Lumbar plexus terminal branch block, a safe alternative for transfemoral aortic valve implantation. Case report

Transcatheter aortic valve implantation is an alternative treatment for patients with severe aortic stenosis, it is conventionally performed under general anaesthesia or local anaesthesia plus sedation. We present the first case of trans-femoral, trans-catheter aortic valve implantation, performed in our hospital in a patient with severe aortic stenosis, who was a high surgical risk. Anaesthesia consisted of a combination of bilateral selective blockade of the iliohypogastric, ilioinguinal and genitofemoral nerves with the patient awake without sedation, using an ultrasound-guided approach. Transcatheter aortic valve implantation was successful and passed without incident, the patient remained immobile, calm, did not report pain, and sedation or hypnotics were not necessary during dilation of the vascular accesses with the introducer. Standard monitoring demonstrated haemodynamic stability, without cardiovascular repercussions and did not necessitate vasopressor or inotropic drug support. After the intervention, the patient was sent to the Cardiac Intensive Care Unit, where he remained asymptomatic and stable. Subsequently, the patient was admitted to the cardiology ward from where he was discharged without complications.

T-cell exhaustion and residency dynamics inform clinical outcomes in hepatocellular carcinoma

BACKGROUND & AIMS

Despite recent translation of immunotherapies into clinical practice, the immunobiology of hepatocellular carcinoma (HCC), in particular the role and clinical relevance of exhausted and liver-resident T cells remain unclear. We therefore dissected the landscape of exhausted and resident T cell responses in the peripheral blood and tumor microenvironment of patients with HCC.

METHODS

Lymphocytes were isolated from the blood, tumor and tumor-surrounding liver tissue of patients with HCC (n = 40, n = 10 treated with anti-PD-1 therapy). Phenotype, function and response to anti-PD-1 were analyzed by mass and flow cytometry ex vivo and in vitro, tissue residence was further assessed by immunohistochemistry and imaging mass cytometry. Gene signatures were analyzed in silico.

RESULTS

We identified significant enrichment of heterogeneous populations of exhausted CD8+ T cells (TEX) in the tumor microenvironment. Strong enrichment of severely exhausted CD8 T cells expressing multiple immune checkpoints in addition to PD-1 was linked to poor progression-free and overall survival. In contrast, PD-1 was also expressed on a subset of more functional and metabolically active CD103+ tissue-resident memory T cells (TRM) that expressed few additional immune checkpoints and were associated with better survival. TEX enrichment was independent of BCLC stage, alpha-fetoprotein levels or age as a variable for progression-free survival in our cohort. These findings were in line with in silico gene signature analysis of HCC tumor transcriptomes from The Cancer Genome Atlas. A higher baseline TRM/TEX ratio was associated with disease control in anti-PD-1-treated patients.

CONCLUSION

Our data provide information on the role of peripheral and intratumoral TEX-TRM dynamics in determining outcomes in patients with HCC. The dynamics between exhausted and liver-resident T cells have implications for immune-based diagnostics, rational patient selection and monitoring during HCC immunotherapies.

LAY SUMMARY

The role of the immune response in hepatocellular carcinoma (HCC) remains unclear. T cells can mediate protection against tumor cells but are frequently dysfunctional and exhausted in cancer. We found that patients with a predominance of exhausted CD8+ T cells (TEX) had poor survival compared to patients with a predominance of tissue-resident memory T cells (TRM). This correlated with the molecular profile, metabolic and functional status of these cell populations. The enrichment of TEX was independently associated with prognosis in addition to disease stage, age and tumor markers. A high TRM proportion was also associated with better outcomes following checkpoint therapy. Thus, these T-cell populations are novel biomarkers with relevance in HCC.

Abstract B33: Tumor cell-intrinsic EPHA2 suppresses antitumor immunity by regulating PTGS2 (COX-2) in pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PDA) is highly refractory to immunotherapy, a consequence of T-cell exclusion from the tumor microenvironment (TME). Based on a pathway analysis of human PDAs, we hypothesized that the receptor tyrosine kinase ephrin A2 (EPHA2) drives this immunosuppressive TME, as its expression negatively correlated with CD8A, CD3, PRF1, GZMB, and patient survival (EPHA2low/EPHA2high log rank hazard ratio 0.115, 95% CI of ratio 0.0315-0.416, TCGA dataset). Deletion of Epha2 in tumor cells increased T-cell influx, decreased the number of infiltrating myeloid suppressor cells, and sensitized tumors to therapy. Treatment of Epha2-deficient tumors with combination of chemo and immunotherapy resulted in suppressed tumor growth or tumor regression in up to 85% of cases. Examination of Epha2-dependent gene expression nominated Ptgs2 as a downstream mediator of T-cell exclusion. Like EPHA2, PTGS2 exhibited a negative correlation with intratumoral T cells, cytolytic activity, and patient survival (PTGS2low/PTGS2high log rank hazard ratio 0.152, 95% CI of ratio 0.054-0.430, TCGA dataset). KPCY mice (mutant KrasG12D (K), dominant negative p53R172H (P), Cre recombinase (C), YFP protein (Y)) deficient in pancreatic ductal cell Ptgs2 had significantly increased overall survival compared to Ptgs2 sufficient KPCY mice (Ptgs2def/Ptgs2suff log rank hazard ratio 0.5001, 95% CI of ratio 0.294-0.851). Ptgs2 deletion promoted T-cell influx in both autochthonous and implanted tumors. Inversely, overexpression of Ptgs2 decreased the number of tumor-infiltrating T cells, increased the proportion of suppressor myeloid cells, and conferred resistance to the combination therapy. Remarkably, pharmacologic inhibition of PTGS2 sensitized the tumors to immunotherapy, suppressing the growth of implanted tumors and increasing the survival of treated KPCY mice (median survival of untreated and treated mice 151 and 199 days, respectively; survival curve log rank p-value= 0.017). These studies suggest that a tumor cell-intrinsic EPHA2-PTGS2 signaling axis regulates the immune TME in PDA and suggests that a two-step approach targeting T-cell exclusion and exhaustion holds promise for this treatment-refractory disease.

Citation Format: Nune Markosyan, Jinyang Li, Yu Sun, Lee Richman, Jeffrey Lin, Fangxue Yan, Liz Quinones, Yogev Sela, Taiji Yamazoe, Naomi Gordon, John Tobias, Katelyn Byrne, Andrew Rech, Garret FitzGerald, Ben Stanger, Robert Vonderheide. Tumor cell-intrinsic EPHA2 suppresses antitumor immunity by regulating PTGS2 (COX-2) in pancreatic adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B33.

Abstract A094: mPGES1 deletion increases tumor susceptibility to immune suppression

The pro-tumor contributions of prostaglandin (PG) E2 are established, as is the clinical efficacy of pharmacological inhibition of COX-2, the rate-limiting enzyme in PGE2 synthesis. In addition to the desired suppression of tumor PGE2, collateral loss of endothelial COX-2-derived PGI2 imposes a cardiovascular hazard that limits clinical use of COX-2 inhibitors. mPGES1, the terminal enzyme in the PGE2 synthesis pathway, is an alternative target to interrupt COX-2-driven events in tumors without elevating cardiovascular risk. We engineered mice transgenic for an activated HER2/neu oncogene to lack mPGES1 globally (mPGES1 KOgl) or only in mammary epithelial cells (mPGES1 KOepi). Abdominal mammary glands from wild type (WT), heterozygous (het), mPGES1 KOgl, and mPGES1 KOepi mice were harvested at 22 weeks of age, paraffin embedded, H&E stained, and scanned for whole slide imaging (WSI). Tumor multiplicity was calculated based on the number of lesions on WSI. Adjacent sections were immunostained for Ki67, caspase 3, Factor VIII, CD3, and F4/80, to assess proliferation, apoptosis, angiogenesis, and tumor lymphocyte and macrophage infiltration. Tumor multiplicity was significantly higher in WT compared to either mPGES1 KOgl or mPGES1 KOepi mice. By immunohistochemistry, no difference was observed in proliferation and apoptosis markers, as well as in the number of tumor infiltrating macrophages and lymphocytes, between WT, mPGES1 KOgl, and mPGES1 KOepi tumors. In contrast to our previous study in mice lacking epithelial COX-2 (COX-2 KOepi), vascularization was not different between mPEGS-1 KOepi and WT tumors suggesting divergence in the anti-tumorigenic mechanisms in mPEGS-1 KOepi and COX-2 KOepi tumors. By flow cytometry there was no difference in infiltrating macrophage and lymphocyte density or functional phenotypes, between WT and mPGES1 KOepi tumors. In the orthotopic mammary tumor model, no difference was observed in the number of macrophages and myeloid derived suppressor cells in spleens from mPGES1 sufficient and mPGES1 KD orthotopic tumor bearing mice. In contrast, decreased co-inhibitory molecule PD-1 expressing CD4+ and CD8+ lymphocyte numbers were evident in draining lymph nodes in mice injected with mPGES1 KD cells compared to controls. Depletion of CD8+ cells alone, or together with CD4+ cells, significantly accelerated the growth of mPGES1 KD orthotopic tumors. This finding indicates that the absence of mPGES1-derived PGE2 renders tumor cells less efficient in creating and maintaining an immunosuppressive tumor microenvironment, and that targeting mPGES1 may enhance anti-tumor immune mechanisms.

Citation Format: Nune Markosyan, Andrew Rech, Robert Vonderheide. mPGES1 deletion increases tumor susceptibility to immune suppression [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A094.

Abstract PR05: Mechanisms of tumor response and resistance to radiation and dual checkpoint blockade in mice and patients

Immune checkpoint inhibitors result in impressive clinical responses but optimal results will require combination with each other and other therapies. This raises fundamental questions about mechanisms of non-redundancy and resistance. Here, we report major tumor regressions in a subset of patients with metastatic melanoma treated with an anti-CTLA4 antibody (anti-CTLA4) and radiation (RT) on a phase one clinical trial and reproduced this effect in mouse models. Although combined treatment improved responses in irradiated and unirradiated tumors, resistance was common. Computational analysis of genome-wide and immune profiles of mice revealed resistance was due to T cell exhaustion driven by adaptive resistance and prolonged interferon-gamma exposure, resulting in STAT1-mediated upregulation of PD-L1 on melanoma cells and tumor macrophages. Accordingly, optimal response in melanoma and other cancer types requires RT, anti-CTLA4, and anti-PD-L1/PD-1. Anti-CTLA4 predominantly inhibits T regulatory cells, and macrophage depletion and/or PD-L1 blockade reverses T cell exhaustion. RT promotes the infiltration of intratumoral antigen-specific CD8 T cells and enhances the diversity of the T cell receptor (TCR) repertoire. RT with dual checkpoint blockade shapes the TCR repertoire of the expanded peripheral clones in a manner consistent with antigen-driven selection. Similar to results from mice, patients on our clinical trial with tumors showing high PD-L1 did not respond to RT + anti-CTLA4, demonstrated persistent T cell exhaustion, and rapidly progressed. In contrast, patients with low PD-L1 on melanoma cells or macrophages had markedly improved survival, with the best survival observed among those patients with low PD-L1 on both cell types. Thus, our results suggest that 1) RT can enhance response to anti-CTLA4 when the TCR and/or antigen repertoire are sub-optimal, 2) upregulation of PD-L1 through STAT1-mediated adaptive resistance mechanisms inhibits response to anti-CTLA4-based therapy unless PD-L1/PD-1 is blocked, and 3) the combination of RT, anti-CTLA4, and anti-PD-L1 promotes response and immunity through distinct mechanisms. Finally, although PD-L1 was a dominant resistance mechanism in our models, PD-L1-independent resistance mechanisms were also evident. The next generation of clinical trials based on these findings are underway.

Citation Format: Christina Twyman-Saint Victor, Andrew Rech, Joseph Benci, Amit Maity, Ramesh Rengan, Kristen Pauken, Erietta Stelekati, Bihui Xu, Hannah Dada, Pamela Odorizzi, Ramin Herati, Ravi Amaravadi, Lynn Schuchter, Hemant Ishwaran, Rosemarie Mick, Daniel Pryma, Xiaowei Xu, Michael Feldman, Tara Gangadhar, Steve Hahn, John Wherry, Robert Vonderheide, Andy Minn. Mechanisms of tumor response and resistance to radiation and dual checkpoint blockade in mice and patients. [abstract]. In: Proceedings of the Fourth AACR International Conference on Frontiers in Basic Cancer Research; 2015 Oct 23-26; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2016;76(3 Suppl):Abstract nr PR05.

Abstract 469: mPGES1 deletion and the mechanisms of tumor growth suppression

The pro-tumor contributions of prostaglandin (PG) E2 are established, as is the clinical efficacy of pharmacological inhibition of COX-2, the rate-limiting enzyme in PGE2 synthesis. In addition to the desired suppression of tumor PGE2, collateral loss of endothelial COX-2-derived PGI2 imposes a cardiovascular hazard that limits clinical use of COX-2 inhibitors. mPGES1, the terminal enzyme in the PGE2 synthesis pathway, is an alternative target to interrupt COX-2-driven events in tumors without elevating cardiovascular risk. We engineered mice transgenic for an activated HER2/neu oncogene to lack mPGES1 globally (mPGES1 KOgl) or only in mammary epithelial cells (mPGES1 KOepi). Abdominal mammary glands from wild type (WT), heterozygous (het), mPGES1 KOgl, and mPGES1 KOepi mice were harvested at 22 weeks of age, paraffin embedded, H&E stained and scanned for whole slide imaging (WSI). Tumor multiplicity was calculated based on the number of lesions on WSI. Adjacent sections were immunostained for Ki67, caspase 3, Factor VIII, CD3, and F4/80, to assess proliferation, apoptosis, angiogenesis, and tumor lymphocyte and macrophage infiltration. Tumor multiplicity was significantly higher in WT compared to either mPGES1 KOgl or mPGES1 KOepi mice. Concordantly, shRNA knock down (KD) of mPGES1 in mammary tumor cells dramatically suppressed their growth as orthotopic tumors in syngeneic immune competent WT hosts: 4 weeks after the injections, 6 out of 6 non-target shRNA control tumors grew successfully while 6 out of 10 mPGES1 KD cells failed to grow. In separate experiments, 14 of 14 non-target shRNA cells formed tumors after 2 weeks while 12 out of 18 mPGES1 KD tumors failed. By immunohistochemistry, no difference was observed in proliferation and apoptosis markers, as well as in the number of tumor infiltrating macrophages and lymphocytes, between WT, mPGES1 KOgl, and mPGES1 KOepi tumors. In contrast to our previous study in mice lacking epithelial COX-2 (COX-2 KOepi), vascularization was not different between mPEGS-1 KOepi and WT tumors suggesting divergence in the anti-tumorigenic mechanisms in mPEGS-1 KOepi and COX-2 KOepi tumors. By flow cytometry there was no difference in infiltrating macrophage and lymphocyte density or functional phenotypes, between WT, mPGES1 KOepi, and mPGES1 KD orthotopic tumors. Similarly, no difference was observed in the number of macrophages and myeloid derived suppressor cells in spleens from mPGES1 sufficient and mPGES1 KD orthotopic tumor bearing mice. In contrast, decreased co-inhibitory molecule PD-1 expressing CD4+ and CD8+ lymphocyte numbers were evident in draining lymph nodes in mice injected with mPGES1 KD cells compared to WT. This finding indicates that the absence of mPGES1-derived PGE2 renders tumor cells less efficient in creating and maintaining an immunosuppressive tumor microenvironment and that targeting mPGES1 may enhance anti-tumor immune mechanisms.

Citation Format: Nune Markosyan, Andrew Rech, Robert H. Vonderheide, Garret A. FitzGerald, Emer M. Smyth. mPGES1 deletion and the mechanisms of tumor growth suppression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 469. doi:10.1158/1538-7445.AM2015-469

Evidences that maternal swimming exercise improves antioxidant defenses and induces mitochondrial biogenesis in the brain of young Wistar rats

Physical exercise during pregnancy has been considered beneficial to mother and child. Recent studies showed that maternal swimming improves memory in the offspring, increases hippocampal neurogenesis and levels of neurotrophic factors. The objective of this work was to investigate the effect of maternal swimming during pregnancy on redox status and mitochondrial parameters in brain structures from the offspring. Adult female Wistar rats were submitted to five swimming sessions (30 min/day) prior to mating with adult male Wistar rats, and then trained during the pregnancy (five sessions of 30-min swimming/week). The litter was sacrificed when 7 days old, when cerebellum, parietal cortex, hippocampus, and striatum were dissected. We evaluated the production of reactive species and antioxidant status, measuring the activities of superoxide-dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPx), as well as non-enzymatic antioxidants. We also investigated a potential mitochondrial biogenesis regarding mitochondrion mass and membrane potential, through cytometric approaches. Our results showed that maternal swimming exercise promoted an increase in reactive species levels in cerebellum, parietal cortex, and hippocampus, demonstrated by an increase in dichlorofluorescein oxidation. Mitochondrial superoxide was reduced in cerebellum and parietal cortex, while nitrite levels were increased in cerebellum, parietal cortex, hippocampus, and striatum. Antioxidant status was improved in cerebellum, parietal cortex, and hippocampus. SOD activity was increased in parietal cortex, and was not altered in the remaining brain structures. CAT and GPx activities, as well as non-enzymatic antioxidant potential, were increased in cerebellum, parietal cortex, and hippocampus of rats whose mothers were exercised. Finally, we observed an increased mitochondrial mass and membrane potential, suggesting mitochondriogenesis, in cerebellum and parietal cortex of pups subjected to maternal swimming. In conclusion, maternal swimming exercise induced neurometabolic programing in the offspring that could be of benefit to the rats against future cerebral insults.

Two cases of autochthonous Plasmodium falciparum malaria in Germany with evidence for local transmission by indigenous Anopheles plumbeus

Autochthonous Plasmodium falciparum malaria (PFM) in Central Europe has been reported repeatedly, transmission of the parasite being attributed to blood transfusion or imported P. falciparum-infected vectors. We report two cases of PFM in German children without travel history to malaria-endemic areas. Both infections occurred during a stay in a hospital where a child from Angola with chronic P. falciparum infection was hospitalized at the time. Known routes of transmission, such as imported mosquitoes or blood transfusion, were very unlikely or could be excluded, whereas evidence was obtained for transmission by the indigenous mosquito species Anopheles plumbeus.

[Clinical manifestations of schizencephaly and its sonographic diagnosis]

Schizencephaly is defined as a cerebral malformation of the CNS with various clefts of the cerebral cortex. We report on two patients referred to our department with neurological abnormalities. In both cases the cranial sonography already provided for the clinical picture of schizencephaly. A MR-scan confirmed the diagnosis. In addition one of the patients proved to have a migrational disorder. The analysis of these cases and the relevant literature point out how difficult the etiologic differentiation is and, on the other hand, how various the manifestations of the malformation can be. The important role of cranial sonography as a screening method is shown.

Bilateral ablation of auditory cortex in Mongolian gerbil affects discrimination of frequency modulated tones but not of pure tones

This study examines the role of auditory cortex in the Mongolian gerbil in differential conditioning to pure tones and to linearly frequency-modulated (FM) tones by analyzing the effects of bilateral auditory cortex ablation. Learning behavior and performance were studied in a GO/NO-GO task aiming at avoidance of a mild foot shock by crossing a hurdle in a two-way shuttle box. Hurdle crossing as the conditioned response to the reinforced stimulus (CR+), as false alarm in response to the unreinforced stimulus (CR-), intertrial activity, and reaction times were monitored. The analysis revealed no effects of lesion on pure tone discrimination but impairment of FM tone discrimination. In the latter case lesion effects were dependent on timing of lesion relative to FM tone discrimination training. Lesions before training in naive animals led to a reduced CR+ rate and had no effect on CR- rate. Lesions in pretrained animals led to an increased CR- rate without effects on the CR+ rate. The results suggest that auditory cortex plays a more critical role in discrimination of FM tones than in discrimination of pure tones. The different lesion effects on FM tone discrimination before and after training are compatible with both the hypothesis of a purely sensory deficit in FM tone processing and the hypothesis of a differential involvement of auditory cortex in acquisition and retention, respectively.