Human duodenal submucosal glands contain a defined stem/progenitor subpopulation with liver-specific regenerative potential

BACKGROUND & AIMS

Common precursors for the liver, biliary tree, and pancreas exist at an early stage of development in the definitive endoderm forming the foregut. We have identified and characterised endodermal stem/progenitor cells with regenerative potential persisting in the adult human duodenum.

METHODS

Human duodena were obtained from organ donors, and duodenal submucosal gland cells were isolated after removal of the mucosa layer. Cells were cultured on plastic or as organoids and were transplanted into severe combined immunodeficient (SCID) mouse livers.

RESULTS

In situ studies of submucosal glands in the human duodenum revealed cells expressing stem/progenitor cell markers that had unique phenotypic traits distinguishable from intestinal crypt cells. Genetic signature studies indicated that the cells are closer to biliary tree stem cells and to definitive endodermal cells than to adult hepatocytes, supporting the interpretation that they are endodermal stem/progenitor cells. In vitro, human duodenal submucosal gland cells demonstrated clonal growth, capability to form organoids, and ability to acquire functional hepatocyte traits. In vivo, transplanted cells engrafted into the livers of immunocompromised mice and differentiated to mature liver cells. In an experimental model of fatty liver, human duodenal submucosal gland cells were able to rescue hosts from liver damage by supporting repopulation and regeneration of the liver.

CONCLUSIONS

A cell population with clonal growth and organoid formation capability, which has liver differentiation potency in vitro and in vivo in murine experimental models, is present within adult duodenal submucosal glands. These cells can be isolated, do not require reprogramming, and thus could potentially represent a novel cell source for regenerative medicine of the liver.

IMPACT AND IMPLICATIONS

Cell therapies for liver disease could represent an option to support liver function, but the identification of sustainable and viable cell sources is critical. Here, we describe a cell population with organoid formation capability and liver-specific regenerative potential in submucosal glands of the human duodenum. Duodenal submucosal gland cells are isolated from adult organs, do not require reprogramming, and could rescue hepatocellular damage in preclinical models of chronic, but not acute, liver injury. Duodenal submucosal gland cells could represent a potential candidate cell source for regenerative medicine of the liver, but the determination of cell dose and toxicity is needed before clinical testing in humans.

Network analysis to determine association between immuno-related toxicities and immune soluble profile in patients treated with anti–PD-1

2553

Background: Immune checkpoint inhibitors (ICIs) have peculiar, immune-related adverse events (irAEs), as a consequence of interfering with self-tolerance mechanisms. The incidence of irAEs varies by ICI class, administered dose and treatment schedule. The aim of the study was to define a baseline (T0) immune profile (IP) predictive of irAE development. Methods: A prospective, multicenter study evaluating the IP of 79 patients with advanced cancer, treated with anti-PD-1drugs as a first- or second-line setting was performed. The results were then correlated with irAEs onset. The IP was studied by means of multiplex assay, evaluating circulating concentration of 12 cytokines, 5 chemokines, 13 soluble immune checkpoints and 3 adhesion molecules. IDO levels were evaluated through a modified liquid chromatography–tandem mass spectrometry. Data were first pre-processed by performing logarithmic transformation and Shapiro-Wilk-test. A connectivity heatmap was obtained by calculating Spearman correlation coefficients. Two different networks of connectivity were constructed, based on the toxicity profile. Results: Toxicity was predominantly of low/moderate grade. High-grade irAEs were relatively rare, while cumulative toxicity was high (23%). A positive and statistically significant correlation between the cumulative toxicity and IP10 and IL8, sLAG3, sPDL-2 sHEVM, sCD137, sCD27 and sICAM1 was found. Moreover, patients who experienced irAEs had a markedly different connectivity pattern characterized by disruption of most of the paired connections between cytokines (all the connections of the cytokine IL8, most of the connections between the pro-inflammatory chemokines, or all the connections of CD137, CD27, and CD28), while sPDL-2 pair-wise connectivity values seemed to be intensified. Network connectivity analysis identified a total of 187 statistically significant interactions in patients without toxicity and a total of 126 interactions in patients with toxicity. Ninety-eight interactions were common to both networks, while 29 were specifically observed in patients with toxicity. Conclusions: A peculiar pattern of immune dysregulation in patients who develop irAEs was defined. This immune serological profile could lead to the design of a personalized therapeutic strategy in order to prevent, monitor and treat irAEs at an early stage.

AB0119 ROLE OF COSTIMULATORY MOLECULES IN SYSTEMIC LUPUS ERYTHEMATOSUS: FOCUS ON CD137

Background

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterized by a wide autoantibodies production. The traditionally concept of a B-cell driven disease has been changed in the last years due to the evidence demonstrating the crucial role of T cells in SLE pathogenesis. In particular, regulatory (Treg) and memory T cells seem act through co-stimulatory and co-inhibitory molecules, such as CD137, PD1-1 and CTLA4. The over-expression of this molecules on lymphocytes may contribute to immune system dysregulation.

Objectives

The primary objective of the present case-control study was to evaluate the expression of CD137, PD1-1 and CTLA4 on T cell surface of SLE patients by using flow-cytometry. Secondly, we evaluated the percentage of Treg and memory T cells.

Methods

We enrolled patients SLE patients (2019 ACR/EULAR criteria) and sex/age-matched healthy subjects (HS). Demographic, clinical, and laboratory data were collected in a standardized computerized electronically filled form. Disease activity was assessed by SLEDAI-2k. Each subject underwent peripheral blood sample collection. By using flow-cytometry we evaluated the expression of FOXP3, CD137, PD1-1 and CTLA4, CD45, CD25, CCR7 to determine the percentage of Treg and memory T cells.

Results

The present analysis included 21 SLE patients [M/F 1/20 median age 48 years (IQR 17), median disease duration 144 months (IQR 204)]. The Treg percentage was significantly lower in SLE compared to HS [median 4.2 (IQR 0.32) versus 2.5 (IQR 2.44); p=0.001, Figure 1A]. Moving on effector Treg (eTreg), SLE patients with high disease activity (SLEDAI > 4) showed a significantly higher prevalence for these cells compared to patients with SLEDAI ≤ 4 [1.16 (IQR 0.51) versus 0.53 (IQR 0.8), p=0.014, Figure 1B]. Moreover, inverse correlation was found between eTreg percentage and SLEDAI-2k [p=0.029, r=-0.47 (CI 0.75 – 0.04) Figure 1C]. The evaluation of CD137 expression was significantly higher in SLE patients compared to HS on CD3+ cells [median 5.32 (IQR 6.11) versus 3.3 (IQR 1.7), p=0.001, Figure 1F]. On CD4+ cells, CD137 expression positively correlated with disease activity [p=0.0082, r=0.58 (CI 0.15-0.82)]. Finally, when analysing memory T cells subpopulations, inverse correlation has been found between effector memory T cells (TEM, CD45RA-CCR7-) and SLEDAI-2k when considering CD3+ [p=0.029, r=-0.56 (CI 0.81 – 0.12)] and CD4+ cells [p=0.016, R=-0.54 (CI -0.80 - -0.1)]. Of note, CD137 expression on T central memory cells (TCM, CD45RA-CCR7+) positively correlated with SLEDAI-2k [(p=0.019, r=0.52 (CI 0.09 – 0.79)].

Figure 1.

A) Comparison of the percentage of Treg in HS and SLE patients. B) Comparison of the percentage of eTreg in SLE patients with high disease activity and low disease activity C) Correlation between % eTreg and SLEDAI-2k. D) Comparison of the percentage of CD3+CD137+ cells in HS and SLE patients. E) Comparison of % of CD4+CD137+ cells in SLE patients with high disease activity and low disease activity F) Correlation between % of CD4+CD137+ cells and SLEDAI-2k.

Conclusion

Our results suggest a possible role of CD137-CD137L axis in SLE pathogenesis. The stimulatory role of this molecule is indicated by the positive correlation between SLEDAI-2k values and surface expression of CD137. Moreover, inverse correlation between SLEDAI-2k and eTreg percentage suggests a possible Treg dysregulation in SLE.

Table 1.

SLE cohort features

Clinical and Laboratory FeaturesMucocutaneous80.9%Articular76.1%Serositis19.0%Kidney23.8%Haematological48.2%CNS/PNS9.5%Thrombotic events4.7%anti-dsDNA68.4%anti-SSA/anti-SSB47.6%anti-RNP19.0%anti-Sm33.0%Antiphospholipid antibodies14.2%Low C3/C457.1%Previous TherapyGlucocorticoid90.5%Hydroxychloroquine95.2%Methotrexate23.8%Mofetil Mycophenolate33.3%Ciclosporin28.5%Cyclophosphamide9.5%Azathioprine33.3%Rituximab14.3%Antiplatelet23.8%Anticoagulant therapy4.7%

Disclosure of Interests

None declared

A combined genomic and immune profile in patients with head and neck squamous cell carcinoma treated with immunotherapy: A pilot study

e18506

Background: In head and neck squamous cell carcinoma (HNSCC) only a small subset of patients (pts) really benefits from immunotherapy, suggesting the need of validated molecular and immunological predictive biomarkers. The aim of the study was to evaluate both the genomic and immune profile of HNSCC correlating it to early progression to immunotherapy. Methods: This is a pilot study evaluating immune and molecular profile in platinum-refractory HNSCC pts treated with Nivolumab. Blood samples were collected at baseline (T0) and at second cycle of therapy (T1). The immune profile was studied by multiplex assay, evaluating circulating: CD137, CTLA4, PD1, PDL1, PDL2, CD27, TIM3, LAG3, GITR, HVEM, BTLA, CD80, CD28 and IDO. The comprehensive genomic profile was evaluated at baseline on formalin-fixed paraffin-embedded samples of the tumor through Foundation One Cdx test. The results obtained were correlated with early progression (within 3 months from the start of therapy). Results: Ten pts were enrolled in the study. Early progression occurred in 6 pts (60%). Median progression free survival and overall survival were 3 months (1-11) and 6.5 months (1-12), respectively. In all patients ≥ 5 genetic mutations were detected; median number of mutation was 6 (5-14); 8/10 pts had a tumor mutational burden less than 10 Muts/mb. The more frequent genetic alterations involved the cycline-dependent-kynase pathway (9/10), the transcription factor associated gene TP53 (8/10) and the PI3K-Akt-PTEN signaling pathways (5/10). Less frequent alterations involved FGFR family (4/10), NOTCH signaling pathway (3/10) and TERT (4/10). Early progression was slightly associated with the number of mutations detected (p = 0.06). The rising or falling trend of circulating levels of biomarkers were detected in 9/10 pts and included modification in IDO (1/10), LAG3 (3/10), GITR (3/10), BTLA (3/10), CD137 (4/10), CTLA4 (4/10), PD1 (2/10), Tim3 (3/10), CD28 (3/10), HVEM (3/10), CD80 (2/10). No modifications were recorded in PDL1, PDL2 and CD27. Conclusions: Our results, although in a small cohort, highlighted the complexity and heterogeneity of landscape in HNSCC pts. A novel evaluation that combines molecular and immune profile is needed. In the context of a poor prognosis disease the combination of personalized molecular and immune approaches could represent a promising strategy to improve survival.

Immune profile of metastatic uveal melanoma during treatment with pembrolizumab

9536

Background: Metastatic uveal melanoma (mUM) is a rare and aggressive disease. No standard therapy has been established. All the available treatments derive from trials in cutaneous melanoma. A minority of patients with mUM can benefit from immunotherapy. Immunological features of a group of patients with metastatic UM treated with Pembrolizumab were analyzed in order to explore the immune-response in this disease and the potential factors able to select the patients who can benefit from immunotherapy. Methods: Blood samples from 12 UM patients before (T0) and during treatment with Pembrolizumab (T1: after 1 cycle of Pembrolizumab; T2: after 3 cycle of Pembrolizumab) were collected. Peripheral blood mononucleated cells (PBMCs) were isolated and characterized for markers expression. Sera were analyzed for a panel of soluble (s) immune checkpoints and cytokines. The correlation between immunological parameters with PFS and OS was explored. Blood samples from 6 metastatic cutaneous melanoma (CM) patients with a confirmed response to anti PD-1 agents were also collected during the treatment and analyzed for PBMCs and sera. Results: Soluble CTLA4, sPD-L1, sCD137, sTIM3 were significantly higher in UM than in CM. CD137 was significantly higher in UM patients progressed with Pembrolizumab than in the 2 responsive patients (512 pg/ml vs < 12.9 pg/ml, respectively, p = 0.04) who are still alive and on treatment after a median follow-up of 24 months. Low sGITR, sCD137, sHVEM, and sTIM3 are associated with longer PFS. IL-8 was lower in CM than UM (2.5 pg/ml vs 40.7 pg/ml) and in the responsive versus progressed UM patients (3,7 pg/ml vs 118 pg/ml, p = 0,042). Low levels of IL-8 and IL-1-alpha are significantly associated with longer PFS (p = 0.011 and 0.010 respectively). In responsive patients CD137 expression on CD3+, CD4+ and CD8+ T cells was higher than in progressed patients, while sCD137 was absent. Conclusions: A group of s-immune checkpoints and cytokines correlate with Pembrolizumab effectiveness in mUM. High expression of CD137 on T cells associated with the absence of its soluble form in responders could suggest the correlation between the retention of this co-stimulatory molecule and efficacy of anti-PD1.

Can IDO activity predict primary resistance to anti-PD-1 treatment in NSCLC?

Background

Immune checkpoint inhibitors have revolutionized the treatment paradigm of highly lethal malignancies like advanced non-small cell lung cancer (NSCLC), demonstrating long-term tumour control and extended patient survival. Unfortunately, only 25–30% of patients experience a durable benefit, while the vast majority demonstrate primary or acquired resistance. Recently, indoleamine 2,3-dioxygenase (IDO) activity has been proposed as a possible mechanism of resistance to anti-PD-1 treatment leading to an immunosuppressive microenvironment.

Methods

Pre-treatment serum concentrations of tryptophan (trp) and kynurenine (kyn) were measured by high-performance liquid chromatography tandem mass spectrometry in NSCLC patients treated with second-line nivolumab. The IDO activity was expressed with kyn/trp ratio. The associations between kyn/trp ratio and early progression, performance status (PS), age, sex, brain metastases, pleural effusion, progression free survival (PFS) and overall survival (OS) were analyzed using Spearman test and Mann–Whitney test.

Results

Twenty-six NSCLC patients were included in our study; 14 of them (54%) presented early progression (< 3 months) to nivolumab treatment. The median value of kyn/trp ratio was 0.06 µg/ml and the median value of quinolinic acid was 68.45 ng/ml. A significant correlation between early progression and higher kyn/trp ratio and quinolinic acid concentration was observed (p = 0.017 and p = 0.005, respectively). Patients presenting lower values of kyn/trp ratio and quinolinic acid levels showed longer PFS (median PFS not reached versus 3 months; HR: 0.3; p = 0.018) and OS (median OS not reached vs 3 months; HR: 0.18; p = 0.0005).

Conclusion

IDO activity, expressed as kyn/trp ratio, is associated with response to immunotherapy; in particular, higher kyn/trp ratio could predict resistance to anti-PD-1 treatment. These preliminary results suggest the possibility of using anti-PD-1 plus IDO inhibitor in those patients with high level of kyn/trp ratio.

Abstract 5705: The key role of kynurenine in anti-PD-1 failure

Background: Immune checkpoint inhibitors have revolutionized treatment and outcome of severe and often fatal disease, as metastatic lung cancer, demonstrating long-term tumor control and extended patient survival. Unfortunately, only 25-30% of patients have a long-term benefit from immunotherapy, while the remaining 70-75% demonstrate primary or acquired resistance. Recently, indoleamine 2,3-dioxygenase (IDO) has been proposed as a possible mechanism of resistance to anti-PD1 treatment. Indeed, IDO catalyzes the degradation of tryptophan (Trp) into kynurenine (Kyn), which seems to enhance the activity of Treg, leading to an immunosuppressive microenvironment.

Methods: The serum concentrations of Trp and Kyn were measured by high-performance liquid chromatography tandem mass spectrometry in 26 patients affected by non-small cell lung cancer (NCLSC) before the start of the second-line therapy with nivolumab. The IDO activity was expressed with Kyn/Trp ratio. The associations between Kyn/Trip ratio and early progression, PS, age, sex, brain metastases and pleural effusion were analyzed using Spearman test and Mann Whitney test.

Results: 14 out of 26 patients (54%) presented early progression (defined as progression of the disease within 6 months from the beginning of nivolumab treatment). The median value of Kyn/Trp ratio was 0.073 (0.024-0.18). We found a significant association between Kyn/Trp ratio and early progression (p= 0.009), while no statistical associations were found between Kyn/Trp ratio and PS, age, sex, brain metastases and pleural effusion. Indeed, patients with early progressive disease presented a median value of Kyn/Trp ratio significantly higher than other patients (0.094 vs 0.052; p= 0.01).

Conclusion: The pretreatment evaluation of IDO activity, expressed as Kyn/Trp ratio, seems to be associated with response to immunotherapy. In particular, higher Kyn/Trp ratio could predict resistance to anti-PD-1 treatment. These preliminary results suggest the possibility of using anti-PD-1 plus IDO inhibitor in patients with high level of Kyn/Trp ratio.

Citation Format: Andrea Botticelli, Bruna Cerbelli, Luana Lionetto, Ilaria Zizzari, Annalina Pisano, Michela Roberto, Elisa Onesti, Francesca Romana DI Pietro, Chiara Napoletano, Laura Pizzuti, Patrizia Vici, Giulia D'Amati, Federica Mazzuca, Maurizio Simmaco, Marianna Nuti, Paolo Marchetti. The key role of kynurenine in anti-PD-1 failure [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5705.

The sexist behaviour of immune checkpoint inhibitors in cancer therapy?

BACKGROUND

Immune checkpoint inhibitors, targeting the molecules CTLA-4, PD-1 and PD-L1, showed efficacy against several type of cancers and are currently used in clinical practice. An important biological variable that influences innate and adaptive immunity is the sex, acting through genetic, hormonal and environmental factors. The overall differences between sexes could be crucial to evaluate the response to ICIs.

MATERIALS AND METHODS

We performed a meta-analysis of Phase II-III Clinical Trials published up to June 2017 in which anti-CTLA-4, anti-PD-1 and anti-PD-L1 were studied. We extracted the OS and PFS HR differentiated by sex from subgroups analysis of each trial. We analyzed the three classes of drugs separately.

RESULTS

We selected 36 Phase II-III Clinical Trials, 9 of which reported results for OS and 6 for PFS. We analyzed 2 Clinical Trials for OS with anti-CTLA-4, including 1178 patients, observing a benefit for males vs females (HR 0.65, 95% CI 0.55-0.77 vs HR 0.79, 95% CI 0.65-0.96, p 0.078).Not statistically significant results were observed with anti-PD-1 neither for OS (males vs females: HR 0.72, 95% CI 0.64-0.83 vs HR 0.81, 95% CI 0.70-0.94, p 0.285) neither for PFS (males vs females: HR 0.66, 95% CI 0.52-0.82 vs HR 0.85, 95% CI 0.66-1.09, p 0.158). We cannot perform a meta-analysis for anti-PD-L1 due to the lack of data.

CONCLUSIONS

Different mechanisms could be involved in sex differences with regard to immunotherapy. These differences could be relevant to identify immunological targets in order to draw studies exploring novel combinations of immunotherapy agents.

Immunomodulatory effects of tyrosine kinase inhibitors (TKIs) in renal cell carcinoma (RCC) patients

e14506

Background: RCC is considered a highly immunogenic tumor responding to anti-angiogenetic TKI and immunotherapy. A better understanding of the functions of immune cells in RCC, the immune-modulatory effects of TKIs treatment as well as defining patients most likely to benefit to the different therapies will be crucial to optimize combined or sequential immunotherapeutic approaches in RCC patients. Methods: Monocyte derived Dendritic Cells (DCs) from 10 healthy donors were differentiated in presence of Pazopanib and Sunitinib used at plasmatic equivalent concentration (Sigma-Aldricht). At the end of the culture, DCs were characterized for marker expression, endocytosis, signal transduction and microvesicle release. Similarly, DCs derived from RCC patients were analyzed together with circulating T cells before and during TKI treatments. Results: Pazopanib and Sunitinib differently affect DC differentiation. Pazopanib, but not Sunitinib, strongly improves DC performance as antigen-presenting cells, promoting the upregulation of the maturation markers HLA-DR (+1,5 fold increase compared to Sunitinib-treated DCs), CD40 (+3 fold increase) and CCR7 (+2 fold increase) a decrease in phagocytosis and the inhibition of pERK1/2 signaling. 99% of Sunitinib-DCs expressed PD-L1 vs 80% Pazopanib-DCs , with a higher expression of the receptor as indicated by mean fluoresce intensity (MFI fold increase of +2,1). Similar results were obtained analyzing shedded microvesicles. Results were confirmed in DCs differentiated from RCC patients during Pazopanib treatment (before and at 30 and 60 days) and suggest a reverse of the tumor induced immunosuppression. Moreover, only Pazopanib treatment appears to induce in these patients a defined circulating CD4+ T cell population highly expressing CD137 molecule (%CD4+CD137+: T0:0,3; T30: 4,7; T60:29,4). Conclusions: TKIs can affect immunity in RCC patients. In particular, Pazopanib appears to function as a potent activator of DCs in vitro and in vivo associated with the neo-activation of a CD137+ T cell population. These results can guide for designing novel protocols to combine TKIs with immunoregulatory receptors targeting in RCC.

Cross-talk between microbiota and immune fitness to steer and control response to anti PD-1/PDL-1 treatment

Immune Checkpoint Inhibitors (ICIs) are improving the survival of cancer patients, however only the 20-30% of treated patients present clinical benefits. Toxicity represents the major cause of reduced dosage, delayed drug administration and therapy discontinuation. Hence in the context of multiple treatment possibilities, the identification of predictive markers of response and toxicity is a challenging approach for drug selection in order to obtain the best clinical benefit while minimizing the side effects. The loss of the protective function of intestinal barriers that interacts with the environment measured as increased intestinal permeability and the changes occurring in the microbiota composition have been proposed as a mechanism potentially explaining the pathogenesis of immune related toxicity.In this review we discuss the new perspectives on the involvement of PD-1 and PDL-1 in the cross talk between gut microbiota and immune fitness and how gut microbiota impacts on the efficacy of anti-PD-1 and anti-PDL-1 treatments in cancer.