Ageing is a global burden. Increasing age is associated with increased incidence of infections and cancer and decreased vaccine efficacy. This increased morbidity observed with age, is believed to be due in part to a decline in adaptive immunity, termed immunosenescence. However not all aspects of immunity decrease with age as ageing presents with systemic low grade chronic inflammation, characterised by elevated concentrations of mediators such as IL-6, TNFα and C Reactive protein (CRP). Inflammation is a strong predictor of morbidity and mortality, and chronic inflammation is known to be detrimental to a functioning immune system. Although the source of the inflammation is much discussed, the key cells which are believed to facilitate the inflammageing phenomenon are the monocytes and macrophages.

In this review we detail how macrophage and monocyte phenotype and function change with age. The impact of ageing on macrophages includes decreased phagocytosis and immune resolution, increased senescent-associated markers, increased inflammatory cytokine production, reduced autophagy, and a decrease in TLR expression. With monocytes there is an increase in circulating CD16⁺ monocytes, decreased type I IFN production, and decreased efferocytosis. In conclusion, we believe that monocytes and macrophages contribute to immunosenescence and inflammageing and as a result have an important role in defective immunity with age.

老龄化是全球负担。年龄增加与感染和癌症发病率增加以及疫苗效力降低有关。这种随年龄增长而增加的发病率被认为部分是由于适应性免疫的下降，称为免疫衰老。然而，并非免疫的所有方面都随着年龄的增长而降低，因为衰老会出现全身性低度慢性炎症，其特征是 IL-6、TNFα 和 C 反应蛋白 (CRP) 等介质浓度升高。炎症是发病率和死亡率的强预测因子，已知慢性炎症对免疫系统功能有害。尽管对炎症的来源进行了大量讨论，但据信促进炎症现象的关键细胞是单核细胞和巨噬细胞。

在这篇综述中，我们详细介绍了巨噬细胞和单核细胞的表型和功能如何随年龄变化。衰老对巨噬细胞的影响包括吞噬作用和免疫分辨率降低、衰老相关标志物增加、炎性细胞因子产生增加、自噬减少和 TLR 表达降低。对于单核细胞，循环 CD16 ⁺单核细胞增加，I 型 IFN 产生减少，胞吞作用减少。总之，我们认为单核细胞和巨噬细胞有助于免疫衰老和炎症，因此在随着年龄的增长而导致的免疫缺陷中起重要作用。