Citations

Src homology 2-domain containing protein tyrosine phosphatase 2 (SHP2), encoded by the Ptpn11 gene (Tyrosine-protein phosphatase non-receptor type 11), is a key downstream effector of PD-1/PD-L1 signaling and is likely important, in addition to immune modulation, in tumor development and vascular homeostasis. SHP2 conveys PD-1 mediated inhibitory signaling in T cells, and is emerging as a therapeutic target. Importantly, there is an association between immune checkpoint inhibitors (ICIs), immune-related adverse events (irAEs), and cardiovascular complications, underscoring the need to understand SHP2’s role in these processes. This review aims to summarize current knowledge on SHP2/PTPN11 biology, its role in immune regulation, cancer progression, and vascular homeostasis, and to discuss emerging therapeutic strategies targeting this pathway. The concept of using SHP2 inhibitors with immune checkpoint inhibitors (ICIs) is being investigated to address ICI resistance and to improve anti-tumor efficacy substantially. SHP2 is also being studied in non-cancer cell contexts, and signaling responses can differ by large magnitudes depending on the biological context and stimuli. Under normal circumstances, SHP2 promotes vascular homeostasis in endothelial cells (ECs) and myeloid cells and inhibits inflammation, and the reduction in SHP2 activity by oxidative stress, such as in atherosclerosis or diabetes, upregulates inflammation. In contrast, in response to radiation, the fibrotic response and subsequent lung injury were increased by endothelial SHP2 induction via Notch-Jag1 signaling. Vascular smooth muscle cells SHP2 act as a pro-atherogenic effector by enhancing ERK/MAPK signaling, and the upregulation of mitochondria localized SHP2 can also induce cellular senescence-associated inflammation by upregulating mitochondrial reactive oxygen species. Taken together, the two opposite signaling effects of SHP2 suggest that both the immune and vascular system responses appear to be more modulated by the redox, cell, and compartment-specific signaling of SHP2. More studies are needed for mitigating cardiovascular toxicity to patients, particularly with ICI-based treatment regimens.

ABSTRACT Introduction/Aims Ultrasound (US) guidance may ensure proper needle placement during electromyography (EMG) when assessing for suitable donor muscles for upper limb reconstruction. A distinct intermuscular fascial border aids in delineating the separation between the brachioradialis (BR) and extensor carpi radialis longus (ECRL) muscles. However, this border may be absent, making correct needle placement complex and assessment more difficult. The purpose of this study was to describe the presence and absence of this fascial border in healthy individuals to help with accurate EMG needle placement. Methods Twenty healthy patients underwent sonographic examination by a single sonographer physician of the ECRL and BR to identify the presence or absence of the intermuscular fascial border. Results The fascial border that routinely separates the ECRL and BR was absent in at least one arm in 20% of subjects (12.5% of upper limbs). One subject had an absent fascial border in both upper limbs. Discussion US can assess for the presence or absence of intermuscular fascial borders. This assessment is important for accurate EMG needle placement and localization. While the clinical significance of an absent ECRL‐BR fascial border is currently unknown, future studies should examine the effect of absent ECRL‐BR fascial borders on wrist extension.

Abstract The publication rate of abstracts presented at a conference can provide some insight into its academic quality, although it is hardly the sole metric. We evaluated 351 SHEA Spring Conference abstracts; 49.9% were published. Findings demonstrate the strong academic output of SHEA conferences.

Abstract This study examined the acoustic profiles of five basic emotions in American English and Mandarin Chinese using a big data approach. A total of 6,373 features were extracted using the openSMILE toolkit, and key discriminative features were identified through random forest classification. In American English, vocal emotions were primarily conveyed through pitch-related features, while Mandarin Chinese, shaped by its tonal constraints, relied more on spectral and voice quality cues, including MFCCs, HNR, and shimmer. Linear mixed-effects models confirmed significant effects of emotion on the top-ranked features, and Cohen’s d further supported distinct acoustic profiles for each emotion. K-means clustering revealed both categorical groupings and dimensional overlaps, such as the clustering of high-arousal emotions like happy and surprised, and low-arousal emotions like sad and neutral. These results suggest that vocal emotion expression is shaped by language-specific prosodic systems, as well as by both discrete emotion categories and continuous affective dimensions, supporting an integrated model of emotional prosody.

Abstract Description Since cancer is an evolving disease with rapid proliferation and dynamic evolution, maintaining efficient killing of cancer cells by cytotoxic T lymphocytes (CTLs) is necessary for immunotherapy to be effective. However, the regulation of the cytotoxic capacity has not been clearly defined in CD8 T cells in responses to cancer immunotherapy. We previously identified ETS proto-oncogene 1 (ETS1) as a negative regulator of NKG7 as well as granzyme B, two key effector molecules in cytotoxic CD8 T cells. Although ETS1 downregulation using siRNA in healthy donor CD8 T cells leads to higher cytotoxicity, the tumor growth was faster and response to immunotherapy was poor in ETS1 CD8 conditional knockout model (CD8cre ETS-1fl/fl) compared to control mice. To address the dual regulatory role of ETS1 in CD8 T cell function, we found an activation-induced alternative splice event which leads to the expression of p27 of ETS1, which functions as a dual-dominant negative regulator of canonical ETS-1 (p51). From our cross-analysis of ATAC and TAF-ChIP NGS data from human CD8 T cells, we found that upon activation there is greater ETS-1 binding to open chromatin. To determine the role of each ETS1 isoform, we over-expressed p51, p42, and p27 in human CD8 T cells and found each isoform varies in their regulation of T cell cytotoxicity and degranulation. Our results suggest ETS1 is a temporal regulator of effector molecules in cytotoxic CD8 T cells via activation-induced alterative splicing. Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

Abstract Description Despite significant efforts to identify targetable, immunogenic antigens in vitro, variability in population wide immune responses, combined with our inability to rank the relative immunogenicity of individual antigens, has led to frequent failures in validating predicted candidates in vivo. Recently, in an animal model of biomaterial biocompatibility, we observed that only ∼3% of residual antigens induced a graft-specific IgG-response ∼30% as strong as native tissue. Leveraging an optimized, shotgun immunoproteomics pipeline, we identified and quantified the magnitude of response toward each, individual, xeno-antigen present in this in vivo model. Additionally, we quantify the abundance (i.e. dose) of each antigen, within native tissue vs. the antigen removed biomaterial. By combining data on the strength of the residual immune response with the dose of each antigen, we developed and validated the Ratio of Immunogenicity (ROI; % residual response/% residual abundance), a novel and quantitative metric which can rank the relative immunogenicity of all antigens in an in vivo system. The ROI metric reveals that inherent properties (i.e., independent of dose) of individual antigens modulate their immune stimulatory capacity, from highly (i.e. strong) to minimally (i.e. weak) antigenic. The ROI is a new tool, with broad utility, which can identify highly immunogenic target antigens, and offers insight into basic immune biology and guiding developments to enhance clinical practice. Funding Sources Supported by R01HL153098 & the Mayo Clinic Foundation for Medical Research Topic Categories Technological Innovations in Immunology (TECH)

Abstract Description Vaccination is essential for preventing viral infections and promoting public health; however, its efficacy may vary due to factors such as the nature of the pathogen, vaccine type, and individual immune response. It is known that intranasal immunizations can enhance the immune response by stimulating tissue-resident memory T cells (TRMs), which promote early viral clearance at the infection site. Our study aims to optimize the generation and maintenance of TRMs in the lungs using purinergic signaling components as adjuvants. For this, we crossed B knockout mice with hACE2 mice, generating a B cell-deficient lineage capable of internalizing active SARS-CoV-2 (BKO-hACE2). C57BL/6 and BKO-hACE2 mice were immunized with inactivated SARS-CoV-2 receiving one intravenous dose followed by three intranasal booster doses. After 30 days, lungs were analyzed by flow cytometry and histopathology. Additionally, we evaluated the effects of ATP (0.5 mM to 10 mM) during immunizations, finding that lower doses (0.5 mM) increased the frequency of TRMs (CD4+ and CD8+), while higher doses reduced this population. This suggests that ATP may interact with the P2X7 receptor, promoting either proliferation or cell death. Although infection data did not provide conclusive evidence of T cell-mediated protection in the absence of antibodies, the potential of ATP as a possible adjuvant opens new avenues for enhancing immune responses in experimental models. Funding Sources FAPESP - 2023/15373-9 Topic Categories Viral Immunology (VIR)

Abstract Description Rationale Mice are used for models of human diseases. The immune cell composition of specific-pathogen-free (SPF) mice closely resembles that of newborn humans. Adult humans have been exposed to a multitude of pathogens throughout their lives. In this project, we sought to create a mouse model resembling humans by co-housing SPF mice to pet store mice. Methods Male and Female SPF B6 mice were co-housed with pet store mice. Multiplexed PCR was used to assess pathogen transmission. After 2 months, lungs, small intestines, and colons were analyzed by high-dimensional mass cytometry and multiplexed cytokine assay. Results Co-housed male mice frequently succumbed to infection. After two months, co-housed males still exhibited signs of active infection across all organs examined including profound myeloid and T effector cell infiltration. In female mice, infection was less fatal and active sickness resolved by two months. Across tissues, T cells exhibited both memory and effector phenotypes. Increases in monocytes and granulocytes were observed in lungs and colons while CD8+ T cells increased in the small intestine. Importantly, innate lymphoid cells were not displaced but underwent phenotypic changes. Conclusion Asynchronous systemic exposure to multiple pathogens in mice results in dramatic alterations to the immune landscape in a sex- and tissue-dependent manner. When used in disease models, these mice may provide new insight beyond those obtained previously with SPF mice. Funding Sources •NIAID R37 AL71106 Topic Categories Mucosal and Regional Immunology (MUC)

Abstract Description The presence of Foxp3+CD4+ regulatory T cells (Tregs) hinders the protective antitumor T cell responses to lung cancer. The accumulation of Tregs is linked to lung cancer progression, resulting in poorer survival rates. However, the mechanisms behind this accumulation are not fully understood. Tregs express elevated levels of the extracellular ATP (eATP) receptor P2RX7 in both human and mouse lung cancer. Here, we show that P2RX7 is crucial for the accumulation of Tregs in lung tumor, promoting tumor growth in a murine lung cancer model. We observed, in T cell-specific P2RX7-KO mice (CD4-cre P2rx7fl/fl), reduced Treg infiltration and a concomitant increase in tumor CD4+ effector T cells, leading to better tumor control. In contrast, P2RX7-KO Tregs accumulated in mediastinal lymph nodes, suggesting that blocking P2RX7-KO signaling impairs the Tregs migratory ability. P2RX7+ Tregs had increased expression of T-bet and KLRG1, which are associated with greater suppressive function. Finally, Treg-specific P2RX7-KO mice (Foxp3-Cre-ERT2 P2rx7fl/fl) had reduced tumor growth and Treg tumor accumulation, indicating that P2RX7 controls lung tumor Tregs in a cell-intrinsic way. These results suggest that P2RX7 promotes lung tumor Treg infiltration and subsequent loss of cancer control. They also suggest that P2RX7 blockade can be used as a therapy to improve lung cancer control, which we are currently exploring in proof-of-concept experiments. Funding Sources Mayo Clinic and National Institutes of Health (NIH - H.B.d.S.: R01 AI170649) Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Abstract Purpose This study investigates a novel optimization framework that integrates the newly developed MCF MKM relative biological effectiveness (RBE) model into intensity modulated particle therapy (IMPT) planning for carbon ion therapy. Unlike conventional RBE models such as MKM or LEM, the MCF MKM provides detailed microdosimetric information, which improves predictive accuracy of cell survival but elevates both memory and time requirement in the optimization process. Furthermore, to the implicit nature of the MCF MKM, the gradient information, which is essential in inverse planning, is hardly accessible. In response, a randomized gradient‐free optimization method (RGFM) was developed to mitigate the computational challenge and achieve improved RBE dose distributions. Materials and Methods An RBE dose optimization problem was formulated based on the discretized MCF MKM, known as the Abridged Microdosimetry Distribution Model (AMDM). The RGFM was derived to find feasible and high‐quality settings of monitor unit for IMPT plans without the need for explicit gradient calculations. To verify the clinical plausibility of the proposed method, it was tested on two clinical scenarios—prostate and brain cases in comparison with benchmark plans derived solely from physical dose optimization. Computational times and dose‐volume histograms (DVHs) for both physical and RBE doses were evaluated. Results The RGFM algorithm successfully optimized the MCF MKM‐based IMPT plans. Compared to the benchmark, the RBE dose distributions showed improved coverage of the target and reduced hot spots. Such improvements were observed to coincide with trade‐offs in physical dose distributions. The complexity of the MCF MKM extended the computational time, yet high‐quality solutions were attainable in a clinically reasonable timeframe. Multi‐field optimization (MFO) further enhanced target coverage and critical organ sparing over single‐field optimization (SFO). Conclusions This proof‐of‐principle study confirmed the feasibility of using a randomized gradient‐free method to optimize RBE dose based on the MCF MKM in IMPT planning for carbon ion therapy. The approach provides a pathway for clinical adoption of advanced RBE models, potentially leading to more biologically informed and effective carbon ion therapy treatments. Future work involves refining algorithms, incorporating parallel computing, and performing additional case studies to improve computational efficiency and generalizability.