Transcription factor TCF1 binds to RORγt and orchestrates a regulatory network that determines homeostatic Th17 cell state.

T helper (Th) 17 cells encompass a spectrum of cell states, including cells that maintain homeostatic tissue functions and pro-inflammatory cells that can drive autoimmune tissue damage. Identifying regulators that determine Th17 cell states can identify ways to control tissue inflammation and restore homeostasis. Here, we found that interleukin (IL)-23, a cytokine critical for inducing pro-inflammatory Th17 cells, decreased transcription factor T cell factor 1 (TCF1) expression.

BACH2 regulates diversification of regulatory and proinflammatory chromatin states in T17 cells.

Interleukin-17 (IL-17)-producing helper T (T17) cells are heterogenous and consist of nonpathogenic T17 (npT17) cells that contribute to tissue homeostasis and pathogenic T17 (pT17) cells that mediate tissue inflammation. Here, we characterize regulatory pathways underlying T17 heterogeneity and discover substantial differences in the chromatin landscape of npT17 and pT17 cells both in vitro and in vivo. Compared to other CD4 T cell subsets, npT17 cells share accessible chromatin configurations with regulatory T cells, whereas pT17 cells exhibit features of both npT17 cells and type 1 helper T (T1) cells.

Sex-dependent APOE4 neutrophil-microglia interactions drive cognitive impairment in Alzheimer's disease.

APOE4 is the strongest genetic risk factor for Alzheimer's disease (AD), with increased odds ratios in female carriers. Targeting amyloid plaques shows modest improvement in male non-APOE4 carriers. Leveraging single-cell transcriptomics across APOE variants in both sexes, multiplex flow cytometry and validation in two independent cohorts of APOE4 female carriers with AD, we identify a new subset of neutrophils interacting with microglia associated with cognitive impairment.

Pan-cancer mapping of single CD8 T cell profiles reveals a TCF1:CXCR6 axis regulating CD28 co-stimulation and anti-tumor immunity.

CD8 T cells must persist and function in diverse tumor microenvironments to exert their effects. Thus, understanding common underlying expression programs could better inform the next generation of immunotherapies. We apply a generalizable matrix factorization algorithm that recovers both shared and context-specific expression programs from diverse datasets to a single-cell RNA sequencing (scRNA-seq) compendium of 33,161 CD8 T cells from 132 patients with seven human cancers.

Bacteroidota inhibit microglia clearance of amyloid-beta and promote plaque deposition in Alzheimer's disease mouse models.

The gut microbiota and microglia play critical roles in Alzheimer's disease (AD), and elevated Bacteroides is correlated with cerebrospinal fluid amyloid-β (Aβ) and tau levels in AD. We hypothesize that Bacteroides contributes to AD by modulating microglia. Here we show that administering Bacteroides fragilis to APP/PS1-21 mice increases Aβ plaques in females, modulates cortical amyloid processing gene expression, and down regulates phagocytosis and protein degradation microglial gene expression.

APOE4 impairs the microglial response in Alzheimer's disease by inducing TGFβ-mediated checkpoints.

The APOE4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). The contribution of microglial APOE4 to AD pathogenesis is unknown, although APOE has the most enriched gene expression in neurodegenerative microglia (MGnD). Here, we show in mice and humans a negative role of microglial APOE4 in the induction of the MGnD response to neurodegeneration.

Tumor immunogenicity dictates reliance on TCF1 in CD8 T cells for response to immunotherapy.

Stem-like CD8 T cells are regulated by T cell factor 1 (TCF1) and are considered requisite for immune checkpoint blockade (ICB) response. However, recent findings indicate that reliance on TCF1CD8 T cells for ICB efficacy may differ across tumor contexts. We find that TCF1 is essential for optimal priming of tumor antigen-specific CD8 T cells and ICB response in poorly immunogenic tumors that accumulate TOX dysfunctional T cells, but is dispensable for T cell priming and therapy response in highly immunogenic tumors that efficiently expand transitory effectors.