Danilo G. Norata, Italy
University of Milan Department of Pharmacological and Biomolecular Sciences (DiSFeB)Presenter of 1 Presentation
Adoptive cell transfer of vasculatropic T regulatory cells dampens the immuno-inflammatory response in the atherosclerotic plaque
Abstract
Background and Aims
Patients with FH showed impaired immunosuppressive response associated with increased inflammation. We tested Adoptive Cell Therapy (ACT) with Treg engineered to selectively migrate in the atherosclerotic plaque and dampen the immune-inflammatory response in the arterial wall.
Methods
WT Treg were retrovirally (IRES-EGFP vector) transfected with a specific chemokine receptor or empty vector and i.v. injected (2x105 GFP+cells/mouse) in 8-week high-cholesterol diet (WTD) fed male LDLR-KO to drive Treg selectively to the plaque. Homing of engineered Treg to the plaque, atherosclerosis progression and plaque composition was analysed by flow cytometry, histology and shotgun proteomics.
Results
Plaque chemokines mRNA profiling showed that CX3CL1 is selectively expressed in the aorta but not in other districts (lymphonods, liver) of LDLR-KO while this is not the case for CCL2,CCL4, CCL5 and others. 24h after ACT, CX3CR1-Treg were detected in the aorta (2.5% of GFP+/lived cell compared to 0.6% of ctrl-Treg) of LDL-R KO mice, while a similar distribution in other tissues between CX3CR1-Treg and ctrl-Treg was observed. This results indicate that the CX3CL1/CX3CR1 axis preferentially vehiculate Treg to the plaque and therefore the effect of ACT with engineered Treg on atherosclerosis progression, was tested in LDLR-KO mice. ACT with CX3CR1-Treg reduced plaque progression (-40%,p<0.05) and lipid deposition (-11%,p<0.05), ameliorated plaque stability (collagen increased by +27%,p<0.05) and decreased the number of pro-inflammatory macrophages. Shotgun proteomics of the aorta confirmed the improvement of immunometabolic pathways following Treg-ACT.
Conclusions
ACT with vasculotropic Treg appears as a promising strategy to selectively target immune activation in the atherosclerotic plaque.