enrichment-retinal-endothelial-cells-mller-glia-enable-comprehensive

Enrichment of Retinal Endothelial Cells and M&#252;ller Glia Enable Comprehensive scRNA-Seq Profiling of the Blood-Retinal Barrier

Obtaining high-quality single-cell suspensions from neural tissues such as the murine retina remains technically challenging due to cellular fragility, ...

University of Freiburg

Ciliary neurotrophic factor (CNTF) is a well-characterized neurotrophic factor currently in clinical trials for the treatment of macular telangiectasia type II. Our previous work showed that CNTF-induced STAT3 signaling is a potent inhibitor of pathologic preretinal neovascular tuft formation in the mouse model of oxygen-induced retinopathy. In this study, we investigated the effect of CNTF on outer retinal and choroidal angiogenesis and the mechanisms that underpin the observed decrease in outer retinal neovascularization following CNTF treatment.

CNTF Prevents Development of Outer Retinal Neovascularization Through Upregulation of CxCl10.

Aberrant angiogenesis is a hallmark of cardiovascular and retinal neovascular disease. The STAT3 signaling pathway represents a potential pharmacological target for these diseases due to its impact on angiogenesis. Surprisingly, some STAT3 activators, such as the IL-6 cytokine family member oncostatin M (OSM), enhance angiogenesis, whereas others, such as ciliary neurotropic factor (CNTF), reduce it. This study aimed to clarify these conflicting effects. In contrast to the anti-angiogenic cytokine CNTF, the pro-angiogenic cytokine OSM was able to activate intracellular signaling pathways beyond the STAT3 pathway, including the ERK and AKT pathways. These differences translated into transcriptomic and metabolic shifts. siRNA-mediated STAT3 knockdown experiments showed a decrease in VEGF-induced endothelial migration and sprouting, enhancing the pro-angiogenic drive of OSM and switching the CNTF response from anti-angiogenic to pro-angiogenic. These effects correlated with a transcriptomic shift representing enhanced STAT1 and ERK activity following STAT3 knockdown, including a compensatory prolonged phosphorylated STAT1 activity. In conclusion, the angiogenic effect of STAT3 appears to be determined by cytokine-induced STAT3 specificity and simultaneous activity of other intracellular signaling pathways, whereas the STAT3 pathway, predominantly recognized for its pro-angiogenic phenotypes, reveals novel anti-angiogenic potential.

STAT3 signaling induced by the IL-6 family of cytokines modulates angiogenesis.

γδ T cells maintain intestinal immune homeostasis, but their contributions to human ulcerative colitis (UC) are poorly understood. We characterized γδ T cells in intestinal biopsies obtained from patients with UC and healthy donors using single-cell RNA sequencing, T cell receptor profiling, and mass cytometry. UC reduced CD103Vγ4Vδ1 γδ intraepithelial lymphocytes (γδ IELs) and increased γδ T cell subsets with stemlike phenotypes expressing TCF-1 (T cell factor 1) and PD-1 (programmed cell death receptor 1) or effector-like phenotypes expressing granzyme B, perforin, and T-bet in the lamina propria. γδ T cell composition changes in UC correlated with decreased expression of epithelial  and  and increased  and , suggesting altered recruitment and activation. Clinical improvement recovered γδ IELs and reduced inflammation-associated subsets. Inflammation-associated changes were observed in peripheral blood γδ T cells. Thus, distinct γδ T cell subsets in different niches exert protective or pathogenic functions in UC.

Single-cell profiling reveals diverse γδ T cell subsets in ulcerative colitis.

Virus-specific CD4 T cells are essential for coordinating adaptive immunity during infection, but their differentiation and maintenance in chronic infection remain unclear. Using human hepatitis C virus (HCV) infection as a model, we assessed the determinants of virus-specific CD4 T cell immunity in acute, spontaneously cleared, chronic, and therapeutically cured infections. During acute infection, multiple subsets of progenitor CD4 T cells emerged, including subsets that are also found in chronic infection. In chronic infection, stem-like Bcl-2 CD4 T cells and T-bet effector CD4 T cells existed in a progenitor/progeny relationship. Following therapy-mediated HCV cure, these cells retained their chronic signature but formed a stable memory pool that persisted for years and was distinct from HCV-specific CD4 T cell memory after spontaneous clearance. Collectively, our findings highlight differences in CD4 T cell fates that depend on infection outcomes and reveal common principles of CD4 and exhausted CD8 T cell maintenance during and after chronic infection.

Article	Year
CNTF Prevents Development of Outer Retinal Neovascularization Through Upregulation of CxCl10. Investigative ophthalmology & visual science\| PubMed ID: 32780864	2020
STAT3 signaling induced by the IL-6 family of cytokines modulates angiogenesis. Journal of cell science\| PubMed ID: 36458801	2023
Single-cell profiling reveals diverse γδ T cell subsets in ulcerative colitis. Science immunology\| PubMed ID: 41650251	2026
Acute and chronic infections drive distinct trajectories in human memory CD4 T cell formation. Immunity\| PubMed ID: 41928520	2026

Jakob Arnold

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