Sangamo BioSciences (United States)

The extracellular matrix (ECM) is known to regulate innate immune cells but its role in T cell functions is poorly understood. Here, we show a protective role for ECM proteoglycans, lumican and biglycan in hapten-induced contact dermatitis that is achieved through limiting proinflammatory CD4 + T cells. Lumican and biglycan-null mice develop significant inflammation with greater numbers of CD4 + T cells in hapten-challenged ear pinnae, while their draining lymph nodes show increased T-bet-STAT1 signaling, Th1 commitment, and IFN-γ secreting CD4 + T cell proliferation. Wild type mouse lymph node fibroblastic reticular cells secrete lumican, biglycan and decorin, a related proteoglycan, while none are expressed by naive or activated T cells. In vitro , lumican and biglycan co-localize with LFA-1 on T cell surfaces, and all three proteoglycans suppress LFA-1 mediated T cell activation. Overall, this study elucidates a novel paracrine regulation of Th1 cells by ECM proteoglycans to limit inflammation and tissue damage.

Abstract Background Regulatory T cells (Tregs) are key immunomodulators to maintain immune homeostasis and self-tolerance, including in the intestine. Disrupted immune homeostasis is associated with Crohn’s Disease (CD) pathogenesis. As a living drug, Treg therapy is a promising treatment for restoring immune balance and achieving durable tissue tolerance in the diseased intestine. By targeting a disease-relevant protein, Interleukin-23 receptor (IL23R), we engineered Tregs expressing IL23R-chimeric antigen receptor (CAR) to create IL23R-CAR-Tregs for treating CD. Methods IL23R protein expression in CD intestine was verified by immunohistochemical analysis. Tonic signaling and CAR-specific activation were quantified during the IL23R-CAR screening. The IL23R-CAR-Treg phenotype was assessed by monitoring the expression of FoxP3 and Helios transcription factors, and the demethylation status of FoxP3 Treg-specific demethylated region (TSDR). The suppressive function of IL23R-CAR-Tregs was evaluated using in vitro assays and a colitis mouse model. The functionality of IL23R-CAR-Tregs were further assessed using intestinal biopsy-derived cells from CD patients in an in vitro activation assay. Transcriptomic and proteomic analyses were performed to associate molecular profiles with IL23R-CAR-Treg activation. Results Our highly potent IL23R-CAR lead candidate displays negligible tonic signalling and a strong signal-to-noise ratio. The resulting IL23R-CAR-Tregs maintain their regulatory phenotype with high FoxP3 and Helios expression and TSDR demethylation during in vitro expansion, CAR-specific stimulation, and in the presence of proinflammatory cytokines. In accordance with their regulatory phenotype, IL23R-CAR-Tregs exhibit CAR-dependent suppressive activity, promote a tolerogenic environment, and protect mice from colitis. The expression of IL23R was also confirmed in the intestinal mucosa from CD patients. Importantly, IL23R-CAR-Tregs elicit activation following exposure to intestinal biopsy-derived cells from CD, demonstrating the engagement and potency of IL23R-CAR towards their target in CD. We also identified molecular profiles that correlated with IL23R-CAR activation and, more broadly, showed their potential to monitor IL23R-CAR-Treg activity in CD patients. Conclusion Our results demonstrate that an IL23R-CAR-Treg product could be a promising therapy for CD patients, with the potential long-term benefits of immune tolerance.

Mucopolysaccharidosis type I (MPS I) is a severe disease due to deficiency of the lysosomal hydrolase α-L-iduronidase (IDUA) and the subsequent accumulation of the glycosaminoglycans (GAG), leading to progressive, systemic disease and a shortened lifespan. Current treatment options consist of hematopoietic stem cell transplantation, which carries significant mortality and morbidity risk, and enzyme replacement therapy, which requires lifelong infusions of replacement enzyme; neither provides adequate therapy, even in combination. A novel in vivo genome-editing approach is described in the murine model of Hurler syndrome. A corrective copy of the IDUA gene is inserted at the albumin locus in hepatocytes, leading to sustained enzyme expression, secretion from the liver into circulation, and subsequent uptake systemically at levels sufficient for correction of metabolic disease (GAG substrate accumulation) and prevention of neurobehavioral deficits in MPS I mice. This study serves as a proof-of-concept for this platform-based approach that should be broadly applicable to the treatment of a wide array of monogenic diseases.