Ultrahypofractionated radiotherapy (UHRT) has emerged as an effective treatment option for localized prostate cancer (PCa), but the systemic immunological consequences of different radiotherapy (RT) regimens remain largely overlooked. In particular, the relative contribution of fractionation schedule and irradiation volume to long-term immune remodelling has not been systematically investigated. We conducted a longitudinal immune-monitoring study in peripheral blood from PCa patients treated with five different RT schedules, including three UHRT regimens. Complete blood counts and multiparametric flow cytometry were performed before treatment and longitudinally up to 12 months after RT completion to assess lymphocyte counts, immune-cell composition, and differentiation status of T- and B-cell compartments. B-cell functionality was evaluated by flow-cytometric analysis following CpG stimulation. In a subset of patients, tertiary lymphoid structures (TLS) were investigated in prostate tissue by immunohistochemistry using anti-CD20 and anti-CD3 antibodies, together with CD21 and CD23 staining to assess TLS maturation. Conventional fractionated RT was associated with persistent lymphopenia, increased neutrophil-to-lymphocyte ratio, reduction of CD3⁺ and conventional CD4⁺ T cells, enrichment of activated regulatory T-cell subsets, and prolonged depletion of memory B cells. Functional analyses demonstrated a marked impairment of B-cell responsiveness following conventional RT, whereas patients treated with UHRT maintained substantially preserved B-cell function after CpG stimulation. In contrast to conventional RT, UHRT-based regimens induced limited and largely reversible immune alterations, with progressive restoration of both T- and B-cell compartments and recovery of B-cell functionality. Importantly, peripheral immune profiles returned close to baseline values approximately one year after treatment completion, even in patients receiving pelvic irradiation. Comparison between pelvic conventional RT and pelvic UHRT further suggested that cumulative radiation exposure contributes to systemic immune disruption beyond the effect of irradiation volume alone. Different RT schedules exert distinct effects on long-term systemic immune proficiency. Compared with conventional fractionated RT, UHRT preserves immune-cell homeostasis, maintains B-cell functional competence, and supports recovery of peripheral immune compartments within one year after treatment. These findings provide a strong rationale for optimizing RT fractionation strategies and for the future integration of UHRT with immunotherapeutic approaches in prostate cancer. Clinicaltrials.gov NCT04774133, registered February 23 2021, retrospectively registered; https://clinicaltrials.gov/ct2/show/NCT04774133

OBJECTIVE:VEGF-A exerts complex immunomodulatory effects that foster an immunosuppressive tumour microenvironment, including impaired dendritic cell (DC) maturation, expansion of regulatory T cells (Tregs), and induction of T-cell exhaustion, while transiently enhancing effector T-cell responses. This dual activity underscores the need to clarify the immunosuppressive versus immunostimulatory consequences of VEGF-A receptor activation to optimise selective inhibition. This proof-of-concept study evaluated whether selective VEGFR-1 blockade can counteract VEGF-A-driven immunosuppression in human immune cells using the monoclonal antibody (mAb) D16F7, which inhibits membrane-bound VEGFR-1 while preserving the decoy and anti-angiogenic activity of its soluble form. METHODS:The impact of VEGFR-1 blockade by D16F7 mAb on VEGF-A-mediated immune modulation was assessed by multiparametric flow cytometry using primary immune cells from healthy donors. Human DCs were generated from CD14+ monocytes and cultured with VEGF-A; tolerogenic and pro-exhaustion activity was evaluated via maturation markers (CD80, CD83, HLA-DR) and PD-1 expression on DC-stimulated T cells after 14 days. Short-term effects on effector T cells, stratified by PD-1 and CD28 expression, were analysed by intracellular cytokine staining at 5-6 and 18 h. Purified Tregs, isolated via a two-step magnetic separation, were cultured for 1 week to assess the acquisition of an immunosuppressive phenotype by measuring the expression of checkpoint markers (PD-1, ICOS, TIM-3). RESULTS:D16F7 reversed VEGF-A-induced DC maturation defects, reduced DC-mediated T-cell tolerance, and attenuated the emergence of a highly immunosuppressive Treg phenotype, while largely preserving short-term effector T-cell function. CONCLUSIONS:Despite the limitations of an in vitro PBMC-based system, selective VEGFR-1 blockade by D16F7 mAb alleviates VEGF-A-driven immune tolerance while preserving T-cell activation, supporting its translational potential as a complementary immunomodulatory approach.

BACKGROUND:Cancer-associated fibroblasts (CAFs) significantly impact cancer progression and CAF subtypes are key determinants of response to immune checkpoint therapy (ICT). The transforming growth factor-β (TGF-β) signaling is a main pathway in protumorigenic activity of CAFs and resistance to ICT. The actin cytoskeleton regulator hMENA plays crucial roles in epithelial-mesenchymal transition (EMT) and regulates pathways critical to antitumor immune response, such as interferon-I and Axl-GAS6. METHODS:We constructed a single-cell atlas of CAFs using integrated public dataset. Experimental data were obtained by biochemical and molecular approaches in CAFs from freshly explanted non-small cell lung cancer (NSCLC) tissues hMENA silenced and in tumor cell lines or peripheral blood mononuclear cells treated with CAF conditioned medium. Multiparametric flow cytometry was used to characterize T cells. A gene signature indicative of ICT response was developed by a machine learning model. RESULTS:Computational analysis indicates that hMENA is primarily overexpressed in a myofibroblast cluster enriched for a TGF-β-activated CAF signature. Experimentally, we showed that TGF-β1 treatment increases hMENA expression and, reciprocally, hMENA/hMENAΔv6 modulate TGF-β1/2 production and secretion and transforming growth factor-β type II receptor expression in CAFs. Functionally, hMENA contributes to TGF-β1-driven CAF phenotype, programmed death-ligand 1 (PD-L1) upregulation, extracellular matrix remodeling and secretion of immunosuppressive cytokines/chemokines. The hMENA-driven TGF-β secretion in CAFs promotes PD-L1 expression and EMT in cancer cells by activating TGF-β signaling. On the tumor cell side, hMENA expression sustains the TGF-β signaling and EMT mediated by hMENA-driven CAFs secretome. This immunosuppressive secretome favors regulatory T cell (Treg) abundance and reduces CD8+ and CD4+ T cell functionality. Finally, based on the hMENA and TGF-β enriched CAF subtype, we developed a 9-gene signature, which in combination with hMENA/hMENAΔv6 correlates with increased Treg abundance and poor prognosis in the Cancer Genome Atlas NSCLC and associates with ICT resistance in Stand Up To Cancer (SU2C) and in phase III clinical trial (OAK) (NCT02008227) datasets. CONCLUSIONS:Our findings indicate that hMENA overexpression in CAFs defines a myofibroblast-like subset predominantly driven by TGF-β signaling, which sustains TGF-β1-mediated crosstalk between cancer cells and CAFs and impairs T-cell functionality. In NSCLC tissues, hMENAhigh CAFs associate with TGF-β and regulatory T-cell signatures and correlate with poor patient prognosis and resistance to immune checkpoint therapies, supporting their role as key contributors to an immunosuppressive, ICT-refractory tumor microenvironment.

Multiple myeloma (MM) continues to be an incurable malignancy, even with recent therapeutic advancements. Although epigenetic dysregulation at cis-regulatory elements is known to drive disease progression, the complete molecular mechanisms underlying these alterations are poorly understood. Using Assay for Transposase-Accessible Chromatin with high-throughput sequencing analysis combined with the computational footprinting of CD138+ cells from 55 patients with MM, we depicted the dynamic changes in chromatin accessibility during disease progression and identified nuclear respiratory factor 1 (NRF1) as a master regulator of vital MM survival pathways. We demonstrated that NRF1 maintains proteasome homeostasis by orchestrating the ubiquitination pathway, which is essential for MM cell survival. We discovered a novel enhancer element that physically interacts with the NRF1 promoter, sustaining its expression. Targeting this enhancer RNA reduced NRF1 levels and increased tumor cell sensitivity to bortezomib (BTZ), suggesting therapeutic potential. In xenograft models, we showed that antisense oligonucleotides targeting the NRF1 enhancer, either alone or combined with BTZ, significantly decreased tumor burden and improved survival. Our findings reveal a previously unknown NRF1-dependent mechanism regulating MM cell survival and present a promising therapeutic approach through the manipulation of its regulatory network.

The tumor microenvironment (TME) represents a complex ecosystem composed of tumor cells and various non-cancerous cell types, embedded within an altered extracellular matrix (ECM). In solid tumors, the ECM plays multiple roles: it provides mechanical support, delivers signaling molecules and transmits biophysical stimuli that influence cellular functions. Various cell types, primarily cancer-associated fibroblasts (CAFs) and immune cells such as macrophages, actively participate in the secretion and remodeling of ECM. However, whether the ECM directly instructs or educates immune cells, particularly macrophages within the TME, remains poorly understood. Here, we present a protocol to investigate the impact of ECM derived from non-small cell lung cancer (NSCLC) CAFs on macrophage state.

T cells are central mediators of anti-tumor immune responses, with their activation critically depending on finely tuned, and kinetically controlled signaling through the T cell receptor (TCR)-CD3 complex. Early TCR-proximal phosphorylation events shape downstream pathways that govern T-cell proliferation, differentiation, and effector functions, including responses to cancer immunotherapies, thus playing a pivotal role for effective tumor surveillance and eradication. Despite their importance, accurately capturing these early signaling events, at the single-cell level, remains technically challenging. Here, we present an optimized flow cytometry-based phospho-profiling protocol to assess early TCR signaling dynamics, using ERK phosphorylation as a sensitive readout. By overcoming the challenges of traditional approaches, this protocol provides an easy, yet powerful tool to evaluate T cell functionality both systemically and within the tumor immune microenvironment (TIME). Its application holds significant promise for advancing our understanding of T cell biology and for guiding the development and likely refinement of next-generation cancer immunotherapies.

Improving cancer immunotherapy efficacy hinges on identifying key T-cell populations critical for tumor control and response to Immune Checkpoint Blockade (ICB). We have recently reported that while the co-expression of PD-1 and CD28 is associated with impaired functionality in peripheral blood, it significantly enhances T-cell fitness in the tumor site of non-small cell lung cancer (NSCLC) patients. To uncover the underlying mechanisms, we explored the role of CD26, a key player in T-cell activation through its interaction with adenosine deaminase (ADA), a crucial intra/extracellular enzyme able to neutralize local adenosine (ADO). We found that an autocrine ADA/CD26 axis enhances CD8+PD-1+CD28+ T-cell function, particularly within an immunosuppressive environment marked by CD39 expression. Then, we interrogated the TCGA and OAK datasets to gain insight into the prognostic/predictive potential of our findings. We identified a signature predicting overall survival (OS) in LUAD patients and response to atezolizumab in advanced LUAD cases. These findings suggest promising avenues for therapeutic intervention targeting the ADA/CD26 axis.

BACKGROUND:Tertiary Lymphoid Structures (TLS) correlate with positive outcomes in patients with NSCLC and the efficacy of immune checkpoint blockade (ICB) in cancer. The actin regulatory protein hMENA undergoes tissue-specific splicing, producing the epithelial hMENA11a linked to favorable prognosis in early NSCLC, and the mesenchymal hMENAΔv6 found in invasive cancer cells and pro-tumoral cancer-associated fibroblasts (CAFs). This study investigates how hMENA isoforms in tumor cells and CAFs relate to TLS presence, localization and impact on patient outcomes and ICB response. METHODS:Methods involved RNA-SEQ on NSCLC cells with depleted hMENA isoforms. A retrospective observational study assessed tissues from surgically treated N0 patients with NSCLC, using immunohistochemistry for tumoral and stromal hMENA isoforms, fibronectin, and TLS presence. ICB-treated patient tumors were analyzed using Nanostring nCounter and GeoMx spatial transcriptomics. Multiparametric flow cytometry characterized B cells and tissue-resident memory T cells (TRM). Survival and ICB response were estimated in the cohort and validated using bioinformatics pipelines in different datasets. FINDINGS:Findings indicate that hMENA11a in NSCLC cells upregulates the TLS regulator LTβR, decreases fibronectin, and favors CXCL13 production by TRM. Conversely, hMENAΔv6 in CAFs inhibits LTβR-related NF-kB pathway, reduces CXCL13 secretion, and promotes fibronectin production. These patterns are validated in N0 NSCLC tumors, where hMENA11ahigh expression, CAF hMENAΔv6low, and stromal fibronectinlow are associated with intratumoral TLS, linked to memory B cells and predictive of longer survival. The hMENA isoform pattern, fibronectin, and LTβR expression broadly predict ICB response in tumors where TLS indicates an anti-tumor immune response. INTERPRETATION:This study uncovers hMENA alternative splicing as an unexplored contributor to TLS-related Tumor Immune Microenvironment (TIME) and a promising biomarker for clinical outcomes and likely ICB responsiveness in N0 patients with NSCLC. FUNDING:This work is supported by AIRC (IG 19822), ACC (RCR-2019-23669120), CAL.HUB.RIA Ministero Salute PNRR-POS T4, "Ricerca Corrente" granted by the Italian Ministry of Health.

Background Immune checkpoint blockade (ICB) has significantly prolonged survival of non-small cell lung cancer (NSCLC) patients, although most patients develop mechanisms of resistance. Recently single-cell RNA-sequencing (scRNA-Seq) revealed a huge T-cell phenotypic and (dys)functional state variability. Accordingly, T-cell exhaustion is recognized as a functional adaptation, with a dynamic progression from a long-lived “pre-exhausted stem-like progenitor” to a “terminally exhausted” state. In this scenario it is crucial to understand the complex interplay between co-stimulatory and inhibitory molecules in CD8 + T-cell functionality. Methods To gain a baseline landscape of the composition, functional states, and transcriptomic signatures predictive of prognosis, we analyzed CD8 + T-cell subsets characterized by the presence/absence of PD1 and CD28 from periphery, adjacent non-tumor tissue and tumor site of a cohort of treatment-naïve NSCLC patients, by integrated multiparametric flow cytometry, targeted multi-omic scRNA-seq analyses, and computational pipelines. Results Despite the increased PD1 levels, an improved PD1 + CD28 + T-cell polyfunctionality was observed with the transition from periphery to tumor site, associated with lack of TIGIT, TIM-3 and LAG-3, but not with Ag-experienced-marker CD11a. Differently from CD28 + T cells, the increased PD1 levels in the tumor were associated with reduced functionality in PD1 + CD28 − T cells. CD11a high , although expressed only in a small fraction of this subset, still sustained its functionality. Absence of TIGIT, TIM-3 and CTLA-4, alone or combined, was beneficial to CD28 − T cells. Notably, we observed distinct T RM phenotypes in the different districts, with CD28 + T cells more capable of producing TGFβ in the periphery, potentially contributing to elevated CD103 levels. In contrast CD28 − T RM mainly produced CXCL13 within the tumor. ScRNA-seq revealed 5 different clusters for each of the two subsets, with distinctive transcriptional profiles in the three districts. By interrogating the TCGA dataset of patients with lung adenocarcinoma (LUAD) and metastatic NSCLC treated with atezolizumab, we found signatures of heterogeneous T RM and "pre-exhausted" long-lived effector memory CD8 + T cells associated with improved response to ICB only in the presence of CD28. Conclusions Our findings identify signatures able to stratify survival of LUAD patients and predict ICB response in advanced NSCLC. CD28 is advocated as a key determinant in the signatures identified, in both periphery and tumor site, thus likely providing feasible biomarkers of ICB response. Graphical Abstract

IntroductionDespite the recent approval of several therapies in the adjuvant setting of melanoma, tumor relapse still occurs in a significant number of completely resected stage III-IV patients. In this context, the use of cancer vaccines is still relevant and may increase the response to immune checkpoint inhibitors. We previously demonstrated safety, immunogenicity and preliminary evidence of clinical efficacy in stage III/IV resected melanoma patients subjected to a combination therapy based on peptide vaccination together with intermittent low-dose interferon-α2b, with or without dacarbazine preconditioning (https://www.clinicaltrialsregister.eu/ctr-search/search, identifier: 2008-008211-26). In this setting, we then focused on pre-treatment patient immune status to highlight possible factors associated with clinical outcome.MethodsMultiparametric flow cytometry was used to identify baseline immune profiles in patients’ peripheral blood mononuclear cells and correlation with the patient clinical outcome. Receiver operating characteristic curve, Kaplan-Meier survival and principal component analyses were used to evaluate the predictive power of the identified markers.ResultsWe identified 12 different circulating T and NK cell subsets with significant (p ≤ 0.05) differential baseline levels in patients who later relapsed with respect to patients who remained free of disease. All 12 parameters showed a good prognostic accuracy (AUC>0.7, p ≤ 0.05) and 11 of them significantly predicted the relapse-free survival. Remarkably, 3 classifiers also predicted the overall survival. Focusing on immune cell subsets that can be analyzed through simple surface staining, three subsets were identified, namely regulatory T cells, CD56dimCD16- NK cells and central memory γδ T cells. Each subset showed an AUC>0.8 and principal component analysis significantly grouped relapsing and non-relapsing patients (p=0.034). These three subsets were used to calculate a combination score that was able to perfectly distinguish relapsing and non-relapsing patients (AUC=1; p=0). Noticeably, patients with a combined score ≥2 demonstrated a strong advantage in both relapse-free (p=0.002) and overall (p=0.011) survival as compared to patients with a score <2.DiscussionPredictive markers may be used to guide patient selection for personalized therapies and/or improve follow-up strategies. This study provides preliminary evidence on the identification of peripheral blood immune biomarkers potentially capable of predicting the clinical response to combined vaccine-based adjuvant therapies in melanoma.

BACKGROUND:Understanding how cancer signaling pathways promote an immunosuppressive program which sustains acquired or primary resistance to immune checkpoint blockade (ICB) is a crucial step in improving immunotherapy efficacy. Among the pathways that can affect ICB response is the interferon (IFN) pathway that may be both detrimental and beneficial. The immune sensor retinoic acid-inducible gene I (RIG-I) induces IFN activation and secretion and is activated by actin cytoskeleton disturbance. The actin cytoskeleton regulatory protein hMENA, along with its isoforms, is a key signaling hub in different solid tumors, and recently its role as a regulator of transcription of genes encoding immunomodulatory secretory proteins has been proposed. When hMENA is expressed in tumor cells with low levels of the epithelial specific hMENA11a isoform, identifies non-small cell lung cancer (NSCLC) patients with poor prognosis. Aim was to identify cancer intrinsic and extrinsic pathways regulated by hMENA11a downregulation as determinants of ICB response in NSCLC. Here, we present a potential novel mechanism of ICB resistance driven by hMENA11a downregulation.METHODS:Effects of hMENA11a downregulation were tested by RNA-Seq, ATAC-Seq, flow cytometry and biochemical assays. ICB-treated patient tumor tissues were profiled by Nanostring IO 360 Panel enriched with hMENA custom probes. OAK and POPLAR datasets were used to validate our discovery cohort.RESULTS:Transcriptomic and biochemical analyses demonstrated that the depletion of hMENA11a induces IFN pathway activation, the production of different inflammatory mediators including IFNβ via RIG-I, sustains the increase of tumor PD-L1 levels and activates a paracrine loop between tumor cells and a unique macrophage subset favoring an epithelial-mesenchymal transition (EMT). Notably, when we translated our results in a clinical setting of NSCLC ICB-treated patients, transcriptomic analysis revealed that low expression of hMENA11a, high expression of IFN target genes and high macrophage score identify patients resistant to ICB therapy.CONCLUSIONS:Collectively, these data establish a new function for the actin cytoskeleton regulator hMENA11a in modulating cancer cell intrinsic type I IFN signaling and extrinsic mechanisms that promote protumoral macrophages and favor EMT. These data highlight the role of actin cytoskeleton disturbance in activating immune suppressive pathways that may be involved in resistance to ICB in NSCLC.

ABSTRACT The impact of radiotherapy (RT) on immune cell status in prostate cancer (PCa) is only partially determined. The aim of this study was to assess the effect of different RT strategies on peripheral B, T, and Natural killer (NK) lymphocytes at precise longitudinal time-points in PCa. 18 patients treated with stereotactic body radiation therapy (SBRT) (40 Gy/3FRX), definitive moderate-hypofractionation (62 Gy/20FRX), or post-operative conventional-fractionation RT (66–69 Gy/30FRX) were prospectively evaluated for the immune cell profile in terms of immune cell composition, differentiation stage, cytokine production and inhibitory receptor (IR) expression. The immune-monitoring of the 18 patients revealed that RT affects the balance of systemic immune cells, with the main differences observed between SBRT and conventionally fractionated RT. SBRT favorably impacts immune response in term of increased B cells, central-memory and effector-memory CD8+ T cells, along with decreased Treg cells after treatment. On the contrary, conventional fractionated RT had a long-term negative effect on the systemic immune profile, including a decrease of total lymphocyte counts accompanied by an increase of neutrophils-to-lymphocytes ratio. Total B and T cells decreased and Treg-to-CD8+ ratio increased. Functionality of T lymphocytes were not affected by any of the 3-fractionation schedules. Interestingly, SBRT significantly up-regulates the expression of V-domain immunoglobulin suppressor of T-cell activation (VISTA) in CD8+ T cells in the absence of other IRs. Our results indicate the relevance of systematic immunomonitoring during RT to identify novel immune-related target to design trials of combined radio-immunotherapy as a promising strategy in the clinical management of PCa.

Additional file 1: Table S1. Clinical-pathological characteristics of NSCLC patients.

Profiling the T-Cell Receptor (TCR) repertoire is establishing as a potent approach to investigate autologous and treatment-induced antitumor immune response. Technical and computational breakthroughs, including high throughput next-generation sequencing (NGS) approaches and spatial transcriptomics, are providing unprecedented insight into the mechanisms underlying antitumor immunity. A precise spatiotemporal variation of T-cell repertoire, which dynamically mirrors the functional state of the evolving host-cancer interaction, allows the tracking of the T-cell populations at play, and may identify the key cells responsible for tumor eradication, the evaluation of minimal residual disease and the identification of biomarkers of response to immunotherapy. In this review we will discuss the relationship between global metrics characterizing the TCR repertoire such as T-cell clonality and diversity and the resultant functional responses. In particular, we will explore how specific TCR repertoires in cancer patients can be predictive of prognosis or response to therapy and in particular how a given TCR re-arrangement, following immunotherapy, can predict a specific clinical outcome. Finally, we will examine current improvements in terms of T-cell sequencing, discussing advantages and challenges of current methodologies.

Endogenous acetaldehyde production from the metabolism of ingested alcohol exposes hematopoietic progenitor cells to increased genotoxic risk. To develop possible therapeutic strategies to prevent or reverse alcohol abuse effects, it would be critical to determine the temporal progression of acute ethanol toxicity on progenitor cell numbers and proliferative status. We followed the variation of the cell proliferation rate in bone marrow and spleen in response to acute ethanol intoxication in the MITO-Luc mouse, in which NF-Y-dependent cell proliferation can be assessed in vivo by non-invasive bioluminescent imaging. One week after ethanol administration, bioluminescent signals in bone marrow and spleen decreased below the level corresponding to physiological proliferation, and they progressively resumed to pre-treatment values in approximately 4 weeks. Boosting acetaldehyde catabolism by administration of an aldehyde dehydrogenase activity activator or administration of polyphenols with antioxidant activity partially restored bone marrow cells' physiological proliferation. These results indicate that in this mouse model, bioluminescent alteration reflects the reduction of the physiological proliferation rate of bone marrow progenitor cells due to the toxic effect of aldehydes generated by alcohol oxidation. In summary, this study presents a novel view of the impact of acute alcohol intake on bone marrow cell proliferation in vivo.

Clinical studies based on novel rationales and mechanisms of action of chemotherapy agents and cytokines can contribute to the development of new concepts and strategies of antitumor combination therapies. In previous studies, we investigated the paradoxical immunostimulating effects of some chemotherapeutics and the immunoadjuvant activity of interferon alpha (IFN-α) in preclinical and clinical models, thus unraveling novel rationales and mechanisms of action of chemotherapy agents and cytokines for cancer immunotherapy. Here, we carried out a randomized, phase II clinical trial, in which we analyzed the relapse-free (RFS) and overall survival (OS) of 34 completely resected stage III–IV melanoma patients, treated with peptide-based vaccination (Melan-A/MART-1 and NY-ESO-1) in combination with IFN-α2b, with (arm 2) or without (arm 1) dacarbazine preconditioning. All patients were included in the intention-to-treat analysis. At a median follow-up of 4.5 years (interquartile range, 15.4–81.0 months), the rates of RFS were 52.9 and 35.3% in arms 1 and 2, respectively. The 4.5-year OS rates were 68.8% in arm 1 and 62.7% in arm 2. No significant differences were observed between the two arms for both RFS and OS. Interestingly, the RFS and OS curves remained stable starting from 18 and 42 months, respectively. Grade 3 adverse events occurred in 5.9% of patients, whereas grade 4 events were not observed. Both treatments induced a significant expansion of vaccine-specific CD8+ T cells, with no correlation with the clinical outcome. However, treatment-induced increase of polyfunctionality and of interleukin 2 production by Melan-A–specific CD8+ T cells and expansion/activation of natural killer cells correlated with RFS, being observed only in nonrelapsing patients. Despite the recent availability of different therapeutic options, low-cost, low-toxic therapies with long-lasting clinical effects are still needed in patients with high-risk resected stage III/IV melanoma. The combination of peptide vaccination with IFN-α2b showed a minimal toxicity profile and resulted in encouraging RFS and OS rates, justifying further evaluation in clinical trials, which may include the use of checkpoint inhibitors to further expand the antitumor immune response and the clinical outcome.Clinical Trial Registration:https://www.clinicaltrialsregister.eu/ctr-search/search, identifier: 2008-008211-26

Intestinal microbiota have been proposed to induce commensal-specific memory T cells that cross-react with tumor-associated antigens. We identified major histocompatibility complex (MHC) class I-binding epitopes in the tail length tape measure protein (TMP) of a prophage found in the genome of the bacteriophage Enterococcus hirae Mice bearing E. hirae harboring this prophage mounted a TMP-specific H-2Kb-restricted CD8+ T lymphocyte response upon immunotherapy with cyclophosphamide or anti-PD-1 antibodies. Administration of bacterial strains engineered to express the TMP epitope improved immunotherapy in mice. In renal and lung cancer patients, the presence of the enterococcal prophage in stools and expression of a TMP-cross-reactive antigen by tumors correlated with long-term benefit of PD-1 blockade therapy. In melanoma patients, T cell clones recognizing naturally processed cancer antigens that are cross-reactive with microbial peptides were detected.

BACKGROUND:Personalised medicine in oncology needs standardised immunological assays. Flow cytometry (FCM) methods represent an essential tool for immunomonitoring, and their harmonisation is crucial to obtain comparable data in multicentre clinical trials. The objective of this study was to design a harmonisation workflow able to address the most effective issues contributing to intra- and interoperator variabilities in a multicentre project.METHODS:The Italian National Institute of Health (Istituto Superiore di Sanità, ISS) managed a multiparametric flow cytometric panel harmonisation among thirteen operators belonging to five clinical and research centres of Lazio region (Italy). The panel was based on a backbone mixture of dried antibodies (anti-CD3, anti-CD4, anti-CD8, anti-CD45RA, and anti-CCR7) to detect naïve/memory T cells, recognised as potential prognostic/predictive immunological biomarkers in cancer immunotherapies. The coordinating centre distributed frozen peripheral blood mononuclear cells (PBMCs) and fresh whole blood (WB) samples from healthy donors, reagents, and Standard Operating Procedures (SOPs) to participants who performed experiments by their own equipment, in order to mimic a real-life scenario. Operators returned raw and locally analysed data to ISS for central analysis and statistical elaboration.RESULTS:Harmonised and reproducible results were obtained by sharing experimental set-up and procedures along with centralising data analysis, leading to a reduction of cross-centre variability for naïve/memory subset frequencies particularly in the whole blood setting.CONCLUSION:Our experimental and analytical working process proved to be suitable for the harmonisation of FCM assays in a multicentre setting, where high-quality data are required to evaluate potential immunological markers, which may contribute to select better therapeutic options.

Tumor-infiltrating immune cells play a key role against cancer. However, malignant cells are able to evade the immune response and establish a very complex balance in which different immune subtypes may drive tumor progression, metastatization and resistance to therapy. New immunotherapeutic approaches aim at restoring the natural balance and increase immune response against cancer by different mechanisms. The complexity of these interactions and the heterogeneity of immune cell subpopulations are a real challenge when trying to develop new immunotherapeutics and evaluate or predict their efficacy in vivo. To this purpose, molecular imaging can offer non-invasive diagnostic tools like radiopharmaceuticals, contrast agents or fluorescent dyes. These agents can be useful for preclinical and clinical purposes and can overcome [ 18 F]FDG limitations in discriminating between true-progression and pseudo-progression. This review provides a comprehensive overview of immune cells involved in microenvironment, available immunotherapies and imaging agents to highlight the importance of new therapeutic biomarkers and their in vivo evaluation to improve the management of cancer patients.