Functional tumor cell-intrinsic STING, not host STING, drives local and systemic antitumor immunity and therapy efficacy following cryoablation

BACKGROUND

Despite its potential utility in delivering direct tumor killing and in situ whole-cell tumor vaccination, tumor cryoablation produces highly variable and unpredictable clinical response, limiting its clinical utility. The mechanism(s) driving cryoablation-induced local antitumor immunity and the associated abscopal effect is not well understood.

METHODS

The aim of this study was to identify and explore a mechanism of action by which cryoablation enhances the therapeutic efficacy in metastatic tumor models. We used the subcutaneous mouse model of the rhabdomyosarcoma (RMS) cell lines RMS 76-9STINGwt or RMS 76-9STING-/-, along with other murine tumor models, in C57BL/6 or STING-/- (TMEM173-/- ) mice to evaluate local tumor changes, lung metastasis, abscopal effect on distant tumors, and immune cell dynamics in the tumor microenvironment (TME).

RESULTS

The results show that cryoablation efficacy is dependent on both adaptive immunity and the STING signaling pathway. Contrary to current literature dictating an essential role of host-derived STING activation as a driver of antitumor immunity in vivo, we show that local tumor control, lung metastasis, and the abscopal effect on distant tumor are all critically dependent on a functioning tumor cell-intrinsic STING signaling pathway, which induces inflammatory chemokine and cytokine responses in the cryoablated TME. This reliance extends beyond cryoablation to include intratumoral STING agonist therapy. Additionally, surveys of gene expression databases and tissue microarrays of clinical tumor samples revealed a wide spectrum of expressions among STING-related signaling components.

CONCLUSIONS

Tumor cell-intrinsic STING pathway is a critical component underlying the effectiveness of cryoablation and suggests that expression of STING-related signaling components may serve as a potential therapy response biomarker. Our data also highlight an urgent need to further characterize tumor cell-intrinsic STING pathways and the associated downstream inflammatory response evoked by cryoablation and other STING-dependent therapy approaches.

Oral TGF-βR1 inhibitor Vactosertib promotes osteosarcoma regression by targeting tumor proliferation and enhancing anti-tumor immunity

Osteosarcoma (OS) is an aggressive malignant bone cancer, with refractory and metastatic disease remaining a significant challenge. Transforming growth factor-β1 (TGF-β) is a potent immune suppressive cytokine in OS and the TGF-β is increased in the sera of OS patients and this increase is associated with high-grade OS and lung metastases. Therefore, blocking TGF-β1 signaling may be a novel therapy for OS treatment. Here we show that blocking TGF-β1 signaling using TGF-βR1 inhibitor, Vactosertib, significantly inhibited OS proliferation in vitro and in vivo. Notably, Vactosertib inhibits c-Myc expression in the OS cells. Vactosertib increased immune effectors (IFNγ+CD8+ cells and NK cells) and inhibited immune suppressors (M2-like TAM, MDSC) in the OS tumor microenvironment. Our results suggest that inhibition of TGF-β1 signaling is an effective therapeutic strategy against OS through a multi-pronged approach that targets tumor intrinsic and extrinsic factors to achieve optimal immune-effector functions and maximal clinical response.

Assessment of therapeutic role of mesenchymal stromal cells in mouse models of graft-versus-host disease using cryo-imaging

Insights regarding the biodistribution and homing of mesenchymal stromal cells (MSCs), as well as their interaction with alloreactive T-cells are critical for understanding how MSCs can regulate graft-versus-host disease (GVHD) following allogeneic (allo) bone marrow transplantation (BMT). We developed novel assays based on 3D, microscopic, cryo-imaging of whole-mouse-sized volumes to assess the therapeutic potential of human MSCs using an established mouse GVHD model. Following infusion, we quantitatively tracked fluorescently labeled, donor-derived, T-cells and third party MSCs in BMT recipients using multispectral cryo-imaging. Specific MSC homing sites were identified in the marginal zones in the spleen and the lymph nodes, where we believe MSC immunomodulation takes place. The number of MSCs found in spleen of the allo BMT recipients was about 200% more than that observed in the syngeneic group. To more carefully define the effects MSCs had on T cell activation and expansion, we developed novel T-cell proliferation assays including secondary lymphoid organ (SLO) enlargement and Carboxyfluoescein succinimidyl ester (CFSE) dilution. As anticipated, significant SLO volume enlargement and CFSE dilution was observed in allo but not syn BMT recipients due to rapid proliferation and expansion of labeled T-cells. MSC treatment markedly attenuated CFSE dilution and volume enlargement of SLO. These assays confirm evidence of potent, in vivo, immunomodulatory properties of MSC following allo BMT. Our innovative platform includes novel methods for tracking cells of interest as well as assessing therapeutic function of MSCs during GVHD induction. Our results support the use of MSCs treatment or prevention of GVHD and illuminate the wider adoption of MSCs as a standard medicinal cell therapy.

Mechanosensory channel Piezo1 is essential in pathogenic T cell-mediated intestinal inflammation

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder in the gastrointestinal tract. CD4+ T cells are especially known to be the main drivers of IBD when they show an elevated level of activation. Elevation of intracellular Ca2+ is one of the key triggering signals for T cell activation. Piezo1 is a mechanosensitive nonselective Ca2+-permeable cation channel, which is broadly expressed in mammalian cells. However, the role of Piezo1 in the pathogenesis of T cell-mediated colitis remains unknown. We have generated T cell-specific Piezo1 knockout (Piezo1fl/flxCD4-cre) mice and observed that loss of Piezo1 in CD4+ T cell increased Th1 and Th17 cell polarization. RNA-sequence analysis of Piezo1fl/flxCD4-cre T cells identified elevated pathogenic Th17 cell pathway, IFN-γ signaling pathways and inflammatory response gene signature compared to that of wild type. These results suggest that Piezo1 controls the inflammatory response of pathogenic T cells. Next, we examined the function of Piezo1 on intestinal inflammation in vivo using acute and chronic colitis mouse model. For the acute colitis mouse model, we used a chemically induced mouse model of colitis using DSS in drinking water. Piezo1fl/flxCD4-cre mice with DSS developed severe colitis compared to Piezo1fl/fl mice with DSS. However, in chronic colitis mouse model, which is the adaptive transfer of naïve CD4+ T cells (CD4+CD45RBhigh) from Piezo1fl/fl or Piezo1fl/flxCD4cre into Rag1−/− mice, T cells from Piezo1fl/flxCD4cre mice failed to induce colon inflammation, while mice that received T cells from Piezo1fl/fl mice developed severe intestinal inflammation. Thus, our data demonstrate a critical role of Piezo1 in CD4+ T cell-mediated intestinal inflammation.

Supported by R03 CA230840, P30 CA043703, St. Baldrick’s Foundation, Hyundai Hope-on-Wheels Scholar Hope Grant, Andrew McDonough B+ Foundation, Curing Kids Cancer, Center for Pediatric Immunotherapy at Rainbow

705 Aortic Graft Infection Managed with Bovine Patch, A Case Report and Literature Review

Aim

to describe good outcomes in a case with Aortic graft infection (AGI) managed with Bovine patch and outline management of AGI.

Method

Literature review utilising keywords ‘’Aortic graft infection’’AND’’Bovine Patch’’ revealed initially 1350 articles, all studies in English were included, all duplicates were removed, screening was performed using the PRISMA flow. To correlate with the findings, we followed up a 72-year-old patient who presented with aortic graft infection followed by graft explantation and a fashioned Bovine graft insertion and followed up for 1 year for any re-infection in the clinics.

Results

Literature search resulted 73 articles discussing the role of Bovine Patch as a choice in prevention of Aortic graft re-infection. In our case, there was no clinical nor radiological evidence of Bovine patch re-infection for over a year. Literature review showed that AGI is a rare but serious complication with mortality up to 60%.The main management is IV antibiotics, followed by graft explantation and consideration of re-implantation of various types of grafts. The European society of vascular surgery (ESVS) guidelines recommend re-implantation with an aortic antibiotic soaked graft, yet re-infection rate is quoted at 20%. however, in our case Bovine graft was free from re-infection at 1 year follow up.

Conclusions

IV anitbioics and explantation remain the mainstay for treatment of aortic grafts infection, however, there is increasing evidence that Bovine grafts show excellent freedom from re-infection at follow up. Hence, this might be the conduit of choice when performing such surgeries; however, more evidence is needed.

Human multipotent adult progenitor cells effectively reduce graft-vs-host disease while preserving graft-vs-leukemia activity

Graft‐vs‐host disease (GvHD) limits successful outcomes following allogeneic blood and marrow transplantation (allo‐BMT). We examined whether the administration of human, bone marrow‐derived, multipotent adult progenitor cells (MAPCs™) could regulate experimental GvHD. The immunoregulatory capacity of MAPC cells was evaluated in vivo using established murine GvHD models. Injection of MAPC cells on day +1 (D1) and +4 (D4) significantly reduced T‐cell expansion and the numbers of donor‐derived, Tumor Necrosis Factor Alpha (TNFα) and Interferon Gamma (IFNγ)‐producing, CD4+ and CD8+ cells by D10 compared with untreated controls. These findings were associated with reductions in serum levels of TNFα and IFNγ, intestinal and hepatic inflammation and systemic GvHD as measured by survival and clinical score. Biodistribution studies showed that MAPC cells tracked from the lung and to the liver, spleen, and mesenteric nodes within 24 hours after injection. MAPC cells inhibited mouse T‐cell proliferation in vitro and this effect was associated with reduced T‐cell activation and inflammatory cytokine secretion and robust increases in the concentrations of Prostaglandin E2 (PGE2) and Transforming Growth Factor Beta (TGFβ). Indomethacin and E‐prostanoid 2 (EP2) receptor antagonism both reversed while EP2 agonism restored MAPC cell‐mediated in vitro T‐cell suppression, confirming the role for PGE2. Furthermore, cyclo‐oxygenase inhibition following allo‐BMT abrogated the protective effects of MAPC cells. Importantly, MAPC cells had no effect on the generation cytotoxic T lymphocyte activity in vitro, and the administration of MAPC cells in the setting of leukemic challenge resulted in superior leukemia‐free survival. Collectively, these data provide valuable information regarding the biodistribution and regulatory capacity of MAPC cells, which may inform future clinical trial design.

Cryo-imaging of Stem Cell Biodistribution in Mouse Model of Graft-Versus-Host-Disease

We demonstrated the use of multispectral cryo-imaging and software to analyze human mesenchymal stromal cells (hMSCs) biodistribution in mouse models of graft-versus-host-disease (GVHD) following allogeneic bone marrow transplantation (BMT). We injected quantum dot labeled MSCs via tail vein to mice receiving BMT and analyzed hMSC biodistribution in major organs (e.g. lung, liver, spleen, kidneys and bone marrow). We compared the biodistribution of hMSCs in mice following allogeneic BMT recipients (with GVHD) to the biodistribution following syngeneic BMT (without GVHD). Cryo-imaging system revealed cellular biodistribution and redistribution patterns in the animal model. We initially found clusters of cells in the lung that eventually dissociated to single cells and redistributed to other organs within 72 h. The in vivo half-life of the exogenous MSCs was about 21 h. We found that the biodistribution of stromal cells was not related to blood flow, rather cells preferentially homed to specific organs. In conclusion, cryo-imaging was suitable for analyzing the cellular biodistribution. It could provide capabilities of visualizing cells anywhere in the mouse model with single cell sensitivity. By characterizing the biodistribution and anatomical specificity of a therapeutic cellular product, we believe that cryo-imaging can play an important role in the advancement of stem and stromal cell therapies and regenerative medicine.

Posttransplant Intramuscular Injection of PLX-R18 Mesenchymal-Like Adherent Stromal Cells Improves Human Hematopoietic Engraftment in A Murine Transplant Model

Late-term complications of hematopoietic cell transplantation (HCT) are numerous and include incomplete engraftment. One possible mechanism of incomplete engraftment after HCT is cytokine-mediated suppression or dysfunction of the bone marrow microenvironment. Mesenchymal stromal cells (MSCs) elaborate cytokines that nurture or stimulate the marrow microenvironment by several mechanisms. We hypothesize that the administration of exogenous MSCs may modulate the bone marrow milieu and improve peripheral blood count recovery in the setting of incomplete engraftment. In the current study, we demonstrated that posttransplant intramuscular administration of human placental derived mesenchymal-like adherent stromal cells [PLacental eXpanded (PLX)-R18] harvested from a three-dimensional in vitro culture system improved posttransplant engraftment of human immune compartment in an immune-deficient murine transplantation model. As measured by the percentage of CD45⁺ cell recovery, we observed improvement in the peripheral blood counts at weeks 6 (8.4 vs. 24.1%, p < 0.001) and 8 (7.3 vs. 13.1%, p < 0.05) and in the bone marrow at week 8 (28 vs. 40.0%, p < 0.01) in the PLX-R18 cohort. As measured by percentage of CD19⁺ cell recovery, there was improvement at weeks 6 (12.6 vs. 3.8%) and 8 (10.1 vs. 4.1%). These results suggest that PLX-R18 may have a therapeutic role in improving incomplete engraftment after HCT.

CCL3 Enhances Antitumor Immune Priming in the Lymph Node via IFNγ with Dependency on Natural Killer Cells

Lymph node (LN) plays a critical role in tumor cell survival outside of the primary tumor sites and dictates overall clinical response in many tumor types (1, 2). Previously, we and others have demonstrated that CCL3 plays an essential role in orchestrating T cell—antigen-presenting cell (APC) encounters in the draining LN following vaccination, and such interactions enhance the magnitude of the memory T cell pool (3–5). In the current study, we investigate the cellular responses in the tumor-draining lymph nodes (TDLNs) of a CCL3-secreting CT26 colon tumor (L3TU) as compared to wild-type tumor (WTTU) during the priming phase of an antitumor response (≤10 days). In comparison to WTTU, inoculation of L3TU resulted in suppressed tumor growth, a phenomenon that is accompanied by altered in vivo inflammatory responses on several fronts. Autologous tumor-derived CCL3 (aCCL3) secretion by L3TU bolstered the recruitment of T- and B-lymphocytes, tissue-migratory CD103⁺ dendritic cells (DCs), and CD49b⁺ natural killer (NK) cells, resulting in significant increases in the differentiation and activation of multiple Interferon-gamma (IFNγ)-producing leukocytes in the TDLN. During this early phase of immune priming, NK cells constitute the major producers of IFNγ in the TDLN. CCL3 also enhances CD8+ T cell proliferation and differentiation by augmenting DC capacity to drive T cell activation in the TDLN. Our results revealed that CCL3-dependent IFNγ production and CCL3-induced DC maturation drive the priming of effective antitumor immunity in the TDLN.

CCL3 augment antitumor immune priming in the tumor draining lymph node

Lymph nodes (LNs) represent an area of interest for targeting metastatic tumors because they play an essential role in tumor survival in non-native tissues. The chemokine CCL3 is important in recruiting first-responder immune cells to areas of epithelial insult and orchestrating cellular contacts in the LNs of vaccinated mice that subsequently lead toward the enhancement of memory CD8+ T cell generation. We hypothesize that by introducing a continuous supply of CCL3 into the microenvironment of a metastatic tumor, we can redirect a LN destined for tumor-tolerance toward the production of greater antitumor cellular responses. To interrogate our hypothesis, we subcutaneously inoculated naïve murine recipients with a Balb/c colon metastatic tumor (CT26) that is either the wild-type (WTTUs) or WTTUs transfected to secrete CCL3 (L3TUs). Immunocompetent mice injected with L3TUs resulted in a suppression of tumor growth compared to the WTTU. In vivo analysis across 7-days post-tumor injections with WTTUs or L3TUs, revealed an enhanced accumulation of endogenous DCs, NKs, and lymphocytes in the TDLNs. In vitro analysis showed that OVA-peptide or whole-protein-pulsed bone marrow derived dendritic cells (BMDCs) cultured with CCL3, showed an enhanced capacity to induce proliferation of antigen-specific T cells. Examination of the day-5 TDLNs for direct signs of adaptive antitumor responses also revealed an enhanced production of the antitumor cytokine, IFNγ compared to WTTUs and the specific recruitment of antitumor-associated DCs to the TDLN.

Adoptive natural killer cell therapy is effective in reducing pulmonary metastasis of Ewing sarcoma

The survival of patients with metastatic or relapsed Ewing sarcoma (ES) remains dismal despite intensification of combination chemotherapy and radiotherapy, precipitating the need for novel alternative therapies with minimal side effects. Natural killer (NK) cells are promising additions to the field of cellular immunotherapy. Adoptive NK cell therapy has shown encouraging results in hematological malignancies. Despite these initial promising successes, however, NK cell therapy for solid tumors remains to be investigated using in vivo tumor models. The purpose of this study is to evaluate the efficacy of ex vivo expanded human NK cells in controlling primary and metastatic ES tumor growth in vitro and in vivo. Using membrane-bound IL-21 containing K562 (K562-mbIL-21) expansion platform, we were able to obtain sufficient numbers of expanded NK (eNK) cells that display favorable activation phenotypes and inflammatory cytokine secretion, along with a strong in vitro cytotoxic effect against ES. Furthermore, eNK therapy significantly decreased lung metastasis without any significant therapeutic effect in limiting primary tumor growth in an in vivo xenograft model. Our data demonstrate that eNK may be effective against pulmonary metastatic ES, but challenges remain to direct proper trafficking and augmenting the cytotoxic function of eNK to target primary tumor sites.

Intra-osseous Co-transplantation of CD34-selected Umbilical Cord Blood and Mesenchymal Stromal Cells

Human mesenchymal stromal cells (MSC) have been shown to support the growth and differentiation of hematopoietic stem cells (HSC). We hypothesized that intra-osseous (IO) co-transplantation of MSC and umbilical cord blood (UCB) may be effective in improving early HSC engraftment, as IO transplantation has been demonstrated to enhance UCB engraftment in NOD SCID-gamma (NSG) mice. Following non-lethal irradiation (300rads), 6 groups of NSG mice were studied: 1) intravenous (IV) UCB CD34⁺ cells, 2) IV UCB CD34⁺ cells and MSC, 3) IO UCB CD34⁺ cells, 4) IO UCB CD34⁺ cells and IO MSC, 5) IO UCB CD34⁺ cells and IV MSC, and 6) IV UCB CD34⁺ and IO MSC. Analysis of human-derived CD45⁺, CD3⁺, and CD19⁺ cells 6 weeks following transplant revealed the highest level of engraftment in the IO UCB plus IO MSC cohort. Bone marrow analysis of human CD13 and CD14 markers revealed no significant difference between cohorts. We observed that IO MSC and UCB co-transplantation led to superior engraftment of CD45⁺, CD3⁺ and CD19⁺ lineage cells in the bone marrow at 6 weeks as compared with the IV UCB cohort controls. Our data suggests that IO co-transplantation of MSC and UCB facilitates human HSC engraftment in NSG mice.

Route of delivery influences biodistribution of human bone marrow-derived mesenchymal stromal cells following experimental bone marrow transplantation

Mesenchymal stromal cells (MSCs) have shown promise as treatment for graft-versus-host disease (GvHD) following allogeneic bone marrow transplantation (alloBMT). Mechanisms mediating in vivo effects of MSCs remain largely unknown, including their biodistribution following infusion. To this end, human bone-marrow derived MSCs (hMSCs) were injected via carotid artery (IA) or tail vein (TV) into allogeneic and syngeneic BMT recipient mice. Following xenogeneic transplantation, MSC biodistribution was measured by bioluminescence imaging (BLI) using hMSCs transduced with a reporter gene system containing luciferase and by scintigraphic imaging using hMSCs labeled with [^99mTc]-HMPAO. Although hMSCs initially accumulated in the lungs in both transplant groups, more cells migrated to organs in alloBMT recipient as measured by in vivo BLI and scintigraphy and confirmed by ex vivo BLI imaging, immunohistochemistry and quantitative RT-PCR. IA injection resulted in persistent whole–body hMSC distribution in alloBMT recipients, while hMSCs were rapidly cleared in the syngeneic animals within one week. In contrast, TV-injected hMSCs were mainly seen in the lungs with fewer cells traveling to other organs. Summarily, these results demonstrate the potential use of IA injection to alter hMSC biodistribution in order to more effectively deliver hMSCs to targeted tissues and microenvironments.

Dysregulated intrahepatic CD4+ T-cell activation drives liver inflammation in ileitis-prone SAMP1/YitFc mice

BACKGROUND AND AIMS

Liver inflammation is a common extraintestinal manifestation of inflammatory bowel disease (IBD); however, whether liver involvement is a consequence of a primary intestinal defect or results from alternative pathogenic processes remains unclear. Therefore, we sought to determine the potential pathogenic mechanism(s) of concomitant liver inflammation in an established murine model of IBD.

METHODS

Liver inflammation and immune cell subsets were characterized in ileitis-prone SAMP1/YitFc (SAMP) and AKR/J (AKR) control mice, lymphocyte-depleted SAMP (SAMPxRag-1^-/-), and immunodeficient SCID recipient mice receiving SAMP or AKR donor CD4⁺ T-cells. Proliferation and suppressive capacity of CD4⁺ T-effector (Teff) and T-regulatory (Treg) cells from gut-associated lymphoid tissue (GALT) and livers of SAMP and AKR mice were measured.

RESULTS

Surprisingly, prominent inflammation was detected in 4-wk-old SAMP livers, prior to histologic evidence of ileitis, while both disease phenotypes were absent in age-matched AKRs. SAMP liver disease was characterized by abundant infiltration of lymphocytes, required for hepatic inflammation to occur, a Th1-skewed environment, and phenotypically-activated CD4⁺ T-cells. SAMP intrahepatic CD4⁺ T-cells also had the ability to induce liver and ileal inflammation when adoptively transferred into SCID recipients, whereas GALT-derived CD4⁺ T-cells produced milder ileitis, but not liver inflammation. Interestingly, SAMP intrahepatic CD4⁺ Teff cells showed increased proliferation compared to both SAMP GALT- and AKR liver-derived CD4⁺ Teff cells, while SAMP intrahepatic Tregs were decreased among CD4⁺ T-cells and impaired in in vitro suppressive function compared to AKR.

CONCLUSIONS

Activated intrahepatic CD4⁺ T-cells induce liver inflammation and contribute to experimental ileitis via locally-impaired hepatic immunosuppressive function.

Haplosufficient genomic androgen receptor signaling is adequate to protect female mice from induction of polycystic ovary syndrome features by prenatal hyperandrogenization

Polycystic ovary syndrome (PCOS) is associated with reproductive, endocrine, and metabolic abnormalities. Because hyperandrogenism is the most consistent PCOS feature, we used wild-type (WT) and androgen receptor (AR) knockout (ARKO) mice, together with a mouse model of PCOS, to investigate the contribution of genomic AR-mediated actions in the development of PCOS traits. PCOS features were induced by prenatal exposure to dihydrotestosterone (250 μg) or oil vehicle (control) on days 16-18 of gestation in WT, heterozygote, and homozygote ARKO mice. DHT treatment of WT mice induced ovarian cysts (100% vs 0%), disrupted estrous cycles (42% vs 100% cycling), and led to fewer corpora lutea (5.0±0.4 vs 9.8±1.8). However, diestrus serum LH and FSH, and estradiol-induced-negative feedback as well as hypothalamic expression of kisspeptin, neurokinin B, and dynorphin, were unaffected by DHT treatment in WT mice. DHT-treated WT mice exhibited a more than 48% increase in adipocyte area but without changes in body fat. In contrast, heterozygous and homozygous ARKO mice exposed to DHT maintained comparable ovarian (histo)morphology, estrous cycling, and corpora lutea numbers, without any increase in adipocyte size. These findings provide strong evidence that genomic AR signaling is an important mediator in the development of these PCOS traits with a dose dependency that allows even AR haplosufficiency to prevent induction by prenatal androgenization of PCOS features in adult life.

Abstract 1174: VCAM-1 enhances immune evasion in a murine model of metastatic cervical cancer

Surface over-expression of Vascular Cell Adhesion Molecule-1 (VCAM-1) has recently been identified as a mechanism used by metastatic breast cancer cells to provide pro-survival advantages. It has been previously shown that the metastatic and immune-resistant mouse cervical cancer cell line, A17 has a significantly increased expression of VCAM-1 compared with the primary parental tumor cell line, TC1-P0. Using this metastatic tumor model, we first modulated the surface expression levels of VCAM-1 on A17 in vitro by using an shRNA knockdown approach. We then inoculated these cells intra-venously (iv) and subcutaneously (sq) into C57BL/6 background mice and athymic nude mice to interrogate how VCAM-1 expression affects surrounding immune cell interactions within the tumor microenvironment. To further characterize VCAM-1 dependent immune responses, we used intravital 2-photon laser-scanning microscopy (2P-LPS) to dynamically visualize immune-tumor cells interaction. We observed that VCAM-1 down-regulation reduces the primary tumor growth kinetics in C57BL/6 mice but exhibited similar growth kinetics in nude mice, suggesting that VCAM-1 levels are not responsible for the intrinsic primary tumor growth differences in vivo. Moreover, VCAM-1 down-regulated cell lines showed decreased lung metastasis in both immune-competent mice and athymic nude mice. Furthermore, the metastatic lung parenchyma in mice injected with the non-silencing shVCAM-1 control exhibited immune cell infiltrates with a predominance of M2 polarized macrophages and an altered cytokine production. This may be responsible for decreased susceptibility to immune surveillance. Together, our results demonstrate that tumor-associated VCAM-1 expression helps aggressive tumors circumvent effective immune surveillance, and may represent a target for the development of immune-mediated therapy in metastatic cervical cancer.

Citation Format: Francesca Scrimieri, Iuliana Dit Bobanga, Saada Eid, David J. Corn, Deborah Barkauskas, Jay Jay Myers, Alex Y. Huang. VCAM-1 enhances immune evasion in a murine model of metastatic cervical cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1174. doi:10.1158/1538-7445.AM2014-1174

TNF-receptor inhibitor therapy for the treatment of children with idiopathic pneumonia syndrome. A joint Pediatric Blood and Marrow Transplant Consortium and Children's Oncology Group Study (ASCT0521)

Idiopathic pneumonia syndrome (IPS) is an acute, noninfectious lung disorder associated with high morbidity and mortality after hematopoietic cell transplantation. Previous studies have suggested a role for TNFα in the pathogenesis of IPS. We report a multicenter phase II trial investigating a soluble TNF-binding protein, etanercept (Enbrel, Amgen, Thousand Oaks, CA), for the treatment of pediatric patients with IPS. Eligible patients were < 18 years old, within 120 days after transplantation, and with radiographic evidence of a diffuse pneumonitis. All patients underwent a pretherapy broncho-alveolor lavage (BAL) to establish the diagnosis of IPS. Systemic corticosteroids (2.0 mg/kg/day) plus etanercept (.4 mg/kg twice weekly × 8 doses) were administered. Response was defined as survival and discontinuation of supplemental oxygen support by day 28 of study. Thirty-nine patients (median age, 11 years; range, 1 to 17) were enrolled, with 11 of 39 patients nonevaluable because of identification of pathogens from their pretherapy BAL. In the remaining 28 patients, the median fraction of inspired oxygen at study entry was 45%, with 17 of 28 requiring mechanical ventilation. Complete responses were seen in 20 (71%) patients, with a median time to response of 10 days (range, 1 to 24). Response rates were higher for patients not requiring mechanical ventilation at study entry (100% versus 53%, P = .01). Overall survival at 28 days and 1 year after therapy were 89% (95% confidence interval [CI], 70% to 96%) and 63% (95% CI, 42% to 79%), respectively. Plasma levels of proinflammatory cytokines were significantly increased at onset of therapy, subsequently decreasing in responding patients. The addition of etanercept to high-dose corticosteroids was associated with high response rates and survival in children with IPS.

VCAM-1 enhances immune evasion in a murine model of metastatic cervical cancer (TUM7P.938)

Surface over-expression of Vascular Cell Adhesion Molecule-1 (VCAM-1) was shown to provide a pro-survival advantage in metastatic breast cancer. Similarly, the immune-resistant murine cervical cancer A17 expresses an increased surface VCAM-1 expression compared with the non-metastatic parental tumor, TC1-P0. To test whether VCAM-1 overexpression was responsible for the immune evasive phenotype in A17, we modulated surface VCAM-1 levels on A17 using an shRNA knockdown approach. We inoculated these cells intravenously and subcutaneously into both C57BL/6 and athymic nude mice to interrogate how VCAM-1 affects surrounding immune cell interactions with the tumor, including the use of intravital 2-photon microscopy. VCAM-1lo A17 exhibited reduced growth in C57BL/6 mice but had similar growth kinetics as wild type A17 in nude mice, suggesting an extrinsic T-cell dependent role for tumor-associated VCAM-1 that was responsible for the differences in vivo. Moreover, VCAM-1lo cell lines showed decreased lung metastasis in both immune-competent mice and athymic nude mice, coinciding with changes in M1/M2 polarized macrophages and altered cytokine productions. Together, our results define a functional role for tumor-associated VCAM-1 in helping aggressive tumors circumvent antitumor immune surveillance, and support VCAM-1 as a target for novel immunotherapy against metastatic cervical cancer.

Application of solutions of Rhodamine B in dosimetry

Aqueous solutions of the organic dye Rhodamine B were found to be useful in measuring radiation doses in the range 0.1-2 kGy. Either spectrophotometric or spectrofluorometric measurements can be used. The dosimeter readout is unchanged for at least 60 days after irradiation if the solution is kept in the dark at room temperature. Effects of pH and the dye concentration on the dosimeter response were investigated. Radiation chemical yield and fluorescence quantum yield were also calculated.

Murine leukemia virus envelope gp70 is a shared biomarker for the high-sensitivity quantification of murine tumor burden

The preclinical development of anticancer drugs including immunotherapeutics and targeted agents relies on the ability to detect minimal residual tumor burden as a measure of therapeutic efficacy. Real-time quantitative (qPCR) represents an exquisitely sensitive method to perform such an assessment. However, qPCR-based applications are limited by the availability of a genetic defect associated with each tumor model under investigation. Here, we describe an off-the-shelf qPCR-based approach to detect a broad array of commonly used preclinical murine tumor models. In particular, we report that the mRNA coding for the envelope glycoprotein 70 (gp70) encoded by the endogenous murine leukemia virus (MuLV) is universally expressed in 22 murine cancer cell lines of disparate histological origin but is silent in 20 out of 22 normal mouse tissues. Further, we detected the presence of as few as 100 tumor cells in whole lung extracts using qPCR specific for gp70, supporting the notion that this detection approach has a higher sensitivity as compared with traditional tissue histology methods. Although gp70 is expressed in a wide variety of tumor cell lines, it was absent in inflamed tissues, non-transformed cell lines, or pre-cancerous lesions. Having a high-sensitivity biomarker for the detection of a wide range of murine tumor cells that does not require additional genetic manipulations or the knowledge of specific genetic alterations present in a given neoplasm represents a unique experimental tool for investigating metastasis, assessing antitumor therapeutic interventions, and further determining tumor recurrence or minimal residual disease.

Expression of endogenous para-retroviral genes and molecular analysis of the integration events in its plant host Dahlia variabilis

The dahlia (Dahlia variabilis) genome contains an endogenous pararetrovirus sequence (EPRS) tentatively designated as DvEPRS. The DvEPRS shares genome structure and organization that is typical of members of the Caulimovirus genus. Studies were carried out to better understand the nature of this integration and to determine the gene expression of this DvEPRS. Genomic Southern hybridization showed multiple and random integration events of the DvEPRS in the dahlia genome. To investigate the presence of DvEPRS transcripts, RT-PCR was done on DNase-treated total RNA from DvEPRS-infected dahlia plants. Results showed the expression of open reading frames I, V, and VI. Direct PCR from sap extracts produced more intense DNA amplicons of Dahlia mosaic virus and Dahlia common mosaic virus which are believed to exist as typical episomal caulimoviruses, whereas significantly less intense amplicon was seen in case of DvEPRS in comparison with internal transcribed spacer region of dahlias amplicon. The DvEPRS in wild and cultivated species of Dahlia offer a model system to study the molecular events underlying the ecology, evolution and spread of DvEPRS within natural and managed ecosystems and the factors affecting integration of these EPRS in the plant genome.

Involvement of renal cytochromes P450 and arachidonic acid metabolites in diabetic nephropathy

Diabetic nephropathy (DN) is one of the most serious complications of type I and type II diabetes. DN is characterized by hyperfiltration, hypertrophy, extracellular matrix accumulation, and proteinuria. This advances into renal fibrosis and loss of renal function. Reactive oxygen species (ROS) and TGF-beta have been implicated in the pathogenesis of diabetic nephropathy. Early stages of diabetic nephropathy are also associated with alterations in renal sodium handling as well as hypertension; both are processes linked by involvement of the arachidonic acid (AA) metabolites, 20-hydroxyeicosatetraenoic acid (20-HETE, produced by cytochrome P450-4a, (CYP4A) and epoxyeicosatrienoic acids (EETs). Indeed, metabolism of AA is increased in a rat model of diabetes. In this study, we demonstrate that rats with streptozotocin-induced diabetes of 1 month duration develop renal hypertrophy and increased fibronectin and TGF-beta1 expression/cortical levels concomitant with an increase in CYP4A expression and 20 HETE production. These results were also paralleled by an increase in reactive oxygen species (ROS) production and NADPH oxidase activity. Treatment of diabetic rats with HET0016, selective inhibitor of CYP 4A, prevented all these changes. Our results suggest that diabetes-induced induction of CYP4A and 20-HETE production could be a major pathophysiological mechanism leading to activation of ROS through an NADPH dependent pathway and TGF-beta1 thus resulting in major renal pathology. Inhibitors of 20-HETE production could thus have an important therapeutic potential in the treatment of diabetic nephropathy.

Use of hyaluronan in the selection of sperm for intracytoplasmic sperm injection (ICSI): significant improvement in clinical outcomes--multicenter, double-blinded and randomized controlled trial

STUDY QUESTION

Does the selection of sperm for ICSI based on their ability to bind to hyaluronan improve the clinical pregnancy rates (CPR) (primary end-point), implantation (IR) and pregnancy loss rates (PLR)?

SUMMARY ANSWER

In couples where ≤65% of sperm bound hyaluronan, the selection of hyaluronan-bound (HB) sperm for ICSI led to a statistically significant reduction in PLR.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

HB sperm demonstrate enhanced developmental parameters which have been associated with successful fertilization and embryogenesis. Sperm selected for ICSI using a liquid source of hyaluronan achieved an improvement in IR. A pilot study by the primary author demonstrated that the use of HB sperm in ICSI was associated with improved CPR. The current study represents the single largest prospective, multicenter, double-blinded and randomized controlled trial to evaluate the use of hyaluronan in the selection of sperm for ICSI.

DESIGN

Using the hyaluronan binding assay, an HB score was determined for the fresh or initial (I-HB) and processed or final semen specimen (F-HB). Patients were classified as >65% or ≤65% I-HB and stratified accordingly. Patients with I-HB scores ≤65% were randomized into control and HB selection (HYAL) groups whereas patients with I-HB >65% were randomized to non-participatory (NP), control or HYAL groups, in a ratio of 2:1:1. The NP group was included in the >65% study arm to balance the higher prevalence of patients with I-HB scores >65%. In the control group, oocytes received sperm selected via the conventional assessment of motility and morphology. In the HYAL group, HB sperm meeting the same visual criteria were selected for injection. Patient participants and clinical care providers were blinded to group assignment.

PARTICIPANTS AND SETTING

Eight hundred two couples treated with ICSI in 10 private and hospital-based IVF programs were enrolled in this study. Of the 484 patients stratified to the I-HB > 65% arm, 115 participants were randomized to the control group, 122 participants were randomized to the HYAL group and 247 participants were randomized to the NP group. Of the 318 patients stratified to the I-HB ≤ 65% arm, 164 participants were randomized to the control group and 154 participants were randomized to the HYAL group.

MAIN RESULTS AND THE ROLE OF CHANCE

HYAL patients with an F-HB score ≤65% demonstrated an IR of 37.4% compared with 30.7% for control [n = 63, 58, P > 0.05, (95% CI of the difference −7.7 to 21.3)]. In addition, the CPR associated with patients randomized to the HYAL group was 50.8% when compared with 37.9% for those randomized to the control group (n = 63, 58, P > 0.05). The 12.9% difference was associated with a risk ratio (RR) of 1.340 (RR 95% CI 0.89–2.0). HYAL patients with I-HB and F-HB scores ≤65% revealed a statistically significant reduction in their PLR (I-HB: 3.3 versus 15.1%, n = 73, 60, P = 0.021, RR of 0.22 (RR 95% CI 0.05–0.96) (F-HB: 0.0%, 18.5%, n = 27, 32, P = 0.016, RR not applicable due to 0.0% value) over control patients. The study was originally planned to have 200 participants per arm providing 86.1% power to detect an increase in CPR from 35 to 50% at α = 0.05 but was stopped early for financial reasons. As a pilot study had demonstrated that sperm preparation protocols may increase the HB score, the design of the current study incorporated a priori collection and analysis of the data by both the I-HB and the F-HB scores. Analysis by both the I-HB and F-HB score acknowledged the potential impact of sperm preparation protocols.

BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION

Selection bias was controlled by randomization. Geographic and seasonal bias was controlled by recruiting from 10 geographically unique sites and by sampling over a 2-year period. The potential for population effect was controlled by adjusting for higher prevalence rates of >65% I-HB that naturally occur by adding the NP arm and to concurrently recruit >65% and ≤65% I-HB subjects. Monitoring and site audits occurred regularly to ensure standardization of data collection, adherence to the study protocol and subject recruitment. Subgroup analysis based on the F-HB score was envisaged in the study design.

GENERALIZABILITY TO OTHER POPULATIONS

The study included clinics using different sperm preparation methods, located in different regions of the USA and proceeded in every month of the year. Therefore, the results are widely applicable.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Biocoat, Inc., Horsham, PA, USA. The statistical analysis plan and subsequent analyses were performed by Sherrine Eid, a biostatistician. The manuscript was prepared by Kathryn C. Worrilow, Ph.D. and the study team members. Biocoat, Inc. was permitted to review the manuscript and suggest changes, but the final decision on content was exclusively retained by the authors. K.C.W is a scientific advisor to Biocoat, Inc. S.E. is a consultant to Biocoat, Inc. D.W. has nothing to disclose. M.P., S.S., J.W., K.I., C.K. and T.E. have nothing to disclose. G.D.B. is a consultant to Cooper Surgical and Unisense. J.L. is on the scientific advisory board of Origio.

TRIAL REGISTRATION NUMBER

NCT00741494.

Human biomarker discovery and predictive models for disease progression for idiopathic pneumonia syndrome following allogeneic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (SCT) is the only curative therapy for many malignant and nonmalignant conditions. Idiopathic pneumonia syndrome (IPS) is a frequently fatal complication that limits successful outcomes. Preclinical models suggest that IPS represents an immune mediated attack on the lung involving elements of both the adaptive and the innate immune system. However, the etiology of IPS in humans is less well understood. To explore the disease pathway and uncover potential biomarkers of disease, we performed two separate label-free, proteomics experiments defining the plasma protein profiles of allogeneic SCT patients with IPS. Samples obtained from SCT recipients without complications served as controls. The initial discovery study, intended to explore the disease pathway in humans, identified a set of 81 IPS-associated proteins. These data revealed similarities between the known IPS pathways in mice and the condition in humans, in particular in the acute phase response. In addition, pattern recognition pathways were judged to be significant as a function of development of IPS, and from this pathway we chose the lipopolysaccaharide-binding protein (LBP) protein as a candidate molecular diagnostic for IPS, and verified its increase as a function of disease using an ELISA assay. In a separately designed study, we identified protein-based classifiers that could predict, at day 0 of SCT, patients who: 1) progress to IPS and 2) respond to cytokine neutralization therapy. Using cross-validation strategies, we built highly predictive classifier models of both disease progression and therapeutic response. In sum, data generated in this report confirm previous clinical and experimental findings, provide new insights into the pathophysiology of IPS, identify potential molecular classifiers of the condition, and uncover a set of markers potentially of interest for patient stratification as a basis for individualized therapy.

Conventional splenic dendritic cells regulate development of graft-versus-host disease. (145.10)

The use of allogeneic hematopoietic stem cell transplant (HSCT) to treat hematologic malignancies is associated with the development of graft-versus-host disease (GVHD), a frequently fatal complication that limits successful outcomes. The treatment of GVHD often requires potent immunosuppressive drugs and can predispose to relapse of the original cancer and the development of opportunistic infection. Understanding how GVHD is initiated may help to identify targets for therapeutic interventions that do not require wholesale suppression of the immune response. Prior studies have shown that host antigen presenting cells (APCs) are critical to GVHD induction. We examined how functionally distinct host splenic DC subpopulations (CD4+ vs. CD8+) regulate the development of GVHD mediated by donor CD4+ T cells. When compared to purified Balb/c CD4+ DCs, we found that Balb/c CD8+ DCs significantly increased C57BL/6 CD4+ T cell proliferation and cytolytic activity in vitro. To control the source of T cell stimulation for in vivo HSCT studies, we created chimeric Balb/c mice that have C57BL/6 APCs (C57BL/6 → Balb/c). Subsequently, we found that transplantation of C57BL/6 CD4+ T cells stimulated ex vivo by CD8+ Balb/c DCs resulted in more robust GVHD (survival, clinical score, pathology) compared to T cells activated by CD4+ DCs. Targeting specific DC-T cell interactions early in HSCT may help to control the severity of GVHD without requiring wholesale suppression of the immune system.

Critical role for selectin receptor:ligand interactions in the development of IPS following allogeneic BMT (145.32)

Idiopathic pneumonia syndrome (IPS) is a frequently fatal complication of allogeneic BMT and limits successful outcomes. The pathophysiology of IPS involves the release of soluble inflammatory proteins and the recruitment of donor lymphoid and myeloid effectors into the lung. The entry of leukocytes into inflamed tissue is mediated by several molecules that are orchestrated in a sequential manner. We used well-established mouse BMT models to investigate the role of selectin (sel) receptor:ligand interactions in the development of IPS. Firstly, E and P sel ligands are up-regulated on donor T cells when activated by host APCs in vitro. Next, we found that sel receptor (mRNA) and ligand (protein) expression is significantly increased in the lungs of allo-BMT recipients during the development of IPS. BMT using donor cells deficient in E and P sel ligands resulted in a significant reduction in lung inflammation (cellularity, pathology, cytokines), and mixing studies uncovered a contribution to cells of both lymphoid and myeloid lineage. Experiments using isolated MHC class I or class II disparate strain combinations revealed a more significant effect on donor CD4+ vs. CD8+ T cells. Finally absence of E and P sel in BMT recipient mice conferred near complete protection from IPS especially during CD4+ mediated disease. These data demonstrate a critical role for selectin receptor:ligand interactions in the pathogenesis of IPS and uncover novel strategies to regulate disease severity.

A prospective randomized phase II trial of splenic irradiation (SI) versus supportive therapy (ST) for patients (Pts) with hypersplenism (HS) secondary (2ry) to splenic periportal fibrosis (SPPF)

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Background: HS 2ry to SPPF is a common problem in Egypt as a result of prevalence of bilharziasis. ST is the only option for the majority of pts who have poor performance status (PS) and cannot tolerate/refuse surgery. Methods: Aim of study was to evaluate the effect of SI versus ST on patients with HS 2ry to SPPF. Assessment of treatment was based on changes in Red Cell indices (RCI), Platelet indices (PI), splenic volume (SVol), and splenic vein diameter (SVD). In this study we had 19 evaluable Pts, 10 had SI and 9 had ST. Those who received SI had a twice weekly course of 1.5 Gy for a total of 3 weeks. RCI & PI were measured each visit, SVol & SVD (measured by duplex-Doppler US were measured initially, 3 & 6 months (mos) after treatment). Results: SVol & SVD increased significantly after 3 and 6 mos of ST, compared to insignificant decrease after 3 and 6 mos of SI. Platelet count (PC) significantly increased in all follow-ups (FU) after SI till 1.5 years compared to insignificant decreases in ST group after 3 and 6 mos. FU of mean platelet volume (MPV) and platelet distribution width (PDW) increased in ST group and decreased significantly in SI. Red blood cell (RBC) count and hemoglobin (Hb) levels increased significantly after SI till 6 and 9 mos respectively compared to insignificant decrease in RBC count and significant decrease in Hb level after 6 mos of ST. Changes in white blood cell counts were insignificant. After SI, changes in SVol showed significant positive correlations with changes in SVD and significant negative correlations with changes in PC. Changes in MPV showed significant positive correlation with changes in SVD. Side-effects (SE) seen with SI were moderate and transient. Conclusions: SI is a promising new modality of treatment with acceptable SE for pts with HS. Dose and schedule of SI should be modified according to pts PS. Changes in SVD are highly correlated with the degree of platelet and red cell turnover. Its predictive value for HS should be studied further.

No significant financial relationships to disclose.

[Lactating adenoma: radiologic aspects. A case report]

We report the US and MRI appearance in a patient with a giant lactating adenoma detected during pregnancy and followed-up for 12 months postpartum. The different imaging features of lactating adenomas are discussed, especially at US and MRI. We discuss also the role of core biopsy in diagnosing pregnancy associated breast masses.

The dietary habits of young people

Adolescence is a time when patterns of behaviour can be set for life. This research project sought to listen to young people and understand the things that influence their acceptance of and accessibility to a healthy diet.