Citations

Abstract Germinal center (GC)-derived lymphomas arise within a specialized immune ecosystem, yet whether malignant cells direct its remodeling remains unclear. Integrating genomic, transcriptomic, spatial, and functional analyses across follicular lymphoma and diffuse large B-cell lymphoma, we define a developmental framework linking malignant B-cell differentiation state to tumor microenvironment (TME) organization. Rather than segregating by histology, lymphomas align along a shared differentiation continuum in which proliferative dark zone (DZ) states associate with immune-depleted TMEs, whereas post-GC/memory B-cell (MBC) states drive inflamed but immunosuppressed TMEs. Spatial profiling reveals collapse of GC architecture and emergence of suppressive myeloid niches along this trajectory. Single-cell lineage reconstruction uncovers a DZ-to-MBC developmental axis underlying lymphoma evolution. Genetic reprogramming in vivo demonstrates that malignant differentiation state is sufficient to instruct TME remodeling. Collectively, these findings establish malignant differentiation state as a causal determinant of immune architecture across GC-derived lymphomas and identify lineage-directed immune reprogramming as a potential therapeutic strategy.

ABSTRACT Background and Objectives Non‐rhabdomyosarcoma soft tissue sarcomas (NRSTS) account for less than 4% of pediatric cancers. Treatment and outcomes have been described in adults, but pediatric data are lacking. The purpose of this study is to review our institution's outcomes of extremity NRSTS in pediatric patients. Methods Ninety‐eight (56 male: 42 female) pediatric patients with NRSTS of the extremity at our institution were reviewed. Mean age at diagnosis was 11 ± 5 years, and mean follow‐up was 12 ± 10 years. The most common diagnosis was synovial sarcoma (27%), and 60% were high‐grade. Results Treatment included surgical resection in all patients, with 33% receiving radiation and 37% receiving systemic therapy. 20‐year local recurrence‐ (LRFS) and metastatic disease‐free survival (MDFS) were 91% and 91%, respectively, with 92% disease specific survival (DSS). High grade tumors were associated with lower LRFS ( p = 0.02) and DSS ( p = 0.03). Tumor size < 5 cm demonstrated improved MDFS ( p = 0.03), and stage 3 tumors showed worse MDFS ( p < 0.01). Conclusions Treatment of pediatric NRSTS was variable, with large, deep, high‐grade tumors more likely to receive neoadjuvant and adjuvant treatments. Multidisciplinary treatment was associated with high rates of local control and durable survival. This study provides an extended follow‐up of pediatric patients to identify late complications.

OBJECTIVE This study examines the recovery rates of patients who experience postoperative dysphagia within 1 month following cervical spine surgery. METHODS Data from a prospectively maintained multi-institutional quality registry were retrospectively analyzed. Eating Assessment Tool-10 (EAT-10) questionnaire scores were collected at baseline and 1, 3, and 12 months postoperatively, with total scores ≥ 3 indicating dysphagia. Patients were grouped by whether they reported baseline dysphagia to assess the impact of baseline dysphagia on recovery. Recovery was defined as resolution of postoperative dysphagia and not reporting the condition at any follow-up time point. Patients were excluded from the recovery model if they did not report dysphagia within 1 month of surgery. Recovery to baseline was defined as reporting a postoperative EAT-10 score equal to or less than the baseline score at subsequent time points. Patients were excluded from the recovery-to-baseline model if they did not report EAT-10 scores within 1 month of surgery that were worse than their baseline score. Survival curves were generated for both models. RESULTS Of the 2003 patients in the registry, 627 met inclusion criteria for the recovery curve and 714 for the recovery-to-baseline curve. Of the patients without baseline dysphagia, 498 developed new postoperative dysphagia within 1 month, with cumulative recovery probabilities of 39.5% by 3 months and 59.1% by 12 months after cervical spine surgery. Furthermore, of the patients without baseline dysphagia, 73.5% (175/238) who reported no dysphagia at 3 months and 32.5% (68/209) who reported no dysphagia at 12 months experienced long-term recovery. Eighty patients with baseline dysphagia reported worse EAT-10 scores within 1 month, with cumulative probabilities of improvement to baseline or below of 37.7% by 3 months and 54.1% by 12 months. Patients with baseline dysphagia were significantly less likely to recover than patients without baseline dysphagia (hazard ratio [HR] 0.37, 95% CI 0.26–0.53; p < 0.001) but significantly more likely to recover to baseline (HR 1.45, 95% CI 1.05–2.00; p = 0.025). CONCLUSIONS Patients who develop postoperative dysphagia within 1 month of cervical spine surgery generally see symptomatic improvement over time. This analysis may aid in clinical decision-making when informing patients about the risk of developing postoperative dysphagia and the recovery rate of this surgical complication.

Abstract Introduction It is critical for the immune system to destroy cells harboring intracellular infection to remove pathogen burden. This function is widely attributed to cytotoxic T cells, which can physically engage with their targets through the T cell receptor complex, releasing cytotoxic granules, resulting in a specific death of infected targets. However, effector cytokines tumor necrosis factor-α (TNF) and interferon-γ (IFNγ), secreted by T cells, are themselves cytotoxic in combination to a degree. While TNF has appreciated cell death function through the TNF receptor 1 (TNFR1) signaling pathway, no clear cytotoxic function is attributed to IFNγ. Because of the diffusible nature of these cytokines, it is possible for T cells to elicit cytotoxicity without requiring direct contact with their targets, termed paracrine killing. Whether paracrine killing occurs during viral infection and how it is regulated is unclear. Paracrine killing poses issues of both sensitivity to these cytokines in that high concentrations of these cytokines are needed to affect target cells, as well as specificity in discriminating infected from uninfected host cells. Accounting for both issues, we hypothesize that paracrine killing is elicited through pathogen restriction whereby only infected cells are susceptible to death. Methods Analysis was performed in vitro using the Incucyte live cell imaging system and Western blots with fibroblast targets and a VSV infection model and OT1 T cells were leveraged ex vivo. Results TNF and IFNγ protect cells against the cytopathic effect of the virus. TNF specifically synergizes with VSV resulting in death of the infected cells and the two cytokines have distinct roles that work in concert. We demonstrate that TNF and IFNγ released by activated T cells suppress viral infection of nearby cells in a paracrine manner. Conclusion Here we provide insight and context into how distinct cytokines function in a cooperative manner for immune protection during an infection. Funding Source Mayo Clinic Graduate School of Biomedical Sciences Topic Categories Viral Immunology (VIR)

Abstract Introduction The lifetime risk for colorectal cancer (CRC) in the United States is approximately 4%. Individuals with Inflammatory Bowel Disease, including Ulcerative Colitis and Crohn’s Disease, have a substantially increased risk of developing colorectal cancer. Siglecs (sialic acid immunoglobulin lectin-like proteins) are a family of receptors that regulates the immune response. Siglec-E is a mouse inhibitory receptor that is primarily expressed by innate cells. While others have demonstrated that Siglec-E KO mice reject tumors faster in multiple tumor models, we have found that colorectal cancer is accelerated in Siglec-E KO mice. Here we aim to investigate the role of Siglec-E in immune homeostasis, inflammation and colorectal cancer development. Methods We used two models of colorectal cancer to assess the role of Siglec-E in tumorigenesis: TS4-cre LSL KRASG12D APClox468/wt (TAR mice) and the DSS/AOM model of colitis-associated cancer. Colons were prepared by separating lamina propria (LP) and epithelial (EP) fractions for flow cytometry. 2cm sections were taken from the middle of colons to generate lysates for ELISA. DSS was administered to WT and Siglec-E KO mice to assess the susceptibility to intestinal inflammation. H&E and IHC for PCNA were performed on colonic tissue from experiments. Results We have found that in both the spontaneous and DSS induced models of CRC, Siglec-E KO mice grow more tumors than WT mice. Siglec-E KO mice have an exquisite susceptibility to DSS induced inflammation and reduced number and proportion of neutrophils after treatment. Lastly, we have found that Siglec-E KO mice at baseline have increased VEGF-A in the colon. Conclusion Siglec-E has a critical role in regulating immune homeostasis in the colon. Siglec-E functions as a brake for intestinal inflammation which protects from the development of colorectal cancer. Funding Source This research was funded by NIH grant CA243545-01A1 (VSS), NIH T32 AI170478 (VSS/BM), and and grant R25 GM055252-26 Deans fellowship: Initiative for maximizing student development (IMSD). Topic Categories Cellular Adhesion, Migration, and Inflammation (CAM)

Abstract Introduction The mitochondrial transporter ABCB7 is essential for exporting iron-sulfur (Fe-S) clusters, a function known to be critical in B cells. This study was conducted to investigate the broader, previously unknown roles of ABCB7 in regulating the overall lymphocyte development and homeostasis. Methods The study utilized conditional knockout (cKO) mouse models (CD2-iCre and Mb1-Cre) to create a specific deficiency of ABCB7 in certain immune populations. To determine if the observed effects were due to ABCB7 deletion in myeloid cells, two further models (CD2i-Cre ABCB7 cKO/C/EBPα and CD2-iCre LSL TMT ABCB7 cKO) were developed. The effects of blocking the cytokine G-CSF were also examined to understand its role in the observed myelopoiesis. Results ABCB7 deficiency was found to dramatically impair erythropoiesis while simultaneously driving emergency myelopoiesis. We confirmed that the myeloid expansion was not a direct result of ABCB7 loss in myeloid cells. A significant autoimmune phenotype also developed, characterized by hyperactivated T cells and a sharp decrease in peripheral regulatory T cells (Tregs). This Treg instability was linked to decreased thymic expression of key stability genes (like CD28 and PD-1) and reduced O-GlcNAc modification in T cells, a process crucial for maintaining Treg lineage. Conclusion The findings establish ABCB7 as a pivotal regulator of hematopoietic balance, linking mitochondrial function to both myeloid expansion and Treg stability. Funding Source T32AI170478 Topic Categories Hematopoiesis and Immune System Development (HEM)

Abstract Introduction Immunotherapy approaches against glioblastoma (GBM) such as immune checkpoint inhibitors (ICI), dendritic cell vaccination, and CAR-T have failed to durably cure most patients. Studies analyzing tumors from ICI responders show that abundance of CD4 and CD8 T cells prior to initiation of therapy predicts responsiveness. Thus, targeting the microenvironment to promote CD4 activity may synergize with ICI. The glioblastoma microenvironment contains high proportions of monocyte-derived macrophages which have potent immunosuppressive capabilities. Characterizing and targeting these immunosuppressive programs is a promising strategy for designing effective combination immunotherapies for glioblastoma patients. Methods We analyzed human glioblastoma snRNAseq datasets to find signaling receptors associated with myeloid immunosuppression and employed murine models of glioblastoma for functional validation. Results By analyzing patient-derived -omics datasets, we identified an understudied TNF-superfamily receptor, Fn14, as being upregulated in glioblastoma-associated myeloid cells with immunosuppressive gene signatures. Using in vitro approaches, we found that Fn14 activation in the tumor microenvironment can drive cytokines implicated in GBM immunosuppression such as IL6, IL1B, and IL8. Thus, Fn14 may serve as a surface marker for microenvironment-remodeling myeloid cells recruited to the tumor from peripheral circulation. Furthermore, in murine models of glioblastoma, we discovered Fn14 KO among glioblastoma-associated myeloid cells increases conventional dendritic cell type 1 (cDC1) and Th1 CD4+ T cell abundance in the tumor microenvironment and significantly prolongs survival. Conclusion These results suggest that blocking Fn14 in glioblastoma-associated myeloid cells can enhance Th1 immunity. Thus, Fn14 may represent a promising dual therapy target. Funding Source NIH Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Progranulin (PGRN) deficiency is a common hallmark in frontotemporal dementia (FTD) patients with granulin ( GRN ) mutations (FTD- GRN ). Previous studies by our group and others have observed that reduced PGRN perturbs lysosomal function and microglial activation, which is believed to accelerate neurodegeneration in FTD- GRN patients. Lysosomal function is intrinsically linked to lipid metabolism, and evidence suggests that GRN deficiency can alter lipid profiles in the brain. Unfortunately, studies to date have focused on whole brain or cortical extracts, limiting our ability to assess cell type-dependent changes in lipid metabolism under disease conditions. Here, we employed lipidomic analysis specifically within the pontine microglia of Grn knock-out (KO) mice, a cell population that was previously linked to disease phenotypes in this model. We observed a significant reduction in the endolysosomal lipid bis(monoacylglycero)phosphate (BMP) and the lipid metabolite phosphatidylethanolamine (PE); these microglial-specific lipid alterations mirror previous whole-brain findings, suggesting that similar changes may occur across multiple cell types in the brain. We also detected a significant increase in the myelin-composing factor galactosylceramide (GalCer), which may reflect an aberrant accumulation of myelin debris within microglia that arises due to defective lysosomal clearance. Notably, lipid perturbations were exacerbated with age within Grn KO microglia, suggesting that changes in lipid metabolism are both age- and genotype-dependent in this model. Together, our results support our hypothesis that PGRN acts as a master regulator of critical microglial processes – including lysosomal function, lipid metabolism, and the regulation of myelination – in an age-dependent manner.