Ligand Axis Research Articles

B Cell ADAM10 Controls Murine Lupus Progression through Regulation of the ICOS:ICOS Ligand Axis.

The role of ICOS and its ligand (ICOSL) have both been shown to be essential for proper humoral responses as well as autoimmune Ab development in mouse models of lupus. In this paper, we report a specific role for the metalloprotease ADAM10 on B cells in regulating both ICOSL and ICOS in a mouse model of increased humoral immunity using B6mir146a-/- mice and a model of lymphoproliferative disease using the well-characterized lpr model. B6lpr mice lacking ADAM10 on B cells (A10Blpr) have decreased nodal proliferation and T cell accumulation compared with control B6lpr mice. Additionally, A10Blpr mice have a drastic reduction in autoimmune anti-dsDNA Ab production. In line with this, we found a significant reduction in follicular helper T cells and germinal center B cells in these mice. We also show that lymphoproliferation in this model is closely tied to elevated ICOS levels and decreased ICOSL levels. Overall, our data not only show a role of B cell ADAM10 in control autoimmunity but also increase our understanding of the regulation of ICOS and ICOSL in the context of autoimmunity.

Effect of Platinum-Based Chemotherapy on PD-L1 Expression on Tumor Cells in Non-small Cell Lung Cancer.

PurposeProgrammed death-1 (PD-1)/PD-1 ligand (PD-L1) axis blockades have revolutionized the treatment of advanced non-small cell lung cancer (NSCLC). We assessed the effect of platinum-based chemotherapy on tumor PD-L1 expression and its clinical implications.Materials and MethodsWe used immunohistochemistry to retrospectively evaluate the percentage of tumor cells with membranous PD-L1 staining (tumor proportion score) in paired tumor specimens obtained before and after platinum-based neoadjuvant chemotherapy (NACT) in 86 patients with NSCLC. We analyzed the correlation between the change in PD-L1 tumor proportion score and clinicopathologic characteristics, response to NACT, and survival.ResultsThe PD-L1 tumor proportion score increased in a significant proportion of patients with NSCLC after platinum-based NACT (Wilcoxon signed-rank test, p=0.002). That pattern was consistent across clinically defined subgroups except for patients with partial response to NACT. Tumors from 26 patients (30.2%) were PD-L1‒negative before NACT but PD-L1-positive after NACT, whereas the reverse pattern occurred in six patients (7%) (McNemar’s test, p < 0.001). Increase in PD-L1 tumor proportion score was significantly associated with lack of response to NACT (Fisher exact test, p=0.015). There was a tendency, albeit not statistically significant, for patients with an increase in PD-L1 tumor proportion score to have shorter survival.ConclusionTumor PD-L1 expression increased after platinum-based NACT in a significant proportion of patients with NSCLC. Increase in tumor PD-L1 expression may predict poor clinical outcome.

Metformin inhibits IgE- and aryl hydrocarbon receptor-mediated mast cell activation in vitro and in vivo.

Metformin, an anti-diabetic drug, possesses anti-inflammatory property beyond its glucose-lowering activity, but its regulatory effect on mast cells and allergic responses remains unknown, wherein the aryl hydrocarbon receptor (AhR)-ligand axis is critical in controlling mast cell activation. Herein, we provide evidence supporting the role of metformin in modulating mast cell activation by FcεR1-, AhR-mediated signaling or their combination. Metformin at relatively low doses was shown to suppress FcεR1-mediated degranulation, IL-13, TNF-α and sphingosine-1-phosphate (S1P) secretion in murine bone marrow-derived mast cells (BMMCs). In contrast, metformin at the same doses potently inhibited all parameters in mast cells stimulated with an AhR ligand, 5,11-dihydroindolo[3,2-b]carbazole-6-carbaldehyde (FICZ). Further, metformin was shown to inhibit FcεR1- and AhR-mediated passive cutaneous anaphylaxis (PCA) in vivo, reversible by a S1P receptor 2 antagonist, JTE-013. Using AhR reporter cells, Huh7-DRE-Luc cells, a human mast cell line, HMC-1, and BMMCs, metformin's inhibitory effect was mediated through the suppression of FICZ-induced AhR activity, calcium mobilization and ROS generation. Notably, FICZ-mediated oxidation of S1P lyase (S1PL) and its reduced activity were reversed by metformin, resulting in decreased levels of S1P. Collectively, these results suggested the potential utility of metformin in treating allergic diseases, particularly in cases with comorbid type II diabetes mellitus.

Abstract 469: Therapy-induced senescence associated secretory phenotype enhances breast cancer cell invasion and stemness via CXCR1/2-CXCR1/2 ligands axis

Abstract Various chemotherapeutic agents have been demonstrated to induce senescence of cancer cells in vitro and in vivo. This therapy-induced senescence (TIS) has been regard as a favorable therapeutic response, although it is not a cell death but a permanent cell cycle arrest. However, adverse aspects of TIS have been also suggested since senescence-associated secretory phenotype (SASP) enables to affect microenvironment of senescent cancer cells. Nonetheless, when senescent cancer cells are intermingled with non-senescent cells after chemotherapy, the effects of SASP from senescent cancer cell to non-senescent cell have not yet been fully elucidated. Therefore, TIS, confirmed by measuring senescence associated β-galactosidase activity and cell cycle arrest, was induced by the treatment with adriamycin and cisplatin in variable breast cancer cell lines in vitro. To evaluate the effects of SASP from senescent cancer cell to non-senescent cell, conditioned media (CM) from TIS of MCF7 (poorly-aggressive and non-invasive cell line) was treated in parent non-senescent MCF7 and their invasiveness and stemness were measured by invasion assay and mammosphere forming assay, respectively. In MCF7 treated with CM from TIS, invasiveness and mammosphere forming ability were significantly increased. To discover the mediators of the observed effects, cytokine array was performed by collecting CM from non-senescent control and therapy-induced senescent cells. In the secretome of TIS, CXCR2 ligands, including growth-related protein-α (CXCL1) and interleukin-8 (CXCL8) were focused on for further analysis. Increased mRNA of CXCR2 ligands (CXCL1, 2, 3 and CXCL8) in TIS and increased secretion of CXCL8 protein in CM of TIS were confirmed by real time PCR and ELISA, respectively. To investigate the contribution of CXCR1/2-CXCR1/2 ligands axis in enhanced invasion and stemness ability by CM of TIS, a CXCR1/2 specific inhibitor, SCH-527123, was applied. The pretreatment of SCH-527123 in the concentration without affecting cell proliferation and survival (25, 50μM), significantly inhibited the enhanced invasion and mammosphere forming ability by CM of TIS. The potential mechanisms of cancer cell invasion and stemness enhancement by CXCR1/2-CXCR1/2 ligands axis, are currently under investigated. In summary, SASP of TIS can be harmful by augmenting invasion and stemness of surrounding non-senescent cancer cell thorough the CXCR1/2-CXCR1/2 ligands axis and CXCR1/2 inhibitors can be used as therapeutic agents, by antagonizing the adverse effects of TIS. Citation Format: Yong Won Choi, Hyun-Young Cha, Tae Jun Park, Mi Sun Ahn, Hyun Woo Lee, Seong Hyun Jeong, Seok Yun Kang, Joon Seong Park, Jin-Hyuk Choi. Therapy-induced senescence associated secretory phenotype enhances breast cancer cell invasion and stemness via CXCR1/2-CXCR1/2 ligands axis [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 469.

Abstract 2766: Resistance to radiotherapy and PD-L1 blockade is mediated by TIM-3 upregulation in anti-PD-L1 refractory head and neck cancer

Abstract Background: Clinical trials targeting the programmed-death ligand axis (PD-1/PD-L1) show that a majority of head and neck squamous cell carcinoma (HNSCC) patients are resistant to PD-1/PD-L1 inhibition. Strategies aimed at sensitizing tumors to immunotherapy can provide durable response compared to conventional therapies. We previously reported that local radiation to the tumor can transform the immune landscape and render poorly immunogenic murine orthotopic HNSCC tumors sensitive to PD-L1 inhibition. However, the response to combined radiotherapy (RT) and PD-L1 inhibition was transient. In this work, we characterize the immune landscape of HNSCC tumors during RT and PD-L1 treatment and interrogate mechanisms of resistance. Methods: We employed time-of-flight mass cytometry (CyTOF) for characterizing the tumor immune microenvironment at early and late stages of response to RT and anti-PD-L1. For studying the effect of dual checkpoint blockade and RT, poorly immunogenic murine squamous cell carcinoma cells (LY2 and MOC2) were injected into the right buccal mucosa. Mice were randomized to IgG, anti-PD-L1, anti-TIM-3, RT or combinations of RT, PD-L1 and TIM-3. Mechanistic experiments were performed on tumors harvested 72 hours after treatment. Tumors were assessed for levels of activated T cells (CD44+IFNg+) and regulatory T cells (FoxP3+CD4+) by flow cytometry and T-cell infiltration by immunohistochemistry. Results: Tumors treated with RT and PD-L1 blockade significantly upregulated TIM-3 expression on CD4 and CD8 T cells. Furthermore, the proportion of regulatory T cells expressing TIM-3 was significantly increased during the tumor regrowth phase with RT and anti-PD-L1 treatment. Targeting TIM-3 concurrently with PD-L1 and RT led to significant tumor growth retardation, enhanced T-cell cytotoxicity and improved survival. In addition, dual targeting of PD-L1 and TIM-3 in combination with RT significantly decreased the proportion of regulatory T cells (4.1-fold decrease relative to IgG control and 2.8-fold decrease relative to RT+anti-PD-L1). However, the response to dual checkpoint blockade and RT was not durable and all tumors eventually relapsed. Analysis of relapsed tumors revealed decreased T-cell infiltration, re-emergence of regulatory T cells and decreased proportion of cytotoxic and helper T cells. Conclusion: Our study shows upregulation of TIM-3 in response to RT and PD-L1 inhibition. However, dual targeting of TIM-3 and PD-L1 with RT did not provide a durable response in two genetically distinct HNSSCC tumor models. In light of the increased number of clinical trials employing dual immune checkpoint blockade, our findings reveal the complexity of tumor immune evasion mechanisms and underscore the need for multimodality targeting of HNSCCs. Citation Format: Ayman J. Oweida, Mohammad Hararah, Andy Phan, Shilpa Bhatia, Shelby Lennon, David Binder, David Raben, Lynn Heasley, Eric Clambey, Raphael Nemenoff, Sana D. Karam. Resistance to radiotherapy and PD-L1 blockade is mediated by TIM-3 upregulation in anti-PD-L1 refractory head and neck cancer [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 2766.

Abstract 132: Role of IL-17-CXCR2 axis in neutrophil recruitment facilitating breast cancer metastasis and therapy resistance

Abstract The major challenges for breast cancer includes therapy resistance and metastasis to distant organs. Chronic inflammation has been intimately linked with these processes. We have observed increased level of CXCR2 ligands, inflammatory immunosuppressive microenvironment, and increased metastasis in chemotherapy resistant cells. CXCR2 and its ligands have been shown to be the primary mechanism for neutrophils recruitment to the sites of primary tumors and metastases. However, their precise roles in therapy resistance and metastasis remains unclear. The aim of this project is to investigate the role of neutrophils in chemotherapy resistance and metastasis in breast cancer. In this report, we investigated the mechanisms and putative role of neutrophils in chemotherapy resistance and metastasis. We evaluated the expression level of the factors critical for neutrophil recruitments, such as interleukin (IL)-17 and its receptors (IL-17R), granulocyte colony stimulating factor (GCSF), CXCR2 and its ligands in primary tumors and metastases established from parents and chemotherapy resistant cells. The frequency of neutrophils and T-helper 17 (Th17) cells were analyzed using immunohistochemistry. Chemotherapy-resistant cell lines express higher levels of GCSF, IL-17, and IL-17R compared to Cl66 parent cells. We observed higher expression of IL-17R, CXCR2, and CXCR2 ligands in metastatic lesions compared to primary tumors. Furthermore, there were more recruitments of neutrophils and Th17 cells in resistant tumors than parent tumors. In addition, treatment of tumor cells with IL-17 significantly increased cellular proliferation together with CXCL1 and CXCL5 expression in a concentration-dependent manner. Moreover, we observed higher expression of TGFβ 2 and Th17 cell priming factors, IL-6 and IL-23, in neutrophils co-cultured with therapy resistant cells compared to the control suggesting a feed forward loop. In addition, we observed that IL17 treatment of tumor cells did not increase their tolerance to chemotherapy drug, indicating its role in establishing immune suppressive microenvironments. Together our data demonstrate an IL17-CXCR2 ligands axis induces protumorigenic inflammation, facilitating therapy resistance and metastasis through recruited neutrophils. Citation Format: Lingyun Wu, Bhawna Sharma, Rakesh K. Singh. Role of IL-17-CXCR2 axis in neutrophil recruitment facilitating breast cancer metastasis and therapy resistance [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 132.

Role of osteoprotegerin/receptor activator of nuclear factor kappa B/receptor activator of nuclear factor kappa B ligand axis in nonalcoholic fatty liver disease.

Concomitantly with the increase in the prevalences of overweight/obesity, nonalcoholic fatty liver disease (NAFLD) has worldwide become the main cause of chronic liver disease in both adults and children. Patients with fatty liver display features of metabolic syndrome (MetS), like insulin resistance (IR), glucose intolerance, hypertension and dyslipidemia. Recently, epidemiological studies have linked obesity, MetS, and NAFLD to decreased bone mineral density and osteoporosis, highlighting an intricate interplay among bone, adipose tissue, and liver. Osteoprotegerin (OPG), an important symbol of the receptor activator of nuclear factor-B ligand/receptor activator of nuclear factor kappa B/OPG system activation, typically considered for its role in bone metabolism, may also play critical roles in the initiation and perpetuation of obesity-related comorbidities. Clinical data have indicated that OPG concentrations are associated with hypertension, left ventricular hypertrophy, vascular calcification, endothelial dysfunction, and severity of liver damage in chronic hepatitis C. Nonetheless, the relationship between circulating OPG and IR as a key feature of MetS as well as between OPG and NAFLD remains uncertain. Thus, the aims of the present review are to provide the existent knowledge on these associations and to discuss briefly the underlying mechanisms linking OPG and NAFLD.

Tumor cell-intrinsic programmed death protein 1 expression and induction in human cancer cell lines

Abstract The programmed death protein 1 (PD-1) and ligand (PD-L1) axis inhibits T cell activation and reduces anti-tumor immunity. Most studies of the PD-1/PD-L1 axis test extrinsic, immune-dependent effects. However, tumor cell-intrinsic PD-L1 regulates immune-independent tumor mTOR signals, autophagy, and tumor initiating cell generation. Melanoma cell-intrinsic PD-1 regulates melanoma growth and mTOR. We tested PD-1 expression and induction in multiple human tumor cell lines. We detected PD-1 in human cell lines in vitro from ES2 ovarian cancer, VMM122 melanoma, and RT4 bladder cancer by flow cytometry, Western blot and RT-PCR. All lines were negative for the other PD-L1 receptor, CD80, by flow cytometry. Incubating lines with IFNα or IFNγ for 48 hours further augmented PD-1 expression as detected by flow, Western blot and RT-PCR. αPD-1 antibody (50 μg/ml) reduced proliferation of RT4 bladder cancer cells in vitro, demonstrating a direct PD-1 signal effect in these cells, and αPD-L1 similarly reduced in vitro proliferation. Interestingly, anti-PD-1 effects on reducing proliferation were similar: 41.5% reduction; p&amp;lt;0.0001. We used CRISPR/Cas9 to generate PD-L1KO RT4 cells. αPD-L1 did not reduce in vitro proliferation as expected, but unexpectedly, αPD-1 also had no anti-proliferative effect on PD-L1KO RT4 cells, suggesting a PD-L1/PD-1 interaction. In murine B16 melanoma, we generated PD-L1KO and PD-1KO cells using CRISPR/Cas9. Cell-intrinsic PD-L1 and PD-1 downregulate chemokine production. Among chemokines analyzed, PD-L1 suppressed CCL2 and CCL5, PD-1 suppressed CCL4 and CCL7, and both suppressed CCL3 and CXCL2. Understanding intrinsic PD-1 and PD-L1 effects on tumor cells can be exploited to improve cancer immunotherapy

PD-1/PD-L1 expression in a series of intracranial germinoma and its association with Foxp3+ and CD8+ infiltrating lymphocytes.

One histopathological characteristic of intracranial germinoma is abundant tumor-infiltrating lymphocytes (TILs) showing a two-cell pattern with large undifferentiated tumor cells. The programmed cell death 1 (PD-1)/programmed cell death 1 ligand (PD-L) axis has recently been recognized as an anti-tumor immune system. To evaluate intratumor immune status in intracranial germinoma, we examined expressions of PD-1 and PD-L1 (clone 28–8) and subtypes of TILs. Expressions of PD-1 and PD-L1 were detected immunohistochemically in 25 formalin-fixed, paraffin-embedded tumor specimens from 24 patients with intracranial germinoma consisting of 22 primary and 3 recurrent tumors. To evaluate subtypes of TILs, quantification of lymphocytes with CD3, CD8, CD4, and Foxp3 was performed. Statistical analyses were performed among PD-1, PD-L1 and subtypes of TILs. In 25 tumor tissue, expressions of PD-1 in TILs and PD-L1 in tumor cells were identified in 96% (24/25) and 92% (23/25), respectively. Expression of PD-1 was associated with CD3+ TIL density. Expression of PD-1 correlated with Foxp3+ TIL density and CD8+ TIL density, but not with CD4+ TIL density. Furthermore, expression of PD-1 correlated strongly with Foxp3+/CD4+ ratio. Taken together, increase of PD-1+ expression is associated with accumulation of Foxp3+ and CD8+ TILs. These findings intimate that PD-1/PD-L1 axis might shape the immune infiltration suggesting a modulation of the immune response and subsequent tumor growth in intracranial germinoma. Anti-PD-1 and anti-PD-L1 are potential immune therapeutic strategies in intracranial germinoma.

Immunohistochemical assessment of the diagnostic utility of PD-L1: a preliminary analysis of anti-PD-L1 antibody (SP142) for lymphoproliferative diseases with tumour and non-malignant Hodgkin-Reed-Sternberg (HRS)-like cells.

The programmed death 1 (PD1)/PD1 ligand (PD-L1) axis plays an important role in tumour cells escape from immune control. PD-L1 immunohistochemistry is a useful predictor of immunotherapy response, but is still not used widely in the diagnostic setting. Here we describe results using PD-L1 immunohistochemistry during routine diagnostics in lymphoma. Ninety-one lymphoproliferative disease cases sharing tumour and non-malignant Hodgkin-Reed-Sternberg (HRS)-like cells with and without Epstein-Barr virus (EBV) association were investigated by immunohistochemistry for PD-L1 (clone SP142). PD-L1 expression was present in more than 5% of tumour or non-malignant HRS-like cells in 100% of EBV+ classical (C) Hodgkin lymphoma (HL) (n=10) and EBV-negative nodular sclerosis CHL (n=8); 40% of EBV+ diffuse large B cell lymphoma, not otherwise specified (DLBCL-NOS) (n=20); and 4% of nodal peripheral T cell lymphoma of follicular helper T cell type (PTCL-TFH) (n=22). In contrast, nodular lymphocyte-predominant HL (n=4), lymphocyte-rich CHL (n=6), EBV+ hyperplasia (n=8), plasmablastic lymphoma (n= 3) and anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (n=5) seldom exhibited PD-L1 in their large cells. Assessing PD-L1 positivity in tumour and non-malignant large cells was helpful in differentiating between CHL versus nodal PTCL-TFH (P<0.0001) or EBV+ DLBCL-NOS (P=0.0052) and between EBV+ DLBCL-NOS versus nodal PTCL-TFH (P=0.0052), with PD-L1 expression indicating the first diagnosis in each of those sets. Immunohistochemical evaluation of PD-L1 expression in tumour and non-malignant HRS-like large cells may be useful for assessing either immune escape or immunodeficiency in their pathogenesis.

New Insights into Tumor-Infiltrating B Lymphocytes in Breast Cancer: Clinical Impacts and Regulatory Mechanisms.

Currently, tumor-infiltrating B lymphocytes have been recognized as a new hallmark of breast cancer (BC). The function seems to be controversial, either with positive, negative, or no significance in BC’s prediction and prognosis. Moreover, B-cell infiltrates regulate tumor process through productions of antibodies and interleukin-10. The interactions with other lymphocytes and programmed death-1/PD-1 ligand axis are also documented. The regulatory mechanisms will eventually be incorporated into diagnostic and therapeutic algorithms, thus give guide to clinical treatment. In this review, we give new insights into clinical impacts and regulatory mechanisms of tumor-infiltrating B cells, which heralds a new era in immuno-oncology in BC treatment.

Pembrolizumab and its role in relapsed/refractory classical Hodgkin's lymphoma: evidence to date and clinical utility.

Immune evasion is a critical mechanism of malignant cell survival, and relies in part on molecular signaling through the programmed cell death 1 (PD-1)/PD-1 ligand (PD-L1) axis that contributes to T cell exhaustion. Immune modulatory therapy with monoclonal antibodies against PD-1 designed to enhance antitumor immune response have shown promise in the treatment of advanced solid tumors and hematologic malignancies. Classical Hodgkin's lymphoma (cHL), a unique B cell malignancy characterized by an extensive but ineffective immune cell infiltrate surrounding a small number of tumor cells, has shown significant response to anti-PD-1 directed therapy. The anti-PD-1 monoclonal antibodies nivolumab and pembrolizumab have shown similarly remarkable activity in relapsed/refractory cHL and have been approved by the Food and Drug Administration for treatment of this disease. In this article we review the rationale of targeting the PD-1/PD-L1 axis in cHL and the pharmacology of pembrolizumab, and summarize the data on activity and safety profile of this agent in the treatment of relapsed/refractory cHL. We also discuss the potential benefits and pitfalls of using PD-1 blockade in the setting of allogeneic stem-cell transplantation, and summarize ongoing prospective trials of single-agent pembrolizumab and combination strategies as well as future directions.

The Relationship Between Mismatch Repair Deficiency and PD-L1 Expression in Breast Carcinoma.

Mismatch repair (MMR) deficiency in solid tumors has recently been linked to susceptibility to immunotherapies targeting the programmed cell death-1 (PD-1)/programmed cell death-1 ligand (PD-L1) axis. Loss of MMR proteins has been shown to correlate with tumoral PD-L1 expression in colorectal and endometrial carcinomas, but the association between expression of MMR proteins and PD-L1 has not previously been studied in breast carcinoma, where MMR deficiency is less common. We assessed the relationship between PD-L1 and MMR protein expression by immunohistochemistry in 245 primary and 40 metastatic breast carcinomas. Tumoral staining for PD-L1 was positive in 12% of all cases, including 32% of triple-negative cancers. MMR deficiency was observed in 0.04% of breast cancers; the single MMR-deficient case was a high-grade, triple-negative ductal carcinoma which showed dual loss of MLH1 and PMS2 proteins and expressed PD-L1. Two ER carcinomas initially were scored with MMR protein loss in tissue microarray format but were subsequently shown to be MMR-intact on whole sections. Analysis of MMR gene mutation in The Cancer Genome Atlas corroborates low frequency of MMR deficiency for invasive breast cancer. MMR protein expression is therefore unlikely to show utility as a screen for immunotherapeutic vulnerability in this tumor type, and may provoke unwarranted genetic testing in patients unlikely to have a heritable cancer syndrome. PD-L1 may be a more clinically relevant biomarker for anti-PD-1/PD-L1 therapies in this setting.

Single Nucleotide Polymorphisms in CD40L Predict Endothelial Complications and Mortality After Allogeneic Stem-Cell Transplantation.

Purpose Endothelial vulnerability is a potential risk factor for complications after allogeneic stem-cell transplantation (alloSCT). The CD40/CD40 ligand (CD40L) axis contributes to inflammatory diseases and is upregulated in endothelial cells upon activation, suggesting a role in alloSCT biology. Here, we studied single nucleotide polymorphisms (SNPs) in the CD40L gene in recipients of alloSCT. Patients and Methods Three CD40L SNPs (rs3092920, rs3092952, rs3092936) were analyzed for association with transplant-associated thrombotic microangiopathy, overall nonrelapse mortality (NRM), and NRM after acute graft-versus-host disease in 294 recipients of alloSCT without statin-based endothelial prophylaxis (SEP). The significant genotype was then put into perspective with established thrombomodulin ( THBD) gene polymorphisms. Findings were validated in an independent cohort without SEP and in an additional 344 patients who received SEP. Results The rs3092936 CC/CT genotype was associated with an increased risk of transplant-associated thrombotic microangiopathy ( P = .001), overall NRM ( P = .03), and NRM after acute graft-versus-host disease ( P = .01). The rs3092936 CC/CT genotype was largely mutually exclusive of high-risk THBD SNPs. Both CD40L and THBD SNPs predicted adverse overall survival (OS) and overall NRM to a similar extent in training cohort (OS, P = .04; NRM, P < .001) and validation cohort (OS, P = .01; NRM, P = .001) without SEP. In contrast, SEP completely abolished the influence of the high-risk CD40L and THBD SNPs ( P = .40). Conclusion An increased risk of endothelial complications can be predicted before alloSCT by genetic markers in the recipient's genome. The normalization of mortality risks in patients treated with SEP suggests a way of overcoming the negative effect of high-risk genotypes and warrants further clinical validation.

CCR5+ Myeloid-Derived Suppressor Cells Are Enriched and Activated in Melanoma Lesions.

Accumulation of myeloid-derived suppressor cells (MDSC) in melanoma microenvironment is supported by chemokine receptor/chemokine signaling. Although different chemokines were suggested to be involved in this process, the role of CCR5 and its ligands is not established. Using a Ret transgenic mouse melanoma model, we found an accumulation of CCR5+ MDSCs in melanoma lesions associated with both increased concentrations of CCR5 ligands and tumor progression. Tumor-infiltrating CCR5+ MDSCs displayed higher immunosuppressive activity than their CCR5- counterparts. Upregulation of CCR5 expression on CD11b+Gr1+ myeloid cells was induced in vitro by CCR5 ligands and other inflammatory factors. In melanoma patients, CCR5+ MDSCs were enriched at the tumor site and correlated with enhanced production of CCR5 ligands. Moreover, they exhibited a stronger immunosuppressive pattern compared with CCR5- MDSCs. Blocking CCR5/CCR5 ligand interactions increased survival of tumor-bearing mice and was associated with reduced migration and immunosuppressive potential of MDSCs in tumor lesions. Our findings define a critical role for CCR5 in recruitment and activation of MDSCs, suggesting a novel strategy for melanoma treatment.Significance: These findings validate the importance of the CCR5/CCR5 ligand axis not only for MDSC recruitment but also for further activation of their immunosuppressive functions in the tumor microenvironment, with potentially broad therapeutic implications, given existing clinically available inhibitors of this axis. Cancer Res; 78(1); 157-67. ©2017 AACR.

Reduced-Intensity Chemotherapy in Patients With Advanced-Stage Hodgkin Lymphoma: Updated Results of the Open-Label, International, Randomised Phase 3 HD15 Trial by the German Hodgkin Study Group.

The international, randomized phase 3 HD15 trial established 6xeBEACOPP as standard therapy for patients with newly diagnosed advanced-stage Hodgkin lymphoma (HL) within the German Hodgkin Study Group (GHSG). We performed a follow-up analysis to assess long-term efficacy and safety of this approach. Between 2003 and 2008, 2182 patients aged 18 to 60 years were recruited and randomized in a 1:1:1 ratio between 8 or 6 cycles of eBEACOPP or 8 cycles of the dose-dense BEACOPP-14 regimen, each followed by 30 Gy radiotherapy in case of positron emission tomography (PET)-positive residual lesions ≥2.5 cm. The study aimed at demonstrating non-inferiority regarding efficacy of the 2 experimental arms on a significance level of 2.5% each. The intention-to-treat analysis comprised 2126 patients with a median follow-up of 102 months. Ten-year progression-free survival was 81% (97.5% CI 77–85) with 8xeBEACOPP, 84% (80–87) with 6xeBEACOPP, and 84% (80–87) with 8xBEACOPP-14; the non-inferiority margin of 1.51 for the hazard ratio (HR) could be excluded for both comparisons (6xeBEACOPP, HR = 0.7, 97.5% CI 0.5–1.0; 8xBEACOPP-14, HR = 0.9, 97.5% CI 0.7–1.2). Overall survival at 10 years was 88% (85–91), 90% (88–93), and 92% (89–94), respectively. A total of 142 second malignancies corresponding to 10-year cumulative incidences of 10%, 7%, and 7% and standardized incidence ratios of 4.3, 2.5, and 2.8 were reported for 8xeBEACOPP, 6xeBEACOPP, and 8xBEACOPP-14, respectively. This updated analysis of the HD15 trial thus confirms the efficacy and reports on the long-term safety of a shortened first-line chemotherapy consisting of 6xeBEACOPP followed by PET-guided radiotherapy in advanced-stage HL.

Two Distinct Myeloid Subsets at the Term Human Fetal-Maternal Interface.

During pregnancy, immune cells infiltrate the placenta at different stages of fetal development. NK cells and macrophages are the most predominant cell types. These immune cells play pleiotropic roles, as they control spiral artery remodeling to ensure appropriate blood supply and maintain long-term tolerance to a true allograft; yet, they must be able to mount appropriate immune defenses to pathogens that may threaten the fetus. Whether the same cell type accomplishes all these tasks or if there are dedicated subsets remains controversial. Here, we identify and characterize two distinct subsets of myeloid cells that differ in their pro-inflammatory/regulatory capacity. While one subset predominantly produces the immune-modulating cytokine IL-10, the second subset has superior capacity to secrete pro-inflammatory mediators, such as IL-1β and IL-6. The putative regulatory myeloid cells also express high levels of inhibitory receptors and their ligands, including programmed cell death 1 (PD1) ligands. Importantly, a large fraction of CD8 and CD4 cells in normal term human placenta are PD1 positive, suggesting that the PD1/PD1 ligands axis might be critical to maintain tolerance during pregnancy.

Ionizing radiation sensitizes tumors to PD-L1 immune checkpoint blockade in orthotopic murine head and neck squamous cell carcinoma

ABSTRACTImmunotherapy clinical trials targeting the programmed-death ligand axis (PD-1/PD-L1) show that most head and neck squamous cell carcinoma (HNSCC) patients are resistant to PD-1/PD-L1 inhibition. We investigated whether local radiation to the tumor can transform the immune landscape and render poorly immunogenic HNSCC tumors sensitive to PD-L1 inhibition. We used the first novel orthotopic model of HNSCC with genetically distinct murine cell lines. Tumors were resistant to PD-L1 checkpoint blockade, harbored minimal PD-L1 expression and tumor infiltrating lymphocytes at baseline, and were resistant to radiotherapy. The combination of radiation and PD-L1 inhibition significantly enhanced tumor control and improved survival. This was mediated in part through upregulation of PD-L1 on tumor cells and increased T-cell infiltration after RT, resulting in a highly inflamed tumor. Depletion of both CD4 and CD8 T-cells completely abrogated the effect of anti PD-L1 with radiation on tumor growth. Our findings provide evidence that radiation to the tumor can induce sensitivity to PD-L1 checkpoint blockade in orthotopic models of HNSCC. These findings have direct relevance to high risk HNSCC patients with poorly immunogenic tumors and who may benefit from combined radiation and checkpoint blockade.

Tumor PD-L1 expression is correlated with increased TILs and poor prognosis in penile squamous cell carcinoma

ABSTRACTDespite its rare incidence worldwide, penile squamous cell carcinoma (PeSCC) still presents with significant morbidity and mortality due to the limited treatment options for advanced patients, especially those in developing countries. The program death-1 (PD-1)/PD-1 ligand (PD-L1) axis has been demonstrated to play an important role in tumor immune escape, and immunotherapies targeting this pathway have shown great success in certain cancer types. Here, we analyzed the expression pattern of PD-L1 in tumor cells and tumor-infiltrating lymphocytes (TILs) in PeSCC with a multi-center cohort. We found that the majority of PeSCCs (53.4%) were PD-L1-positive and that high PD-L1 expression in tumor cells was associated with a poor prognosis. Notably, PD-L1 expression in tumor cells was significantly associated with the extent of TILs and CD8+ TILs. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) showed that PD-L1 was positively correlated with interferon-gamma (IFNγ) and CD8+ gene expression. Moreover, we defined the constitutive and inducible surface expression of PD-L1 in newly established primary PeSCC cell lines. Interestingly, two PeSCC cell lines had high intrinsic PD-L1 expression. Another cell line showed low PD-L1 expression, but the PD-L1 expression could be induced by IFNγ stimulation. Overall, our data showed that high PD-L1 expression in penile tumor cells indicated a poor prognosis. The upregulation of PD-L1 in PeSCC included both extrinsic and intrinsic mechanisms. These findings indicated that the PD-1/PD-L1 axis might be a potential therapeutic target for patients with penile squamous cell carcinoma.

Low-density lipoprotein receptor deficiency impaired mice osteoblastogenesis in vitro.

Postmenopausal osteoporosis affected most elderly women with co-existence of lipid and bone metabolism disorders. However, the cellular and molecular mechanisms underlying the parallel progression and cross-talk of these systems remained unclear. In the present study, low-density lipoprotein receptor knockout (LDLR-/-) mice were chosen to elucidate the effect of LDLR in regulating the differentiation of osteoblasts, which were responsible for bone formation and modulation of osteoclastogenesis. Primary osteoblasts were isolated from the calvarium of newborn LDLR-/- or wild-type mice followed by osteoblastic differentiation culture in vitro. Alkaline phosphatase activity was significantly decreased in LDLR-/- osteoblasts compared to wild-type controls, combined with calcium deposit formation delay, implying impaired osteoblastogenesis in vitro. Consistent with these findings, the expression of runt-related transcription factor 2 (Runx2) was decreased 3 days after differentiation in LDLR-/- osteoblasts compared to wild-type controls. Moreover, the expression of Osterix was decreased 7 days after differentiation in LDLR-/- osteoblasts compared to wild-type controls, later than Runx2.However, the osteoclastogenesis modulation role of osteoblasts was unaffected by the LDLR deficiency, evidenced by the same level of osteoprotegerin (OPG)/receptor activator of nuclear factor-κ B ligand (RANKL) axis between LDLR-/- and wild-type control osteoblasts. Our results provide a novel insight into the role of LDLR during osteoblastic differentiation and improve understanding of cross-talk between bone and lipid metabolisms.