Browsing Over 2184 Presentations
4P - Spatially resolved transcriptome elucidates bidirectional tertiary lymphoid structure interacts with tumor microenvironment of non-small cell lung cancer
- Xin Zhao (Shenzhen, China)
Abstract
Background
The presence of tertiary lymphoid structure has a significant correlation with the lung cancer patient's response to immune checkpoint inhibitors. Nonetheless, the developmental characteristics of TLS and their surrounding tumor microenvironmental features in the primary tumor have not been elucidated comprehensively.
Methods
We utilized spatially resolved transcriptome and single-cell RNA sequencing to examine the molecular signatures and the essential cell types of TLS during its maturation process in the tumor microenvironment. Additionally, multiplex immunofluorescence staining and whole transcriptome sequencing were performed for validation.
Results
We categorized 406 potential TLSs into four states: pre-TLS, primary TLS, mature TLS, and aging TLS - based on their spatial molecular characteristics. The high expression of FDCSP in follicular DCs is a novel marker to promote TLS maturation by specifically binding to activated B cells. Three types of receptor-ligand interactions in mature and aging TLS could predict the prognosis in early-stage LUAD. Interestingly, aging TLS with significantly upregulated FOXP3 and TOX2 could limit anti-tumor immunity. Additionally, the molecular characteristics of aging TLS showed a lower expression of a group of CC chemokine ligands compared to mature TLS, which could potentially lead to a weaker anti-tumor response. We also observed an increase in tumor proliferation activity in the periphery of the aging TLS region. One approach to reverse the anti-tumor activity of aging TLS to that of mature TLS could be to increase the concentration of environmental chemokines while simultaneously blocking the upregulation of TIGIT in aging TLS.
Conclusions
Those results demonstrated that the condition of TLS was influenced by the neighboring tumor microenvironment in the early-stage LUAD. And the conventional mature TLS would eventually reach a biologically aged state in the same tumor microenvironment. By regulating chemokine signaling in the aging TLS's surrounding environment, it could potentially serve as an adjuvant therapy to enhance the antitumor activity of immune elements in resectable LUAD patients.
Legal entity responsible for the study
TJMUCH and BGI.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
5P - Tertiary lymphoid structures (TLS) presence and stromal blood vessels heterogeneity differentially influence recurrence, lymphovascular, and perineural invasion in breast cancer molecular subtypes
- Andrei A. Cosma (Timisoara, Romania)
Abstract
Background
Tertiary Lymphoid Structures (TLS) mediate local antitumor immunity. Since cancer immunotherapy, TLS interests grown considerably. We examined TLS and tumor stromal blood vessels for BC molecular subtypes associated with recurrence, lymphovascu-lar (LIV), and perineural invasion (PnI).
Methods
CD34/SMA double immunostaining revealed TLS high endothelial venules and BC tumor stromal immature and mature blood vessels. Statistical study linked microscopic data to recurrence, LIV, and PnI.
Results
TLS- subgroups have higher LIV, PnI, and recurrence (p<0.001), except for Luminal A type. LIV and PnI rise in HER2+/TLS- subgroups (p<0.001). TNBC/TLS- had the highest recurrence and invasion risks. TNBC/TLS- subgroup recurrence is related to tumor grade and LIV/PnI (p<0.001), unlike other TLS- subgroups. PnI but not LVI are related with TNBC/TLS+ subgroup recurrence (p<0.001).
Conclusions
TLS affect BC molecular subtype recurrence, LVI, and PnI differently. Its antitumor immunity mediator seems closely associated to tumor aggressiveness and stromal blood vessels.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
6P - Combined single-cell and spatially resolved mapping of the human lymph node ecosystem reveals fundamental principles of lymphoma tissue organization
- Daniel Hübschmann (Heidelberg, Germany)
Abstract
Background
Lymph nodes (LN) act as central hubs for the orchestration of adaptive immune responses. A network of lymph node stromal cells (LNSC), including mesenchymal and endothelial cells, build a 3D network for immune cells to migrate and home to distinct niches in the LN. Within B cell non-Hodgkin lymphomas, indolent follicular lymphomas (FL) are characterized by subtle structural changes while the compartmentalization of the tissue remains present. In contrast, aggressive diffuse large B cell lymphomas (DLBCL) are defined by a complete loss of tissue organization indicating a potential role of LNSCs in tumorigenesis. While the morphological differences are well-known, the underlying molecular and cellular mechanisms remain poorly understood.
Methods
Here, we dissect the mechanisms underlying loss of structure in lymphomagenesis using combined single-cell transcriptome and spatially-resolved mapping approaches of LNSCs and immune cells.
Results
Using ultra-high plex immunofluorescence imaging, we characterized how lymph node cells organize into spatially distinct cellular neighborhoods, the disruption of which was congruent with lymphoma-induced remodeling. Using single-cell transcriptome data, we investigated the molecular programs driving this loss of organization. In DLBCL, chemokines relevant for immune cell organization were downregulated, while chemokines contributing to inflammation were upregulated, suggesting a phenotypic switch from a structural organized to an inflammatory and fibrotic state.
Conclusions
Collectively, these data suggest that a reprogramming of the LN microenvironment triggers an imbalance in chemokine gradients, which underlies loss of tissue organization in aggressive lymphomas.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
7P - Engineered salmonella blocks cancer metastasis by activating NK cells in an IFN-γ-dependent manner
- JIANDONG HUANG (Hong Kong, Hong Kong PRC)
Abstract
Background
Metastasis accounts for 90% of cancer related deaths and blocking of metastatic cascade has critical clinical impact. However, the clinical drug development for cancer treatment, including cancer immunotherapies, is evaluated largely depending on their ability to cause tumour shrinkage and ignores the effect on metastasis as it has proven challenging to target. Therefore, there is an urgent need for novel therapeutic strategies and agents targeting metastasis. Using an attenuated
Methods
Mutant mice and antibody-mediated cell depletion were used to identify the host genetic and cellular requirement for the bacterial supression of cancer cell metastasis. CyTOF (mass cytometry or cytometry by time of flight) was used to investigate the the innate immune responses after
Results
Our studies showed that suppression of cancer metastasis by attenuated
Conclusions
We found that IFN-γ was mainly produced by NK cells during early
Legal entity responsible for the study
The author.
Funding
This work was supported by grants from the Shenzhen Peacock Team Project (KQTD2015033117210153) and Shenzhen Science and Technology Innovation Committee Basic Science Research Grant (JCYJ20170413154523577).
Disclosure
All authors have declared no conflicts of interest.
8P - Modulating tumor microenvironment using a VEGF active immunotherapeutic approach in gastrointestinal tumors: Beyond angiogenesis modulation
- Mónica Bequet-Romero (Havana, Cuba)
Abstract
Background
Targeting of the vascular endothelial growth factor (VEGF) is known for going beyond mere modification of angiogenesis, and extends to the systemic and intratumoral regulation of immune cells activation state. In this study, we aim to explore the effect of a VEGF active immunotherapy based on a recombinant antigen named CIGB-247, in the systemic and tumor compartments in preclinical settings for mice, and in a subset of 22 patients with advanced gastrointestinal cancer (GIC) from phase I clinical trials (RPCEC00000102 and RPCEC00000155).
Methods
BALB/c mice were immunized with CIGB-247, and challenged with CT26 colon carcinoma cells subcutaneously. A week after the last immunization mice were euthanized and the tumor and the systemic compartment, were analyzed by ELISA, flow cytometry, and RT-QPCR assays. GIC patients’ serum and leukocyte samples were evaluated for cytokines, specific VEGF antibody titers, and VEGFR2 neutralization using ELISA, while the cellular response was assessed by ELISPOT.
Results
The vaccine significantly boosted the infiltration of activated CD3+ cells and caused a decrease in the number of MDSCs and Tregs in analyzed compartments. The levels of VEGF, PLGF, and CXCL1 were significantly reduced in the tumor lysates, while the concentration of CD8 activation-related molecules like IFN-γ, and GRZ-B were induced. Finally, we analyzed GIC cases within the two phase I clinical trials after stratification between responders and non-responders. The evaluations indicate a significant increase in the VEGF-specific humoral and cellular response parallel to a reduction in VEGF that relates significantly to increased survival. Within this small cohort, reduction or stabilization of other proangiogenic factors was also detected.
Conclusions
CIGB-247 antigen-based vaccine increased tumor-infiltrating lymphocytes and reversed the immunosuppressive effect of the tumor microenvironment in the CT26 mouse model. Such results were corroborated in a GIC patient cohort indicating that the strategy might be a successful treatment option for such patients by modifying systemic and tumor microenvironment beyond angiogenesis modulation.
Clinical trial identification
RPCEC00000102, RPCEC00000155.
Legal entity responsible for the study
Center for Genetic Engineering and Biotechnology.
Funding
HEBERBiotec.
Disclosure
All authors have declared no conflicts of interest.
9P - Identification of a μCT-based radiomic signature of CD8+ tumour infiltrating lymphocytes in an orthotopic murine model
- Giulia Mazzaschi (Parma, Italy)
Abstract
Background
In the era of immunotherapy (IT), radiomics emerged as a non-invasive tool to decode tumor immune microenvironment (TIME) and predict IT response. Intrinsic patient and tumor variability challenging the explainability of radiomic readouts might be overcome in preclinical settings. Thus, we aimed to develop a μCT radiomic platform in a CD8 T cell functionally manipulated orthotopic murine model, closely mimicking human head and neck cancer, to validate the biological reality of radiomics in assessing tumor infiltrating lymphocytes (TILs).
Methods
Set-up, training and validation experiments (N Tot = 50 C57BL/6 mice) were conducted as follows: submucosal injection of 0.5 x 106 TC1-luc cells in the right inner lip and generation of an orthotopic model of head and neck cancer (day [D] -7); tailored treatment consisting of irradiation [D0] ± anti-CD8 antibody [D3] to selectively enrich or deplete CD8+ TILs; in vivo preclinical imaging through Quantum FX μCT technology [D3, D4]; mice euthanasia and tumor sampling [D4], followed by immunohistochemical staining for CD8; μCT image pre-processing (voxel resampling, image discretization and delineation of the volume of interest) and radiomic features (RFs) extraction (pyradiomics).
Results
We developed and optimized an efficient quantitative μCT imaging approach. Overall, 106 μCT RFs (shape, first- and second- order) were extracted and correlated with distinct TIME. Following redundant feature elimination (Spearman correlation, cut-off = 0.99) and Z-score standardization, we identified 12 μCT-RFs differentially regulated in T CD8 enriched
Conclusions
Our results document the feasibility and accuracy of radiomics to detect dramatic changes in T cells within the TIME, thus providing effective radio-immune signatures potentially translatable into clinical practice.
Legal entity responsible for the study
Institut Gustave Roussy.
Funding
ESMO (Translational Research Fellowship; Recipient: Dr. Giulia Mazzaschi).
Disclosure
All authors have declared no conflicts of interest.
10P - Cancer cells induce intracellular gap formation in sinusoidal endothelial cells to produce liver metastasis through pro-inflammatory paracrine mechanisms
- Hoang H. Truong (Hanoi, Viet Nam)
Abstract
Background
Engraftment of cancer cells to liver pre-metastatic niches requires complex interaction with liver sinusoidal endothelial cells (LSECs). Intracellular gap (iGap) formation in LSECs is caused by the destruction of fenestrae and appears under pathological conditions. Here, we aimed to explore the novel role of LSECs-iGap in liver metastasis of cancer cells.
Methods
Mouse models using acetaminophen (APAP) or thioacetamide (TAA) followed by intrasplenic injection of hepatocellular carcinoma (HCC) cell line, Hepa1-6 cells, to assess the LSECs-iGap formation. Functional effects of LSECs-iGap on cancer cells were analyzed using MMPs inducer, monocrotaline and inhibitor, doxycycline and MMP2/9 inhibitor. Morphological and molecular features of LSECs-iGap were examined using
Results
APAP-induced liver injury and TAA-induced fibrotic liver resulted in LSECs-iGap formation, which positively correlated with increased numbers of metastatic foci after Hepa1-6 cells injection. In addition, Hepa1-6 cells induced IL-23-dependent TNF-α secretion by LSECs and triggered LSECs-iGap formation, toward which their processes protruded to transmigrate into the liver parenchyma. TNF-α caused depolymerization of F-actin and increased MMP9, ICAM1, and CXCLs expression in LSECs. Moreover, high expression of ICAM1 and MMP9 was significantly associated with intrahepatic metastasis and overall survival of patients with HCC. Blocking MMP9 activity by doxycycline or MMP-2/9 inhibitor eliminated LSECs-iGap formation and attenuated liver metastasis of Hepa1-6 cells.
Conclusions
This study revealed that cancer cells induced LSEC-iGap formation via pro-inflammatory paracrine mechanisms and proposed MMP9 as a novel target for blocking cancer cell metastasis to the liver.
Legal entity responsible for the study
H.H. Truong.
Funding
Japan Agency for Medical Research and Development.
Disclosure
All authors have declared no conflicts of interest.
11P - Targeting stromal cells to reverse immune suppression in triple-negative breast cancer
- Julia Chen (Darlinghurst, Australia)
Abstract
Background
Although there have been some positive results, the success of immune checkpoint inhibition in triple-negative breast cancer (TNBC) to date remains rather limited. A better understanding of mechanisms of immune evasion other than via PD1/PD-L1 axes and how to overcome these is therefore much needed to improve the efficacy of immunotherapy in this poor prognosis disease. Recent studies of the tumour microenvironment (TME) have elucidated the heterogeneity of stromal cells and suggested that stromal subsets play an important role in regulating anti-tumour immunity. Here we investigate how stromal cells contribute to the immunosuppressive TME and as a potential therapeutic target to overcome this.
Methods
Using co-culture models of patient-derived TNBC cancer-associated fibroblasts (CAFs) and peripheral blood mononuclear cells (PBMCs) from healthy donors, we applied flow cytometry and single-cell RNA sequencing (scRNAseq) to assess stromal-immune interactions
Results
TNBC CAFs suppress the proliferative capability of both CD4 and CD8 T cells
Conclusions
Talabostat reverses stromal-mediated T cell suppression and is a potential therapeutic strategy to elicit a more effective immune response.
Legal entity responsible for the study
The authors.
Funding
US Department of Defense grant.
Disclosure
E. Lim: Financial Interests, Institutional, Advisory Board: Gilead, Novartis, Pfizer, Roche, AstraZeneca, MSD, Lilly; Financial Interests, Institutional, Invited Speaker: Roche, Gilead, Novartis, Lilly, AstraZeneca; Financial Interests, Institutional, Research Grant: Pfizer, Novartis; Financial Interests, Institutional, Steering Committee Member: Roche, Lilly, AstraZeneca; Financial Interests, Institutional, Local PI: Novartis, Gilead; Non-Financial Interests, Leadership Role, Scientific Advisory Committee: Breast Cancer Trials Australia; Non-Financial Interests, Leadership Role, Principal Cancer Theme Lead, Faculty of Medicine: University of New South Wales; Non-Financial Interests, Leadership Role, Faculty: Garvan Institute of Medical Research; Non-Financial Interests, Leadership Role, Director Cancer Research: St Vincent's Hospital Sydeny. A. Swarbrick: Financial Interests, Personal and Institutional, Financially Compensated Role, Paid Consultant: Phenomic AI. All other authors have declared no conflicts of interest.
12P - Immuno-suppressive role of tumour-derived GDF-15 on myeloid cells
- Christine Schuberth-Wagner (Planegg-Martinsried, Germany)
Abstract
Background
Growth and differentiation factor 15 (GDF-15), a divergent member of the TGF-β superfamily, shows high expression during pregnancy. Beyond that, GDF-15 is induced in stressed and damaged tissues limiting inflammation. GDF-15 also functions as a prognostic marker in numerous cancers and was shown to be a key inhibitor of T-cell infiltration in solid tumors. However, the impact of GDF-15 on other immune cells in the tumor microenvironment (TME) is still poorly understood.
Methods
M1 and M2 macrophages were derived from either the human monocytic THP-1 cell line or monocytes from healthy donors by incubation with IFNγ and LPS (M1) or IL-4 and IL-13 (M2) in combination with or without GDF-15. Analysis was performed by Western Blot, flow cytometry and RT-qPCR. To investigate the role of GDF-15
Results
Our initial studies have shown that monocytes are sensitive to GDF-15 mediated inhibition of tumor infiltration. Now we wanted to understand how GDF-15 affects the myeloid compartment beyond infiltration. In primary cells, GDF-15 exposure of monocytes during IFNγ or LPS induced M1 polarization led to a reduction of activation marker expression such as HLA-DR, CD80 and CD86 and an altered cytokine secretion profile. M2 macrophages did not show differences in their activation pattern. This effect was transferable to THP-1 derived M1 macrophages. TGF-ß was not able to exert this biologic effect. Activation was restored by addition of a GDF-15 neutralizing antibody.
Conclusions
GDF-15 secretion helps tumors to generate a TME that is poorly infiltrated by anti-tumoral immune cells. GDF-15 counteracts myeloid activation in the TME, a hallmark of initiation of antitumoral immune responses. By inducing a more pro-inflammatory tumor phenotype, anti-GDF-15 antibodies may synergize with other immunotherapeutic agents. A clinical phase 2 trial combining anti-GDF-15 (CTL-002) with anti-PD-1 (NCT04725474) is ongoing.
Legal entity responsible for the study
CatalYm GmbH.
Funding
CatalYm GmbH.
Disclosure
C. Schuberth-Wagner: Financial Interests, Personal, Full or part-time Employment: CatalYm GmbH; Financial Interests, Personal, Stocks/Shares: CatalYm GmbH, Merck & Co; Financial Interests, Personal, Royalties: Rigontec GmbH; Non-Financial Interests, Advisory Role: RNHale GmbH. I. Giese, M. Kist, N. Vashist, S. Genßler, M. Auer, K. Klar: Financial Interests, Personal, Full or part-time Employment: CatalYm GmbH. J. Weigandt: Financial Interests, Personal, Full or part-time Employment, Scientist Role: Catalym; Financial Interests, Personal, Stocks/Shares, small number of shares held privately: AstraZeneca, Moderna. J. Wischhusen: Financial Interests, Personal, Advisory Board: CatalYm; Financial Interests, Personal, Stocks/Shares: CatalYm; Financial Interests, Personal, Advisory Board, Fees received via University of Würzburg as compensation for inventorship: CatalYm; Financial Interests, Institutional, Funding: CatalYm. E. Leo: Financial Interests, Personal, Advisory Board, Advisory role: T-knife GmbH; Financial Interests, Personal, Full or part-time Employment, CMO: CatalYm GmbH; Financial Interests, Personal, Stocks/Shares, Share options: CatalYm GmbH, T-knife GmbH. M. Haake: Financial Interests, Personal, Full or part-time Employment: CatalYm GmbH; Financial Interests, Personal, Stocks/Shares, Co-Founder: CatalYm GmbH; Financial Interests, Personal, Advisory Board: CatalYm GmbH; Non-Financial Interests, Other, Co-founder: CatalYm GmbH. All other authors have declared no conflicts of interest.
13P - Disrupting the immunosuppressive tumor microenvironment using genetically engineered macrophages for triple-negative breast cancer therapy
- Sabrina Traxel (Zürich, Switzerland)
Abstract
Background
Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer and accounts for 40% of breast cancer deaths. Currently, surgery and chemotherapy are standard therapy in TNBC, whereas immunotherapies often fail due to a cold tumor microenvironment (TME), which is mainly generated by tumor associated macrophages (TAMs). Importantly, immunosuppressive M2-like TAMs are associated with worse outcome in TNBC patients. Cytokines like IL-10 and TGFβ induce M2-like TAMs, which inhibit the adaptive immune response and promote tumor growth, migration, and vascularization. In contrast, M1-like macrophages induce an anti-tumor immune response and tumor cell death. Thus, we aim to develop an adoptive cell therapy employing macrophages that are polarized towards a M1-like phenotype by the immunosuppressive cytokines, which will generate an inflamed TME.
Methods
To achieve M1 polarization in a M2-inducing TME, we genetically modified macrophages to express a chimeric cytokine receptor (ChCR), which will induce an M1 signaling upon stimulation with M2 inducing cytokines. Here, we evaluated two ChCR variants activated by IL-10 and TGFβ, respectively. We transduced monocytes to express the ChCR using lentiviruses. Upon differentiation to macrophages, we assessed M1 polarization by analyzing surface marker expression and the secretome. Moreover, we assessed their effect on TNBC cell line viability.
Results
We could successfully transduce macrophages at 80% and confirmed ChCR expression and M1 signaling. Furthermore, we could show that stimulation of ChCR macrophages by IL-10 or TGFβ switches them towards an M1-like phenotype, as analyzed by surface marker expression and IP-10 secretion. Moreover, we found that the viability of TNBC cell lines was reduced upon treatment with supernatants of TGFβ or IL-10 stimulated ChCR macrophages.
Conclusions
We could show that we can engineer macrophages to switch towards an M1-like phenotype in an M2-inducing environment. Thus, ChCR macrophages represent a promising strategy to disrupt the immunosuppressive TME. Currently, we are assessing the effect of ChCR macrophages on immune activation in vitro and their phenotype in TNBC co-cultures.
Legal entity responsible for the study
The authors.
Funding
Gebauer Stiftung, Lotte und Adolf Hotz-Sprenger-Stiftung, Claudia von Schilling, Foundation for Breast Cancer Research, OPO-Stiftung, Stiftung zur Krebsbekämpfung, Alfred und Anneliese Sutter-Stöttner Stiftung, Dr. Arnold U. und Susanne, Huggenberger-Bischoff Stiftung, Novartis Foundation for Medical-Biological Research, UZH Bio & MedTech Entrepreneur Fellowship, UZH Postdoc Grant.
Disclosure
R.F. Speck: Other, Personal and Institutional, Other, Inventor of pending patent EP 22/215498 related to project: University of Zurich. S. Bredl: Financial Interests, Personal and Institutional, Other, Inventor of pending patent EP 22/215498 related to project: University of Zurich. All other authors have declared no conflicts of interest.
14P - Peripheral immune kinetics in survival prediction of small cell lung cancer patients treated with immune checkpoint blockade therapy
- MIGUEL A. GALINDO CAMPOS (Barcelona, Spain)
Abstract
Background
Small cell lung cancer (SCLC) is a lethal neoplasia. Chemotherapy (Ct) plus immune checkpoint blockade therapy (ICBt) is now the standard of care although limited survival benefit. Lack of biomarkers of response leads to suboptimal patient selection, distorting results of clinical trials. Deciphering the ICBt-driven peripheral immune events may recognize those patients who benefit the most. Here, we characterize early peripheral immune kinetics in SCLC patients treated with Ct + ICBt with improved survival.
Methods
SCLC patients from 8 centers were prospectively recruited into 3 cohorts. Cohort 1 include patients treated with Ct (n=24). Cohort 2 (n=37) comprise patients treated with Ct + anti-CTLA-4, and cohort 3 (n=20) patients treated with Ct + anti-PD-1/PD-L1. Peripheral blood mononuclear cells were obtained prior to treatment and after the first dose of ICBt. Variation in proliferation, senescence, adhesion, immunosuppression, and checkpoints markers was assessed by FACS. Kaplan–Meier and log-rank test were used for survival analysis. MaxStat was used to calculate cut points. A p-value <0.05 was considered statistically significant.
Results
We found 6 independent cellular subsets which modulation right after the start of ICBt identify patients with improved survival. An increase in CD8+CD103+Ki67+ cells identify survival benefit in cohorts 1 and 3 (p=0.043; 0.0033). An upregulation of Ki67 in total CD4+ (p=0.012; 0.0027) and CD4+PD-1+ T cells (p=0.026; 0.027), predicts long survival in ICBt cohorts 2 and 3, while a downregulation of CD4+ICOS+ T cells (p=0.025; 0.011) identified survival benefit in these ICBt cohorts. Expansion of Ki67+ and ICOS+ (p=0.0024; 0.0074) CD8+ T cells was also observed in CD8+ T cells from long survivors exclusively from cohort 2.
Conclusions
Expansion of CD8+CD103+Ki67+, CD4+Ki67+, and CD4+PD-1+Ki67+, or a reduction in CD4+ICOS+ circulating T cells subsets identify long survival patients treated with anti-CTLA-4 or anti-PD-1/PD-L1, while an increase in CD8+Ki67+ or CD8+ICOS+ cells predicts benefit only in patients treated with anti-CTLA-4. Assessment of the immune kinetics of these peripheral cellular subsets identify patients who benefit the most from ICBt in SCLC.
Legal entity responsible for the study
The authors.
Funding
Fundació Amics de l'Hospital del Mar.
Disclosure
E. Arriola: Financial Interests, Personal and Institutional, Advisory Role, Speaker, Institutional funding, Travel and educational expenses: BMS, MSD; Financial Interests, Personal and Institutional, Advisory Role, Speaker, Institutional and Research funding, Travel and educational expenses: Roche; Financial Interests, Personal and Institutional, Advisory Role, Speaker, Institutional and Research funding: Pfizer; Financial Interests, Personal, Advisory Role, Speaker, Travel and educational expenses: Lilly; Financial Interests, Personal and Institutional, Advisory Role, Speaker, Institutional funding: AstraZeneca; Financial Interests, Personal, Advisory Role, Speaker: Boehringer Ingelheim, Takeda; Other, Personal, Member of Board of Directors, Co-founder: TrialingHealth. All other authors have declared no conflicts of interest.
15P - CBL E3 ubiquitin ligases are key inhibitory regulators in PD-1/LAG-3 co-signaling in human cancers, targeted through bispecific co-blockade
- Luisa Chocarro (Pamplona, Spain)
Abstract
Background
A significant number of cancer patients do not benefit from PD-L1/PD-1 blockade immunotherapies. PD-1 and LAG-3 co-upregulation in T-cells is one of the major mechanisms of resistance by establishing a highly dysfunctional state in T-cells.
Methods
A high-throughput screening was performed of PD-1/LAG-3 multiomic expression profiles in public databases of human cancer biopsies, to establish relationships between infiltrating tumor-infiltrating PD-1/LAG-3 T cells with biomarkers both in T cells and within the tumour microenvironment. These results were validated in engineered T-cell lines with constitutively active PD-1, LAG-3 pathways, and their combination, analysed by high-throughput quantitative proteomics and validated by conventional molecular techniques on primary T cells from NSCLC patients.
Results
The high-throughput multiomic human cancers screening and the experimental proteomic T cell lines uncovered a strong PD-1/LAG-3 dysfunctionality signature that was found which regulated immune, proteomic, metabolic, genetic, and epigenetic pathways. These mainly relied on differential regulation of E3 ubiquitin ligases CBL-B and C-CBL. Notably, LAG-3 expression has never been associated to CBL ubiquitin ligases before.
Conclusions
PD-1/LAG-3 co-signaling profile uncovers a highly dysfunctional regulated programme. Co-blockade with a bispecific drug but not with a combination of anti-PD-1/anti-LAG-3 antibodies achieved both CBL-B and C-CBL inhibition, reverting T-cell dysfunctionality in lung cancer patients resistant to PD-L1/PD- 1 blockade. These results will help identifying the mechanisms of intrinsic resistance to PD-1 blockade mediated by LAG-3 co-signaling.
Legal entity responsible for the study
Navarrabiomed.
Funding
This research was supported by: The Spanish Association against Cancer (AECC), PROYE16001ESCO; Instituto de Salud Carlos III (ISCIII)-FEDER Project grants FIS PI20/00010, COV20/00000, and TRANSPOCART ICI19/00069; Biomedicine Project Grant from the Department of Health of the Government of Navarre-FEDER funds (BMED 050-2019, 51-2021); Strategic projects from the Department of Industry, Government of Navarre (AGATA, Ref. 0011-1411-2020-000013; LINTERNA, Ref. 0011-1411-2020-000033; DESCARTHES, 0011-1411-2019-000058); European Union Horizon 2020 ISOLDA project, under grant agreement ID: 848166. L.C. is financed by Instituto de Salud Carlos III (ISCIII), co-financed by FEDER funds, "Contratos PFIS: contratos predoctorales de formación en investigación en salud" (FI21/00080); M.E. is financed by the Navarrabiomed- Fundación Miguel Servet predoctoral contract.
Disclosure
C.J. Edwards: Other, Personal, Other, Declares to be inventor of the Humabody CB213 (WO/2019/158942. 603 Crescendo Biologics Ltd.): Crescendo Biologics. J. Leggs: Other, Declares to be e inventor of the Humabody CB213 (WO/2019/158942. 603 Crescendo Biologics Ltd.): Crescendo Biologics. D. Escors: Other, Declares to be e inventor of the Humabody CB213 (WO/2019/158942. 603 Crescendo Biologics Ltd.): Navarrabiomed. All other authors have declared no conflicts of interest.