Macrophages: Traffic centers in the tumor immune microenvironment.

Laryngeal cancer (LC) is a malignant tumor that occurs in the head and neck. Laryngeal cancer is one of the most common cancers of the neck and head, and its prognosis has always been poor. The incidence of LC increased gradually and showed an early rising trend. Laryngeal cancer is rarely studied in relation to immunity, Malignant tumors will change the state of the human body in various ways to adapt to their own survival and avoid the immune system. This study aims to explore the immune molecular mechanism of laryngeal cancer through bioinformatics analysis. The gene expression data was downloaded for 3 microarray datasets: GSE27020, GSE59102, and GSE51985. CIBERSORT algorithm was performed to evaluate immune cell infiltration in tissues between LC and healthy control (HC). Differentially expressed genes (DEGs) were screened. Functional correlation of DEGs were analyzed by Gene Ontology, Gene Set Enrichment Analysis and Kyoto encyclopedia of genes and genomes. Candidate biomarkers were identified by cytoHubba of Cytoscape. Spearman correlations between the above biomarkers and infiltrating immune cells were explored using R software analysis. The immune cell types of LC and HC were significantly different. Twenty-one DEGs were obtained by cross-screening. The function of DEGs is closely related to the number of immune cells. Five central genes (TNNT3, TNNI2, Desmin, matrix metallopeptidase 9 and cytotoxic T lymphocyte antigen 4) were screened. The HUB gene was demonstrated to have the ability to diagnose LC and HC with good specificity and sensitivity. The correlation between immune cells and biomarkers showed that hub gene was positively correlated with macrophages and dendritic cells, and negatively correlated with CD4 + T cell. TNNT3, TNNI2, Desmin, matrix metallopeptidase 9 and cytotoxic T lymphocyte antigen 4 can be used as diagnostic biomarker for LC. Macrophages, dendritic cells and CD4 + T cell may participate in the occurrence and development of LC.

Innate immune cells in the tumor microenvironment.

<div>AbstractPurpose:<p>The immune tumor microenvironment and the potential therapeutic opportunities for immunotherapy in small intestinal neuroendocrine tumors (siNET) have not been fully defined.</p>Experimental Design:<p>Herein, we studied 40 patients with primary and synchronous metastatic siNETs, and matched blood and normal tissue obtained during surgery. We interrogated the immune checkpoint landscape using multi-parametric flow cytometry. In addition, matched FFPE tissue was obtained for multi-parametric IHC to determine the relative abundance and distribution of T-cell infiltrate. Tumor mutational burden (TMB) was also assessed and correlated with immune infiltration.</p>Results:<p>Effector tumor-infiltrating lymphocytes (TIL) had a higher expression of PD-1 in the tumor microenvironment compared with the periphery. In addition, CD8<sup>+</sup> TILs had a significantly higher co-expression of PD-1/ICOS and PD-1/CTLA-4 (cytotoxic T lymphocyte antigen-4) and higher levels of PD-1 expression compared with normal tissue. IHC revealed that the majority of cases have ≤10% intra-tumoral T cells but a higher number of peri-tumoral T cells, demonstrating an “exclusion” phenotype. Finally, we confirmed that siNETs have a low TMB compared with other tumor types in the TCGA database but did not find a correlation between TMB and CD8/Treg ratio.</p>Conclusions:<p>Taken together, these results suggest that a combination therapy approach will be required to enhance the immune response, using PD-1 as a checkpoint immunomodulator backbone in combination with other checkpoint targeting molecules (CTLA-4 or ICOS), or with drugs targeting other pathways to recruit “excluded” T cells into the tumor microenvironment to treat patients with siNETs.</p></div>

Purpose:The immune tumor microenvironment and the potential therapeutic opportunities for immunotherapy in small intestinal neuroendocrine tumors (siNET) have not been fully defined.Experimental Design:Herein, we studied 40 patients with primary and synchronous metastatic siNETs, and matched blood and normal tissue obtained during surgery. We interrogated the immune checkpoint landscape using multi-parametric flow cytometry. In addition, matched FFPE tissue was obtained for multi-parametric IHC to determine the relative abundance and distribution of T-cell infiltrate. Tumor mutational burden (TMB) was also assessed and correlated with immune infiltration.Results:Effector tumor-infiltrating lymphocytes (TIL) had a higher expression of PD-1 in the tumor microenvironment compared with the periphery. In addition, CD8+ TILs had a significantly higher co-expression of PD-1/ICOS and PD-1/CTLA-4 (cytotoxic T lymphocyte antigen-4) and higher levels of PD-1 expression compared with normal tissue. IHC revealed that the majority of cases have ≤10% intra-tumoral T cells but a higher number of peri-tumoral T cells, demonstrating an “exclusion” phenotype. Finally, we confirmed that siNETs have a low TMB compared with other tumor types in the TCGA database but did not find a correlation between TMB and CD8/Treg ratio.Conclusions:Taken together, these results suggest that a combination therapy approach will be required to enhance the immune response, using PD-1 as a checkpoint immunomodulator backbone in combination with other checkpoint targeting molecules (CTLA-4 or ICOS), or with drugs targeting other pathways to recruit “excluded” T cells into the tumor microenvironment to treat patients with siNETs.

<div>AbstractPurpose:<p>The immune tumor microenvironment and the potential therapeutic opportunities for immunotherapy in small intestinal neuroendocrine tumors (siNET) have not been fully defined.</p>Experimental Design:<p>Herein, we studied 40 patients with primary and synchronous metastatic siNETs, and matched blood and normal tissue obtained during surgery. We interrogated the immune checkpoint landscape using multi-parametric flow cytometry. In addition, matched FFPE tissue was obtained for multi-parametric IHC to determine the relative abundance and distribution of T-cell infiltrate. Tumor mutational burden (TMB) was also assessed and correlated with immune infiltration.</p>Results:<p>Effector tumor-infiltrating lymphocytes (TIL) had a higher expression of PD-1 in the tumor microenvironment compared with the periphery. In addition, CD8<sup>+</sup> TILs had a significantly higher co-expression of PD-1/ICOS and PD-1/CTLA-4 (cytotoxic T lymphocyte antigen-4) and higher levels of PD-1 expression compared with normal tissue. IHC revealed that the majority of cases have ≤10% intra-tumoral T cells but a higher number of peri-tumoral T cells, demonstrating an “exclusion” phenotype. Finally, we confirmed that siNETs have a low TMB compared with other tumor types in the TCGA database but did not find a correlation between TMB and CD8/Treg ratio.</p>Conclusions:<p>Taken together, these results suggest that a combination therapy approach will be required to enhance the immune response, using PD-1 as a checkpoint immunomodulator backbone in combination with other checkpoint targeting molecules (CTLA-4 or ICOS), or with drugs targeting other pathways to recruit “excluded” T cells into the tumor microenvironment to treat patients with siNETs.</p></div>

BackgroundImmune checkpoint regulators, cytotoxic T lymphocyte antigen 4 (CTLA-4) and the programmed cell death protein-1/programmed death-ligand 1 (PD-1/PD-L1) have emerged as promising new targets for cancer therapeutics. While tumor expression of PD-L1 has been shown to have objective responses to anti-PD-L1 immunotherapies, the clinical implications of CTLA-4 expression in tumor cells or immune cells in the tumor microenvironment is still controversial. We investigated the expression of CTLA-4 and PD-L1 in human breast tumors and provided a scoring system for the systematic evaluation of CTLA-4 staining.MethodsImmunohistochemical staining for PD-L1 and CTLA-4 expression was performed on a tissue microarray of 102 cores, which included normal and neoplastic breast tissues. Neoplastic cores were divided into four groups: Ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC) and invasive tubular carcinoma (ITC). PD-L1 and CTLA-4 expressions were scored based on a system which accounted for the percentage and intensity of positivity and results provided in conjunction with available clinical and demographic data.ResultsOverall, CTLA-4 was over-expressed in 49 of 93 (52.7%) breast tumors. Subcategorically, CTLA-4 was positive in 3 of 8 (37.5%) ductal carcinoma in situ, 40 of 73 (55%) of invasive ductal carcinomas, 4 of 10 (40%) of invasive lobular carcinomas and 2 of 2 (100%) of invasive tubular carcinomas. All 6 normal breast tissues were interpreted as negative for CTLA-4 staining. Only 4.1% of the invasive ductal carcinomas were positive for PD-L1 reactivity and the remaining carcinomas stained negative.ConclusionsThis study shows a significant overexpression of CTLA-4 in >50% of breast carcinomas with no such overexpression of CTLA-4 in benign breast tissues. PDL-1 staining is seen in only a small number of invasive ductal carcinomas (4.1%). These findings suggest the need for further investigation of anti-CTLA-4 and anti-PD-L1 immunotherapies and their efficacy in the treatment of breast carcinomas with overexpression of these immune modulators. In addition, the proposed scoring system will facilitate a more systematic correlation between tumor reactivity and clinical outcome which can be applied to all intracytoplasmic tumor markers.

We have previously shown that tumor-associated or infiltrating T cells (TALs or TILs) often co-express immune inhibitory receptors lymphocyte activation gene-3 (LAG-3) and programmed cell death 1 (PD-1) in human and murine ovarian tumor microenvironment (TME). Dual antibody blockade or genetic knockout of LAG3 and PD1 significantly enhanced T effector function and delayed ovarian tumor growth. The relative contribution of other immune inhibitory receptors to immune suppression in the ovarian TME, and whether they co-regulate each other are currently unknown. To address this, we analyzed the expression of multiple immune checkpoint proteins and their cognate ligands in ovarian tumor-bearing wild-type (WT), LAG3KO and PD1KO mice. We found that PD-1, cytotoxic T lymphocyte antigen 4 (CTLA-4), LAG-3, T-cell immunoglobulin domain and mucin domain 3 (TIM-3) and CD160 were elevated in TILs from the WT mice. Interestingly, compared with TILs of WT mice, the levels of LAG-3, TIM-3, and CTLA-4 were further significantly elevated in TILs from the tumor-bearing PD1KO mice; while the levels of PD-1, CTLA-4, and CD160 were further increased in the tumor-bearing LAG3KO mice. These results suggest that PD-1 and LAG-3 regulate the expression of multiple inhibitory receptors in the ovarian TME. Furthermore, combinatorial blockade with anti-LAG3 and anti-CTLA4 antibodies in the tumor-bearing PD1KO mice resulted in 30% tumor-rejection as compared to 10% by anti-CTLA4 alone or only delayed tumor growth by anti-LAG3. These data provide a strong basis for rational clinical testing of combinatorial blockade of the PD-1, LAG-3 and CTLA-4 immune inhibitory pathways for ovarian cancer immunotherapy. This abstract is also presented as Poster A51. Citation Format: Ruea-Yea Huang, AJ McGray, Kunle Odunsi. Combinatorial blockade of PD-1, CTLA-4, and LAG-3 pathways inhibits murine ovarian tumor growth. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr PR03.

The immunobiology of hepatocellular carcinoma in humans and mice: Basic concepts and therapeutic implications

To date, the preliminary research for understanding the underlying cancer etiology has made great progress. However, due to the heterogeneity of cancer and the complexity of tumor microenvironment, as well as the evasion of tumor cells from the immune surveillance, only a few people are rehabilitated with the eradicative cancer therapy so far. In the recent few years, the immunotherapy to stimulate the immune response or inhibit the immunosuppression against cancer has achieved unprecedented efficacy in refractory patients. There are two main streams of the immunoregulation for cancer treatment, immune checkpoint monoclonal antibodies (mAbs) and adoptive cell therapy (ACT). Nowadays, three kinds of checkpoints-blockade inhibitors, cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed cell death protein-1 (PD-1)/PD-L1 mAbs, have been approved by the United States Food and Drug Administration (FDA) to treat several types of cancer in clinic, including melanoma, non-small cell lung cancer, renal cell carcinoma and leukemia. Although the current cancer immunotherapy can successfully lead to durable outcomes, the therapeutic effect is still limited and patients are even suffering from the adverse reactions. Thus, it is urgent to develop a localized and efficient immunoregulation strategy against cancer. Encouragingly, nanotechnology is a promising tool to optimize the tumor co-localization, bio-distribution and pharmacokinetics for the molecular probes, cytotoxic pharmaceuticals, immunostimulators, various ligands (e.g., antibodies or aptamers) and other biological agents. The conventional cancer treatment with nanoparticle administration is to increase the cancer cellular uptake by enhanced permeation and retention (EPR) effect, which is a kind of passive accumulation due to the leaky vasculature but is proven somewhat elusive. In contrast, leukocytes of immune system in vivo can actively trace through chemokine gradients to the tumor cells, and then recognize and kill them by binding to the the tumor specific antigens. Besides, secondary lymphoid organs do not exhibit physical barriers as tumor microenvironment. Owing to the similar size to pathogens, nanoparticles are also able to accumulate in these fenestrated structures and readily uptaken by antigen-presenting cells (APCs), such as dendritic cells (DCs) and other natural phagocytes. The most typical application of nanotechnology on immunotherapy is cancer vaccines, and the nanoparticles are serving as antigen reservoirs to mimic both prime and boost injections after a single administration. The nanovaccines are able to induce robust DCs or CD8+ T cells response and confer cross-priming efficacy observed in preclinical animal models, which is an important breakthrough in the development of the soluble vector-free cancer vaccines. In addition, nanotechnology- mediated immunotherapy can enhance the treatment efficacy in combination with other approaches, such as surgery, radio-/chemo-therapy or ablation therapy. Meanwhile, there are numerous novel nanotechnology-based strategies for the regulation of both immune system and tumor microenvironment. For example, polymer scaffold can be implanted in vivo to establish a condition for the T-cell engineering; nanocarriers are intended to increase the intercellular avidity by targeting the circulating T cells, macrophages and cancer cells; drug-loaded nanoparticles will deliver DNase to destroy the neutrophil extracellular trappings (NETs). Looking ahead, the field of enhancing immunotherapy by nanotechnology will be developed to permit the analysis of multiple cell subtypes or immune cell activation state. What is more important, the researchers should take the responsibility to place an emphasis on the study of profound theory for immunology, innovative biomaterials for nanoparticles and clinical translation for engineered immunotherapeutic products. Hence, the nanotechnology-enhanced immunotherapy will enable the evaluation of treatment suitability and consequently improve the personalized immunotherapy. In conclusion, the concentrated immune response realized by nanotechnology can not only lower the drug dose and improve the efficacy, but also prevent the systemic toxicity in patients. It will definitely become the mainstay in immunotherapy in clinic. Therefore, this review is going to summarize the current situation of immunotherapy, and to analyze the opportunities, challenges and development of nanotechnology-enhanced immunotherapy in the future.

P-0035 - Immunosuppressive Protein Expression on Tumor and the Presence of Immune Cells Within Tumor Microenvironment in Curatively Resected Gastric Cancer

Integrative genomics highlights opportunities for innovative therapies targeting the tumor microenvironment in gallbladder cancer

Background: Data supporting high tumor mutational burden (TMB-H) as a lone biomarker for an immune responsive tumor microenvironment (TME) or of response to immune checkpoint inhibition (ICI) in metastatic breast cancer (MBC) is weak; yet the tumor agnostic approval in TMB-H advanced tumors makes ICI an option in the clinic. PDL-1 positivity (PDL-1+) is the only consistent biomarker for ICI benefit in metastatic triple-negative BC (mTNBC). We sought to further evaluate concurrent predictors of an immune responsive or non-responsive TME within TMB-H MBC. Methods: Tumor samples (N=5621) obtained from patients with MBC were analyzed by next-generation sequencing (NGS) of DNA (592-gene panel or whole exome sequencing) and RNA (whole transcriptome sequencing) at Caris Life Sciences (Phoenix, AZ). Friends of Cancer Research TMB Harmonization Project (Merino et al., 2020) recommendations, with the TMB-H threshold set to ≥ 10 muts/Mb, were used. PDL-1+ (≥1% immune cells stained) assessed by IHC (Ventana SP142). Deficient-mismatch repair (dMMR) and high microsatellite instability (MSI-H) were determined by IHC and NGS, respectively. Gene expression profiling assessed 21 immune-related signatures and TMEs using MCP-counter (Betch et al., 2016) and quanTIseq (Finotello et al., 2019). Immune cell types were classified as immune-responsive (CD8+ and CD4+ T cells, B cells, myeloid dendritic cells, M1 macrophages, NK cells, and neutrophils) or non-responsive (Tregs, M2 macrophages, and monocytes). P-values adjusted by the Benjamini-Hochberg procedure. Exploratory p-values reported for sub-analyses of TMB-H responsive vs nonresponsive TME and PDL1+ vs PDL1- subgroups. Results: TMB-H was identified in 461/5621 (8.2%) MBC samples. TMB-H tumors exhibit significant enrichment of dMMR/MSI-H (7 vs 0%, p<0.0001) and IHC-PDL1+ (36 vs 28%, p<0.05) compared to TMB-L. TMB-H was not associated with increased abundance or proportion of immune responsive cell types or immune response gene signatures (e.g. antigen presentation), yet positive trends were observed. To identify predictive biomarkers of immune responsive (hot) or non-responsive (cold) TME profiles within TMB-H MBC, we generated a composite TME score representing the overall proportion of hot vs cold immune cell types. APOBEC mutagenesis was common in TMB-H tumors (72%) and was more frequently associated with an immune cold TME (77 vs 66% in hot TME subgroup, p=0.068). Within TMB-H tumors, cold TMEs were enriched with mutations (muts) in PIK3CA (61 vs 47%), CHEK2 (5 vs 0%), CBFB (4 vs 0%), amplifications (amp) of CCND1 (13 vs 4%), FGF19 (16 vs 5%), FGF4 (11 vs 4%), and MMLT6 (6 vs 0%), and expression of IHC-AR (75 vs 58%) compared to hot TMEs (all p<0.05). Hot TMEs had increased frequency of MSI-H (12 vs 5%) and KMT2D muts (12 vs 3%) compared to cold TMEs (all p<0.05). Amongst TMB-H and TMB-L tumors, PDL1+ was significantly associated with increased proportion of immune responsive cell types (ie CD8+) compared to PDL1- tumors (0.14 vs -0.08 TME score, p<0.0001). Comparison of TMB-H tumors by PDL1 status revealed enrichment of TP53 (67 vs 53%) and B2M (8 vs 0%) muts in PDL1+ tumors, while IHC-ER positivity (68 vs 54%) and CDH1 muts (32 vs 16%) were increased in PDL1- tumors (all p<0.05). Conclusions: High TMB alone does not strongly correlate with immune infiltrate or immune response gene signatures in MBC. Within TMB-H MBC, concurrent mutations in MSI-H and KMT2D are associated with an immune responsive TME while mutations in PIK3CA, CHEK2, CBFB, amplifications of CCND1, FGF19, FGF4, and MMLT6, and expression of IHC-AR are associated with an immune non-responsive TME. Co-occurring biomarkers within TMB-H breast cancer warrant evaluation in prospective cohorts for response or resistance to ICI to help develop composite biomarkers in breast cancer. Citation Format: Sarah Sammons, Andrew Elliott, Jeremy Force, Saranya Chumsri, Carey Anders, Antoinette R Tan, Daniel Magee, Jia Zeng, W. Michael Korn, Mustafa Kahsraw, Evanthia T Roussos Torres. Concurrent predictors of an immune responsive tumor microenvironment within tumor mutational burden-high breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-08-08.

Immune checkpoints (ICs) have pivotal roles in regulating immune responses. The inhibitory ICs in the tumor microenvironment (TME) have been implicated in the immune evasion of tumoral cells. Therefore, identifying and targeting these inhibitory ICs might be critical for eliminating tumoral cells. V-domain immunoglobulin suppressor of T cell activation (VISTA) is a novel inhibitory IC that is expressed on myeloid cells, lymphoid cells, and tumoral cells; therefore, VISTA can substantially regulate innate and adaptive anti-tumoral immune responses. Besides, growing evidence indicates that VISTA blockade can enhance the sensitivity of tumoral cells to conventional IC-based immunotherapy, e.g., cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors. In this regard, the current study aimed to review the current evidence about the structure and expression pattern of VISTA, its role in TME, the clinicopathological significance of VISTA, and its prognostic values in various cancers. Besides, this review intended to collect the lessons from the recent pre-clinical and clinical studies and propose a strategy to overcome tumor immune-resistance states.

Year in review: Liver cancer research in 2022: tumor microenvironment takes the central stage.

BackgroundLung cancer and chronic obstructive pulmonary disease (COPD) are major global health challenges, and their coexistence in patients presents unique clinical complexities. Interestingly, patients with both lung adenocarcinoma (LUAD) and COPD show reduced responses to conventional chemotherapy and targeted therapies but demonstrate enhanced sensitivity to immunotherapy.MethodsWe investigated this phenomenon using a cohort of 248 LUAD patients undergoing immunotherapy. Single-cell transcriptomic analysis was performed on 187,123 cells from tumor samples, adjacent normal tissues, and peripheral blood mononuclear cells from six treatment-naïve LUAD patients—three with COPD and three without. To further validate these findings, we conducted multiplex fluorescent immunohistochemical (mfIHC) analysis on 34 additional treatment-naïve LUAD patients and analyzed an independent cohort of 65 LUAD patients undergoing immunotherapy.ResultsWe found that COPD-associated LUAD tumors exhibited distinctive features, including elevated expression of human leukocyte antigen I (HLA-I) on malignant cells and a less aggressive tumor phenotype. The immune microenvironment in these tumors was more active, with increased infiltration of NK cells, effector CD4+ T cells, and effector CD8+ T cells. Additionally, we observed higher numbers of exhausted C-X-C motif chemokine ligand 13+ CD8+ T cells and mature dendritic cells enriched in immunoregulatory molecules expressing immune checkpoint genes. These findings were confirmed in both the mfIHC cohort and the independent immunotherapy cohort, where we observed that COPD-related features correlated with improved responses to immunotherapy.ConclusionOur study reveals that COPD leads to elevated HLA-I expression and a more active immune microenvironment in LUAD tumors, characterized by enhanced cytotoxic immune cell infiltration and a shift towards immunoregulatory profiles. These features correlate with improved immunotherapy responses, highlighting the potential for optimizing treatment strategies in LUAD patients with COPD.