qs), a program shared with KC in the adjacent uninvolved tissue, and include another intratumoral subset enriched for the expression of TREM2 and GPNMB. Guided by these results, we are developing an IHC antibody panel that allows to visualize distinct MΦ localization in the TME. Intratumoral MΦ interface with, and potentially regulate, the T cell compartment within the TME. We are analyzing HCC tumor lesions in our treatment-naïve cohort and in patients treated with neoadjuvant anti-PD-1 therapy (NCT03916627) to study direct interaction of MΦ and T cells using an innovative technology of physically-interacting cell sequencing (PICseq). This analysis enables us to identify MΦ with direct cell-cell contact with T cells, and our preliminary analysis demonstrates an enrichment in MΦ with a highly immunosuppressive phenotype. We are also using PICseq to map the molecular program of MΦ that are interacting with T cells and that we will corroborated with additional patients. Taken together, our data provide a new understanding of intratumoral MΦ diversity and highlight the presence of specific immunoregulatory MΦ programs unique to tumor lesions, with subsets of these MΦ found to be directly interacting with T cells, potentially modulating anti-tumor responsiveness. Our analysis of resected tumor from anti-PD-1 treated patients, will allow us to correlate MΦ programs, and direct T cell interaction, with clinical response, and will inform therapeutic trials targeting specific MΦ populations so as to improve clinical efficacy of cancer immunotherapy.

Citation Format: Pauline Hamon, Assaf Magen, Merav Cohen, Alexandra Tabachnikova, Christie Chang, Mark Buckup, Leanna Troncoso, Zhen Zhao, Joel Kim, Amir Giladi, Nausicaa Malissen, Fiona Desland, Jessica Le Berichel, Ido Amit, Ephraim Kenigsberg, Myron Schwartz, Thomas Marron, Miriam Merad. Characterization of molecular and spatial diversity of macrophages in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 64.

Structural, electrical characterization and oxygen-diffusion paths in LaSrGa1−xMgxO4−δ (x = 0.0–0.2) layered perovskites: an impedance spectroscopy and neutron diffraction study

We present the diffusion pathways in perovskite-like structures. The modules of Gfourir and BondStr of Fullprof are feasible to obtain different paths in first approximation.

Defective Sr0.9Mo0.9O3−δ perovskites with exsolved Ni nanoparticles as high-performance composite anodes for solid-oxide fuel cells

An A-site deficient perovskite with metallic Ni in exsolution, Ni–Sr_0.9Mo_0.9O_3−δ, has been prepared, characterized and tested as an anode material in intermediate-temperature solid-oxide fuel cells (IT-SOFCs).

Structural characterization and electrochemical properties of (La,Sr)(Al,Mg)O4−δ perovskites

LaSrAl_1−xMg_xO_4−δ (x = 0.0–0.3) layered perovskites were synthesized by a nitrate–citrate route followed by annealing in air at 1100 °C, and studied as potential electrolyte materials in solid oxide fuel cells (SOFCs).

Natural arrangement of AgCu bimetallic nanostructures through oleylamine reduction

The use of AgCu bimetallic NPs as a catalyst is highly desired. To accomplish this, the morphology of nanostructures is a key factor.

Water insertion and combined interstitial-vacancy oxygen conduction in the layered perovskites La1.2Sr0.8−xBaxInO4+δ

H₂O molecules are split within the structure with protons bonded to the axial oxygens of the InO₆ octahedra, and with OH units occupying the interstitial space.

[Eosinophilic cystitis: review and two case reports]

Eosinophilic cystitis is a low frequency disease, with less than 200 reported cases in the world. It is characterized by a bladder wall inflammation, mainly by eosinophils, with fibrosis and muscle necrosis areas. Its origin seems to be immunological, although the triggers are not well known. Several predispose factor have been described such as allergic diseases, bladder injuries, drugs, infections, etc. It affects patient of all ages, mainly adults. It presents with frecuency, haematuria and suprapubic pain. Other less frequent symptoms are disuria, urinary retention, nicturia, and enuresis. The laboratory study (urinalysis, urinalysis and haemogram) and radiology (ultrasound, intravenous pyelography, computed tomography and nuclear magnetic resonance) are non specific. The lesions observed in the cystoscopy could emulate other diseases, that why the proper diagnostic is the histological analysis. The management could be observation o antihistaminic, anti-inflammatory and corticoid treatment. In refractory cases, surgery is an alternative. In this work, two male adult cases are reported with their symptoms, studies and management.

[Intrauterine device migration to the bladder: four case reports]

The intrauterine device has been commonly used in our population for many years as contraceptive method. One of the complications is the device migration out of the uterus. One of the most uncommon fait of this migration is the bladder, with few reports on the literature. In this work, four cases are reported with their clinical presentation, study and treatment.

Allozyme variation in populations of Pleurodema thaul (Lesson, 1826) (Anura; Leptodactylidae)

Genetic variation of 18 loci detected in 13 Chilean and one Argentinian population of the toad Pleurodema thaul are described. Seven loci were polymorphic in at least one of the studied populations. The average heterozygosity values observed for locus went from H = 0.00 for the Las Cardas population to 0.114 in the Lautaro locality, with a global average of 5.2%. The genetic similarity values gave an average of 0.875 (range 0.726-1.00). Accordingly, similarity values were possible to distinguish three groups: north, central and Osorno. The Osorno population differed from the central group in Est-1 and Est-2, yet the Osorno population is only 20 km from a population of the central group.

[Etiologic research in massive spasms]

A systematic clinical protocol was applied in 16 infants that suffered from infantile spasms (IS) in order to identify etiologic factors. A positive family history was present in 2/16 patients and relevant perinatal or postnatal pathology in 5/16. Psychomotor retardation and other seizures anteceded IS in 10/16 and 8/16 infants respectively. Physical and neurologic examination revealed microcephalia (4/16), dysmorphic features (2/16), hypopigmented skin lesions (1/16) and pyramidal syndrome (8/16). Neuroimaging technics yielded positive findings in 9/16 patients, diffuse or localized atrophy (7/16), porencephalic cysts (3/16), periventricular calcifications (1/16), callosal agenesis (1/16). Laboratory examination allowed diagnosis of two metabolic diseases: congenital hyperlactatemia an maple syrup urine disease. Two patients were classified as cryptogenetic and fourteen as symptomatic. Within the latter an etiologic factor was identified in 12/14. This study underlines the value of etiologic search in IS, because it may contribute substantially to specific treatment and genetic counselling.