Immunological features of circulating monocyte subsets in patients with squamous cell carcinoma of the head and neck

Association between circulating immune cells and the risk of prostate cancer: a Mendelian randomization study

Background

There is still limited research on the association between immune cells and the risk of prostate cancer. Further investigations are warranted to comprehend the intricate associations at play.

Methods

We used a bidirectional two-sample Mendelian randomization (MR) analysis to investigate the causal relationship between immune cell phenotypes and prostate cancer. The summary data for immune cell phenotypes was derived from a study cohort, including 3,757 individuals from Sardinia with data on 731 immune cell phenotypes. The summary data for prostate cancer were obtained from the UK Biobank database. Sensitivity analyses were conducted, and the combination of MR-Egger and MR-Presso was used to assess horizontal pleiotropy. Cochran's Q test was employed to evaluate heterogeneity, and the results were subjected to FDR correction.

Results

Our study identified two immune cell phenotypes significantly associated with the risk of prostate cancer, namely CD25 on naive-mature B cells (OR = 0.998, 95% CI, 0.997-0.999, P = 2.33E-05, FDR = 0.017) and HLA DR on CD14- CD16- cells (OR = 1.001, 95% CI, 1.000-1.002, P = 8.01E-05, FDR = 0.03). When adjusting FDR to 0.2, we additionally found six immune cell phenotypes influencing the incidence of prostate cancer. These include FSC-A on B cells (OR = 1.002, 95% CI, 1.001-1.002, P = 7.77E-04, FDR = 0.133), HLA DR on plasmacytoid dendritic cells (OR = 1.001, 95% CI, 1.000-1.001, P = 0.001, FDR = 0.133), CD14+ CD16- monocyte % monocytes (OR = 1.002, 95% CI, 1.001-1.003, P = 0.001, FDR = 0.133), and HVEM on effector memory CD4+ T cells (OR = 1.001, 95% CI, 1.000-1.002, P = 0.002, FDR = 0.169), which are positively correlated with the risk of prostate cancer. Conversely, CD25 on IgD+ B cells (OR = 0.998, 95% CI, 0.997-0.999, P = 0.002, FDR = 0.169) and Monocytic Myeloid-Derived Suppressor Cells AC (OR = 0.999, 95% CI, 0.999-1.000, P = 0.002, FDR = 0.17) are negatively correlated with the risk of prostate cancer.

Conclusion

This study has revealed causal relationships between immune cell phenotypes and prostate cancer, supplying novel insights that might aid in identifying potential therapeutic targets of prostate cancer.

Monocytes in Tumorigenesis and Tumor Immunotherapy

Monocytes are highly plastic innate immune cells that display significant heterogeneity during homeostasis, inflammation, and tumorigenesis. Tumor-induced systemic and local microenvironmental changes influence the phenotype, differentiation, and distribution of monocytes. Meanwhile, monocytes and their related cell subsets perform an important regulatory role in the development of many cancers by affecting tumor growth or metastasis. Thanks to recent advances in single-cell technologies, the nature of monocyte heterogeneity and subset-specific functions have become increasingly clear, making it possible to systematically analyze subset-specific roles of monocytes in tumorigenesis. In this review, we discuss recent discoveries related to monocytes and tumorigenesis, and new strategies for tumor biomarker identification and anti-tumor immunotherapy.

Quantitative, Spatially Defined Expression of Leukocyte-associated Immunoglobulin-like Receptor in Non-small Cell Lung Cancer

Targeting the interaction of leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) and its ligands has been shown to reinstate antitumor immunity. In addition, the introduction of the LAIR-1 decoy protein, LAIR-2, sensitizes previously resistant lung tumors to programmed death-1 (PD-1) blockade, indicating the potential of LAIR-1 as an alternative marker for anti-PD-1 resistance in lung cancer. Here, we assessed LAIR-1 as compared with programmed death-ligand 1 (PD-L1) expression in various tumors, with a focus on non-small cell lung cancer (NSCLC) and its histologic subtypes using multiplexed quantitative immunofluorescence (mQIF) in 287 (discovery cohort) and 144 (validation cohort) patients with NSCLC. In addition, using multispectral imaging technology on mQIF images, we evaluated the localization of LAIR-1 on various cell types. We observed that CD14+, CD68+, and CD163+ monocytes and CK+ tumor cells predominantly expressed LAIR-1 more than other cell types. Furthermore, LAIR-1 expression in the tumor compartment was significantly higher in patients with lung adenocarcinoma (LUAD) than those with lung squamous cell carcinoma subtype (**, P = 0.003). Our results indicated that high tumor LAIR-1 expression in patients with LUAD is negatively associated with OS (overall survival, HR = 2.4; *, P = 0.02) highlighting its prognostic value in LUAD but not in other subtypes. The Pearson correlation between LAIR-1 and PD-L1 is 0.31; however, mutual exclusive staining pattern (i.e., several cases were positive for LAIR-1 and negative for PD-L1) was observed. Altogether, our data suggest that the combination therapy of anti-PD-1/PD-L1 with anti-LAIR-1 or the anti-LAIR-1 monotherapy alone may be promising cancer immunotherapeutic strategies.

Significance

The spatial, quantitative assessment of LAIR-1 in NSCLC shows positive association of OS with high LAIR-1+/CD68+ cell densities and negative association of OS with high LAIR-1 expression in LUAD tumor subtype.

Macrophage and monocyte subsets as new therapeutic targets in cancer immunotherapy

The introduction of immune checkpoint inhibitors (ICIs) for the treatment of solid cancers dramatically turned the tables in clinical routine. However, therapy success is still limited with up to 70% of non-responders in patients with ICI treatment. Traditionally, most immunotherapy approaches aim at directly stimulating anti-tumor T cell responses. More recently, tumor-associated macrophages have come into focus due to their predominance in solid tumors. Intensive cross-talk with tumor cells and immune as well as stromal cells within the tumor microenvironment can drive either pro- or anti-tumorigenic macrophage phenotypes. In turn, tumor-associated macrophages strongly shape cytokine and metabolite levels in the tumor microenvironment and thus are central players in anti-tumor immunity. Thus, ambivalent macrophage populations exist which raises therapeutic possibilities to either enhance or diminish their functionality. However, molecular signals controlling tumor-associated macrophage polarization are incompletely understood. Gaining in-depth understanding of monocyte/macrophage properties both in circulation and within distinct tumor microenvironments would (i) allow the development of new therapeutic approaches, and (ii) could additionally aid our understanding of underlying mechanisms limiting current therapy with the option of combinatorial therapies to increase efficacy. In this review, we summarize recent data addressing heterogeneity of tumor-associated macrophage populations and we discuss strategies to target macrophages using known molecular pathways with the potential for straight-forward clinical application.

Ewing Sarcoma and Osteosarcoma Have Distinct Immune Signatures and Intercellular Communication Networks

PURPOSE

Ewing sarcoma and osteosarcoma are primary bone sarcomas occurring most commonly in adolescents. Metastatic and relapsed disease are associated with dismal prognosis. Although effective for some soft tissue sarcomas, current immunotherapeutic approaches for the treatment of bone sarcomas have been largely ineffective, necessitating a deeper understanding of bone sarcoma immunobiology.

EXPERIMENTAL DESIGN

Multiplex immunofluorescence analysis of immune infiltration in relapsed versus primary disease was conducted. To better understand immune states and drivers of immune infiltration, especially during disease progression, we performed single-cell RNA sequencing (scRNAseq) of immune populations from paired blood and bone sarcoma tumor samples.

RESULTS

Our multiplex immunofluorescence analysis revealed increased immune infiltration in relapsed versus primary disease in both Ewing sarcoma and osteosarcoma. scRNAseq analyses revealed terminally exhausted CD8+ T cells expressing co-inhibitory receptors in osteosarcoma and an effector T-cell subpopulation in Ewing sarcoma. In addition, distinct subsets of CD14+CD16+ macrophages were present in Ewing sarcoma and osteosarcoma. To determine pathways driving tumor immune infiltration, we conducted intercellular communication analyses and uncovered shared mechanisms of immune infiltration driven by CD14+CD16+ macrophages and unique pathways of immune infiltration driven by CXCL10 and CXCL12 in osteosarcoma.

CONCLUSIONS

Our study provides preclinical rationale for future investigation of specific immunotherapeutic targets upon relapse and provides an invaluable resource of immunologic data from bone sarcomas.

Inflammatory landscape in Xeroderma pigmentosum patients with cutaneous melanoma

Xeroderma pigmentosum (XP) is a DNA repair disease that predisposes to early skin cancers as cutaneous melanoma. Melanoma microenvironment contains inflammatory mediators, which would be interesting biomarkers for the prognosis or for the identification of novel therapeutic targets. We used a PCR array to evaluate the transcriptional pattern of 84 inflammatory genes in melanoma tumors obtained from XP patients (XP-Mel) and in sporadic melanoma (SP-Mel) compared to healthy skin. Commonly expressed inflammatory genes were further explored via GTEx and GEPIA databases. The differentially expressed inflammatory genes in XP were compared to their expression in skin exposed to UVs, and evaluated on the basis of the overall survival outcomes of patients with melanoma. Monocyte subsets of patients with SP-Mel, XP and healthy donors were also assessed. PCR array data revealed that 34 inflammatory genes were under-expressed in XP-Mel compared to SP-Mel. Differentially expressed genes that were common in XP-Mel and SP-Mel were correlated with the transcriptomic datasets from GEPIA and GTEx and highlighted the implication of KLK1 and IL8 in the tumorigenesis. We showed also that in XP-Mel tumors, there was an overexpression of KLK6 and KLK10 genes, which seems to be associated with a bad survival rate. As for the innate immunity, we observed a decrease of intermediate monocytes in patients with SP-Mel and in XP. We highlight an alteration in the immune response in XP patients. We identified candidate biomarkers involved in the tumorigenesis, and in the survival of patients with melanoma. Intermediate monocyte's in patients at risk could be a prognostic biomarker for melanoma outcome.

Increased Abundances of CD16+ Non-Classical Monocytes Accompany with Elevated Monocytic PD-L1 and CD4+ T Cell Disturbances in Oropharyngeal Cancer

Background: Patients with human papilloma virus (HPV)-related oropharyngeal cancer have a better prognosis than nonvirally associated patients, most likely because of better immune responses. Increased infiltration of T lymphocytes into the oropharyngeal tumor tissue has been observed, but the dynamics of circulating lymphocytes and monocytes are not fully understood. The aim of this study was to understand the population dynamics of circulating monocyte subsets in oropharyngeal cancer (OPC) patients with regard to the clinicopathological parameters and accompanying immunological consequences in view of the CD4/CD8 T cell subset composition, and the expression of checkpoint pathway proteins programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1). Materials and Methods: The abundance of circulating monocyte subsets and peripheral blood CD4/CD8 T cells of oropharyngeal cancer patients and their PD-L1 and PD-1 expression levels were analyzed by flow cytometry. Results: The studied oropharyngeal cancer patients revealed heterogeneous individual redistributions of CD14++CD16− (classical), CD14++CD16+ (intermediate), and CD14dim+CD16+ (nonclassical) monocyte subsets compared with healthy donors. These differences in monocyte subset alterations were independent in patients with TNM or HPV status but entailed further immunological consequences. Increased percentages of nonclassical monocytes significantly correlated with increased levels of monocytic PD-L1 expression. We observed significantly decreased levels of CD4+ effector T cells, which were accompanied by increased CD4+ effector memory T cells in OPC patients compared with healthy donors, each having a stronger effect in patients with decreased levels of classical monocytes. Conclusion: We conclude that oropharyngeal cancer, as a malignancy from a lymphoid-tissue-rich anatomical region, has a strong systemic impact on the differentiation and regulation of circulating innate and adaptive immune cells. Further comprehensive investigations are required for the possible future usability of the described immunological alterations as bioliquid parameters for prognosis or therapy response prediction.

Smoking-, Alcohol-, and Age-Related Alterations of Blood Monocyte Subsets and Circulating CD4/CD8 T Cells in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) represents a heterogeneous malignant disease of the oral cavity, pharynx, and larynx. Although cigarette smoking, alcohol abuse, and aging are well-established associated factors for HNSCC, their respective influence on immunologic alterations of monocyte subsets or T-cell compositions in the peripheral blood has not yet been fully unveiled. Using flow cytometry, whole blood measurements of CD14/CD16 monocyte subsets and analyses of T-cell subsets in isolated PBMC fractions were carried out in 64 HNSCC patients in view of their tobacco and alcohol consumption, as well as their age, in comparison to healthy volunteers. Flow cytometric analysis revealed significantly increased expression of monocytic CD11b, as well as significantly decreased expression levels of CX3CR1 on classical and intermediate monocyte subsets in smoking-related and in alcohol-related HNSCC patients compared to healthy donors. Peripheral monocytes revealed an age-correlated significant decrease in PD-L1 within the entirety of the HNSCC cohort. Furthermore, we observed significantly decreased abundances of CD8+ effector memory T cells in active-smoking HNSCC patients and significantly increased percentages of CD8+ effector T cells in alcohol-abusing patients compared to the non-smoking/non-drinking patient cohort. Our data indicate an enhanced influence of smoking and alcohol abuse on the dynamics and characteristics of circulating monocyte subsets and CD4/CD8 T-cell subset proportions, as well as an age-related weakened immunosuppression in head and neck cancer patients.

The Role of miRNA in Regulating the Fate of Monocytes in Health and Cancer

Monocytes represent a heterogeneous population of blood cells that provide a link between innate and adaptive immunity. The unique potential of monocytes as both precursors (e.g., of macrophages) and effector cells (as phagocytes or cytotoxic cells) makes them an interesting research and therapeutic target. At the site of a tumor, monocytes/macrophages constitute a major population of infiltrating leukocytes and, depending on the type of tumor, may play a dual role as either a bad or good indicator for cancer recovery. The functional activity of monocytes and macrophages derived from them is tightly regulated at the transcriptional and post-transcriptional level. This review summarizes the current understanding of the role of small regulatory miRNA in monocyte formation, maturation and function in health and cancer development. Additionally, signatures of miRNA-based monocyte subsets and the influence of exogenous miRNA generated in the tumor environment on the function of monocytes are discussed.