Radiation Augments the Local Anti-Tumor Effect of In Situ Vaccine With CpG-Oligodeoxynucleotides and Anti-OX40 in Immunologically Cold Tumor Models

Introduction

Combining CpG oligodeoxynucleotides with anti-OX40 agonist antibody (CpG+OX40) is able to generate an effective in situ vaccine in some tumor models, including the A20 lymphoma model. Immunologically "cold" tumors, which are typically less responsive to immunotherapy, are characterized by few tumor infiltrating lymphocytes (TILs), low mutation burden, and limited neoantigen expression. Radiation therapy (RT) can change the tumor microenvironment (TME) of an immunologically "cold" tumor. This study investigated the effect of combining RT with the in situ vaccine CpG+OX40 in immunologically "cold" tumor models.

Methods

Mice bearing flank tumors (A20 lymphoma, B78 melanoma or 4T1 breast cancer) were treated with combinations of local RT, CpG, and/or OX40, and response to treatment was monitored. Flow cytometry and quantitative polymerase chain reaction (qPCR) experiments were conducted to study differences in the TME, secondary lymphoid organs, and immune activation after treatment.

Results

An in situ vaccine regimen of CpG+OX40, which was effective in the A20 model, did not significantly improve tumor response or survival in the "cold" B78 and 4T1 models, as tested here. In both models, treatment with RT prior to CpG+OX40 enabled a local response to this in situ vaccine, significantly improving the anti-tumor response and survival compared to RT alone or CpG+OX40 alone. RT increased OX40 expression on tumor infiltrating CD4+ non-regulatory T cells. RT+CpG+OX40 increased the ratio of tumor-infiltrating effector T cells to T regulatory cells and significantly increased CD4+ and CD8+ T cell activation in the tumor draining lymph node (TDLN) and spleen.

Conclusion

RT significantly improves the local anti-tumor effect of the in situ vaccine CpG+OX40 in immunologically "cold", solid, murine tumor models where RT or CpG+OX40 alone fail to stimulate tumor regression.

Identification of unique clusters of T, dendritic, and innate lymphoid cells in the peritoneal fluid of ovarian cancer patients

PROBLEM

We hypothesize that activated peritoneal immune cells can be redirected to target ovarian tumors. Here, we obtain fundamental knowledge of the peritoneal immune environment through deep immunophenotyping of T cells, dendritic cells (DC), and innate lymphoid cells (ILC) of ovarian cancer patients.

METHOD OF STUDY

T cells, DC, and ILC from ascites of ovarian cancer patients (n = 15) and peripheral blood of post-menopausal healthy donors (n = 6) were immunophenotyped on a BD Fortessa cytometer using three panels-each composed of 16 antibodies. The data were analyzed manually and by t-SNE/DensVM. CA125 levels were obtained from patient charts.

RESULTS

We observed decreased CD3⁺ T cells and a higher proportion of activated CD4⁺ and effector memory CD4⁺ /CD8⁺ T cells, plasmacytoid DC, CD1c⁺ and CD141⁺ myeloid DC and CD56^Hi NK cells in ascites. t-SNE/DensVM identified eight T cell, 17 DC, and 17 ILC clusters that were unique in the ascites compared to controls. Hierarchical clustering of cell frequency distinctly segregated the T-cell and ILC clusters from controls. Increased CA125 levels were associated with decreased CD8⁺ /CD45RA⁺ /CD45RO^- /CCR7^- T cells.

CONCLUSION

The identified immune clusters serve as the basis for interrogation of the peritoneal immune environment and the development of novel immunologic modalities against ovarian cancer.

Mass Spectrometry Imaging of N-Glycans from Formalin-Fixed Paraffin-Embedded Tissue Sections Using a Novel Subatmospheric Pressure Ionization Source

N-linked glycosylation, featuring various glycoforms, is one of the most common and complex protein post-translational modifications (PTMs) controlling protein structures and biological functions. It has been revealed that abnormal changes of protein N-glycosylation patterns are associated with many diseases. Hence, unraveling the disease-related alteration of glycosylation, especially the glycoforms, is crucial and beneficial to improving our understanding about the pathogenic mechanisms of various diseases. In past decades, given the capability of in situ mapping of biomolecules and their region-specific localizations, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has been widely applied to the discovery of potential biomarkers for many diseases. In this study, we coupled a novel subatmospheric pressure (SubAP)/MALDI source with a Q Exactive HF hybrid quadrupole-orbitrap mass spectrometer for in situ imaging of N-linked glycans from formalin-fixed paraffin-embedded (FFPE) tissue sections. The utility of this new platform for N-glycan imaging analysis was demonstrated with a variety of FFPE tissue sections. A total of 55 N-glycans were successfully characterized and visualized from a FFPE mouse brain section. Furthermore, 29 N-glycans with different spatial distribution patterns could be identified from a FFPE mouse ovarian cancer tissue section. High-mannose N-glycans exhibited elevated expression levels in the tumor region, indicating the potential association of this type of N-glycans with tumor progression.

Uterine leiomyosarcoma diffusely express disialoganglioside GD2 and bind the therapeutic immunocytokine 14.18-IL2: implications for immunotherapy

Uterine leiomyosarcoma comprises <1 % of uterine malignancies and is known for its clinically aggressive course. Extrapelvic recurrences are common and often lethal. No adjuvant therapies have been shown to significantly improve overall survival, highlighting the need for new and novel therapies. Our objective was to determine whether GD2-specific immunocytokine therapy may be explored for the treatment for uterine leiomyosarcoma. To do so, frozen tissue sections were obtained from the Gynecologic Oncology Group tumor bank and evaluated by immunohistochemistry (IHC) for GD2 expression using both the parent mouse monoclonal antibody 14G2A and immunocytokine 14.18-IL2 generated from the 14G2A sequence. Immunoreactivity was detected by avidin-biotin complex with DAB substrate. Specimens were reviewed by a pathologist with light microscopy and classified as negative, 1+, 2+ or 3+, compared to human melanoma cells as positive control and tissue incubated in the absence of primary antibody as negative control. GD2 was diffusely present in all evaluable samples. 10 tumors (67 %) demonstrated 3+ IHC intensity for GD2, two tumors (13 %) demonstrated 2+ intensity, and 3 (20 %) tumors demonstrated 1+ intensity. Eleven cases had sufficient tissue to assess 14.18-IL2 binding. All 11 cases bound 14.18-IL2 in a pattern identical to the parent antibody. Uterine leiomyosarcoma diffusely express GD2 and bind the therapeutic immunocytokine 14.18-IL2. This warrants further exploration to determine whether immunocytokine therapy may have a clinical role in the management of these aggressive tumors.

Abstract 683: Biological significance of conjugated linoleic acid in ovarian carcinoma

Background: Conjugated linoleic acid (CLA) has long been recognized to exert protective effects on carcinogenesis in breast, prostate and colon malignancies. Recent data suggests that CLA plays a key role in inhibiting several important survival pathways in breast cancer cell. However, data on effects of CLA in epithelial ovarian carcinoma are lacking and was the focus of this study.

Methods: A2780 and SKOV3 ovarian cancer cell were treated with increasing concentrations of two different isomers of CLA (9:11, 10:12) and effect of CLA on cell viability was determined using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at different time points with and without oxaliplatin. Additionally, effect of CLA isomer 10:12 were evaluated on A2780 ovarian cancer cell apoptosis by flow (Annexin V/PE).

Results: CLA isomer-10:12 significantly affected the ovarian cancer cell viability in a time and dose dependent fashion. Seventy-two to 96h of CLA treatment (isomer 10:12, 7µμ) resulted in ∼50% reduction in cell viability compared to control (p&lt;0.01). A 20 µM dose of the CLA isomer 10:12 resulted in &gt;80% reduction in live cell compared to controls. However, CLA isomer 9:11 had no effect in all doses and time points tested (0.001 µM- 50mM). Additionally, at IC50 dose of oxaliplatin treatment, the addition of CLA, resulted in a substantial reduction (by ∼50%, p&lt;0.05) in percent live cell compared to oxaliplatin monotherapy.

Conclusion: Our data indicate that CLA can significantly hamper the survival of ovarian cancer cell. These findings may have therapeutic implications for ovarian cancer management and needs further exploration.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 683. doi:10.1158/1538-7445.AM2011-683

A solid waste audit and directions for waste reduction at the University of British Columbia, Canada

A novel design for a solid waste audit was developed and applied to the University of British Columbia, Canada, in 1998. This audit was designed to determine the characteristics of the residual solid waste generated by the campus and provide directions for waste reduction. The methodology was constructed to address complications in solid waste sampling, including spatial and temporal variation in waste, extrapolation from the study area, and study validation. Accounting for spatial effects decreased the variation in calculating total waste loads. Additionally, collecting information on user flow provided a means to decrease daily variation in solid waste and allow extrapolation over time and space. The total annual waste estimated from the experimental design was compared to documented values and was found to differ by -18%. The majority of this discrepancy was likely attributable to the unauthorised disposal of construction and demolition waste. Several options were proposed to address waste minimisation goals. These included: enhancing the current recycling program, source reduction of plastic materials, and/or diverting organic material to composting (maximum diversion: approximately 320, approximately 270, and approximately 1510 t yr(-1), respectively). The greatest diversion by weight would be accomplished through the diversion of organic material, as it was estimated to comprise 70% of the projected waste stream. The audit methodology designed is most appropriate for facilities/regions that have a separate collection system for seasonal wastes and have a means for tracking user flow.