Systemic lupus erythematosus (SLE) is characterized by a systemic autoimmune response with profound and diverse T cell changes. Dendritic cells (DCs) are important orchestrators of immune responses and have an important role in the regulation of T cell function. The objective of this study was to determine whether myeloid DCs from individuals with SLE display abnormalities in phenotype and promote abnormal T cell function. Monocyte-derived DCs and freshly isolated peripheral blood myeloid DCs from lupus patients displayed an abnormal phenotype characterized by accelerated differentiation, maturation, and secretion of proinflammatory cytokines. These abnormalities were characterized by higher expression of the DC differentiation marker CD1a, the maturation markers CD86, CD80, and HLA-DR, and the proinflammatory cytokine IL-8. In addition, SLE patients displayed selective down-regulation of the maturation marker CD83 and had abnormal responses to maturation stimuli. These abnormalities have functional relevance, as SLE DCs were able to significantly increase proliferation and activation of allogeneic T cells when compared with control DCs. We conclude that myeloid DCs from SLE patients display significant changes in phenotype which promote aberrant T cell function and could contribute to the pathogenesis of SLE and organ damage.

Objective To define the inflammatory cell infiltrate preceding fibrosis in a laryngotracheal stenosis (LTS) murine model. Study Design Prospective controlled murine study. Setting Tertiary care hospital in a research university. Subjects and Methods Chemomechanical injury mice (n=44) sustained bleomycin-coated wire-brush injury to the laryngotracheal complex while mechanical injury controls (n=42) underwent PBS-coated wire-brush injury. Mock surgery controls (n=34) underwent anterior transcervical tracheal exposure only. Inflammatory and fibrosis protein and gene expression was assessed in each condition. Immunohistochemistry served as a secondary outcome. Results In chemomechanical injury mice, there was an up-regulation of: Collagen I (p<0.0001, p<0.0001), Tgf-β (p=0.0023, p=0.0008), and elastin (p<0.0001, p<0.0001) on Day 7, acute inflammatory gene: Il1β (p=0.0027, p=0.0008) on Day 1, and macrophage gene: CD11b (p=0.0026, p=0.0033) on Day 1 versus mechanical and mock controls respectively. M1 marker iNOS expression decreased (p=0.0014) while M2 marker arg1 (p=0.0002) increased on Day 7 compared to mechanical controls. Flow cytometry demonstrated increased macrophages (p=0.0058, day 4) and M1 macrophages (p=0.0148, day 4, p=0.0343, day 7, p=0.0229, day 10) compared to mock controls. There were similarities between chemomechanical and mechanical injury mice with an increase in M2 macrophages at day 10 (p=0.0196). Conclusions The mouse model demonstrated increased macrophages involved with the development of LTS. Macrophage immunophenotype suggested that dysregulated M2 macrophages have a role in abnormal laryngotracheal wound healing in both species. These results support this animal model as a representation for human disease. Furthermore, this data delineates inflammatory cells and signaling pathways in LTS that may potentially be modulated to lessen fibroblast proliferation and collagen deposition.

Objective/Purpose Laryngotracheal stenosis (LTS) is a chronic fibrotic disease characterized by fibroblast proliferation, collagen deposition, and matrix remodeling in the lamina propria of the larynx and/or trachea. Current medical therapies are limited by a poor understanding of the effector cell’s (fibroblasts) cellular biology and metabolism. The purpose of this study is to compare cellular proliferation, function, and metabolism between normal and LTS-derived fibroblasts in vitro. Methods Human biopsies of normal and iatrogenic LTS tissue (n=7) were obtained and fibroblasts were isolated and cultured in vitro. Cellular proliferation, cellular histology, gene expression and metabolic analyses were performed. Statistical analyses comparing normal and scar-derived fibroblasts were performed. Results LTS fibroblast proliferation rate, cellular surface area, and collagen-1 expression were increased compared to normal fibroblasts. Cellular metabolic analysis of LTS-derived fibroblasts demonstrated reduced oxidative phosphorylation and increased glycolysis/oxidative phosphorylation ratio compared with normal fibroblasts. Conclusion Human iatrogenic LTS-derived fibroblasts demonstrated aberrant behavior when compared with normal fibroblasts. A Warburg-like effect was revealed suggesting human iatrogenic LTS fibroblasts drive their proliferation with aerobic glycolysis. The distinct metabolism suggests metabolic inhibitors could reduce fibroblast hyperplasia and hypertrophy in LTS and fibrosis in general.