A heart-brain-spleen axis controls cardiac remodeling to hypertensive stress.

Hypertensive heart disease (HTN-HD) meaningfully contributes to hypertension morbidity and mortality. Initially established as an adaptive response, HTN-HD progresses toward worsening of left ventricule (LV) function and heart failure (HF). Hypertensive stress elevates sympathetic nervous system (SNS) activity, a negative clinical predictor, and expands macrophages.

Three tissue resident macrophage subsets coexist across organs with conserved origins and life cycles.

Resident macrophages orchestrate homeostatic, inflammatory, and reparative activities. It is appreciated that different tissues instruct specialized macrophage functions. However, individual tissues contain heterogeneous subpopulations, and how these subpopulations are related is unclear.

Dynamic CD4 T cell heterogeneity defines subset-specific suppression and PD-L1-blockade-driven functional restoration in chronic infection.

Inhibiting PD-1:PD-L1 signaling has transformed therapeutic immune restoration. CD4 T cells sustain immunity in chronic infections and cancer, yet little is known about how PD-1 signaling modulates CD4 helper T (T) cell responses or the ability to restore CD4 T-mediated immunity by checkpoint blockade. We demonstrate that PD-1:PD-L1 specifically suppressed CD4 T1 cell amplification, prevents CD4 T1 cytokine production and abolishes CD4 cytotoxic killing capacity during chronic infection in mice.

Selective loss of resident macrophage-derived insulin-like growth factor-1 abolishes adaptive cardiac growth to stress.

Hypertension affects one-third of the world's population, leading to cardiac dysfunction that is modulated by resident and recruited immune cells. Cardiomyocyte growth and increased cardiac mass are essential to withstand hypertensive stress; however, whether immune cells are involved in this compensatory cardioprotective process is unclear. In normotensive animals, single-cell transcriptomics of fate-mapped self-renewing cardiac resident macrophages (RMs) revealed transcriptionally diverse cell states with a core repertoire of reparative gene programs, including high expression of insulin-like growth factor-1 (Igf1).

Publisher Correction: Self-renewing resident cardiac macrophages limit adverse remodeling following myocardial infarction.

In the version of this article initially published, the equal contribution of the third author was omitted. The footnote links for that author should be "Sara Nejat" and the correct statement is as follows: "These authors contributed equally: Sarah A. Dick, Jillian A.

Self-renewing resident cardiac macrophages limit adverse remodeling following myocardial infarction.

Macrophages promote both injury and repair after myocardial infarction, but discriminating functions within mixed populations remains challenging. Here we used fate mapping, parabiosis and single-cell transcriptomics to demonstrate that at steady state, TIMD4LYVE1MHC-IICCR2 resident cardiac macrophages self-renew with negligible blood monocyte input. Monocytes partially replaced resident TIMD4LYVE1MHC-IICCR2 macrophages and fully replaced TIMD4LYVE1MHC-IICCR2 macrophages, revealing a hierarchy of monocyte contribution to functionally distinct macrophage subsets.

Fzd4 Haploinsufficiency Delays Retinal Revascularization in the Mouse Model of Oxygen Induced Retinopathy.

Mutations in genes that code for components of the Norrin-FZD4 ligand-receptor complex cause the inherited childhood blinding disorder familial exudative vitreoretinopathy (FEVR). Statistical evidence from studies of patients at risk for the acquired disease retinopathy of prematurity (ROP) suggest that rare polymorphisms in these same genes increase the risk of developing severe ROP, implying that decreased Norrin-FZD4 activity predisposes patients to more severe ROP. To test this hypothesis, we measured the development and recovery of retinopathy in wild type and Fzd4 heterozygous mice in the absence or presence of ocular ischemic retinopathy (OIR) treatment.

IFN-gamma and Fas/FasL pathways cooperate to induce medial cell loss and neointimal lesion formation in allograft vasculopathy.

Using a clinically relevant, fully disparate, allogeneic aortic transplant mouse model of allograft vasculopathy, we have demonstrated that neointimal proliferation is dependent on CD8(+) T cell effector pathways in the presence of therapeutic doses of calcineurin inhibitor (CNI) immunosuppression. CD4(+) T cell pathways are ablated by CNI immunosuppression. In the current study, we examined the relationship between CD8(+) T cell activities, medial SMC loss and neointimal hyperplasia.

Immunologic targets in the etiology of allograft vasculopathy: endothelium versus media.

The respective roles of the endothelium and the media as allo-immune targets in the generation of allograft vasculopathy (AV) have yet to be clearly defined. Although endothelial damage has been implicated in the progression of AV, evidence from mechanical vascular injury models suggests that medial injury may play a more dominant role. The overall objective of this research was to determine the relative importance of the endothelium versus the media as a target for immune injury and induction of AV.

CD8(+) T cells mediate aortic allograft vasculopathy under conditions of calcineurin immunosuppression: role of IFN-gamma and CTL mediators.

We have developed a model of aortic allograft vasculopathy (AV) that uses mouse strains that are fully disparate at Class I, Class II and minor histocompatibility antigens. Acute rejection is ablated with therapeutic doses of the calcineurin inhibitor Cyclosporine A (CyA). In this way we successfully mimic human disease.