BACKGROUNDInflammatory macrophages in failing myocardium secrete CCL17, which targets CCR4 in immunosuppressive Tregs and inhibits the intracellular second messenger ARRB2-mediated cardiac chemotaxis. Traditional Chinese medicine (TCM) LuQi formula (LQF) is safe and effective in treating heart failure (HF). This study aims to elucidate the cardioprotective mechanism of LQF through its modulation of cardiac macrophages and Tregs.METHODSIn vivo, the HF mouse model was established via transverse aortic constriction (TAC), with the superagonistic anti-CD28 monoclonal antibody (CD28-SA)-induced Tregs expansion as a positive control. Proteomics analysis elucidated the core link of LQF in anti-HF. In vitro, bone marrow-derived macrophages (BMDMs) were isolated, and Naive CD4+T cells were sorted and stimulated to differentiate into Tregs. The pharmacological mechanism of LQF was confirmed through histological and molecular biology experiments.RESULTSProteomics reveals that LQF modulates the immune microenvironment of failing myocardium. We revealed that LQF inhibited cardiac inflammatory macrophage infiltration and NF-κB (p50, p65)/CCL17 axis expression, and promoted cardiac Tregs recruitment against HF, with the comparable efficacy of CD-SA28-induced Tregs expansion. Mechanistically, LQF inhibited the NF-κB activator 1-induced NF-κB (p50, p65)/CCL17 axis overexpression, and JSH-23 (NF-κB Inhibitor) abolished NF-κB (p50, p65)/CCL17 axis expression in inflammatory macrophages. Furthermore, the inhibition of CCL17 expression in inflammatory macrophages by LQF was found to be mediated by NF-κB (p50, p65). LQF concentration-dependently promoted Tregs CD73/Foxp3 axis expression, enhancing Tregs immunosuppressive function. LQF activated CCR4-ARRB2 complex and CCR4/ARRB2 axis expression in Tregs. Although AZD2098 (CCR4 Inhibitor) blocked CCR4 expression and CCR4-ARRB2 complex, LQF promoted ARRB2-mediated Tregs cardiac chemotaxis independent of the CCR4. We revealed that NF-κB p50SEP337-CCL17, NF-κB p65SEP536-CCL17, and CCR4-ARRB2 highly bound subunit interface targets. Molecular docking analysis demonstrated that the LQF's active ingredients exhibit good binding affinity with the NF-κB (p50, p65) /CCL17 axis in macrophages and Foxp3 in Tregs.CONCLUSIONLQF has the potential to enhance the cardiac immune microenvironment and effectively prevent and treat HF by modulating both innate and adaptive immune responses. It achieves this by inhibiting the infiltration of inflammatory macrophages, suppressing the NF-κB (p50, p65)/CCL17 axis, and promoting Tregs recruitment. The active ingredients of LQF provide valuable candidate compounds for developing new anti-HF drugs. Furthermore, CD-28SA-induced Tregs expansion showed cardioprotective effects in TAC-induced non-ischemic HF models.