Abstract
Lymphocytes have been shown to modulate angiogenesis. Our previous work showed that T regulatory (Treg) cell depletion prevented angiogenesis. In the present study, we sought to examine T-cell populations during lung angiogenesis and subsequent angiostasis. In a mouse model of ischemia-induced systemic angiogenesis in the lung, we examined the time course (0-35 d) of neovascularization and T-cell phenotypes within the lung after left pulmonary artery ligation (LPAL). T cells increased and reached a maximum by 10 days after LPAL and then progressively decreased, suggestive of a modulatory role during the early phase of new vessel growth. Because others have shown IFN-γ to be angiostatic in tumor models, we focused on this effector T-cell cytokine to control the magnitude of angiogenesis. Results showed that IFN-γ protein is secreted at low levels after LPAL and that mice required Treg depletion to see the full effect of effector T cells. Using Foxp3DTR and diphtheria toxin to deplete T regulatory cells, increased numbers of effector T cells (CD8+) and/or increased capacity to secrete the prominent angiostatic cytokine IFN-γ (CD4+) were seen. In vitro culture of mouse systemic and pulmonary microvascular endothelial cells with IFN-γ showed increased endothelial cell apoptosis. CD8-/- mice and IFN-γR-/- mice showed enhanced angiogenesis compared with wild-type mice, confirming that, in this model, IFN-γ limits the extent of systemic neovascularization in the lung.
Original language | English (US) |
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Pages (from-to) | 394-401 |
Number of pages | 8 |
Journal | American journal of respiratory cell and molecular biology |
Volume | 54 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2016 |
Keywords
- Angiogenesis
- Angiostasis
- IFN-γ
- Ischemia
- Regulatory T-cells
ASJC Scopus subject areas
- Molecular Biology
- Pulmonary and Respiratory Medicine
- Clinical Biochemistry
- Cell Biology