Laboratory of Physiopharmacology, GENCOR, University of Antwerp, Belgium.
Research Group Cardiovascular Diseases, GENCOR, University of Antwerp, Belgium.
Exerc Immunol Rev. 2021;27:84-124.
Toll-like receptors (TLRs) are a family of transmembrane pattern recognition receptors that are mainly expressed on immune cells. Recognition of various exogenous and endogenous molecular patterns activates the TLR signalling cascade, which orchestrates an inflammatory immune response. Dysfunctional immune responses, including aberrant TLR signalling, are increasingly implicated in the associations between sedentarism, chronic low-grade systemic inflammation and various non-communicable diseases. Conversely, exercise exerts anti-inflammatory effects, which could be conferred through its immunomodulatory properties, potentially affecting TLRs. This study aims to systematically review the effects of exercise on human TLR expression.
A systematic literature search of Pubmed, Embase, The Cochrane Library and SPORTDiscus for articles addressing the impact of exercise (as isolated intervention) on TLRs in humans was conducted, ending in February 2020.
A total of 66 articles were included. The publications were categorised according to exercise modality and duration: acute resistance exercise (4 studies), acute aerobic exercise (26 studies), resistance training program (9 studies), aerobic training program (16 studies), combined (i.e. resistance and aerobic) training program (8 studies) and chronic exercise not otherwise classifiable (9 studies). Five articles investigated more than one of the aforementioned exercise categories. Several trends could be discerned with regard to the TLR response in the different exercise categories. Acute resistance exercise seemed to elicit TLR upregulation, whereas acute aerobic exercise had less activating potential with the majority of responses being neutral or, especially in healthy participants, downregulatory. Chronic resistance and combined exercise programs predominantly resulted in unaltered or decreased TLR levels. In the chronic aerobic exercise category, mixed effects were observed, but the majority of measurements demonstrated unchanged TLR expression.
Currently published research supports an interplay between exercise and TLR signalling, which seems to depend on the characteristics of the exercise. However, there was large heterogeneity in the study designs and methodologies. Therefore, additional research is required to further corroborate these findings, to define its pathophysiological implications and to elucidate the mechanism(s) linking exercise to TLR signalling.
Toll 样受体（TLR）是一类主要表达于免疫细胞的跨膜模式识别受体。识别各种外源性和内源性分子模式激活 TLR 信号级联反应，从而协调炎症免疫反应。功能失调的免疫反应，包括异常的 TLR 信号，与久坐不动、慢性低度全身炎症和各种非传染性疾病之间的关联越来越密切。相反，运动具有抗炎作用，这可能通过其免疫调节特性来实现，从而可能影响 TLR。本研究旨在系统综述运动对人 TLR 表达的影响。
对 Pubmed、Embase、The Cochrane Library 和 SPORTDiscus 进行系统文献检索，以确定探讨运动（作为单一干预措施）对人类 TLR 影响的文章，检索截止日期为 2020 年 2 月。
共纳入 66 篇文章。根据运动方式和持续时间对出版物进行分类：急性抗阻运动（4 项研究）、急性有氧运动（26 项研究）、抗阻训练计划（9 项研究）、有氧训练计划（16 项研究）、联合（即抗阻和有氧）训练计划（8 项研究）和慢性运动（9 项未另分类）。有 5 篇文章调查了上述运动类别中的一项以上。在不同的运动类别中，TLR 反应呈现出一些趋势。急性抗阻运动似乎会引起 TLR 上调，而急性有氧运动的激活潜力较小，大多数反应呈中性，或尤其是在健康参与者中，呈下调。慢性抗阻和联合训练计划主要导致 TLR 水平不变或降低。在慢性有氧运动类别中，观察到混合效应，但大多数测量结果表明 TLR 表达不变。
目前已发表的研究支持运动与 TLR 信号之间的相互作用，这种相互作用似乎取决于运动的特点。然而，研究设计和方法存在很大的异质性。因此，需要进一步的研究来进一步证实这些发现，以确定其病理生理学意义，并阐明将运动与 TLR 信号联系起来的机制。
