Accumulation of tolerogenic human 6-sulfo LacNAc dendritic cells in renal cell carcinoma is associated with poor prognosis

Patients with metastatic renal cell carcinoma who receive immune-targeted therapy may derive survival benefit from nephrectomy

BACKGROUND

Nephrectomy, whether in the era of cytokine therapy or targeted therapy, has an important role in the treatment of metastatic renal cell carcinoma. With the advent of immunotherapy, immunotherapy combined with targeted therapy has become the mainstream of systemic therapy, but the role of nephrectomy in metastatic renal cell carcinoma is unclear. In this study, we retrospectively analyzed the impact of nephrectomy on survival in patients with metastatic renal cell carcinoma who received immune-targeted therapy.

METHODS

Patients with metastatic renal cell carcinoma who received immune-targeted therapy at three centers between May 17, 2019 and August 1, 2022 were collected, who were divided into two groups based on whether nephrectomy was performed or not. Survival, response rate and adverse event were compared between the two groups. The primary end point was progression free survival, Subgroup analysis and univariate and multivariable prognostic analyses were also assessed.

RESULTS

With a median follow-up time of 29.3 months (95% CI 28.5-30.2), 165 patients were recruited and divided into two groups based on whether they underwent nephrectomy or not. There were 68 patients in the non-nephrectomy group, 97 in the nephrectomy group. Compared to patients treated with immune-targeted therapy, patients treated with immune-targeted therapy plus nephrectomy were able to achieve survival benefits, with a median PFS of 10.8 months (95% CI 8.3-13.3) and 14.4 months (95% CI 12.6-16.2), respectively, as well as an HR of 0.476 (95% CI 0.323-0.701, p = 0.0002). The 12-month and 18-month PFS rates were 30.9% versus 60.8% and 7.4% versus 25.8%, respectively. The objective response rate (ORR) was 52.9% and 60.8%, respectively, in the non-nephrectomy and nephrectomy groups (p = 0.313), and the disease control rate (DCR) was 75% and 83.5%, respectively (p = 0.179). The most common adverse events related to treatment were hypothyroidism, immune-related pneumonitis and rash. Multivariate analysis showed that primary tumor nephrectomy prior to immune-targeted therapy, clear cell renal carcinoma and oligo metastasis were independent prognostic factors.

CONCLUSIONS

Nephrectomy may provide PFS benefit with tolerable safety for patients with metastatic renal cell carcinoma who receive immune-targeted therapy. In multivariate analysis, nephrectomy, clear cell carcinoma, and oligo-organ metastasis were found to be favorable independent prognostic factors.

The synergistic function of long and short forms of β4GalT1 in p53-mediated drug resistance in bladder cancer cells

β1,4-galactosyltransferase-1 (β4GalT1) is a type II membrane protein that catalyzes the transfer of galactose (Gal) from UDP-Gal to N-acetylglucosamine (GlcNAc) and forms a LacNAc structure. β4GalT1 has a long form (termed β4GalT1-L) and a short form (termed β4GalT1-S) in mammalian cells. Although β4GalT1 has been proven to play an important role in many biological and pathological processes, such as differentiation, immune responses and cancer development, the different functions of the two β4GalT1 forms remain ambiguous. In this study, we demonstrated that total β4GalT1 was upregulated in bladder cancer. Overexpression of β4GalT1-S, but not β4GalT1-L, increased drug resistance in bladder epithelial cells by upregulating p53 expression. Glycoproteomic analysis revealed that the substrate specificities of the two β4GalT1 forms were different. Among the LacNAcylated proteins, the E3 ligase MDM2 could be preferentially modified by β4GalT1-L compared to β4GalT1-S, and this modification could increase the binding of MDM2 and p53 and further facilitate the degradation of p53. Our data proved that the two forms of β4GalT1 could synergistically regulate p53-mediated cell survival under chemotherapy treatment. These results provide insights into the role of β4GalT1-L and β4GalT1-S and suggest their differentially important implications in the development of bladder cancer.

Potential upstream lncRNA-miRNA-mRNA regulatory network of the ferroptosis-related gene SLC7A11 in renal cell carcinoma

Background

SLC7A11 is a key regulator of ferroptosis, which mediates cysteine uptake for glutathione biosynthesis and maintains redox homeostasis. Emerging evidence has shown that SLC7A11 is upregulated in many human tumors. Nevertheless, the prognosis and posttranslational regulatory mechanism of SLC7A11 in renal cell carcinoma (RCC) remains obscure.

Methods

The Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), and The Cancer Genome Atlas (TCGA) databases were used to analyze the difference in SLC7A11 expression between malignant and normal tissues. Furthermore, the GEPIA, the University of ALabama at Birmingham CANcer data analysis Portal (UALCAN), and starBase databases were used to conduct the survival analyses. For correlation analysis, the UALCAN and starBase databases were employed. The Tumor Immune Estimation Resource (TIMER) database was used to approximate the abundance of immune infiltration.

Results

We confirmed that SLC7A11 was upregulated in most human cancers, including 3 types of RCC. SLC7A11 overexpression was linked to poor prognosis of individuals with kidney renal clear cell carcinoma (KIRC), kidney chromophobe cell carcinoma (KICH), and kidney renal papillary cell carcinoma (KIRP). SLC7A11 expression was also linked to immune cell infiltration levels. After performing a comprehensive analysis of the regulatory mechanisms of SLC7A11 expression, the results depicted a potential noncoding (ncRNA)-messenger RNA (mRNA) axis, incorporating SNHG6-miR-26a-5p-SLC7A11 networks in KICH, CASC19/CYTOR/LINC00997-miR-27b-3pSLC7A11 networks in KIRC, and CASC19/CYTOR/PVT1-miR27b-3p-SLC7A11 networks in KIRP as partially responsible for the functions of SLC7A11 in RCC. SLC7A11 expression was positively linked to infiltrated immune cells and their matching marker sets in 3 types of RCC, including CD8⁺ and myeloid dendritic cells.

Conclusions

Our research elucidated the crucial functions and the upstream long noncoding RNA (lncRNA)-microRNA (miRNA) regulatory network of SLC7A11 in RCC. Importantly, SLC7A11 can be used as a potential prognostic biomarker for 3 types of RCC and to determine the infiltration of immune cells in malignant tissues.

Transcriptome Profiling Reveals B-Lineage Cells Contribute to the Poor Prognosis and Metastasis of Clear Cell Renal Cell Carcinoma

Although immune therapy can improve the treatment of clear cell renal cell carcinoma (ccRCC) significantly, there are still a large proportion of ccRCC patients who progress to metastasis. Targeting the pro-metastatic immune cell in the ccRCC microenvironment could provide a solution to this problem. In this study, B cells in ccRCC biopsies were identified by using scRNA-seq and flow cytometry. The findings indicated the presence of a pro-metastatic B cell type which could be further classified into 3 subpopulations, MARCH3, B2M and DTWD1, based on their large-scaled genetic profiles, rather than traditional Immature/Mature ones. Although all of the 3 subpopulations appeared to contribute to distant metastasis, B cell (B2M) was deemed to be the most essential. Moreover, STX16, CLASRP, ATIC, ACIN1 and SEMA4B, were genes found to be commonly up-regulated in the 3 subpopulations and this was correlated to a poor prognosis of ccRCC. Furthermore, the heterogeneity of plasma cells in ccRCC was also found to contribute to metastasis of the disease. This study offers potential novel therapeutic targets against distant metastasis of cancers, and can help to improve the therapeutic efficiency of ccRCC patients.

Reduced frequencies and functional impairment of dendritic cell subsets and non-classical monocytes in myelodysplastic syndromes

In myelodysplastic syndromes (MDS) the immune system is involved in pathogenesis as well as in disease progression. Dendritic cells (DC) are key players of the immune system by serving as regulators of immune responses. Their function has been scarcely studied in MDS and most of the reported studies didn't investigate naturally occurring DC subsets. Therefore, we here examined the frequency and function of DC subsets and slan+ non-classical monocytes in various MDS risk groups. Frequencies of DC as well as of slan+ monocytes were decreased in MDS bone marrow (BM) compared to normal bone marrow (NBM) samples. Transcriptional profiling revealed down-regulation of transcripts related to pro-inflammatory pathways in MDS-derived cells as compared to NBM. Additionally, their capacity to induce T cell proliferation was impaired. Multidimensional mass cytometry showed that whereas healthy donor-derived slan+ monocytes supported Th1/Th17/Treg differentiation/expansion their MDS-derived counterparts also mediated substantial Th2 expansion. Our findings point to a role for an impaired ability of DC subsets to adequately respond to cellular stress and DNA damage in the immune escape and progression of MDS. As such, it paves the way toward potential novel immunotherapeutic interventions.

Differential effect on different immune subsets of neoadjuvant chemotherapy in patients with TNBC

Background

Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer (BC). Due to the absence of targets such as HER2 or hormone receptors, early TNBC is treated with surgery and chemotherapy. Since TNBC is also considered the most immunogenic type of BC with tumor infiltrating lymphocytes that are predictive for chemotherapy response and prognostic for patients′ survival, many different immunotherapeutic strategies are currently explored in clinical trials for the treatment of this disease. In order to efficiently combine chemotherapy with immunotherapy, it is important to evaluate the effect of chemotherapy on immune cells in vivo.

Methods

Peripheral blood was taken from 56 patients with TNBC undergoing neoadjuvant chemotherapy with nanoparticle albumin-bound paclitaxel (Nab-Pac) followed by epirubicin and cyclophosphamide (EC) at three different time points. Multicolor flow cytometry was used to characterize the immune cell composition and functional properties along neoadjuvant chemotherapy.

Results

Whereas the first phase of the neoadjuvant chemotherapy did not significantly alter the patients′ immune cell composition, after the second phase of chemotherapeutic administration most B cells (>90%) were lost and the frequency of natural killer (NK) cells and CD4⁺ T lymphocytes decreased approximately to 50%. In contrast, the frequency of CD8⁺ T cells were less affected.

Conclusions

Despite late consequences of Nab-Pac cannot be ruled out, these data suggest that different chemotherapeutics might have distinct effects on the immune cell repertoire and that different immune cell populations exhibit a specific susceptibility to these chemotherapies with B and NK cells being more affected than T cells. This might also have an impact on the combination of chemotherapies with immunotherapies.

Trial registration number

NCT02685059.

The immunology of renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer and comprises several subtypes with unique characteristics. The most common subtype (~70% of cases) is clear-cell RCC. RCC is considered to be an immunogenic tumour but is known to mediate immune dysfunction in large part by eliciting the infiltration of immune-inhibitory cells, such as regulatory T cells and myeloid-derived suppressor cells, into the tumour microenvironment. Several possible mechanisms have been proposed to explain how these multiple tumour-infiltrating cell types block the development of an effective anti-tumour immune response, including inhibition of the activity of effector T cells and of antigen presenting cells via upregulation of suppressive factors such as checkpoint molecules. Targeting immune suppression using checkpoint inhibition has resulted in clinical responses in some patients with RCC and combinatorial approaches involving checkpoint blockade are now standard of care in patients with advanced RCC. However, a substantial proportion of patients do not benefit from checkpoint blockade. The identification of reliable biomarkers of response to checkpoint blockade is crucial to facilitate improvements in the clinical efficacy of these therapies. In addition, there is a need for the development of other immune-based strategies that address the shortcomings of checkpoint blockade, such as adoptive cell therapies.

Comprehensive insights on pivotal prognostic signature involved in clear cell renal cell carcinoma microenvironment using the ESTIMATE algorithm

Emerging evidence has highlighted that the immune and stromal cells formed the majority of tumor microenvironment (TME) which are served as important roles in tumor progression. In our study, we aimed to screen vital prognostic signature associated with TME in clear cell renal cell carcinoma (ccRCC). We obtained total 611 samples from TCGA database consisting of transcriptome profiles and clinical data. ESTIMATE algorithm was applied to estimate the infiltrating fractions of immune/stromal cells. We found that the immune scores revealed more prognostic significance in overall survival and positive associations with risk clinical factors than stromal scores. We carried out differential expression analysis between Immunescore and stromalscore groups to obtain the 72 intersect genes. Protein to protein interaction (PPI) network and functional analysis was performed to indicate potential altered pathways. Additionally, we further conducted multivariate Cox analysis to identify 12 hub genes associated highly with TME of ccRCC using a stepwise regression procedure. Accordingly, risk score was constructed from the multivariate Cox results and Receiver Operating Characteristic (ROC) curve was used to assess the predictive value (AUC = 0.781). The ccRCC patients with high risk scores suffered poor survival outcomes than that with low risk scores. In the validation cohort from GSE53757, TNFSF13B, CASP5, and GJB6 correlated positively with tumor stages, while FREM1 negatively correlated with tumor stages. Importantly, we further observed that TNFSF13B, CASP5 and XCR1 showed the remarkable correlations with tumor‐infiltrating immune cells. Taken together, our research identified specific signatures that related to the infiltration of stromal and immune cells in TME of ccRCC using the transciptome profiles, which reached a comprehensive understanding of tumor microenvironment in ccRCC.

Characteristics of Tumor-Infiltrating Lymphocytes Prior to and During Immune Checkpoint Inhibitor Therapy

The tumor immune contexture plays a major role for the clinical outcome of patients. High densities of CD45RO⁺ T helper 1 cells and CD8⁺ T cells are associated with improved survival of patients with various cancer entities. In contrast, a higher frequency of tumor-infiltrating M2 macrophages is correlated with poor prognosis. Recent studies provide evidence that the tumor immune architecture also essentially contributes to the clinical efficacy of immune checkpoint inhibitor (CPI) therapy in patients. Pretreatment melanoma samples from patients who experienced a clinical response to anti-programmed cell death protein 1 (PD-1) treatment show higher densities of infiltrating CD8⁺ T cells compared to samples from patients that progressed during therapy. Anti-PD-1 therapy results in an increased density of tumor-infiltrating T lymphocytes in treatment responders. In addition, elevated frequencies of melanoma-infiltrating TCF7⁺CD8⁺ T cells are correlated with beneficial clinical outcome of anti-PD-1-treated patients. In contrast, a high density of tumor-infiltrating, dysfunctional PD-1⁺CD38^hi CD8⁺ cells in melanoma patients is associated with anti-PD-1 resistance. Such findings indicate that comprehensive tumor immune contexture profiling prior to and during CPI therapy may lead to the identification of underlying mechanisms for treatment response or resistance, and the design of improved immunotherapeutic strategies. Here, we focus on studies exploring the impact of intratumoral T and B cells at baseline on the clinical outcome of CPI-treated cancer patients. In addition, recent findings demonstrating the influence of CPIs on tumor-infiltrating lymphocytes are summarized.

Current Concepts on 6-sulfo LacNAc Expressing Monocytes (slanMo)

The human mononuclear phagocytes system consists of dendritic cells (DCs), monocytes, and macrophages having different functions in bridging innate and adaptive immunity. Among the heterogeneous population of monocytes the cell surface marker slan (6-sulfo LacNAc) identifies a specific subset of human CD14^- CD16⁺ non-classical monocytes, called slan⁺ monocytes (slanMo). In this review we discuss the identity and functions of slanMo, their contributions to immune surveillance by pro-inflammatory cytokine production, and cross talk with T cells and NK cells. We also consider the role of slanMo in the regulation of chronic inflammatory diseases and cancer. Finally, we highlight unresolved questions that should be the focus of future research.

Neoadjuvant Radiochemotherapy Significantly Alters the Phenotype of Plasmacytoid Dendritic Cells and 6-Sulfo LacNAc+ Monocytes in Rectal Cancer

Neoadjuvant radiochemotherapy (nRCT) can significantly influence the tumor immune architecture that plays a pivotal role in regulating tumor growth. Whereas, various studies have investigated the effect of nRCT on tumor-infiltrating T cells, little is known about its impact on the frequency and activation status of human dendritic cells (DCs). Plasmacytoid DCs (pDCs) essentially contribute to the regulation of innate and adaptive immunity and may profoundly influence tumor progression. Recent studies have revealed that higher pDC numbers are associated with poor prognosis in cancer patients. 6-sulfo LacNAc-expressing monocytes (slanMo) represent a particular proinflammatory subset of human non-classical blood monocytes that can differentiate into DCs. Recently, we have reported that activated slanMo produce various proinflammatory cytokines and efficiently stimulate natural killer cells and T lymphocytes. slanMo were also shown to accumulate in clear cell renal cell carcinoma (ccRCC) and in metastatic lymph nodes from cancer patients. Here, we investigated the influence of nRCT on the frequency of rectal cancer-infiltrating pDCs and slanMo. When evaluating rectal cancer tissues obtained from patients after nRCT, a significantly higher density of pDCs in comparison to pre-nRCT tissue samples was found. In contrast, the density of slanMo was not significantly altered by nRCT. Further studies revealed that nRCT significantly enhances the proportion of rectal cancer-infiltrating CD8⁺ T cells expressing the cytotoxic effector molecule granzyme B. When exploring the impact of nRCT on the phenotype of rectal cancer-infiltrating pDCs and slanMo, we observed that nRCT markedly enhances the percentage of inducible nitric oxide synthase (iNOS)- or tumor necrosis factor (TNF) alpha-producing slanMo. Furthermore, nRCT significantly increased the percentage of mature CD83⁺ pDCs in rectal cancer tissues. Moreover, the proportion of pDCs locally expressing interferon-alpha, which plays a major role in antitumor immunity, was significantly higher in post-nRCT tissues compared to pre-nRCT tumor specimens. These novel findings indicate that nRCT significantly influences the frequency and/or phenotype of pDCs, slanMo, and CD8⁺ T cells, which may influence the clinical response of rectal cancer patients to nRCT.

Phenotype, Function, and Mobilization of 6-Sulfo LacNAc-Expressing Monocytes in Atopic Dermatitis

Mononuclear phagocytes (MPs) are important immune regulatory cells in atopic dermatitis (AD). We previously identified 6-sulfo LacNAc-expressing monocytes (slanMo) as TNF-α- and IL-23-producing cells in psoriatic skin lesions and as inducers of IFN-γ-, IL-17-, and IL-22-producing T cells. These cytokines are also upregulated in AD and normalize with treatment, as recently shown for dupilumab-treated patients. We here asked for the role of slanMo in AD. Increased numbers of slanMo were found in AD skin lesions. In difference to other MPs in AD, slanMo lacked expression of FcɛRI, CD1a, CD14, and CD163. slanMo from blood of patients with AD expressed increased levels of CD86 and produced IL-12 and TNF-α at higher amounts than CD14⁺ monocytes and myeloid dendritic cells. While CD14⁺ monocytes from patients with AD revealed a reduced IL-12 production, we observed no difference in the cytokine production comparing slanMo in AD and healthy controls. Interestingly, experimentally induced mental stress, a common trigger of flares in patients with AD, rapidly mobilized slanMo which retained their high TNF-α-producing capacity. This study identifies slanMo as a distinct population of inflammatory cells in skin lesions and as proinflammatory blood cells in patients with AD. slanMo may, therefore, represent a potent future target for treatment of AD.

Intracapillary immune complexes recruit and activate slan-expressing CD16+ monocytes in human lupus nephritis

Lupus nephritis is a major cause of morbidity in patients with systemic lupus erythematosus. Among the different types of lupus nephritis, intracapillary immune complex (IC) deposition and accumulation of monocytes are hallmarks of lupus nephritis class III and IV. The relevance of intracapillary ICs in terms of monocyte recruitment and activation, as well as the nature and function of these monocytes are not well understood. For the early focal form of lupus nephritis (class III) we demonstrate a selective accumulation of the proinflammatory population of 6-sulfo LacNAc+ (slan) monocytes (slanMo), which locally expressed TNF-α. Immobilized ICs induced a direct recruitment of slanMo from the microcirculation via interaction with Fc γ receptor IIIA (CD16). Interestingly, intravenous immunoglobulins blocked CD16 and prevented cell recruitment. Engagement of immobilized ICs by slanMo induced the production of neutrophil-attracting chemokine CXCL2 as well as TNF-α, which in a forward feedback loop stimulated endothelial cells to produce the slanMo-recruiting chemokine CX3CL1 (fractalkine). In conclusion, we observed that expression of CD16 equips slanMo with a unique capacity to orchestrate early IC-induced inflammatory responses in glomeruli and identified slanMo as a pathogenic proinflammatory cell type in lupus nephritis.

Quantitative and functional alterations of 6-sulfo LacNac dendritic cells in multiple myeloma

Multiple myeloma (MM) results from expansion of abnormal plasma cells in the bone marrow (BM). Previous studies have shown that monocytes play a crucial role in MM pathophysiology. A 6-sulfo LacNAc-expressing population of dendritic cells (Slan-DCs) that overlaps with intermediate and non-classical monocytes in terms of phenotype has been described. Slan-DCs represent a circulating and tissue proinflammatory myeloid population which has been shown to play a role in different cancer contexts, and which exhibits a remarkable plasticity. Herein, we studied Slan-DCs from the BM and blood of MM patients. We performed quantitative and functional analyses of these cells from 54 patients with newly diagnosed, symptomatic MM, 21 patients with MGUS and 24 responding MM patients. We found that circulating Slan-DCs were significantly decreased in MM patients as compared to those of healthy donors or patients with MGUS, while CD14+CD16+ intermediate monocytes accumulate in the BM. Moreover, after activation with TLR7/8 ligand R848, IL-12-producing Slan-DCs from the BM or peripheral blood from MM patients were decreased as compared with healthy donors. We show that MM cell lines or MM cells isolated from patients at diagnosis were able to inhibit the production of IL-12 by Slan-DCs, as well as to shift the phenotype of Slan-DCs towards an intermediate monocyte-like phenotype. Finally, Slan-DCs that have been cultured with MM cells reduced their capacity to induce T cell proliferation and Th1 polarization. We conclude that Slan-DCs represent previously unrecognized players in MM development and may represent a therapeutic target.

Trial watch: Dendritic cell-based anticancer immunotherapy

Dendritic cell (DC)-based vaccines against cancer have been extensively developed over the past two decades. Typically DC-based cancer immunotherapy entails loading patient-derived DCs with an appropriate source of tumor-associated antigens (TAAs) and efficient DC stimulation through a so-called "maturation cocktail" (typically a combination of pro-inflammatory cytokines and Toll-like receptor agonists), followed by DC reintroduction into patients. DC vaccines have been documented to (re)activate tumor-specific T cells in both preclinical and clinical settings. There is considerable clinical interest in combining DC-based anticancer vaccines with T cell-targeting immunotherapies. This reflects the established capacity of DC-based vaccines to generate a pool of TAA-specific effector T cells and facilitate their infiltration into the tumor bed. In this Trial Watch, we survey the latest trends in the preclinical and clinical development of DC-based anticancer therapeutics. We also highlight how the emergence of immune checkpoint blockers and adoptive T-cell transfer-based approaches has modified the clinical niche for DC-based vaccines within the wide cancer immunotherapy landscape.