bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P018: Gut microbiota-driven alterations in tumor immunity can modulate the growth of metastatic brain tumors
Authors: Morad Golnaz , Johnson Sarah B. , Wargo Jennifer A.
Published: January 2022

Background: Metastatic brain tumors are associated with significant morbidity and mortality. The current limited understanding of the mechanisms underlying brain metastasis has hindered the development of efficient diagnostics and therapeutics for this disease. Microbiota has emerged as a novel hallmark of cancer, with a prominent role in tumorigenesis, tumor immunity, and response to treatment. However, the role of the microbiota in tumor metastasis, and in particular brain metastasis, is poorly understood. We hypothesize that distinct microbial communities can alter the immune microenvironment in the brain and modulate the different steps of brain metastasis formation.

Methods: To explore the role of gut microbiota in brain metastasis, we depleted gut microbiota in conventionally raised mice using a broad-spectrum non-absorbable antibiotic regimen. Subsequently, melanoma tumor cells were injected intracranially to evaluate the effect of gut microbiota depletion and associated immune changes on tumor growth. Tumor growth was measured through in vivo bioluminescent imaging and histology. Peripheral and tumor immune profiling was conducted through flow cytometry and immunohistochemistry.

Results: Depletion of the gut microbiota in mice decreased tumor growth in the brain. Evaluation of the peripheral and tumor immune profiles suggested the underlying mechanisms to involve alterations in the circulating cytokine profiles and an increase in anti-tumor T cell activity.

Conclusion: Our clinical studies suggest the association of distinct microbial communities with brain metastasis. Our pre-clinical findings demonstrate that the absence of gut microbiota can modulate the regulation of T cell activity to induce an anti-tumor response in the brain. Further studies, currently in progress, will determine the mechanistic role of dysbiotic microbiota and distinct microbial communities in this process.

Citation Format: Golnaz Morad, Sarah B. Johnson, Jennifer A. Wargo. Gut microbiota-driven alterations in tumor immunity can modulate the growth of metastatic brain tumors [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P018.
Abstract P019: Intra-tumoral nerves regulate the local immune response at the tumor bed
Authors: Restaino Anthony C. , Lucido Christopher T. , Barr Jeffrey , Vermeer Paola D.
Published: January 2022

Patients with highly innervated tumors have a worse prognosis than those with less innervated disease. However, the process by which intra-tumoral nerves contribute to poor outcomes remains unclear. Previously, we identified that head and neck squamous cell carcinomas (HNSCCs) are infiltrated by sensory (TRPV1+) nerves. To map the source of these tumor infiltrating nerves, we intra-tumorally injected the fluorescently tagged nerve tracer lectin, wheat germ agglutinin (WGA), in our hind limb placed HNSCC tumors. Similar to other nerve tracers, WGA is taken up at nerve terminals and retrogradely transported to the neural somas. WGA labeled the somas of dorsal root ganglia (DRG), identifying them as the source of intra-tumoral nerves. Traced nerves were further characterized by immunostaining and identified as TRPV1+ (sensory), consistent with our initial findings. To test the contributions of tumor innervation to tumor growth and survival, wildtype and TRPV1-DTA (genetically deleted of TRPV1+ neurons) mice were implanted with a mouse model of human papillomavirus-induced (HPV+) HNSCC, mEERL cells. The absence of TRPV1 nerves results in slower tumor growth and improves survival. To mechanistically define how depletion of intra-tumoral nerves reduce tumor growth, we first collected tumors 25 days after injection in the hind limb and stained with a 12-color antibody panel. Stained tumors were then analyzed with flow cytometry to identify differences in the infiltrative immune cell populations between tumors grown in C57Bl/6 control mice and our TRPV1-DTA mouse model. Flow cytometry analysis indicated a decrease in the infiltrative myeloid derived suppressor cell (MDSC) population following ablation of TRPV1+ nerves. To understand how loss of TRPV1+ nerves mediate changes in the infiltrative immune cell population we conducted cytokine array analysis of condition media from cancer cells alone and in co-culture with DRG. Results indicate a shift in secreted cytokines following co-culture with DRG. These data indicate that intra-tumoral sensory nerves are recruited from loco-regional DRG to tumors injected in the hind limb. Our data also suggest that ablation of TRPV1+ nerves alter the intra-tumoral MDSC population and, in this way, potentially contributes to tumor growth. Finally, co-culture of mEERL cells with DRG in vitro results in changes in secreted cytokines, potentially explaining the change in the infiltrative immune cell populations. Together, these data indicate a potential role for sensory nerves to regulate the local immune response in developing tumors.

Citation Format: Anthony C. Restaino, Christopher T. Lucido, Jeffrey Barr, Paola D. Vermeer. Intra-tumoral nerves regulate the local immune response at the tumor bed [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P019.
Abstract P022: Reciprocal influence of immune response and tumor hypoxia during glioblastoma progression
Authors: Sattiraju Anirudh , Marallano Valerie , Chen Zhihong , Kang Sangjo , Brusco Concetta , Ramakrishnan Aarthi , Shen Li , Hambardzumyan Dolores , Friedel Roland H. , Zou Hongyan
Published: January 2022

Tumor hypoxia is linked to poor outcome for glioblastoma (GBM), a highly malignant brain cancer, but underlying mechanisms and instigators that initiate tumor hypoxia remain unclear. We tracked tumor hypoxia in GBM in mice using a sensitive fluorescent reporter. We revealed that tumor hypoxia functions as a critical link between immune cells and tumor cells that drives malignant potency and immunosuppression in GBM. Single-cell RNA sequencing analysis revealed that hypoxic GBM cells are quiescent, display a mesenchymal transition, are more represented in recurrent GBM and predict worse patient outcome. Interestingly, the in vivo GBM hypoxia gene signatures surprisingly showed an enrichment for immune pathways. We unveiled two potential mechanisms of hypoxia-induced immunosuppression: by sequestrating activated immune cells in hypoxia zones, thus limiting inflammatory spread and cutting off immune cell communication, and by reprograming entrapped immune cells towards an immunotolerant state. Reciprocally, entrapped TAMs release CCL8 and IL1β as hypoxic niche factors that not only reinforce immune cell retainment in hypoxic cores, but also shape the transcriptional response of hypoxic GBM cells. Contrary to the conventional viewpoint that hypoxia arises from rapid tumor expansion outstripping vascular supply, we discovered anticancer immunity as an important driving force of tumor hypoxia; attenuating immune responses by implanting GBM in host mice with immunodeficiency or IL1β deletion greatly decreased GBM hypoxia. Altogether, our study revealed a reciprocal influence of anticancer immunity and tumor hypoxia, which has significant ramifications for prognosis and immunotherapy for GBM.

Citation Format: Anirudh Sattiraju, Valerie Marallano, Zhihong Chen, Sangjo Kang, Concetta Brusco, Aarthi Ramakrishnan, Li Shen, Dolores Hambardzumyan, Roland H. Friedel, Hongyan Zou. Reciprocal influence of immune response and tumor hypoxia during glioblastoma progression [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P022.
Abstract P024: Using innate immune ligands to activate adaptive immune cells for glioblastoma therapy
Authors: Baugh Richard T. , Khalique Hena , Lei-Rossmann Janet , Seymour Len
Published: January 2022

Glioblastoma (GBM) is one of the most aggressive and immunosuppressive brain tumors in adults. Despite conventional therapy of surgical resection, radiotherapy and temozolomide (TMZ) chemotherapy, tumors invariably recur and become resistant. The Natural Killer Group 2 Member D (NKG2D) receptor plays a key role in the innate immune control of cancers. The ligands for this receptor (NKG2DLs) are minimally expressed or absent on healthy cells. Stressed or malignant cells upregulate NKG2DLs, resulting in immune activation. We have developed a strategy targeting upregulated NKG2DLs on GBM cells with bi-specific T cell engagers (BiTEs). NKG2D BiTE contains a recombinant NKG2D receptor linked to an anti-CD3 domain. Simultaneous binding of the NKG2D BiTE to NKG2DLs on GBM cells and CD3 on T cells causes antigen-independent activation, pro-inflammatory cytokine release, and tumor cell death. Pre-treating GBM cells with radiation and TMZ causes further NKG2DL upregulation, increased NKG2D BiTE-mediated T cell activation, and sensitises GBM cells to T cell lysis. Meanwhile, healthy non-cancer cells exposed to the same pre-treatment do not trigger T cell activation with NKG2D BiTE. To deliver the BiTE directly into the tumor, the NKG2D BiTE has been encoded into the genome of an oncolytic herpes simplex virus 1 (oHSV-1). This oHSV is capable of selective infection, replication and cell lysis within GBM cells, but not healthy cells. Alongside the direct oncolytic capacity of the oHSV-1, it can also act as a gene therapy vector to express the NKG2D BiTE in situ to activate endogenous tumor infiltrating lymphocytes and direct cytotoxicity towards the remaining cancer cells. Combining conventional radio/chemotherapy with NKG2D BiTE immunotherapy presents an opportunity for synergy by enhancing NKG2DL expression on GBM cells and directing T cell lysis specifically towards these tumor cells, whilst avoiding responses towards non-cancerous cells. Meanwhile, local delivery of the NKG2D BiTE using an oncolytic virus endows tumor-specific expression directly within the tumor.

Citation Format: Richard T. Baugh, Hena Khalique, Janet Lei-Rossmann, Len Seymour. Using innate immune ligands to activate adaptive immune cells for glioblastoma therapy [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P024.
Abstract P029: Expression of galectin-3 and pro-inflammatory cytokines in gliomas: Implications and therapeutic potential
Authors: Caniglia John
Published: January 2022

Galectin-3 (gal-3) is an integral protein in gliomagenesis that has been implicated in a myriad of oncogenic processes such as metabolic adaptation, angiogenesis, and tumor invasiveness. Gal-3 also has a well characterized role as a harbinger of inflammation, inducing the release of pro-inflammatory cytokines including interleukin-1 beta (IL-1B) and interleukin 6 (IL-6). However, these findings have not been well translated to oncology to date. Data from The Cancer Genome Atlas (TCGA) shows that gal-3 is highly overexpressed in low grade gliomas as well as glioblastoma (n = 156) compared to healthy brain tissue (n = 5). Further analysis of data from the Chinese Glioma Genome Atlas shows high expression of gal-3, IL-1B, and Il-6 are each associated with significantly (p < 0.001) worse survival in gliomas. Additionally, the expression of gal-3 is significantly correlated with both IL-1B and IL-6 expression across all malignant gliomas. In other cancers including neuroblastoma it has been shown that IL-6 expression is largely dependent upon gal-3 signaling pathways. This has been shown with regards to IL-1B as well, a molecule which along with IL-6 has been well described for promoting angiogenesis and metastasis. Given these cytokines' highly correlated expression to gal-3 in gliomas, it is likely that gal-3 is involved in inducing cytokine expression in glioma. Here we will discuss the myriad of signaling pathways through which gal-3 induces inflammatory cytokine release in cancer, the implications of these pathways on glioma progression, and the therapeutic potential of targeting this axis.

Citation Format: John Caniglia. Expression of galectin-3 and pro-inflammatory cytokines in gliomas: Implications and therapeutic potential [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P029.
Abstract P035: A promising cancer immunotherapy target: Novel fully human agonist antibodies against the human T-cell costimulatory receptor CD27
Authors: Ovechkina Yulia , Sridhar Shaarwari , Jurchen David , Peckham David , Tarcha Eric , Iadonato Shawn , Guillaudeux Thierry
Published: January 2022

CD27 is a member of the TNF receptor superfamily and plays a critical role in T-cell activation by providing a costimulatory signal. CD27 signaling enhances T-cell proliferation, activation and differentiation of effector and memory T cells and therefore promotes cytotoxic T cell (CTL)-based anti-tumor immunity. Agonistic stimulation of CD27 is a promising cancer immunotherapy approach to boost specific T cell driven anti-tumor responses. In this study, we generated a series of 147 fully human monoclonal anti-CD27 antibodies and tested their agonist properties to stimulate T cell activation. Using a NF-κB reporter Jurkat cell line, we evaluated in vitro the ability of anti-CD27 antibodies to induce CD27 receptor activation. With this assay, five antibodies have been selected for their agonist properties. When combined with suboptimal T cell receptor (TCR) stimulation, agonist antibodies induced CD27 receptor activation with an EC50 of 1-5 ug/mL. We also used human peripheral blood T cells to characterize the CD27-mediated costimulatory effects of agonist antibodies in combination with TCR stimulation. Our anti-CD27 monoclonal antibodies boosted T cell proliferation and induced IL-2 and TNFalpha secretion only in a presence of TCR engagement. Moreover, CD27 agonists induce strong T cell proliferation in a Mixed Lymphocyte Reaction. CD27 antibodies were shown to bind human and cynomolgus monkey CD27 with a KD value of 5-20 nM as determined by BioLayer Interferometry, but do not bind to mouse CD27. In vivo experiments are currently ongoing to demonstrate the efficient anti-tumor activity of the selected CD27 agonist antibodies in different mice tumor models. In conclusion, we have developed and successfully selected efficient fully human immunostimulatory agonist CD27 mAbs as a promising cancer immunotherapy.

Citation Format: Yulia Ovechkina, Shaarwari Sridhar, David Jurchen, David Peckham, Eric Tarcha, Shawn Iadonato, Thierry Guillaudeux. A promising cancer immunotherapy target: Novel fully human agonist antibodies against the human T-cell costimulatory receptor CD27 [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P035.
Abstract P040: Harness the immune-modulatory activities of Toxoplasma gondii to improve lymphocyte infiltration into brain tumors
Authors: Nguyen Yen , Zhao Xiaoyu , Ewald Sarah , Harris Tajie , Zong Hui
Published: January 2022

While checkpoint inhibitors carry great promises for T-cells-based immunotherapy for brain tumors, the presence of abundant T cells supported by the tumor microenvironment (TME) is a prerequisite for it to be effective. Our lab and others' work using mouse models and patient samples demonstrated that, Shh-subtype medulloblastoma, a well-studied pediatric brain tumor, lacks both T cell infiltration and a supportive TME, posing a critical barrier for immunotherapy. I envision that the protozoans Toxoplasma gondii (T.gondii) as a biological agent could provide a unique solution, because T.gondii can naturally disseminate to the brain and induce significant infiltration and activation of T cells asymptomatically. We hypothesize that T.gondii could attract T cells into brain tumors while at the same time convert the non-supportive TME into one that is conducive for T cells. Using a mouse model for medulloblastoma based on a genetic system called Mosaic Analysis with Double Markers (MADM) that recapitulates the tumorigenic process in human by producing few and precisely labeled mutant cells, I was able to assess the immuno-modulatory potential of T.gondii in the context of an intact immune system and endogenous TME. Our preliminary data revealed three exciting facets about T.gondii's immunotherapeutic potential. Via histological assessment and flow cytometry, we found that at 24 days post infection, abundant T cells are recruited into TME. Correspondingly, we detected significant elevation of IFNg and IFNg-driven genes in the tumors, suggesting Th-1 immunity presence in TME. Lastly, we found that T.gondii challenge is associated with reduced tumor incidence. These results indicates T.gondii holds potent immuno-modulatory capability and potentially anti-tumoral functions. My follow-up studies with dive more deeply into three aspects: 1) determine whether T. gondii can sustainably recruit functional T cells into the tumor mass; 2) determine whether T. gondii can help shape a T cell-supportive TME, especially through activating Th1-immune response in innate immune cells; and 3) identify the underlying mechanisms for T.gondii to exert tumor-suppressing activities.

Citation Format: Yen Nguyen, Xiaoyu Zhao, Sarah Ewald, Tajie Harris, Hui Zong. Harness the immune-modulatory activities of Toxoplasma gondii to improve lymphocyte infiltration into brain tumors [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P040.
Abstract P042: Chemokine dysregulation creates the immunosuppressive tumor microenvironment and promotes human papillomavirus-associated head and neck cancer
Authors: Vermeer Daniel , Westrich Joseph , Colbert Paul , Welbon Craig , Lee John H. , Raben David , Spanos William C. , Pyeon Dohun
Published: January 2022

Human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is a fast-growing health problem in the United States. By analyzing the transcriptomes of HPV-positive (HPV+) and HPV-negative (HPV-) HNSCC patient tissues, we previously revealed that expression of CXCL14, constitutively expressed in basal epithelial cells, is downregulated in HPV-positive HNSCC. In contrast, the expression of proinflammatory chemokines, particularly CXCL1, CXCL2, and CXCL8, are significantly upregulated in both HPV+ and HPV- HNSCCs. We further showed that restored expression of CXCL14 in HPV+ HNSCC cells leads to tumor-free survival in vivo by increasing MHC-I antigen presentation on the cancer cell surface and CD8+ T cell activation. Interestingly, high CXCL1, CXCL2, and CXCL8 expression levels significantly correlate to poor HNSCC patient survival, showing an exact opposite pattern of the clinical outcomes associated with the CXCL14 expression levels. To determine the roles of these chemokines in HPV+ HNSCC development, CXCL1 and CXCL2 genes (no murine CXCL8 ortholog) were deleted using a CRISPR-Cas9 knockout system in HPV+ murine HNSCC cells. Using these stably engineered HNSCC cells, we investigated tumor growth, immune cell infiltration, and metastasis in immunocompetent syngeneic mice. Interestingly, the deletion of CXCL1 and CXCL2 significantly delays in vivo tumor growth, decreases myeloid-derived suppressor cell (MDSC) infiltration in the tumor, and decreases lung metastasis. However, the numbers of natural killer (NK), CD4+, and CD8+ T cells in the tumor microenvironment were not affected by CXCL1 and CXCL2 knockout. Next, mice injected with the murine HNSCC cells were treated twice daily with AZD5068, a selective inhibitor of CXCR2, which is a common receptor of CXCL1, CXCL2, and CXCL8 expressed on myeloid cells. Our result showed that the treatment of CXCR2 suppresses in vivo tumor growth in a similar pattern with CXCL1 and CXCL2 knockout. These results suggest that the dysregulation of chemokine expression in HPV-infected cells plays an important role in regulating tumor growth, antitumor immune responses, and metastasis of HPV+ HNSCC. Our findings may provide promising strategies to develop novel immunotherapies for HPV+ HNSCC patients which can likely be extended to other non-viral cancers with immunosuppressive phenotypes.

Citation Format: Daniel Vermeer, Joseph Westrich, Paul Colbert, Craig Welbon, John H. Lee, David Raben, William C. Spanos, Dohun Pyeon. Chemokine dysregulation creates the immunosuppressive tumor microenvironment and promotes human papillomavirus-associated head and neck cancer [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P042.
Abstract P059: An increase in eosinophils is associate with response to chemo-immunotherapy in metastatic triple negative breast cancer
Authors: Ghebeh Hazem , Elshenawy Mahmoud A. , Al-Sayed Adher , Al-Tweigeri Taher
Published: January 2022

Background: Several trials have reported on eosinophilia in cancer patients receiving immunotherapy therapy of cancer especially checkpoint inhibitors. There is limited reports on eosinophilia and immunotherapy in triple-negative breast cancer (TNBC).

Patients: We are reporting on eosinophilia and the increase in eosinophil count in a trial testing the combination of Durvalumab band paclitaxel in metastatic TNBC NCT02628132. In this trial 19 patients were recruited, however, only 14 received the combination therapy while the 5 drop out due to progression on paclitaxel alone priming cycle.

Results: One of the patients developed eosinophilia after having a complete response status. The developed eosinophilia lasted for a year and subsided with temporary holding treatment. Among all patients enrolled who received the combination therapy, there was a statistically significant correlation between an increase in eosinophil count (>300/mm3) during treatment and a having partial or complete response to the combination therapy (p 0.028). In agreement, survival analysis showed a significant association between disease-free survival (DFS) and higher PCE count (p 0.005). A similar trend existed with overall survival (OS), although it did not reach significance (p 0.167). The increase in eosinophil count correlated significantly with skin rash/pruritus (p 0.028). On the other hand, the association between baseline PEC before treatment and response to treatment was not statistically significant despite the positive trend.

Conclusions: An increase in circulating eosinophil count correlates with response to therapy with chemo-immunotherapy combination in metastatic TNBC. This study supports the role eosinophils are playing in the treatment of cancer.

Citation Format: Hazem Ghebeh, Mahmoud A. Elshenawy, Adher Al-Sayed, Taher Al-Tweigeri. An increase in eosinophils is associate with response to chemo-immunotherapy in metastatic triple negative breast cancer [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P059.
Abstract P060: Identification of host-intrinsic resistance mechanisms to immune checkpoint inhibitors (ICI) in Diversity Outbred mice
Authors: Hackett Justin , Glassbrook James , Muniz Maria , Gibson Heather M.
Published: January 2022

The advent of immune checkpoint inhibitors (ICI) for cancer therapy has improved outcomes for a variety of malignancies, however many a significant proportion of patients fail to benefit. While tumor-intrinsic mechanisms are likely involved in therapy resistance, it is unclear to what extent genetic heterogeneity of the host plays in response. To investigate this in a pre-clinical setting, we utilize the Diversity Outbred (DO) and Collaborative Cross (CC) mouse models. DO mice are genetically distinct animals generated by cross-breeding 8 inbred founder strains, and CC mice are recombinant inbred mice generated from the same 8 founders as DO. We find a wide variation in response to anti-PD-1/anti-CTLA-4 ICI in B16F0-bearing (C57BL/6xDO)F1 mice (n=142) with ~30% showing partial response with delayed tumor onset and ~13% showing complete tumor elimination with protection against subsequent contralateral rechallenge. Genetic linkage analysis using the R/qtl2 package identifies genomic loci associated with therapeutic outcomes. Importantly, the MHC locus was not significantly associated with response. Of the strongly associated loci, the region within chromosome 13 was further validated in CC mice bearing the positive (NZO) versus negative (C57BL/6) driver genotypes at this locus. ICI response was detected in 2/3 (C57BL/6xCC)F1 predicted responder models, with no response in predicted non-responders. This locus solely contains the murine prolactin family. Prolactin is a known immunomodulating cytokine with association to various autoimmune disorders. To directly test whether prolactin influences ICI response rates, we implanted inbred C57BL/6 mice, which notoriously fail to respond to ICI alone against B16F0 tumors, with subcutaneous slow-release prolactin pellets to induce mild hyperprolactinemia. Combined ICI with prolactin shows an interaction effect against B16F0, with 5/8 mice exhibiting slowed tumor growth relative to controls. To test whether this host-derived phenomenon applies to additional tumor models, we tested ICI response to Lewis Lung Carcinoma (LLC) in a (C57BL/6xCC)F1 model where response to B16F0 was observed. Relative to inbred C57BL/6 mice, where no response to ICI is observed, this (C57BL/6xCC)F1 model shows a similar response to ICI against LLC as was detected for B16F0. Collectively, this study shows that host genetics play a role in ICI response and that prolactin may be a positive regulator of ICI efficacy.

Citation Format: Justin Hackett, James Glassbrook, Maria Muniz, Heather M. Gibson. Identification of host-intrinsic resistance mechanisms to immune checkpoint inhibitors (ICI) in Diversity Outbred mice [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P060.
Abstract P061: Dendritic cell paucity in mismatch repair-proficient colorectal cancer liver metastases limits the efficacy of immune checkpoint blockade
Authors: Ho William W. , Gomes-Santos Igor L. , Aoki Shuichi , Datta Meenal , Kawaguchi Kosuke , Talele Nilesh P , Roberge Sylvie , Ren Jun , Liu Hao , Chen Ivy X , Andersson Patrik , Chatterjee Sampurna , Kumar Ashwin S. , Amoozgar Zohreh , Zhang Qixian , Huang Peigen , Ng Mei Rosa , Chauhan Vikash P , Xu Lei , Duda Dan G. , Clark Jeffrey W. , Pittet Mikael J. , Fukumura Dai , Jain Rakesh K
Published: January 2022

Liver metastasis is a major cause of mortality for patients with colorectal cancer (CRC). Mismatch repair-proficient (pMMR) CRCs make up about 95% of metastatic CRCs, and are unresponsive to immune checkpoint blockade (ICB) therapy. Here we show that mouse models of orthotopic pMMR CRC liver metastasis accurately recapitulate the inefficacy of ICB therapy in patients, whereas the same pMMR CRC tumors are sensitive to ICB therapy when grown subcutaneously. To reveal local, nonmalignant components that determine CRC sensitivity to treatment, we compared the microenvironments of pMMR CRC cells grown as liver metastases and subcutaneous tumors. We found a paucity of both activated T cells and dendritic cells in ICB-treated orthotopic liver metastases, when compared to their subcutaneous tumor counterparts. Furthermore, treatment with FMS-like tyrosine kinase 3 ligand (Flt3L) plus ICB therapy increased dendritic cell infiltration into pMMR CRC liver metastases and improved mouse survival. Lastly, we show that human CRC liver metastases and microsatellite stable (MSS) primary CRC have a similar paucity of T cells and dendritic cells. These studies indicate that orthotopic tumor models, but not subcutaneous models, should be used to guide human clinical trials. Our findings also posit dendritic cells as antitumor components that can increase the efficacy of immunotherapies against pMMR CRC.

Citation Format: William W. Ho, Igor L. Gomes-Santos, Shuichi Aoki, Meenal Datta, Kosuke Kawaguchi, Nilesh P Talele, Sylvie Roberge, Jun Ren, Hao Liu, Ivy X Chen, Patrik Andersson, Sampurna Chatterjee, Ashwin S. Kumar, Zohreh Amoozgar, Qixian Zhang, Peigen Huang, Mei Rosa Ng, Vikash P Chauhan, Lei Xu, Dan G. Duda, Jeffrey W. Clark, Mikael J. Pittet, Dai Fukumura, Rakesh K Jain. Dendritic cell paucity in mismatch repair-proficient colorectal cancer liver metastases limits the efficacy of immune checkpoint blockade [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P061.
Abstract P064: Dual effect of epigenetic inhibitor and CAR-NK cell therapy in bladder cancer
Authors: Morales Lucia , Nunes Sandra Pinto , Munera-Maravilla Ester , Casado Jose Antonio , Río Paula , Valeri Antonio , José-Enériz Edurne San , Agirre Xavier , Prosper Felipe , Paramio Jesús María
Published: January 2022

Bladder cancer (BC) causes 220,000 deaths per year worldwide since current therapies cannot be used in a large proportion of patients due to comorbidities. Recently, new treatments have been developed, including immunotherapies aimed to induce an antitumor response by activating the patients' immune system. However, since those treatments are only effective in a small subset of patients, new therapies are needed. Epigenetic modifications are drivers of BC and their modulation by inhibitors is considered a promising approach for BC management. Moreover, these compounds also show immunomodulatory properties, including NK cells antitumor activities. We observed that novel inhibitor of epigenetic machinery CM-1758, against histone deacetylases, display growth inhibition in a variety of human BC cell lines (5637, RT112, 253J, J82 and TCCSUP) in the low micromolar range. In addition, the compound induced the surface expression of NK cell ligands (NKG2DLs) in four of these tumor cells as measured by flow cytometry. Furthermore, we developed chimeric antigen receptor (CAR)-NK cells that express high levels of CAR composed by a fusion of NKG2D receptor ectodomain with 4-1BB and CD3z. Cytotoxic effects of NKG2D CAR-NK cells in co-culture with BC tumor cells were significantly potentiated as compared with parental NK-92 cells. In particular, 253J cells treated with CM-1758, that augmented its NKG2DLs levels, increased their sensitivity to NKG2D CAR-NK cells in co-culture and this effect was dependent on NKG2D receptor. Our results support that treatment with epigenetic inhibitors may facilitate the use of CAR-NK-based cell therapies as a promising strategy for BC management.

Citation Format: Lucia Morales, Sandra Pinto Nunes, Ester Munera-Maravilla, Jose Antonio Casado, Paula Río, Antonio Valeri, Edurne San José-Enériz, Xavier Agirre, Felipe Prosper, Jesús María Paramio. Dual effect of epigenetic inhibitor and CAR-NK cell therapy in bladder cancer [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P064.
Abstract P065: Effects of targeted radiotherapy on tumor immune landscape in diverse murine tumor models
Authors: Wirtz Tristan , Lee Catherine , Xie Tao , Manzuk Lisa , Kraus Manfred , Dillon Christopher , Affolter Timothy , Giddabasappa Anand
Published: January 2022

Radiotherapy (RT) has traditionally been seen as a means to induce targeted tumor cell death, and more than 50% of all cancer patients receive RT. RT is also known to induce immune cell activation, and the advent of immunotherapeutic treatments such as checkpoint inhibition has sparked increased interest in using RT to enhance an anti-tumor immune response. However, to take advantage of the immunological effects of RT, a deeper understanding of the effects of RT on tumor-infiltrating leukocytes (TILs) is essential. Therefore, we systematically analyzed the effects of RT on tumor growth and the tumor-infiltrating immune cells in five syngeneic tumor models with diverse immune cell-infiltration profiles. These tumor types show strong differences in the overall immune cell infiltration, as well as in the composition of the infiltrating immune cell populations. After RT, tumors that were characterized as hot (e.g. CT26) showed increased sensitivity and dose-dependent tumor growth inhibition compared to cold tumor models (e.g. B16F10). Immune cell profiling indicated that RT led to strong changes in TILs of some tumor types, such as MC38 and CT26. These changes included reduced fractions of macrophages and increases in NK cells and also CD8 T cells. Single cell RNA sequencing also revealed an increase in CD8 T cells expressing proliferation-related genes. Furthermore, macrophage clusters expressing markers of proliferation were specifically eradicated by RT, while monocytes and neutrophils were less affected. The monocytes and neutrophils in the models that showed little changes in TILs after RT expressed marker genes of type-I interferon response. These findings predict that tumors that are highly infiltrated by neutrophils and monocytes, with little intra-tumoral proliferation and type-I interferon response signature, are likely resistant to an RT-mediated anti-tumor immune response. The present work has laid a strong foundation to develop next-generation combinatorial treatments using RT and immunotherapy.

Citation Format: Tristan Wirtz, Catherine Lee, Tao Xie, Lisa Manzuk, Manfred Kraus, Christopher Dillon, Timothy Affolter, Anand Giddabasappa. Effects of targeted radiotherapy on tumor immune landscape in diverse murine tumor models [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P065.
Abstract P070: The safety and efficacy of Durvalumab and Paclitaxel combination in metastatic triple-negative breast cancer: An open-label phase I/II trial with 2-years follow-up
Authors: Ghebeh Hazem , Al-Sayed Adher , Suleman Kauser , Eiada Riham Eiada , Tulbah Asma , Al-Tweigeri Taher
Published: January 2022

Weekly paclitaxel is an excellent therapeutic choice for metastatic triple-negative breast cancer, a type of cancer that typically has short survival. There is evidence that TNBC is relatively more immunogenic; THEREFORE, we tested the safety and efficacy of weekly paclitaxel at 80 mg/m2/IV given in combination with Durvalumab, (an anti-PD-L1). During a period of 24 MONTHS, 14 patients received the combination OF six cycles of concurrent weekly paclitaxel given on days 1, 8, and 15/IV and Durvalumab given on days 1 and 15/IV of every 28 days' cycle. Upon completion of this combination, Durvalumab was given every 2 weeks until disease progression or unacceptable toxicity. The combination therapy had an excellent safety profile with no dose reduction, dose-limiting toxicity, OR death related to combination therapy. Adverse events (AEs) reported in 10 (71%) of patients, regardless of grade, while grade 3 or 4 AEs happening in 3 (21%) patients only. The most common AEs, were peripheral neuropathy and headache, which happened in 4 patients (29%) followed by fatigue and skin rash occurred in 3 patients (21%). Other less common AEs included: Anemia, leukopenia and/or neutropenia, diarrhea, alopecia, palpitation, and weight gain. The overall response rate for the combination was 36% (confirmed), with a median duration OF RESPONSE of 10 months. The median progression-free survival (PFS) and overall survival (OS) was 5.0 AND 20.7 months, respectively. In conclusion, WE ARE REPORTING an excellent safety profile for the weekly paclitaxel and Durvalumab combination. The data should be looked at with caution due to the small number of patients. Due to excellent safety profile, further trials involving additional, possibly synergistic, agents to the paclitaxel/Durvalumab combination are encouraged.

Citation Format: Hazem Ghebeh, Adher Al-Sayed, Kauser Suleman, Riham Eiada Eiada, Asma Tulbah, Taher Al-Tweigeri. The safety and efficacy of Durvalumab and Paclitaxel combination in metastatic triple-negative breast cancer: An open-label phase I/II trial with 2-years follow-up [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P070.
Abstract P073: Gut microbiota shift in melanoma patients undergoing immunotherapy is associated with clinical response
Authors: Macandog Angeli Dominique , Catozzi Carlotta , Cassano Ester , Gandini Sara , Ferrucci Pier Francesco , Cocorocchio Emilia , Manzo Teresa , Nezi Luigi
Published: January 2022

Background: The high resistance of melanoma to targeted therapy has made it a persistently lethal cancer type. Although the advent of immune checkpoint inhibition (ICI) therapy markedly improved outcome for melanoma in recent years, response remains heterogenous, with only 20-40% of patients achieving clinical response for anti-CTLA4 or anti-PD1 therapy. This variability in response has urged research towards host factors that drive response to immunotherapy, and studies have come out to show that the gut microbiota influences immunotherapy response. More importantly, mouse studies and more recent human clinical trials demonstrate that transplantation of responder (R) microbiota improves host immunity and alleviates tumor growth during immunotherapy. Although these findings confirm a close relationship between the gut microbiota and antitumor host immunity, FMT human clinical trials on melanoma patients report success in only 30-40% of patients, suggesting that current knowledge of underlying immunomodulatory mechanisms of the gut microbiota are still limited, and that analysis of data collected only before start of therapy is insufficient. Notably, there is a lack of published longitudinal studies that monitor gut microbiome changes during melanoma immunotherapy.

Methods: We performed longitudinal analysis of the gut microbiota in melanoma patients undergoing NEOAJUVANT immunotherapy, revealing distinct dynamics between R and non-responders (NR) over the course of treatment. Sequencing data were paralleled with a quantitative analysis of circulating inflammatory molecules, suggesting a dynamic interaction between the gut microbiota and immune system. Here, we will present key modulators of the immune cell compartment.

Conclusions: Overall, our results highlight the importance of longitudinal analysis to dissect the role of the gut microbiota on response to immunotherapy.

Citation Format: Angeli Dominique Macandog, Carlotta Catozzi, Ester Cassano, Sara Gandini, Pier Francesco Ferrucci, Emilia Cocorocchio, Teresa Manzo, Luigi Nezi. Gut microbiota shift in melanoma patients undergoing immunotherapy is associated with clinical response [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P073.
Abstract P077: Composition of CD4 T cell subsets and impact on tumor growth control across mouse syngeneic tumor models
Authors: Xu Chunxiao , Webb Lindsay , Yalavarthi Sireesha , Bourin Clotilde , Moisan Jacques
Published: January 2022

CD4 T cells include multiple sublineages orchestrating a broad range of effector activities during the initiation, promotion, and progression of carcinogenesis. Although regulatory T cells (Tregs) are well-characterized to promote tumor progression, the impact of effector CD4+ T cell subsets (Teff) in anti-tumor immunity is less well known. Further, the relative contribution of Teff and Treg cell subsets in different syngeneic tumor models has not been characterized. We observed that CD4 depletion had significantly different impact of tumor growth across different syngeneic tumor models: no effect on MC38 tumor growth; enhanced tumor growth in CT26.KSA tumor model; while almost complete tumor regression in the EMT-6 tumor model. We hypothesized that each tumor model has a vastly different composition in the CD4 T cell compartment. To test this, we characterized expression of activation and CD4 T cell differentiation markers as well as cytokine production from CD4 TILs in each of the syngeneic tumor models. We found that while effector CD4 TILs (FoxP3−CD4+) from MC38 and CT26.KSA tumors expressed high levels activation and differentiation markers, Teff from EMT-6 tumors expressed very low levels of T cell activation and differentiation markers, suggesting the Teff in EMT-6 tumors are largely dysfunctional. Ex vivo restimulation of tumor samples with anti-CD3/anti-CD28 promoted IFNγ production in CD4 TILs from MC38 and CT26.KSA tumor models, but not from EMT-6 tumor models, further supporting that Teff from MC38 and CT26.KSA tumors remain highly active, while CD4 TILs from EMT-6 tumors are dysfunctional. When looking at the Treg compartment, the frequency of Tregs in CT26.KSA tumors was reduced compared to MC38 and EMT-6 tumors. Further, Tregs in MC38 and EMT-6 tumors expressed very high levels of CD69, a marker of highly immunosuppressive Tregs, while Tregs in CT26.KSA tumors expressed lower levels of CD69, suggesting that these Tregs may be less immunosuppressive. In summary, the CD4 T cell compartment is vastly different across CT26.KSA, MC38 and EMT-6 syngeneic tumor models, resulting in very different impact of tumor growth control.

Citation Format: Chunxiao Xu, Lindsay Webb, Sireesha Yalavarthi, Clotilde Bourin, Jacques Moisan. Composition of CD4 T cell subsets and impact on tumor growth control across mouse syngeneic tumor models [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P077.
Abstract PR08: Context is everything: Microbiota-specific T follicular helper cells in colorectal cancer
Authors: Overacre-Delgoffe Abigail E. , Bumgarner Hannah J. , Cillo Anthony R. , Burr Ansen H. P. , Tometich Justin T. , Bhattacharjee Amrita , Bruno Tullia C. , Vignali Dario A. A. , Hand Timothy W.
Published: January 2022

Colorectal cancer (CRC) is the third most common and one of the deadliest cancers in the US, and the survival rate for advanced cases is poor. Immunotherapy, especially checkpoint blockade, has revolutionized the way cancer is treated and has resulted in longterm, durable responses for some epithelial cancers. Unfortunately, CRC remains largely unresponsive to current immunotherapies, with only ~6% of total patients responding to anti-PD1. Therefore, it is necessary to not only determine hurdles that are preventing checkpoint blockade response, but to also develop novel therapies to use in conjunction with current therapies. The microbiome has recently been associated with better anti-PD1 response in melanoma patients; however, the underlying mechanism by which select bacteria provide a benefit and whether this can be applied to other cancer types remains unclear. The majority of microbes live within the gut, and adherent bacteria can have direct interaction with the colonic epithelium, resulting in a bacteria-specific immune response. Therefore, we hypothesized that rational modification of the microbiome may support anti-tumor immunity through activation of microbiota-specific T cells. Using a carcinogen-induced mouse model of CRC, we found that addition of a single colonic-residing, adherent bacteria (Helicobacter hepaticus, Hhep) after tumors had formed led to a significant reduction in tumor burden and a 2-3 fold increase in overall survival. Interestingly, Hhep colonization led to the activation of Hhep-specific T follicular helper cells (TFHs) that supported formation of large, organized tertiary lymphoid structures (TLS) found adjacent to or within tumors themselves. The presence of TLS supported an increase in cytotoxic lymphocytes (T and NK cells) specifically within the tumor core. Somewhat strikingly, the anti-tumor response was dependent on CD4+ T cells but not CD8+ T cells. Using TFH KO mice, we found that Hhep-specific T cells were both necessary and sufficient to drive TLS maturation, anti-tumor immunity, and ultimately, longterm survival in CRC. Overall, these findings suggest that microbiome modulation and the subsequent microbiota-specific CD4+ T cell response may represent a new immunotherapeutic target for cancer subtypes that remain resistant to checkpoint blockade.

Citation Format: Abigail E. Overacre-Delgoffe, Hannah J. Bumgarner, Anthony R. Cillo, Ansen H. P. Burr, Justin T. Tometich, Amrita Bhattacharjee, Tullia C. Bruno, Dario A. A. Vignali, Timothy W. Hand. Context is everything: Microbiota-specific T follicular helper cells in colorectal cancer [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr PR08.
Colitis due to Cytomegalovirus and Herpes Simplex Type 2 as a Complication of a First Presentation of Inflammatory Bowel Disease
Authors: Leal Tiago , Arroja Bruno , Costa Dalila , Ferreira Carla , Soares João Bruno , Gonçalves Raquel
Published: January 2022

Introduction: The first presentation of ulcerative colitis may be an acute flare in about 15% of patients, requiring hospital admission. In acute severe steroid-refractory ulcerative colitis, cytomegalovirus (CMV) should be sought because it is a frequent cause of refractory disease. Herpes simplex colitis constitutes a rarer event in ulcerative colitis patients and it is usually associated with immunosuppression. Case Presentation: We report a case of a first presentation of ulcerative colitis complicated by CMV and herpes simplex type 2 coinfection. After a long period of systemic corticosteroids, the diagnosis of both CMV and herpes colitis was made. Despite antiviral treatment, colectomy was required due to a contained perforation. Discussion/Conclusion: This report highlights the importance of a high degree of suspicion for opportunistic infections in steroid/immunomodulator refractory ulcerative colitis, even in the first flare.
Economic design of sleeve rotor induction motor using rotor ends
Authors: Daif Omar S. , Abd El-Raouf M. Helmy , Esmaeel Mohamed Adel , B. Kotb Abd Elsamie
Published: January 2022

In this paper, the field analysis of the sleeve rotor induction motor (IM) is carried out taking the rotor ends into consideration. Here, the field system equations are derived using the cylindrical model with applying Maxwell's field equations. It is expected that, both starting and maximum torques will increase with taking the rotor ends than that without rotor ends. A simple model is used to establish the geometry of the rotor ends current density and to investigate the air gap flux density. The magnetic flux is assumed to remain radially constant through the very small air gap length between the sleeve and stator surfaces. Variation of the field in the radial direction is ignored and the skin effect in the axial direction is considered. The axial distributions of the air gap flux density, the sleeve current density components and the force density have been determined. The motor performance is carried out taking into account the effects of the rotor ends on the starting and normal operations. The sleeve rotor resistance and leakage reactance have been obtained in terms of the cylindrical geometry of the machine. These equivalent circuit parameters have been calculated and plotted as functions of the motor speed with and without the rotor ends.