Regulatory T cells ameliorate angiotensin II-induced cardiac damage.
BACKGROUND
Hypertensive target organ damage, especially cardiac hypertrophy with heart failure and arrhythmia, is a major source of morbidity and mortality. Angiotensin II, a major mediator of hypertension and cardiac damage, has proinflammatory properties. Inflammation and activation of the immune system play a pivotal role in pathogenesis of hypertensive target organ damage. However, the role of immunosuppressive CD4+CD25+ regulatory T (Treg) cells in the pathogenesis of hypertensive target organ damage is unexplored.


RESULTS
We conducted adoptive transfer of Treg cells into angiotensin II-infused hypertensive mice. Treg cell recipients exhibited improved cardiac hypertrophy and less cardiac fibrosis despite sustained hypertension. Amelioration of cardiac morphology was accompanied by an improvement in arrhythmogenic electric remodeling, indicating the functional significance of the enhanced cardiac morphology. Delocalization of the connexin 43 gap junction protein is one of the major pathomechanisms in electric remodeling. Pronounced connexin 43 immunoreactivity was found at the lateral borders of cardiomyocytes in angiotensin II-treated mice. In contrast, connexin 43 was restricted to the intercalated disk regions in sham controls. Surprisingly, angiotensin II+Treg-treated mice showed normal connexin 43 gap junction protein localization. Adoptive Treg cell transfer resulted in a marked reduction in cardiac CD4+, CD8+, and CD69+ cell and macrophage infiltration.


CONCLUSIONS
Immunosuppressive effects of transferred Treg cells ameliorated cardiac damage and accounted for the improved electric remodeling independently of blood pressure-lowering effects. Our results provide new insights into the pathogenesis of hypertensive cardiac damage and could therefore lead to new therapeutic approaches that involve manipulation of the immune system.
Kvakan
Heda
H
Franz Volhard Clinic, HELIOS Clinic Berlin-Buch, Berlin, Germany.
Kleinewietfeld
Markus
M
Qadri
Fatimunnisa
F
Park
Joon-Keun
JK
Fischer
Robert
R
Schwarz
Ines
I
Rahn
Hans-Peter
HP
Plehm
Ralph
R
Wellner
Maren
M
Elitok
Saban
S
Gratze
Petra
P
Dechend
Ralf
R
Luft
Friedrich C
FC
Muller
Dominik N
DN
D019264:Adoptive Transfer / Q000379:methods*; D000804:Angiotensin II / Q000009:adverse effects*; D000818:Animals; D006332:Cardiomegaly / Q000628:therapy; D005355:Fibrosis / Q000628:therapy; D006331:Heart Diseases / Q000139:chemically induced / Q000517:prevention & control / Q000628:therapy*; D007165:Immunosuppression Therapy / Q000379:methods; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D050378:T-Lymphocytes, Regulatory / Q000637:transplantation*; D016896:Treatment Outcome
D000804:Angiotensin II