Tavallaie Mojdeh, Hsu Cheng-Chieh, Hardaway Brian D, Dou Huijuan, Fidler Trevor, Kim Eunyoung, Abramowicz Sandra E, Ngai David, Xiao Tong, Wang Nan, Westerterp Marit, Tall Alan R
bioRxiv. 2025 Jun 6:2025.06.03.657754. doi: 10.1101/2025.06.03.657754.
Inflammasome activation promotes atherosclerosis in clonal hematopoiesis (CH). Active inflammasomes secrete both IL-1β and IL-18. Plasma IL-18 levels are elevated in CH. Genetic deficiency of IL-18 has been shown to reduce atherosclerosis in non-CH murine models. However, whether IL-18 inhibition promotes atherosclerosis in control or CH is unknown.
mice were transplanted with bone marrow (BM) from (20%) and wild-type (80%) mice or with control BM, fed a Western-type diet (WTD) for 8, 10 or 16 weeks and administered control or IL-18 IgG from 4 weeks onwards. IL-18 antibody treatment increased plaque collagen content and cap thickness. Unexpectedly, IL-18 antibody treatment increased the size of early lesions and promoted formation of advanced lesions with large necrotic cores in CH mice. IL-18 antibody treatment was associated with diminished interferon (IFN)-γ and AIM2 levels and reduced macrophage pyroptosis especially in CH mice. However, IL-18 antibodies increased cleaved Caspase-3 and TUNEL macrophages (indicating increased apoptosis) and reduced efferocytosis. Sc-RNA-seq analysis showed that IL-18 antibody treatment reduced expression of genes, a marker of IFN-γ signaling, and of genes mediating efferocytosis ( , in resident-like macrophage subpopulations in CH mice. Consistently, IFN-γ injection increased and expression in resident peritoneal macrophages.
Despite improvements in collagen and fibrous cap thickness in CH mice, IL-18 antibody treatment increased advanced necrotic lesions, reflecting a shift from pyroptotic to apoptotic cell death coupled with defective efferocytosis, events which were coordinated by reduced IFN-γ signaling. These findings indicate a mixed atherosclerosis phenotype resulting from IL-18 inhibition, advocating for alternative therapeutic strategies. Inhibition of IL-18 has been considered as a novel therapeutic approach to reduce atherosclerosis and stabilize atherosclerotic plaques. We show that IL-18 antibodies have adverse effects on atherosclerotic lesional necrosis, calling this approach into question.
Inflammasome activation produces active IL-1 and IL-18 and worsens atherosclerosis in clonal hematopoiesis (CH) however the contribution of IL-18 is unknown. Antibody inhibition of IL-18 increased plaque collagen but also increased early lesion area and late lesions with large necrotic cores in CH mice. There was a reversal of AIM2 inflammasome activation but a switch to apoptosis which along with reduced efferocytosis increased necrosisThese events appeared to be coordinated by reduced IFN-γ which increased collagen but also decreased expression of efferocytotic genes. Our studies call into question whether inhibition of IL-18 would stabilize plaques in CH.
炎性小体激活促进克隆性造血（CH）中的动脉粥样硬化。活化的炎性小体分泌白细胞介素-1β（IL-1β）和白细胞介素-18（IL-18）。CH患者血浆IL-18水平升高。在非CH小鼠模型中，IL-18基因缺陷已被证明可减轻动脉粥样硬化。然而，IL-18抑制是否会促进正常或CH状态下的动脉粥样硬化尚不清楚。
将小鼠移植来自（20%）和野生型（80%）小鼠的骨髓（BM）或对照BM，给予西式饮食（WTD）8、10或16周，并从第4周起给予对照或IL-18 IgG。IL-18抗体治疗增加了斑块胶原含量和帽厚度。出乎意料的是，IL-18抗体治疗增加了CH小鼠早期病变的大小，并促进了具有大坏死核心的晚期病变的形成。IL-18抗体治疗与干扰素（IFN）-γ和AIM2水平降低以及巨噬细胞焦亡减少有关，尤其是在CH小鼠中。然而，IL-18抗体增加了裂解的半胱天冬酶-3和TUNEL巨噬细胞（表明凋亡增加）并减少了噬菌作用。单细胞RNA测序分析表明，IL-18抗体治疗降低了CH小鼠中IFN-γ信号标志物基因以及介导噬菌作用的基因（，在驻留样巨噬细胞亚群中）的表达。一致地，IFN-γ注射增加了驻留腹膜巨噬细胞中 和 的表达。
尽管CH小鼠的胶原和纤维帽厚度有所改善，但IL-18抗体治疗增加了晚期坏死病变，反映了从焦亡到凋亡性细胞死亡的转变以及噬菌作用缺陷，这些事件由IFN-γ信号减少所协调。这些发现表明IL-18抑制导致了混合性动脉粥样硬化表型，提倡采用替代治疗策略进行治疗。抑制IL-18被认为是一种减少动脉粥样硬化和稳定动脉粥样硬化斑块的新型治疗方法。我们表明，IL-18抗体对动脉粥样硬化病变坏死有不良影响，使这种方法受到质疑。
炎性小体激活产生活性IL-1和IL-18并加重克隆性造血（CH）中的动脉粥样硬化，然而IL-18的作用尚不清楚。抗体抑制IL-18增加了斑块胶原，但也增加了CH小鼠的早期病变面积和具有大坏死核心的晚期病变。AIM2炎性小体激活发生了逆转，但转变为凋亡，这与噬菌作用减少一起增加了坏死。这些事件似乎由IFN-γ减少所协调，IFN-γ增加了胶原，但也降低了噬菌相关基因的表达。我们的研究对抑制IL-18是否会稳定CH中的斑块提出了质疑。
