Lactate was long dismissed as the terminal glycolytic byproduct. The review’s opening argument reframes lactate as an active immunometabolic regulator that actively sculpts inflammatory responses. Short bursts of lactate accumulation can accompany immune activation. Prolonged or compartmentalised lactate pools may correlate with inflammatory resolution in other settings. The authors reported an apparent paradox: the same metabolite can either amplify immune activation or promote resolution depending on context. This paradox drives the central thesis — lactate operates as a context-dependent rheostat that integrates multiple inputs to modulate immune behaviour.
The review organises lactate’s dual actions around four interacting determinants. First, lactate concentration — the authors point out that local levels influence whether signalling pathways drive activation or suppression, though specific threshold values were not reported in the abstract. Second, cellular identity — different cell types process lactate distinctly and therefore respond differently. Third, disease stage — early inflammatory phases versus resolution phases can reverse the functional outcome of lactate signalling. Fourth, the inflammatory microenvironment — coexisting metabolites, cytokines and oxygen tension modulate lactate’s effects. The team proposed that these four factors integrate to determine whether lactate promotes activation or resolution in any given tissue niche.
Authors summarised multiple mechanisms by which lactate exerts influence. Metabolic reprogramming is one axis: lactate can feed intracellular metabolic pathways and shift cellular bioenergetic states. Intercellular lactate shuttling was described as a route for metabolic coupling between neighbouring cells. Receptor-mediated signalling pathways mediate extracellular lactate sensing, and intracellular sensors translate lactate abundance into downstream responses. A distinct mechanism—protein lactylation—was noted as a post-translational modification that can alter gene expression programs. The review emphasised coordinated control across these mechanisms, arguing that their interplay governs immune activation and resolution. The abstract did not provide experimental details or quantitative data for any specific mechanism.
The authors walked through cell-specific responses in detail, focusing on several cell classes. Endothelial cells, for example, respond to lactate with changes that affect vascular behaviour and leukocyte trafficking. Macrophages display metabolic and phenotypic plasticity influenced by lactate exposure; the direction of polarization varies with context. Fibroblast-like synoviocytes were described in relation to rheumatoid arthritis models, where local lactate can reshape synovial inflammation. Neutrophils and lymphocytes also show context-dependent functional modulation by lactate; however, the abstract did not report precise mechanistic steps for each cell type. Data cited in the review integrate observations from multiple experimental systems rather than a single unified dataset.
Representative inflammatory disease models featured in the review include rheumatoid arthritis, sepsis and atherosclerosis. In these models, investigators reported divergent roles for lactate that depend on timing and microenvironmental context. For instance, in some sepsis-related contexts lactate accumulation accompanies immune dysregulation; in other models, lactate signalling appears to support resolution pathways. The authors argued that these disease-specific examples illustrate why indiscriminate lactate blockade may be ineffective or harmful. The abstract does not list experimental protocols, sample sizes or outcome measures from individual studies discussed in the review.
The review summarises emerging strategies aimed at modulating lactate biology. Approaches span inhibition of lactate production, blockade or modulation of lactate transporters, interference with receptor-mediated sensing, and manipulation of lactate metabolism or protein lactylation. The authors recommended against blanket inhibition of lactate across all settings. Instead, they proposed that therapeutic approaches should be tailored to disease stage and the immune landscape present in the affected tissue. The abstract did not report clinical trial data or specific therapeutic agents with proven clinical efficacy.
Mechanistic duality remains incompletely understood, the authors noted. This incomplete understanding constrains the rational design of lactate-targeted therapies and poses translational challenges. The abstract explicitly states that mechanisms underlying the functional duality are not fully resolved; it did not offer definitive biomarkers, consensus dosing strategies, or validated patient selection criteria for lactate-directed interventions. Unanswered questions that the review raises include precise concentration thresholds that shift lactate’s effect from proinflammatory to proresolution, the relative contributions of specific receptors versus intracellular sensing, and how coexisting microenvironmental factors quantitatively modify outcomes. These knowledge gaps represent practical barriers before broad clinical adoption of lactate-modulating treatments is possible.