Low-Density Lipoprotein-Reactive T Cells Regulate Plasma Cholesterol Levels and Development of Atherosclerosis in Humanized Hypercholesterolemic Mice.
Circulation 2019;
138:2513-2526. [PMID:
29997115 PMCID:
PMC6254780 DOI:
10.1161/circulationaha.118.034076]
[Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Supplemental Digital Content is available in the text.
Background:
Atherosclerotic cardiovascular disease is a chronic inflammatory process initiated when cholesterol-carrying low-density lipoprotein (LDL) is retained in the arterial wall. CD4+ T cells, some of which recognize peptide components of LDL as antigen, are recruited to the forming lesion, resulting in T-cell activation. Although these T cells are thought to be proatherogenic, LDL immunization reduces disease in experimental animals. These seemingly contradictory findings have hampered the development of immune-based cardiovascular therapy. The present study was designed to clarify how activation of LDL-reactive T cells impacts on metabolism and vascular pathobiology.
Methods:
We have developed a T-cell receptor–transgenic mouse model to characterize the effects of immune reactions against LDL. Through adoptive cell transfers and cross-breeding to hypercholesterolemic mice expressing the antigenic human LDL protein apolipoprotein B-100, we evaluate the effects on atherosclerosis.
Results:
A subpopulation of LDL-reactive T cells survived clonal selection in the thymus, developed into T follicular helper cells in lymphoid tissues on antigen recognition, and promoted B-cell activation. This led to production of anti-LDL immunoglobulin G antibodies that enhanced LDL clearance through immune complex formation. Furthermore, the cellular immune response to LDL was associated with increased cholesterol excretion in feces and with reduced vascular inflammation.
Conclusions:
These data show that anti-LDL immunoreactivity evokes 3 atheroprotective mechanisms: antibody-dependent LDL clearance, increased cholesterol excretion, and reduced vascular inflammation.
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