Lymph node targeted multi-epitope subunit vaccine promotes effective immunity to EBV in HLA-expressing mice

The recent emergence of a causal link between Epstein-Barr virus (EBV) and multiple sclerosis has generated considerable interest in the development of an effective vaccine against EBV. Here we describe a vaccine formulation based on a lymph node targeting Amphiphile vaccine adjuvant, Amphiphile-CpG, admixed with EBV gp350 glycoprotein and an engineered EBV polyepitope protein that includes 20 CD8+ T cell epitopes from EBV latent and lytic antigens. Potent gp350-specific IgG responses are induced in mice with titers >100,000 in Amphiphile-CpG vaccinated mice. Immunization including Amphiphile-CpG also induces high frequencies of polyfunctional gp350-specific CD4+ T cells and EBV-specific CD8+ T cells that are 2-fold greater than soluble CpG and are maintained for >7 months post immunization. This combination of broad humoral and cellular immunity against multiple viral determinants is likely to provide better protection against primary infection and control of latently infected B cells leading to protection against the development of EBV-associated diseases.

Freshwater and anadromous fishing in Ice Age Beringia

While freshwater and anadromous fish have been critical economic resources for late prehistoric and modern Native Americans, the origin and development of fishing is not well understood. We document the earliest known human use of freshwater and anadromous fish in North America by 13,000 and 11,800 years ago, respectively, from primary anthropogenic contexts in central Alaska (eastern Beringia). Fish use appears conditioned by broad climatic factors, as all occurrences but one are within the Younger Dryas chronozone. Earlier Bølling-Allerød and later early Holocene components, while exhibiting similar organic preservation, did not yield evidence of fishing, suggesting that this was a response to changing environmental factors, perhaps reductions in higher ranked resources such as large terrestrial mammals. Late Pleistocene and recent Indigenous peoples harvested similar fish taxa in the region (salmon, burbot, whitefish, and pike). We characterize late Pleistocene fishing in interior Beringia as an important element of broad-spectrum foraging rather than the intensive communal fishing and storage common among recent peoples.

Inhibiting DNA methylation and RNA editing upregulates immunogenic RNA to transform the tumor microenvironment and prolong survival in ovarian cancer

BACKGROUND

Novel therapies are urgently needed for ovarian cancer (OC), the fifth deadliest cancer in women. Preclinical work has shown that DNA methyltransferase inhibitors (DNMTis) can reverse the immunosuppressive tumor microenvironment in OC. Inhibiting DNA methyltransferases activate transcription of double-stranded (ds)RNA, including transposable elements. These dsRNAs activate sensors in the cytoplasm and trigger type I interferon (IFN) signaling, recruiting host immune cells to kill the tumor cells. Adenosine deaminase 1 (ADAR1) is induced by IFN signaling and edits mammalian dsRNA with an A-to-I nucleotide change, which is read as an A-to-G change in sequencing data. These edited dsRNAs cannot be sensed by dsRNA sensors, and thus ADAR1 inhibits the type I IFN response in a negative feedback loop. We hypothesized that decreasing ADAR1 editing would enhance the DNMTi-induced immune response.

METHODS

Human OC cell lines were treated in vitro with DNMTi and then RNA-sequenced to measure RNA editing. Adar1 was stably knocked down in ID8 Trp53^-/- mouse OC cells. Control cells (shGFP) or shAdar1 cells were tested with mock or DNMTi treatment. Tumor-infiltrating immune cells were immunophenotyped using flow cytometry and cell culture supernatants were analyzed for secreted chemokines/cytokines. Mice were injected with syngeneic shAdar1 ID8 Trp53^-/- cells and treated with tetrahydrouridine/DNMTi while given anti-interferon alpha and beta receptor 1, anti-CD8, or anti-NK1.1 antibodies every 3 days.

RESULTS

We show that ADAR1 edits transposable elements in human OC cell lines after DNMTi treatment in vitro. Combining ADAR1 knockdown with DNMTi significantly increases pro-inflammatory cytokine/chemokine production and sensitivity to IFN-β compared with either perturbation alone. Furthermore, DNMTi treatment and Adar1 loss reduces tumor burden and prolongs survival in an immunocompetent mouse model of OC. Combining Adar1 loss and DNMTi elicited the most robust antitumor response and transformed the immune microenvironment with increased recruitment and activation of CD8+ T cells.

CONCLUSION

In summary, we showed that the survival benefit from DNMTi plus ADAR1 inhibition is dependent on type I IFN signaling. Thus, epigenetically inducing transposable element transcription combined with inhibition of RNA editing is a novel therapeutic strategy to reverse immune evasion in OC, a disease that does not respond to current immunotherapies.

Amphiphile-CpG vaccination induces potent lymph node activation and COVID-19 immunity in mice and non-human primates

Despite the success of currently authorized vaccines for the reduction of severe COVID-19 disease risk, rapidly emerging viral variants continue to drive pandemic waves of infection, resulting in numerous global public health challenges. Progress will depend on future advances in prophylactic vaccine activity, including advancement of candidates capable of generating more potent induction of cross-reactive T cells and durable cross-reactive antibody responses. Here we evaluated an Amphiphile (AMP) adjuvant, AMP-CpG, admixed with SARS-CoV-2 Spike receptor binding domain (RBD) immunogen, as a lymph node-targeted protein subunit vaccine (ELI-005) in mice and non-human primates (NHPs). AMP-mediated targeting of CpG DNA to draining lymph nodes resulted in comprehensive local immune activation characterized by extensive transcriptional reprogramming, inflammatory proteomic milieu, and activation of innate immune cells as key orchestrators of antigen-directed adaptive immunity. Prime-boost immunization with AMP-CpG in mice induced potent and durable T cell responses in multiple anatomical sites critical for prophylactic efficacy and prevention of severe disease. Long-lived memory responses were rapidly expanded upon re-exposure to antigen. In parallel, RBD-specific antibodies were long-lived, and exhibited cross-reactive recognition of variant RBD. AMP-CpG-adjuvanted prime-boost immunization in NHPs was safe and well tolerated, while promoting multi-cytokine-producing circulating T cell responses cross-reactive across variants of concern (VOC). Expansion of RBD-specific germinal center (GC) B cells in lymph nodes correlated to rapid seroconversion with variant-specific neutralizing antibody responses exceeding those measured in convalescent human plasma. These results demonstrate the promise of lymph-node adjuvant-targeting to coordinate innate immunity and generate robust adaptive responses critical for vaccine efficacy.

Inhibition of DNMTs and RNA editing increases immunogenic transposable element RNA to reduce tumor burden and prolong survival in a murine ovarian cancer model

Novel therapies are urgently needed for ovarian cancer (OC), the fifth deadliest cancer in women. Preclinical data shows great promise for the treatment of OC with epigenetic therapy. The inhibition of DNMT activates transcription of double-stranded (ds)RNA, including transposable elements. These dsRNAs activate sensors in the cytoplasm and trigger the induction of type I interferon signaling. Adenosine deaminase 1 (ADAR1) is induced by interferon signaling and edits mammalian dsRNA with an A-to-I nucleotide change. These edited dsRNAs cannot be sensed by dsRNA sensors, and thus ADAR1 inhibits the type I interferon response. We show that transposable elements including Alus, LINEs, and ERVs, are edited by ADAR1 in human OC cell lines after DNMTi treatment.

We hypothesized that increased ADAR1 editing reduces the DNMTi immune response and treated Adar1 knockdown cells with DNMT1 in vitro and in vivo. Combining ADAR1 knockdown with DNMTi significantly increased pro-inflammatory cytokine production compared to either perturbation alone. We treated an immunocompetent mouse model of OC with DNMTi after implanting them with Adar1 knockdown cells or control cells (ID8 Trp53−/−) and found that DNMTi treatment and Adar1 loss reduces tumor burden and extends survival in this model, and the combination of both is the most effective. Combining Adar1 loss and DNMTi transforms the immune microenvironment, including increased recruitment of natural killer cells and M1 macrophage polarization. This survival benefit is a result of type I interferon signaling and CD8+ T cells. Thus, epigenetically inducing transposable element transcription, followed by inhibition of RNA editing, is a novel therapeutic strategy to reverse immune evasion in OC.

Research was supported by the National Cancer Institute R00CA204592 and R37CA251270 (to KBC), the DOD Ovarian Cancer Research Program (W81XWH2010273 to KBC), and by the Marlene and Michael Berman Endowed Fund for Ovarian Cancer Research. JIM was supported by an NCI NRSA Institutional Research Training Program grant (T32 CA 247756). SG was supported by a NRSA Predoctoral Fellowship (NIH/NCI 1F31CA254315-01). The authors would like to acknowledge the Institute for Biomedical Sciences at the George Washington University for graduate student support and training (SG, EEG, TK, VB).

CD137 agonist potentiates the abscopal efficacy of nanoparticle-based photothermal therapy for melanoma

Despite the promise of immunotherapy such as the immune checkpoint inhibitors (ICIs) anti-PD-1 and anti-CTLA-4 for advanced melanoma, only 26%-52% of patients respond, and many experience grade III/IV immune-related adverse events. Motivated by the need for an effective therapy for patients non-responsive to clinically approved ICIs, we have developed a novel nanoimmunotherapy that combines locally administered Prussian blue nanoparticle-based photothermal therapy (PBNP-PTT) with systemically administered agonistic anti-CD137 monoclonal antibody therapy (aCD137). PBNP-PTT was administered at various thermal doses to melanoma cells in vitro, and was combined with aCD137 in vivo to test treatment effects on melanoma tumor progression, animal survival, immunological protection against tumor rechallenge, and hepatotoxicity. When administered at a melanoma-specific thermal dose, PBNP-PTT elicits immunogenic cell death (ICD) in melanoma cells and upregulates markers associated with antigen presentation and immune cell co-stimulation in vitro. Consequently, PBNP-PTT eliminates primary melanoma tumors in vivo, yielding long-term tumor-free survival. However, the antitumor immune effects generated by PBNP-PTT cannot eliminate secondary tumors, despite significantly slowing their growth. The addition of aCD137 enables significant abscopal efficacy and improvement of survival, functioning through activated dendritic cells and tumor-infiltrating CD8⁺ T cells, and generates CD4⁺ and CD8⁺ T cell memory that manifests in the rejection of tumor rechallenge, with no long-term hepatotoxicity. This study describes for the first time a novel and effective nanoimmunotherapy combination of PBNP-PTT with aCD137 mAb therapy for melanoma.

Phase I Study of Entinostat in Combination with Enzalutamide for Treatment of Patients with Metastatic Castration-Resistant Prostate Cancer

LESSONS LEARNED

Entinostat at the selected dose levels in combination with a standard dose of enzalutamide showed a promising safety profile in this small phase I study BACKGROUND: Entinostat inhibits prostate cancer (PCa) growth and suppresses Treg cell function in vitro and in vivo.

METHODS

This was a phase I study to explore the safety and preliminary efficacy of entinostat (3 and 5 mg orally per week) in combination with enzalutamide in castration resistant PCa (CRPC). The study was carried out in an open-label two-cohort design. Patients who had developed disease progression on or were eligible for enzalutamide were enrolled in the study. The safety profile of the combination therapy, Prostate specific antigen (PSA) levels, the pharmacokinetics of enzalutamide after entinostat administration, peripheral T-cell subtype (including Treg quantitation), and mononuclear cell (PBMC) histone H3 acetylation were analyzed.

RESULTS

Six patients with metastatic CRPC were enrolled. There was no noticeable increment of fatigue related to entinostat. Toxicities possibly or probably related to entinostat or the combination therapy included grade 3 anemia 1/6 (17%), grade 2 white blood cell (WBC) decrease 1/6 (17%), and other self-limiting grade 1 adverse events (AEs). Median duration of treatment with entinostat was 18 weeks. Entinostat did not affect the steady plasma concentration of enzalutamide. Increased PBMC histone H3 acetylation was observed in blood samples. No evident T-cell subtype changes were detected, including in Treg quantitation.

CONCLUSION

Entinostat 5 mg weekly in combination with enzalutamide showed an acceptable safety profile in this small phase I study. A planned phase II part of the trial was terminated because of sponsor withdrawal.

Abstract 1268: A novel treatment approach for melanoma by dually targeting MCT1 and MCT4 lactate transporters

Cancer cells are metabolically rewired to activate glycolysis, which results in the generation and excretion of lactate as a byproduct. Although lactate was previously thought to be a waste product of anaerobic respiration, increasing evidence has revealed that distinct cell populations within tumors use lactate as a source of energy through TCA cycle. This metabolic symbiosis between distinct cell populations, hypoxic lactate consumers, and oxidative glycolytic lactate exporters within the tumor is regulated by differential expression of lactate transporters, mainly MCT1 and MCT4. Therefore, dual targeting of MCT1 and MCT4 is a novel approach to treat cancer. We have developed a compound, NGY-B, which binds and inhibits both MCT1 and MCT4 transporters. This compound has shown to significantly increase intracellular lactate levels in melanoma models and thereby decreasing in vitro cell proliferation. When cultured in the media with exogenous lactate to mimic the tumor microenvironment, NGY-B greatly reduced lactate uptake by cancer cells. Mechanistically, NGY-B deactivated glycolytic pathway by reducing hexokinase 2 (HK2), phosphoglycerate dehydrogenase (PHGDH), and pyruvate dehydrogenase kinase 1 (PDK1) expression. Additionally, NGY-B treatment strongly decreased STAT3 and mTOR signaling pathways. Furthermore, the in vivo therapeutic efficacy of NGY-B was validated in xenograft and syngeneic mouse models of melanoma. While a significant reduction in tumor size was observed in A375 xenograft model treated with NGY-B, a robust tumor growth reduction was evident in SM1 immunocompetent syngeneic melanoma mouse model, suggesting the involvement of immune cells for higher response in this model. Supporting this premise, we also found that NGY-B treated cells showed a decrease in PD-L1, B7-H3, and B7-H4 expression. Overall, our results indicate that NGY-B inhibits melanoma by targeting metabolic symbiosis and activating antitumor immune response mechanisms.

Citation Format: Sambad Sharma, Gregory Goreczny, Satish Kumar Noonepalle, Erica Palmer, Maria Garcia-Hernandez, Daliya Banerjee, Jaime Escobedo, Alejandro Villagra, Vincent Sandanayaka. A novel treatment approach for melanoma by dually targeting MCT1 and MCT4 lactate transporters [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1268.

Loss of Adar1 increases T cell migration and prolongs survival in ovarian cancer

Novel therapies are urgently needed for ovarian cancer (OC), the fifth deadliest cancer in women. OC is generally characterized by an immunosuppressive tumor microenvironment (TME) and less than 10% of patients respond to immune checkpoint blockade (ICB) therapy, though better OC prognosis is associated with high tumor-infiltrating CD8 T cells. DNA methyltransferase inhibitors (DNMTis) remove methylation and activate transcription of double-stranded (ds)RNA in OC. These dsRNAs are sensed in the cytoplasm and trigger the induction of type I IFN and also the transcription of interferon-stimulated genes (ISGs). Adenosine deaminase 1 (ADAR1) is an ISG that edits mammalian dsRNA with an A-to-I nucleotide change. These edited dsRNAs cannot be sensed by dsRNA sensors, and thus ADAR1 can inhibit this type I IFN response. Our preliminary RNA-seq analysis from human OC cell lines indicates that RNA editing by ADAR1 is increased after DNMTi treatment.

To test the hypothesis that Adar1 loss will amplify the DNMTi-induced IFN response in OC, we implanted mice with syngeneic ID8 murine OC Adar1 knockdown (KD) cells or control cells and treated with DNMTi. We show that DNMTi treatment reduces tumor burden and extends survival in this OC model. Loss of Adar1 significantly prolongs survival in this model, which is further improved with DNMTi treatment. DNMTi treatment of murine OC cells combined with Adar1 KD increases T cell migration in transwell migration assays and also enhances expression of chemokines CCL5, CCL2, and CXCL10. We are currently performing immunophenotyping analyses to interrogate the composition of immune cells in the TME in the mouse model of OC. These studies thus describe a role of Adar1 in the DNMTi-induced immune response in OC.

Phase I study of entinostat in combination with enzalutamide for treatment of patients with castration-resistant prostate cancer

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Background: Entinostat (SNDX-275, MS-275) is an oral histone deacetylase (HDAC) inhibitor with selectivity towards class I and IV HDACs. Entinostat inhibits prostate cancer (PCa) growth and suppresses Treg cell function in vitro and in vivo. The primary objective of this study was to determine the safe dose of Entinostat in combination with Enzalutamide in prostate cancer patients (PCa). Methods: Phase I, 2 cohorts "3+3", dose-escalation study to explore the safety and preliminary efficacy of Entinostat in combination with Enzalutamide in castration-resistant PCa (CRPC). The planned dose level of Entinostat was 3 and 5 mg orally per week. CRPC Patients progressed on Enzalutamide or eligible for Enzalutamide, able to tolerate 160 mg daily dose (in the initial run-in phase if Enzalutamide naïve), ECOG 0-1, and acceptable organ functions were enrolled in the study. The safety profile of the combination therapy, PSA, pharmacokinetics of Enzalutamide post-Entinostat administration, and peripheral T cell subtype (including Treg), mononuclear cell (PBMC) histone 3 acetylation were analyzed. Results: Total 6 mCRPC patients were enrolled. There was no dose limiting toxicity related to Entinostat in these patients. No obvious increased fatigue related to Entinostat. Toxicities possibly or probably related to Entinostat or the combination therapy included G3 anemia 1/6 (17%), G2 WBC decrease 1/6 (17%), All other toxicities were grade 1 only (Nausea 2/6, anorexia 1/6, emesis 1/6, constipation 1/6, headache 1/6, platelet count decrease 1/6, hypokalemia 1/6, hypoalbuminemia 1/6, hypermagnesemia 1/6). The median duration of treatment with Entinostat was 18 weeks. For patients already progressed on Enzalutamide there was no PSA response after Entinostat was added. Entinostat did not affect the steady plasma concentration of Enzalutamide. Increased PBMC H3 acetylation was observed (up to 3.6 fold from baseline) in the tested samples. No evident T cell subtype, including Treg, changes from these sample analysis. Phase II part of the trial was terminated because of sponsor withdrawal. Conclusions: Entinostat at the selected dose levels in combination with standard dose of enzalutamide showed promising safety profile in this small phase I study. Clinical trial information: NCT03829930.

CpG-coated prussian blue nanoparticles-based photothermal therapy combined with anti-CTLA-4 immune checkpoint blockade triggers a robust abscopal effect against neuroblastoma

High-risk neuroblastoma, which is associated with regional and systemic metastasis, is a leading cause of cancer-related mortality in children. Responding to this need for novel therapies for high-risk patients, we have developed a "nanoimmunotherapy," which combines photothermal therapy (PTT) using CpG oligodeoxynucleotide-coated Prussian blue nanoparticles (CpG-PBNPs) combined with anti-CTLA-4 (aCTLA-4) immunotherapy. Our in vitro studies demonstrate that in addition to causing ablative tumor cell death, our nanoimmunotherapy alters the surface levels of co-stimulatory, antigen-presenting, and co-inhibitory molecules on neuroblastoma tumor cells. When administered in a syngeneic, murine model of neuroblastoma bearing synchronous Neuro2a tumors, the CpG-PBNP-PTT plus aCTLA-4 nanoimmunotherapy elicits complete tumor regression in both primary (CpG-PBNP-PTT-treated) and secondary tumors, and long-term survival in a significantly higher proportion (55.5%) of treated-mice compared with the controls. Furthermore, the surviving, nanoimmunotherapy-treated animals reject Neuro2a rechallenge, suggesting that the therapy generates immunological memory. Additionally, the depletion of CD4+, CD8+, and NK+ populations abrogate the observed therapeutic responses of the nanoimmunotherapy. These findings demonstrate the importance of concurrent PTT-based cytotoxicity and the antitumor immune effects of PTT, CpG, and aCTLA-4 in generating a robust abscopal effect against neuroblastoma.

HDAC6 Plays a Noncanonical Role in the Regulation of Antitumor Immune Responses, Dissemination, and Invasiveness of Breast Cancer

Despite the outstanding clinical results of immune checkpoint blockade (ICB) in melanoma and other cancers, clinical trials in breast cancer have reported low responses to these therapies. Current efforts are now focused on improving the treatment efficacy of ICB in breast cancer using new combination designs such as molecularly targeted agents, including histone deacetylase inhibitors (HDACi). These epigenetic drugs have been widely described as potent cytotoxic agents for cancer cells. In this work, we report new noncanonical regulatory properties of ultra-selective HDAC6i over the expression and function of epithelial-mesenchymal transition pathways and the invasiveness potential of breast cancer. These unexplored roles position HDAC6i as attractive options to potentiate ongoing immunotherapeutic approaches. These new functional activities of HDAC6i involved regulation of the E-cadherin/STAT3 axis. Pretreatment of tumors with HDAC6i induced critical changes in the tumor microenvironment, resulting in improved effectiveness of ICB and preventing dissemination of cancer cells to secondary niches. Our results demonstrate for the first time that HDAC6i can both improve ICB antitumor immune responses and diminish the invasiveness of breast cancer with minimal cytotoxic effects, thus departing from the cytotoxicity-centric paradigm previously assigned to HDACi. SIGNIFICANCE: Ultraselective HDAC6 inhibitors can reduce tumor growth and invasiveness of breast cancer by noncanonical mechanisms unrelated to the previously cytotoxic properties attributed to HDAC inhibitors.

Subduing the influence of PCR inhibitors on amplifying aged, degraded, and low copy number DNA: PCR enhancer cocktail-p and rescue PCR

PCR inhibitors are a formidable problem to the study of aged, degraded, and/or low copy number DNA. As a result, there is a need to find alternate methods that ameliorate the efficacy of PCR. In this study, we attempted to use genetic methods to identify the species of salmonid (Oncorhynchus spp.) remains recovered from archaeological sites along the Feather River located in northern California, United States. In the process of doing so, we compared the efficacy of a PCR enhancer cocktail called “PEC-P” and a reagent rich PCR recipe called “rescue PCR” over standard PCR. Across all treatments (full concentration and 1:10 dilute eluates subjected to standard PCR, PEC-P, and rescue PCR) species identification was possible for 74 of 93 archaeological fish specimens (79.6%). Overall, six of the 93 samples (6.5%) consistently yielded species identification across all treatments. The species of ten specimens (10.8%) were uniquely identified from amplicons produced with either PEC-P or rescue PCR or both. Notably, the species of seven samples (7.5%) were uniquely identified with standard PCR over the alternative treatments. Considering both full concentration and 1:10 dilute eluates (N = 186), standard PCR performed as well as PEC-P (p = 0.1451) and rescue (p = 0.6753). Yet, considering results from full concentration eluates alone (N = 93), PEC-P (60.2%) outperformed both standard PCR (44.1%; p = 0.0277) and rescue PCR (40.9%; p = 0.0046). Stochasticity observed in our study cautions us against choosing a “best” performing method of those explored here and suggests their respective potentials to improve success may be sample dependent. When working with samples compromised by PCR inhibitors, it is useful to have alternative methodologies for subduing the problem. Both PEC-P and rescue PCR represent useful alternative methods for the study of aged, degraded, and/or low copy number DNA samples compromised by PCR inhibitors.

DNMTi plus anti-4-1BB therapy reverses suppressive tumor microenvironment and reduces tumor burden in ovarian cancer

Novel therapies are urgently needed for ovarian cancer (OC), the fifth deadliest cancer in women. Better OC prognosis is associated with high tumor-infiltrating CD8 T cells, but OC is generally characterized by an immunosuppressive tumor microenvironment (TME), with less than 10% of patients responding to immune checkpoint blockade therapy in clinical trials. DNA methyltransferase inhibitors (DNMTi) activate transcription of repetitive elements to induce a type I interferon response in OC, which recruits and activates host immune cells to fight the tumor. Additionally, changes in DNA methylation in T cells regulate T cell memory. Thus, DNMTi increase anti-tumor immunity through 1) tumor IFN response and 2) reversal of T cell exhaustion.

To test the hypothesis that combination epigenetic and immune therapy could increase the anti-tumor response in OC, we treated an immunocompetent mouse model of OC with DNMTi +/− anti-CD137. The ID8 MOSE P53−/− model grows intraperitoneally and produces ascites, mimicking human OC which is 90% P53 mutant. The TME of this model is immunosuppressive and it is not responsive to immune checkpoint blockade therapy. At 9 weeks post tumor injection, we observed the following survival percentages: 50% for the combination group, 30% for the DNMTi group, and 0% survival for the both the anti-CD137 and mock groups. We also observed statistically significant increases in %CD3+IFNg+ T cells in the spleen for the DNMTi + anti-CD137 group compared to the mock group. We hypothesize that anti-CD137 treatment is activating immune cells recruited by DNMTi. Future experiments will manipulate cytokine expression to delineate mechanism. We thus describe a novel immunotherapeutic combination for ovarian cancer.

Combining DNMT and HDAC6 inhibitors increases anti-tumor immune signaling and decreases tumor burden in ovarian cancer

Novel therapies are urgently needed for ovarian cancer, the deadliest gynecologic malignancy. Ovarian cancer has thus far been refractory to immunotherapies that stimulate the host immune system to recognize and kill cancer cells. This may be because of a suppressive tumor immune microenvironment and lack of recruitment and activation of immune cells that kill cancer cells. Our previous work showed that epigenetic drugs including DNA methyltransferase inhibitors and histone deacetylase 6 inhibitors (DNMTis and HDAC6is) individually increase immune signaling in cancer cells. We find that combining DNMTi and HDAC6i results in an amplified type I interferon response, leading to increased cytokine and chemokine expression and higher expression of the MHC I antigen presentation complex in human and mouse ovarian cancer cell lines. Treating mice bearing ID8 Trp53-/- ovarian cancer with HDAC6i/DNMTi led to an increase in tumor-killing cells such as IFNg+ CD8, NK, and NKT cells and a reversal of the immunosuppressive tumor microenvironment with a decrease in MDSCs and PD-1hi CD4 T cells, corresponding with an increase in survival. Thus combining the epigenetic modulators DNMTi and HDAC6i increases anti-tumor immune signaling from cancer cells and has beneficial effects on the ovarian tumor immune microenvironment.

Earnings among people with multiple sclerosis in Sweden, by education and occupation

Background

Multiple sclerosis (MS) may affect the individual’s working life. We aimed to 1) investigate the mean levels and distributions of earnings among people with MS (PwMS) before and after MS diagnosis compared to people without an MS diagnosis, and whether such differences in earnings were associated with educational level or occupation and 2) assess the prevalence of sickness absence (SA) and disability pension (DP).

Methods

Population-based cohort study (10 years prior to 5 years after MS diagnosis) using microdata linked from nationwide Swedish registers of all individuals aged 30-54 with MS diagnosed in 2003-2006 (n = 2553) and references without MS (n = 7584) randomly selected by stratified matching (sex and age). Annual mean earnings, by educational level and type of occupation, were compared with t-tests. Tobit regressions investigated the associations of earnings with individual characteristics. Lastly, the proportions on SA and DP, stratified by educational level and type of occupation, were examined in the diagnosis year and 5 years later.

Results

Differences in earnings between PwMS and references were observed beginning one year prior to diagnosis and increased with time. PwMS had lower mean earnings for the diagnosis year (difference=SEK 28,000, p-value<0.05), and the difference had more than doubled (p-value<0.05) 5 years later. These differences remained after taking educational level and type of occupation into account. PwMS with university education and/or more qualified occupations had mean earnings most like their respective references’. PwMS had higher prevalence of SA and DP than the references, in both the diagnosis year and 5 years later.

Conclusions

Earnings of people with MS were lower than references’ already one year before diagnosis, and the gap increased thereafter. Results indicate that educational level and type of occupation are of importance for earnings. Moreover, SA and DP were more common among people with MS.

Key messages

Our results indicate that working-aged people with MS have less earnings than references already one year before diagnosis and that thereafter this gap in earnings increases with time. Education and occupation were influential in explaining the people with MS’ heterogeneous earnings, with a hierarchal ordering of who maintained similar earnings to their respective peers.

A retrospective analysis of case-load and supervision from a large anaesthetic logbook database

The recent development of electronic logbooks with secure off-device data storage provides a rich resource for research. We present the largest analysis of anaesthetic logbooks to date, with data from 494,235 cases logged by 964 anaesthetists over a 4-year period. Our analysis describes and compares the annual case-load and supervision levels of different grades of anaesthetists across the UK and Republic of Ireland. We calculated the number of cases undertaken per year by grade (median (IQR [range]) core trainees = 388 (252-512 [52-1204]); specialist trainees = 344 (228-480 [52-1144]); and consultants = 328 (204-500 [52-1316]). Overall, the proportion of cases undertaken with direct consultant supervision was 56.7% and 41.6% for core trainees and specialist trainees, respectively. The proportion of supervised cases reduced out-of-hours, for both core trainees (day 93.5%, evening 86.3%, night 78.6%) and specialist trainees (day 81.0%, evening 67.7%, night 56.4%).

Abstract LB-074: Priming the tumor microenvironment with epigenetic modifiers to overcome resistance to immune checkpoint inhibitors

Histone deacetylases (HDACs) are involved in diverse cellular regulatory mechanisms including functions outside the chromatin environment. Several publications have demonstrated that selective HDAC inhibitors (HDACi) can influence tumor immunogenicity and the functional activity of specific immune cells. In particular, the selective inhibition of HDAC6 has been reported to decrease tumor growth in several malignancies. However, there is still no clarity about the cellular components mediating this effect. In this study, we evaluated the immunological modulation of the HDAC6i Nexturastat A in combination with anti-PD-1 checkpoint blockade therapy and the use of this HDAC6i as a priming agent to facilitate the transition of the tumor microenvironment from “cold” to “hot” in order to more specifically augment immune check-point blockade therapies. This combination of Nexturastat A and anti-PD-1 therapy demonstrated a significant reduction of tumor growth in syngeneic melanoma tumor animal models. Additionally, we observed a complete neutralization of the up-regulation of PD-L1 and other immunosuppressive pathways induced by the treatment with anti-PD-1 blockade. This combination also showed that the pre-treatment with selective HDAC6i induced major changes in the tumor microenvironment such as enhanced infiltration of immune cells, increased central and effector T cell memory, and a significant reduction of pro-tumorigenic M2 macrophages. The evaluation of the effect of HDAC6i on individual immune components suggest that the in vivo anti-tumor activity of HDAC6i is mediated by its effect on tumor cells and tumor associated macrophages, and not directly over T cells. Overall, our results indicate that selective HDAC6i could be used as immunological priming agents to sensitize immunologically “cold” tumors and subsequently improve ongoing immune check-point blockade therapies.

Note: This abstract was not presented at the meeting.

Citation Format: Tessa J. Knox, Eva Sahakian, Debarati Banik, Melissa Hadley, Erica Palmer, Jennifer Kim, Satish Noonepalle, John Powers, Maria Gracia-Hernandez, Vasco Oliveira, Fengdong Cheng, Jie Chen, Cyril Barinka, Javier Pinilla-Ibarz, Norman Lee, Alan Kozikowski, Alejandro Villagra. Priming the tumor microenvironment with epigenetic modifiers to overcome resistance to immune checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-074.

Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu-A spinning top-shaped rubble pile

The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

89 Effect of embryo transfer and recipient breed on offspring performance in equine show jumping

Maternal preconceptional, gestational, and postnatal environments alter offspring phenotype in humans and animals. In particular, embryo technologies were shown in horses and other species to affect offspring growth and metabolism. Quantitative genetic calculations in a database containing genealogy and a measured trait (performance) of individuals enable geneticists to estimate the respective contribution of (A) genetic aptitude for the trait (inherited from all parents), (B) genetic maternal aptitude (additional contribution of the mother and her ancestors, acting through pregnancy, lactation, and nursing), and (C) the permanent maternal environment (similarities between the offspring of a dam that are not attributed to genetics) to the variability of this trait in this population. Additionally, fixed effects can be introduced and estimated to take into account additional factors acting on individual performance. The aim of this project was to apply this method to estimate the respective contributions of A, B, and C as well as the fixed effects of maternal parity (D), age at foaling (E), foaling interval (F), embryo transfer (G), and breed of recipient mare (for ET recipients) on the adult offspring sport performance in show jumping horses. The data came from the French Horse Database established in 1976 for genealogy and performance; calculation was done using WOMBAT® software. The performance of 207,984 horses (4.5 years per horse), born to 90,438 dams (of which 4187 were ET recipients, the others being bred by AI or natural service), were studied. Performance was expressed as follows. For each event, points were distributed depending on the horse’s rank within the event and the event’s difficulty. The logarithm of the sum of points of the year has a Gaussian distribution and is then normalised to mean=0 and standard deviation=1. The genetic maternal aptitude and permanent maternal environment showed a small but significant contribution to the variance of performance (1.4 and 1.5%, respectively) compared to a direct genetic contribution of 24.4%. Within each age class of dam, offspring of primiparous mares have a handicap (−0.04 to −0.06) compared to multiparous mares. Within multiparous mares, a foaling interval of 1 year only provided a small advantage (+0.01, nonsignificant) compared to longer intervals (>2 years). The effect of embryo transfer was strong and significant (+0.24), which could reflect the better management of the horses produced by embryo transfer because of their genetic and financial value rather than a physiologic effect. The performance of offspring born to draft and warmblood recipients (+0.27v. +0.24, nonsignificant) were not different. In conclusion, although jumping performance occurs several years after birth, maternal effects are still measurable and embryo transfer is associated with a strongly increased performance independent of genetic value, probably due to better management of these horses. No effect of recipient mare’s breed was found.

A window of opportunity for cooperativity in the T Cell Receptor

The T-cell antigen receptor (TCR) is pre-organised in oligomers, known as nanoclusters. Nanoclusters could provide a framework for inter-TCR cooperativity upon peptide antigen-major histocompatibility complex (pMHC) binding. Here we have used soluble pMHC oligomers in search for cooperativity effects along the plasma membrane plane. We find that initial binding events favour subsequent pMHC binding to additional TCRs, during a narrow temporal window. This behaviour can be explained by a 3-state model of TCR transition from Resting to Active, to a final Inhibited state. By disrupting nanoclusters and hampering the Active conformation, we show that TCR cooperativity is consistent with TCR nanoclusters adopting the Active state in a coordinated manner. Preferential binding of pMHC to the Active TCR at the immunological synapse suggests that there is a transient time frame for signal amplification in the TCR, allowing the T cells to keep track of antigen quantity and binding time.

T cells can be activated by a small, two-digit, number of antigen peptide molecules even though the receptor for antigen (TCR) is of low affinity. Here the authors present evidence that all TCRs within a nanocluster can become activated when only a subset is bound to antigen.

Abstract 1703: The HDAC6 inhibitor Nexturastat A improves in vivo PD-1 immune blockade

The role of HDACs in cell biology, initially limited to their effects upon histones, now encompasses more complex regulatory functions that vary with their tissue expression, cellular compartmentalization and stage of cellular differentiation. Several recent studies have shown that selective HDAC inhibitors (HDACi) are able to impair in vivo tumor growth. Therefore, there is an emerging interest in the understanding of the molecular mechanisms mediating these anti-tumor properties. In this context, a number of recent publications have demonstrated that the selective inhibition of specific HDACs enhances tumor immunogenicity in a wide variety of tumors, thereby preventing tumor escape and improving immune surveillance. Our group has focused on HDAC6, and shown that both the genetic abrogation and pharmacological inhibition of this HDAC modulates the expression of a variety of immune-regulatory proteins in the tumor microenvironment, including PD-L1, PD-L2, MHC class I, B7-H4 and TRAIL-R1. In particular, we have previously demonstrated that both pharmacological inhibition and/or genetic abrogation of HDAC6 plays a critical role in the immune check point blockade by down-regulating the expression of PD-L1. Moreover, we have also shown that in vivo inhibition of HDAC6 reduces tumor growth in B16 and SM1 murine melanoma models within syngeneic immunocompetent hosts. Additionally, we have found that the combination of the HDAC6i Nexturastat A (NextA) and checkpoint PD-1 immune blockade therapy results in an important improvement in anti-tumor immune responses as evidenced by the reduction of tumor growth when compared to treatment with individual stand-alone agents. Moreover, our data has shown an increase in CD8+, NK+ cell infiltration of tumors treated with the combination therapy versus either standalone treatment. Further analysis of in vivo immune tumor infiltration evidenced that the treatment with NextA importantly diminished the macrophage M2 phenotype in the tumor microenvironment. An outcome that was also observed in combination with PD-1 immune blockade. Lastly, we have found that the anti-PD-1/NextA in vivo combination therapy reduces the expression of PD-L1, PD-L2 and other negative check-point pathways. However, the HDAC6 inhibition has a minimal effect over the expression of their respective counterparts in T cells (i.e. PD-1). Overall, we have found that HDAC6i could be used as a potential adjuvant in ongoing therapeutic options involving immune check-point blockade.

Citation Format: Tessa Knox, Eva Sahakian, Debarati Banik, Melissa Hadley, Erica Palmer, Jennifer Kim, John Powers, Sarthak Shah, Alexa Lowe, Javier Pinilla, Eduardo Sotomayor, Norman Lee, Alan Kozikowski, Alejandro V. Villagra. The HDAC6 inhibitor Nexturastat A improves in vivo PD-1 immune blockade [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 1703.

Abstract 5126: Modulation of lactate in the tumor microenvironment with lactate transporter inhibitor in a melanoma syngeneic mouse model

Solid tumors often have altered metabolism that depend on aerobic glycolysis for energy and macromolecules for cell survival thereby generating lactate as a metabolic byproduct. Lactate is transported across the cell membrane into tumor microenvironment (TME) using monocarboxylate transporters, MCT1 and MCT4. MCTs facilitate proton linked transport of monocarboxylate molecules such as lactate, pyruvate, and ketone bodies across the plasma membrane. Lactate released by glycolytic cells into the TME results in a metabolic symbiosis when other tumor cells utilize lactate as an energy source that undergo oxidative metabolism which is referred to as “lactate shuttle”. Moreover, lactate induces inhibitory pathways on immune cells, especially on cytotoxic CD8+ T-cells resulting in local immunosuppression in the TME. Additionally, acidosis of TME through lactate results in local inflammation and angiogenesis by activation of VEGFR signaling. The net result of an increased lactate in TME is that it generates a conducive milieu for tumor growth and metastasis. Although studies show that MCT inhibitors mitigate the effects of lactate and promote immune function, its effect on immune cells in the context of tumor infiltration is yet to be explored. In this study, we used a MCT inhibitor NGY-A to determine the effect of suppressing lactate levels in the TME and restoring the anti-tumor immunity. In our preliminary studies to determine the cytotoxicity, NGY-A showed significant cancer cell killing in multiple cell lines in vitro. To determine the in vivo effect of NGY-A, syngeneic mouse model of SM1 melanoma cells harboring BRAF mutation in C57BL/6 mice was studied. When treated with NGY-A (10 mg/kg, i.p injection) (n=15), a significant decrease in tumor volumes was observed compared to controls (n=15). Gene expression analysis of total RNA isolated from SM1 tumors by quantitative RT-PCR indicated that expression of immunosuppressive molecules such as Cd274 (PD-L1), Cd276 (B7-H3) and Lgals9 (Galactin-9) was down regulated in NGY-A (n=5) treated tumors compared to the control tumors (n=5). An increase in IFN-γ (IFNG) gene expression in NGY-A treated samples indicated an increase in CD8+ T-cell tumor infiltration. Future studies would include analysis of phenotype of tumor infiltrating immune cells and cytokine profiles after treatment with NGY-A in combination with immune checkpoint blockade inhibitors which could potentially be an effective strategy to treat melanoma.

Citation Format: Satish Kumar Reddy Noonepalle, Jennifer Kim, Melissa Hadley, Erica Palmer, Debarati Banik, Tessa Knox, Sophiya Ephrame, Prathima Vembu, Summer Rudish, Sara Moufarrij, Jaime Escobedo, Vincent Sandanayaka, Alejandro Villagra. Modulation of lactate in the tumor microenvironment with lactate transporter inhibitor in a melanoma syngeneic mouse model [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 5126.

Direct analysis of volatile organic compounds in foods by headspace extraction atmospheric pressure chemical ionisation mass spectrometry

RATIONALE

The rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently, the technique of choice for VOC analysis is gas chromatography/mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet-pump-based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis.

METHODS

Volatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis (PCA) was used to differentiate between different classes of samples.

RESULTS

The interface is shown to be able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter-day reproducibility using an unsupervised PCA model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 μg/mL and 1.316 μg/mL, respectively.

CONCLUSIONS

The described methodology can routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system was demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats.

Commercially available lifestyle modification program: randomized controlled trial addressing heart and bone health in BRCA1/2+ breast cancer survivors after risk-reducing salpingo-oophorectomy

PURPOSE

The goal of this RCT was to examine the efficacy and safety of a web-based program to improve cardiovascular and bone health outcomes, among 35 BRCA1/2+ breast cancer survivors who underwent prophylactic oophorectomy and thus experienced premature surgical menopause.

METHODS

A 12-month commercially available web-based lifestyle modification program (Precision Nutrition Coaching) was utilized. Cardiovascular fitness, dietary intake, leisure time activity, body composition, bone mineral density, bone structure, and muscle strength were assessed.

RESULTS

Average adherence to all program components was 74.8 %. Women in the intervention group maintained their cardiovascular fitness level over the 12 months (1.1 ± 7.9 %), while the control group significantly decreased fitness capacity (-4.0 ± 7.5 %). There was a significant difference between groups in percent change of whole body bone area (-0.8 ± 2.5 control and 0.5 ± 1.30 intervention). We also observed decreased BMI (-4.7 ± 6.2 %) and fat mass (-8.6 ± 12.7 %) in the intervention group due to significant concomitant decreases in caloric intake and increases in caloric expenditure. The control group demonstrated decreased caloric intake and decreased lean tissue mass.

CONCLUSIONS

In this population at high risk for detrimental cardiovascular and bone outcomes, a commercially available lifestyle intervention program mitigated a decline in cardiovascular health, improved bone health, and decreased weight through fat loss.

IMPLICATIONS FOR CANCER SURVIVORS

Precision Nutrition Coaching has shown benefit in breast cancer survivors for reduced risk of deleterious cardiovascular and bone outcomes.

Pain as an Indicator of Bone Metastasis

Patients with breast or prostate cancer routinely referred for bone scintigraphy were evaluated for the presence of skeletal pain, as determined by a self administered questionnaire. Pain was a common finding, whether or not metastatic disease was present, and occurred in over half of patients. Although most patients with bone metastases did report bone pain, a significant fraction (21% of breast and 22% of prostate patients) were asymptomatic. A distinct minority of individual anatomic regions of metastasis were painful: pain was reported in 23 % of sites of breast metastases and 15% of metastatic prostate cancer sites. Of all sites at which pain was present, metastases were demonstrated in only about one half. These results indicate that pain is not a reliable indicator of the presence of location of metastatic bone disease.

A Developmental Deficit in Localizing Objects from Vision

We describe a college student, A H, with a developmental deficit in determining the location of objects from vision The deficit is selective in that (a) localization from auditory or tactile information is intact, (b) A H reports the identity of mislocalized objects accurately, (c) visual localization errors preserve certain parameters of the target location, and (d) visual localization is severely impaired under certain stimulus conditions, but nearly intact under other conditions These results bear on the representation and processing of location information in the visual system, and also have implications for understanding developmental dyslexia