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The Student and Trainee Association for Sexual Health and HIV (STASHH) was founded in spring 2021 with support from the BASHH. The overarching objective is to raise awareness and promote clinical and academic opportunities for medical students and pre-specialty trainees in the specialty of genitourinary medicine (GUM). Here we highlight the four aims of STASHH and their foreseen benefits to medical students and pre-specialty trainees.1 We plan to deliver educational events encompassing current and emerging topics in sexual health and HIV, highlights of recent conferences organised by BASHH, the British HIV Association (BHIVA) and the Faculty of Sexual and Reproductive Healthcare, and examination preparatory sessions. These educational events will be in the form of monthly evening webinars, specialty workshops and podcasts. Our local medical student and pre-specialty doctor representatives will promote these events via emails and social media. Our monthly evening webinars will commence in …

Therapeutic approaches are needed to promote T cell-mediated destruction of poorly immunogenic, "cold" tumors typically associated with minimal response to immune checkpoint blockade (ICB) therapy. Bispecific T cell engager (BiTE) molecules induce redirected lysis of cancer cells by polyclonal T cells and have demonstrated promising clinical activity against solid tumors in some patients. However, little is understood about the key factors that govern clinical responses to these therapies. Using an immunocompetent mouse model expressing a humanized CD3e chain (huCD3e mice) and BiTE molecules directed against mouse CD19, mouse CLDN18.2, or human EPCAM antigens, we investigated the pharmacokinetic and pharmacodynamic parameters and immune correlates associated with BiTE efficacy across multiple syngeneic solid-tumor models. These studies demonstrated that pretreatment tumor-associated T cell density is a critical determinant of response to BiTE therapy, identified CD8+ T cells as important targets and mediators of BiTE activity, and revealed an antagonistic role for CD4+ T cells in BiTE efficacy. We also identified therapeutic combinations, including ICB and 4-1BB agonism, that synergized with BiTE treatment in poorly T cell-infiltrated, immunotherapy-refractory tumors. In these models, BiTE efficacy was dependent on local expansion of tumor-associated CD8+ T cells, rather than their recruitment from circulation. Our findings highlight the relative contributions of baseline T cell infiltration, local T cell proliferation, and peripheral T cell trafficking for BiTE molecule-mediated efficacy, identify combination strategies capable of overcoming resistance to BiTE therapy, and have clinical relevance for the development of BiTE and other T cell engager therapies.

Endothelial Notch signaling is critical for tumor angiogenesis and growth. Inhibition of Notch1 or its ligand, Dll4, can induce tumor vessel hypersprouting, which interferes with perfusion and reduces tumor development. Unfortunately, blocking Notch1 in endothelial cells of normal tissue can lead to tissue hypoxia and vascular neoplasms. Notch4, another member of the Notch family, is upregulated and increased in the endothelium of certain tumor types compared to normal vasculature. Reducing Notch4, unlike Notch1, causes reduction in developmental and tumor angiogenesis. Using a newly developed anti-Notch4 antibody, E7011, we assessed the effects on Notch4 inhibition on developmental retinal angiogenesis. E7011 treatment did not alter capillary density within the vascular plexus or endothelial tip cell number, but did decrease radial outgrowth and vein diameter, supporting the hypothesis that Notch4 functions as a pro-angiogenic signal. These findings suggest that the targeting of Notch4 could interfere with tumor angiogenesis and offer a novel therapeutic avenue. To establish the role of Notch4 within the tumor microenvironment, we analyzed its expression in both human and murine tumor samples. Immunofluorescent staining revealed a range of Notch4 expression in both tumor cells and endothelium in human triple negative breast cancers. Several murine syngeneic tumors examined expressed Notch4 primarily in the endothelium with only rare tumor expression. We treated orthotopically implanted Py8119 murine breast carcinomas and B16F10 melanomas with E7011, which significantly reduced tumor size compared to IgG treated controls, indicating that suppression of Notch4 is anti-tumorigenic. To determine mechanistically how E7011 delays tumor growth, we performed single cell RNA sequencing on E7011 and control treated Py8119 tumors. Surprisingly, we found that while Notch4 transcripts were present only in endothelial cells, E7011 administration dramatically altered macrophage and monocyte populations within the tumor. Taken together, these findings indicate that inhibition of tumor endothelial Notch4 by E7011 can regulate the presence of immune cells within the tumor microenvironment and improve tumor control. Citation Format: Jason Eng, L.A. Naiche, Bhairavi Swaminathan, Yu Kato, Krishna Thakkar, Rahul Vadakath, James Herts, Rajyasree Emmadi, Junji Matsui, Jan Kitajewski. Targeting Notch4 with a novel neutralizing antibody inhibits tumor growth and alters immune cell populations within the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 247.

This essay argues that Tokyo Cancelled (2005) paradoxically seeks to resist the very forms of world-making totality implied in its narration by rendering the world simultaneously as knowable and un...

Shirley Geok-lin Lim has published extensively across a range of literary genres, including life writing, non-fiction, novels, poetry and short stories. An important voice in Asian American literat...

Bone marrow chimeras represent a key tool employed to understand biological contributions stemming from the hematopoietic versus the stromal compartment. In most institutions, cesium irradiators are used to lethally irradiate recipient animals prior to the injection of donor bone marrow. Cesium irradiators, however, have significant liabilities—including concerns around domestic security. Recently, X-ray irradiators have been implemented as a potential alternative to cesium sources. Only a small number of publications in the literature have attempted to compare these two modalities and, in most cases, the emphasis was on irradiation of human blood productions. We were able to find only a single study that directly compared X-ray and cesium technologies in the generation of murine bone marrow chimeras, a standard laboratory practice. This study focused on chimerism in the blood of recipient animals. In the present study, we begin by comparing cesium and X-ray based sources for irradiation, then transition to using X-ray-based systems for immunology models with an emphasis on immunotherapy of cancer in immunocompetent mouse models—specifically evaluating chimerism in the blood, spleen, and tumor microenvironment. While our data demonstrate that the two platforms are functionally comparable and suggest that X-ray based technology is a suitable alternative to cesium sources. We also highlight a difference in chimerism between the peripheral (blood, spleen) and tumor compartments that is observed using both technologies. While the overall degree of chimerism in the peripheral tissues is very high, the degree of chimerism in the tumor is cell type specific with T and NK cells showing lower chimerism than other cell types.

BiTE® constructs redirect T cell cytotoxicity against cancer cells through simultaneous binding to CD3 on T cells and a tumor-associated antigen (TAA) on cancer cells. Blinatumomab, an anti-CD19 BiTE® molecule used to treat pre-B-ALL patients, leads to more than 40% complete remission rates. Only 30% of relapsed patients exhibit loss of CD19 on leukemia cells, indicating that the majority of patients acquire blinatumomab resistance independently of target loss. Understanding such mechanisms could lead to new predictive biomarkers and help improve current BiTE® immunotherapy. To gain insight into the mechanism of resistance to BiTE® cytotoxicity, we performed CRISPR screens to identify tumor-intrinsic genetic factors that modulate BiTE® molecule efficacy in vitro. Cas9 expressing human cancer cells transduced with a genome-wide sgRNA library were incubated with T cells and either a control BiTE® molecule that did not recognize the cancer cells, or an anti-TAA BiTE® molecule at a concentration that induced the lysis of ~90% of target cells. Next-gen sequencing was used to identify enriched or depleted sgRNA, indicative of genes whose loss confers resistance or susceptibility to BiTE®-mediated T cell killing. As expected, the most enriched candidates from the screen were involved in the expression, post-translational modification or surface presentation of the TAA targeted by the BiTE® molecules. In the case of a screen using an anti-MSLN BiTE® molecule, a panel of genes involved in GPI-anchor biosynthesis, required to anchor MSLN to the plasma membrane was uncovered. The screen also revealed genes known to promote immune evasion such as PD-L1 as well as novel genes whose roles in immunotherapy were not extensively studied before, including genes involved in apoptosis and the NF-κB pathway. One of the top enriched candidates was CD58, which encodes a co-stimulatory molecule that binds to CD2 on T cells. Genetic perturbation and pharmacological blockade of CD58-CD2 interaction significantly reduced BiTE®-mediated killing of target cells. Furthermore, re-establishment of CD58-CD2 interaction either by overexpressing CD58 in cancer cells or by using CD2-agonist large molecules improved T cell activation and target cell killing. Moreover, concurrent blocking of CD2 and CD28 co-stimulation inhibited BiTE®-mediated killing more profoundly than blocking either pathway alone, indicating redundancy between CD58- and CD80/86-mediated co-stimulation. Our study reveals an important role of T cell co-stimulatory signals in BiTE®-mediated cytotoxicity. Considering that loss of CD58 is highly prevalent in DLBCL and relapsed Hodgkin lymphoma patients, it could potentially serve as a biomarker to predict response to BiTE®-based therapies. Our study also demonstrates that restoring CD58-CD2 interaction could sensitize cancer cells to BiTE®-mediated killing. Citation Format: Ye Shen, Patrick Collins, Jason Eng, Flordeliza Fajardo, Wendy Zhong, Olivier Nolan-Stevaux. Genetic screens identify T cell co-stimulation as a key modifier of the redirected cytotoxicity of bispecific T cell engager (BiTE®) molecules [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6714.

The development and success of Blincyto®, a Bi-Specific T cell Engager (BiTE®), to treat acute lymphoblastic leukemia has expanded the class of anticancer immunotherapy agents. BiTE® molecules consist of a single-chain Fc antibody containing tandem single-chain variable fragments (scFv) recognizing the CD3 receptor on T lymphocytes and a tumor-associated antigen and induce redirected T-cell cytotoxicity and tumor cell lysis. Despite the clinically validated efficacy of BiTE® molecules, there has been little elucidation of the parameters governing their in vivo activity. This is due, in part, to a lack of immunocompetent murine tumor models that allow for engagement of endogenous T cells in the context of an intact immune system, which more accurately mimic the human therapeutic setting. We have developed a genetically engineered mouse model (huCD3 mouse) in which a human/mouse chimeric CD3ϵ receptor recognized by BiTE® molecules was engineered into the mouse CD3ϵ genomic locus. Here, we characterize the immune cell distribution of the huCD3 mouse and utilize BiTE® molecules and syngeneic tumor models to elucidate pharmacokinetic, pharmacodynamic, and efficacy relationships in vivo. The peripheral B and T cell distribution profile of huCD3 mice and WT littermates are comparable, but T cells isolated from huCD3 mice express lower levels of. In T cell-dependent cytotoxic (TDCC) assays, an anti-huEpCAM BiTE® molecule exhibited similar potency against MC38 mouse cells expressing human EpCAM co-cultured with T cells from the huCD3 mice or a human donor, if mouse T-cells were preactivated in vitro. In vivo, MC38-huEpCAM tumors grew robustly and anti-huEpCAM BiTEÂ treatment resulted in dose-dependent tumor growth inhibition, with several tumor-free animals at higher doses. Flow cytometry analysis of disaggregated tumors and serum cytokine analysis indicated that BiTE® treatment resulted in T-cell activation and a cytokine response at doses that correlate with tumor regression. In vivo studies were also performed using B16F10-huEPCAM cells, which generate tumors with reduced T-cell infiltration compared to MC38-huEpCAM. Additionally, we used WT mice reconstituted with different ratios of huCD3e and WT bone marrow to investigate the T-cell number requirement for optimal BiTE®-mediated efficacy. We also evaluated the efficacy of an anti-mouse CD19 BiTE® molecule against MC38-CD19 tumor cells to compare the requirements for antitumor efficacy versus normal B-cell depletion in the blood and in lymphoid organs. Finally, we performed a rational combination study using BiTE® molecules and a PD1 inhibitor, demonstrating that this combination can lead to the eradication of poorly T cell-infiltrated solid tumors. These data begin to elucidate the in vivo mechanisms regulating the efficacy of BiTE® molecules under physiologically relevant conditions. This abstract is also being presented as Poster A29. Citation Format: Brian Belmontes, Hong Tan, Wendy Zhong, Danny Chui, Kevin Cook, Sarah O'Brien, Melissa Martin, Brandy Alexander, Jason Eng, John Harrold, Famke Aeffner, Matthew Chun, Alice Bakker, Mercedesz Balazs, Jason DeVoss, Angela Coxon, Jude Canon, Jackson Egen, Olivier Nolan-Stevaux. Assessing in vivo mechanisms regulating the therapeutic activity of bi-specific T-cell engager (BiTE®) molecules in immunocompetent mice expressing a chimeric human/mouse CD3ϵ receptor [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr PR12.

Laboratory mice are housed under relatively cool conditions and even though their core temperature remains normal, mice are cold stressed and exhibit significant increases in metabolic heat production. We compared tumor growth in mice housed at a standard ambient temperature (22oC) and at a thermoneutral temperature (30oC) which reduces metabolic effort needed for maintaining core temperature. We found significantly reduced tumor incidence and growth rates in animals housed at thermoneutral vs standard temperature using four different syngeneic tumor models, including a metastasis model. Because this difference was not seen in SCID or NUDE mice or in mice depleted of CD8+ T cells, we suspected that a prominent result of metabolic cold stress is diminished adaptive immunity. Immunohistochemistry and flow cytometry confirmed the presence of more CD8+ T cells (including antigen-specific cells) within the tumor microenvironment and spleens of animals at thermoneutral vs standard temperature. Conversely, animals at standard temperature had significantly increased infiltration of immunosuppressive cell subsets including GR-1+CD11b+ myeloid derived suppressor cells and Foxp3+ cells. These data reveal a fundamental relationship between energy utilized for thermoregulation and CD8+ T cell-dependent immunity and strongly suggest that immunological data collected from tumor bearing mice housed at standard temperature could be significantly biased by chronic cold stress.

The purpose of this study is to investigate the source of information used in secondary school choice and the factors that affect choice of secondary schools. Master of Education