Helen Hieu Nguyen

Immune-stromal crosstalk governs tissue fibrosis, which is marked by dysregulated extracellular matrix (ECM) production and aberrant vasculature. Here, we investigate how γδ T cell interactions with stromal cells shape fibrosis in the foreign body response in a murine biomaterial implant model. During the acute reaction, type-1 (γδIFNγ) and type-17 (γδ17) γδ T cell subsets accumulate at the implant site. While γδIFNγ cells decrease as fibrosis progresses, activated γδ17 cells persist as dominant interleukin-17 producers. The γδ17 cell compartment expands with aging and high-fat diet, both factors associated with chronic inflammation and fibrosis. Fibroblasts co-cultured with γδ17 cells exhibit increased expression of collagen genes and intercellular communication inference links γδ T cell ligands to activation of ECM remodeling and vascular development programs in fibroblasts and endothelial cells. Finally, genetic deletion of γδ T cells in mice alters expression of ECM components and increases vessel size within the fibrotic matrix. Altogether, our findings implicate γδ T cells in regulating stromal cell behavior to modulate composition and vascularity of fibrotic tissues.

Objective: Thyroid and cricoid cartilage fractures that are displaced or have multiple fracture lines are traditionally managed with open reduction and internal fixation (ORIF). In practice, patients with penetrating laryngeal trauma may have small fragments of cartilage that are difficult to reduce and fixate. This study examines outcomes in patients managed with and without ORIF.Methods: A retrospective review was conducted of patients aged 18 years and older with penetrating laryngeal trauma who were treated at a single Level I trauma center affiliated with a tertiary‐level teaching hospital between 2012 and 2022. Demographics, injury characteristics, and fracture management were recorded. The primary outcome was tracheostomy dependence at the last follow‐up. Secondary outcomes included time to laryngeal stent removal, time to tracheostomy decannulation, time to feeding tube removal, voice functionality, and hospital length of stay.Results: Thirty‐two patients were included. Thirty‐one (97%) were men. Mean age was 35 years. The mean injury severity score (ISS) was 19 (range: 5–59). Twenty‐six (81%) patients suffered gunshot wound(s), and six (19%) stab wound(s). Twenty‐two (69%) patients had Schaefer–Fuhrman group 3 or higher injury. Of 22 (69%) patients requiring tracheostomy, 20 (91%) underwent tracheostomy decannulation and resumed an oral diet. Only five (17%) patients underwent ORIF. All surviving patients had functional voices at the time of the last follow‐up, except for two patients unable to voice for neurological reasons.Conclusion: Patients with penetrating laryngeal trauma with a Schaefer–Fuhrman Group 3 or higher injury who were managed without ORIF had good recovery from an airway, voice, and swallowing perspective.Level of Evidence: 4.

Background: The p16/CDKN2A protein is being explored as an independent prognostic marker in laryngeal cancer, with studies suggesting that p16‐positive patients may have a better prognosis. While its role is well‐established in oropharyngeal squamous cell carcinoma (OPSCC) related to HPV, ongoing research indicates its potential prognostic value in laryngeal cancer, even in HPV‐negative cases.Methods: In this study, we investigated the association between survival outcomes and p16 expression in a cohort of 310 laryngeal cancer patients from the Cancer Genome Atlas (TCGA) Program and the University of Maryland Medical Center (UMMC).Results: In the TCGA cohort, patients with high p16 protein expression had a significantly higher probability of disease‐free survival (DFS) at 89%, compared to 51% in the low p16 protein group (p = 0.0266). Additionally, the mean relative p16 protein expression decreased significantly with advancing TNM stage, measured at 1.116 for stage II, 1.075 for stage III, and 0.6204 for stage IV (p = 0.7871 for stage II vs. stage III, p = 0.0065 for stage III vs. stage IV, p = 0.0031 for stage I vs. stage IV). Protein expression for p16 also correlated with CDKN2A retention/deletion status (p = 0.0077), where the DFS was higher in patients with retained CDKN2A than those with deleted CDKN2A (p = 0.0187). Multivariate analysis of the UMMC and TCGA cohorts revealed that both an increase in the patient's age and higher T stage significantly increased the risk of mortality (p = 0.05, p = 0.01, respectively).Conclusion: While this study observes trends suggesting that low p16 protein expression is associated with longer DFS and advanced TNM stage in laryngeal cancer, the multivariate analysis did not establish p16 as an independent prognostic factor. These findings suggest that while p16 may have a biological role in tumor progression, its utility as a standalone prognostic marker in clinical outcomes requires further validation.

The immune system is increasingly recognized as an important regulator of tissue repair. We developed a regenerative immunotherapy from the helminth Schistosoma mansoni soluble egg antigen (SEA) to stimulate production of interleukin (IL)-4 and other type 2-associated cytokines without negative infection-related sequelae. The regenerative SEA (rSEA) applied to a murine muscle injury induced accumulation of IL-4-expressing T helper cells, eosinophils, and regulatory T cells and decreased expression of IL-17A in gamma delta (γδ) T cells, resulting in improved repair and decreased fibrosis. Encapsulation and controlled release of rSEA in a hydrogel further enhanced type 2 immunity and larger volumes of tissue repair. The broad regenerative capacity of rSEA was validated in articular joint and corneal injury models. These results introduce a regenerative immunotherapy approach using natural helminth derivatives.

Senescent cells (SnCs) contribute to normal tissue development and repair but accumulate with aging where they are implicated in a number of pathologies and diseases. Despite their pathological role and therapeutic interest, SnC phenotype and function in vivo remains unclear due to the challenges in identifying and isolating these rare cells. Here, we developed an in vivo -derived senescence gene expression signature using a model of the foreign body response (FBR) fibrosis in a p16 ^Ink4a - reporter mouse, a cell cycle inhibitor commonly used to identify SnCs. We identified stromal cells (CD45 ^- CD31 ^- CD29 ⁺ ) as the primary p16 ^Ink4a expressing cell type in the FBR and collected the cells to produce a SnC transcriptomic signature with bulk RNA sequencing. To computationally identify SnCs in bulk and single-cell data sets across species and tissues, we used this signature with transfer learning to generate a SnC signature score (SenSig). We found senescent pericyte and cartilage-like fibroblasts in newly collected single cell RNAseq (scRNASeq) data sets of murine and human FBR suggesting populations associated with angiogenesis and secretion of fibrotic extracellular matrix, respectively. Application of the senescence signature to human scRNAseq data sets from idiopathic pulmonary fibrosis (IPF) and the basal cell carcinoma microenvironment identified both conserved and tissue-specific SnC phenotypes, including epithelial-derived basaloid and endothelial cells. In a wound healing model, ligand-receptor signaling prediction identified putative interactions between SnC SASP and myeloid cells that were validated by immunofluorescent staining and in vitro coculture of SnCs and macrophages. Collectively, we have found that our SenSig transfer learning strategy from an in vivo signature outperforms in vitro -derived signatures and identifies conserved and tissue-specific SnCs and their SASP, independent of p16 ^Ink4a expression, and may be broadly applied to elucidate SnC identity and function in vivo .