bims-bac4me Biomed News
on Microbiome and trained immunity
Issue of 2025–03–23
thirty-six papers selected by
Chun-Chi Chang, Universitäts Spital Zürich



  1. Clin Rev Allergy Immunol. 2025 Mar 18. 68(1): 31
      The recurrence of inflammatory skin diseases represents a significant challenge in clinical practice, primarily mediated by immune memory. In inflammatory skin diseases, immune memory encompasses adaptive immune memory, trained immunity, and inflammatory memory, which are conducted by adaptive immune cells, innate immune cells, and structural cells, respectively. Adaptive immune memory is established through gene rearrangement, leading to antigen-specific immune memory. In contrast, trained immunity and inflammatory memory are formed through epigenetic and metabolic reprogramming, resulting in non-specific immune memory. Different types of immune memory work synergistically to aggravate localized inflammation in recurrent inflammatory skin diseases. However, immune memory in specific cells, such as macrophages, may also play an immunoregulatory role under certain conditions. We reviewed the immune memory mechanisms in different inflammatory skin diseases and discussed future strategies for targeted regulation of the molecular mechanisms underlying immune memory, such as targeted biological agents and epigenetic modifications. Additionally, we explored the potential for precise regulation of immune memory and its application in personalized treatment for recurrent inflammatory skin diseases.
    Keywords:  Immune memory; Inflammatory memory; Inflammatory skin diseases; Trained immunity
    DOI:  https://doi.org/10.1007/s12016-025-09039-0
  2. Res Vet Sci. 2025 Mar 16. pii: S0034-5288(25)00086-4. [Epub ahead of print]187 105612
      Debaryomyces hansenii CBS 8339 β-glucans induced trained immunity in newborn goats. However, the metabolic shifts and potential signaling pathways have not been described yet. Thus, the present study aims to prove, firstly, modifications in cell metabolism related to trained immunity induction (β-glucans) and inhibition (MCC950) in an in vitro model upon lipopolysaccharide (LPS) re-stimulation; secondly, metabolic changes and possible signaling pathways are related to immune memory induced by β-glucan per os in newborns after ex vivo re-stimulation with a bacterial pathogen. Immune training leads to augmenting glycolysis (glucose and lactate) metabolites. Nevertheless, these changes were unaffected by a NOD-like receptor (NLRP3) inhibitor. In vivo training with oral β-glucan doses also evidenced an increase in glycolysis metabolites mediated by up-regulating AKT/MTOR/HIF1Α genes signaling pathway in monocytes; β-glucan in vivo training up-regulated Dectin1, TLR4, TLR6 RAF1, IL1Β and IL6 gene expressions in monocytes, while TNFΑ gene down-regulated. In conclusion, the results demonstrated that D. hansenii β-glucan induced trained immunity in newborn goat monocytes after LPS re-stimulation through glycolysis shifts, which were not reverted by the MCC950 inhibitor.
    Keywords:  Animal health; Functional carbohydrates; Memory in innate leukocytes; Metabolic shift
    DOI:  https://doi.org/10.1016/j.rvsc.2025.105612
  3. Front Immunol. 2025 ;16 1535796
      Immunometabolism has emerged as a key area of focus in immunology and has the potential to lead to new treatments for immune-related diseases. It is well-established that glycolytic metabolism is essential for adaptation to hypoxia and for macrophage inflammatory function. Macrophages have been shown to upregulate their glycolytic metabolism in response to pathogens and pathogen-associated molecular patterns such as LPS. As a direct link to the external environment, the lungs' distinctive nutrient composition and multiple macrophage subtypes provide a unique opportunity to study macrophage metabolism. This review aims to highlight how the steady-state airway and severely inflamed airway offer divergent environments for macrophage glycolytic metabolism. We describe the differences in glycolytic metabolism between tissue-resident alveolar macrophages, and other lung macrophages at steady-state and during inflammation/injury. We also provide an overview of experimental guidelines on how to assess metabolism at the cellular level using Seahorse-based bioenergetic analysis including a review of pharmacologic agents used to inhibit or activate glycolysis.
    Keywords:  alveolar macrophage; bioenergetics; bone marrow-derived macrophage; cytokines; glycolysis; interstitial macrophage; metabolism; monocyte-derived alveolar macrophage
    DOI:  https://doi.org/10.3389/fimmu.2025.1535796
  4. Infect Immun. 2025 Mar 21. e0002825
      Staphylococcus aureus and its antibiotic-resistant derivative, methicillin-resistant S. aureus (MRSA), are the leading causative agents of skin and soft tissue infections globally. S. aureus transiently colonizes the skin of healthy adults, and this transient colonization likely precedes an active infection. In recent years, there have been efforts to elucidate specific factors that help MRSA transition to an active infection, but the specific genetic determinants required for this transition following skin colonization are largely unknown. To address this question, we developed a model of asymptomatic colonization of mouse skin by MRSA. From this model, we could determine the MRSA and mouse transcriptional profiles by RNA sequencing (RNAseq) at 5- and 24-hour post-colonization. The fadXDEBA locus, required for fatty acid metabolism, was highly upregulated in our data, as were numerous virulence factors. RNAseq data were confirmed via functional in vitro and in vivo promoter-fusion assays using live bioluminescent imaging of the fadXDEBA locus promoter driving fadB transcription. We analyzed the functional capacity of members of the fadXDEBA locus, which encode crucial enzymatic components of the S. aureus β-oxidation pathway. The genes fadD and fadA modulate MRSA resistance to fosfomycin and other oxidative stressors during growth in the presence of the common skin fatty acid, palmitic acid. Overall, our data demonstrate that there are global changes to the MRSA transcriptome, priming the bacteria for survival by upregulation of known virulence factors and metabolic genes implicated in host skin-nutrient utilization.IMPORTANCEStaphylococcus aureus is a major global agent of skin and soft tissue infections. S. aureus colonizes the skin transiently, an important precursor to infection. However, little is known about how S. aureus adapts to the skin at the transcriptional level. This study provides an overview of the S. aureus transcriptome during mouse skin colonization via RNA sequencing. We identified that the most highly upregulated genes during colonization are related to fatty acid metabolism. The disruption of certain genes in the fatty acid degradation pathway altered resistance of S. aureus to the antibiotic fosfomycin. This study provides an important step in understanding the transcriptional changes that occur during S. aureus skin colonization and may reveal novel targets of therapeutic interest for preventing skin infections.
    Keywords:  RNA sequencing; Staphylococcus aureus; antibiotic resistance; bacteriology; host-pathogen interactions; skin microbiota; transcriptomics
    DOI:  https://doi.org/10.1128/iai.00028-25
  5. J Appl Microbiol. 2025 Mar 19. pii: lxaf071. [Epub ahead of print]
       AIMS: To investigate the response of primary nasal epithelial cells (NECs) to novel alpha haemolytic Streptococcus and lactobacilli strains, isolated from the upper respiratory tract of children.
    METHODS AND RESULTS: Submerged cultures of NECs from healthy adult donors were exposed to either novel strains; Lactobacillus rhamnosus D3189, D3160, Streptococcus salivarius D3837; or commercially available probiotic strains L. rhamnosus LB21, S. salivarius K12; or a pathogenic strain (S. pneumoniae 49 619). Cytotoxicity (measured through lactate dehydrogenase release) and cytokine release were quantified 24 hours post-exposure. Exposure to novel and commercially available strains did not induce the production of IFN-β, IFN-λ1/3, IL-1β, IL-6, IL-8 or TNF-α production or the release of LDH. Conversely, the pathogenic strain S. pneumoniae 49 619 significantly elevated the expression of IL-1β, IL-8, TNF-α, and LDH in NECs.
    CONCLUSIONS: The findings within this study highlight the non-pathogenic nature of these novel strains and support further investigation of the potential to develop nasally administered probiotics.
    Keywords:   lactobacillus ; alpha haemolytic streptococcus; innate immunity; nasal epithelium; probiotics
    DOI:  https://doi.org/10.1093/jambio/lxaf071
  6. J Immunol. 2025 Mar 18. pii: vkae061. [Epub ahead of print]
      Staphylococcus aureus is a commensal and opportunist pathogen of the upper respiratory tract. The recognition of pathogen-associated molecular patterns through pattern-recognition receptors is crucial for eliminating microorganisms such as S. aureus. DC-SIGN (CD209) is a pattern-recognition receptor that binds to a broad range of pathogens, promoting phagocytosis. Here we aimed to study the role of mouse homologues of DC-SIGN, CD209d/e, in a methicillin-resistant S. aureus (MRSA) pulmonary infection model. CD209d/e-/- and wild-type C57BL/6 mice were infected with MRSA and inflammatory parameters were evaluated. CD209d/e-/- mice had delayed bacterial burden and mortality together with increased frequency of neutrophils and decreased dendritic cells in the lung compared with control mice. iNOS+ macrophages, and regulatory T cell frequency were decreased in the lungs of CD209d/e-/- mice. CD209d/e-/- mice had increased levels of inflammatory cytokines in the lungs, but levels of IL-12p40 were decreased. MRSA reduced expression of interferon-γ and pattern-recognition receptors in CD209d/e-/- mice. MRSA uptake by phagocytes was decreased in the lungs of CD209d/e-/- versus control mice. CD209d/e-/- bone marrow derived macrophages showed impaired MRSA uptake and killing. These data suggest that CD209d/e are essential receptors to control inflammation by activating macrophages leading to MRSA uptake and killing.
    Keywords:  immunity; inflammation; lung; pattern recognition receptor; pneumonia
    DOI:  https://doi.org/10.1093/jimmun/vkae061
  7. bioRxiv. 2025 Mar 05. pii: 2025.02.28.640814. [Epub ahead of print]
      Macrophages serve as important sites of bacterial replication and host immune response during Mycobacterium tuberculosis (Mtb) infection with distinct roles for alveolar macrophages (AMs) early in infection and monocyte-derived (MDMs) during later stages of disease. Here, we leverage data from human and mouse models to perform a cross-species analysis of macrophage responses to Mtb infection. Overall, we find that both subsets of human and murine macrophages mount a strong interferon response to Mtb infection. However, AM across both species do not generate as strong a pro-inflammatory response as human MDMs or murine bone marrow-derived macrophages (BMDMs), as characterized by TNFA signaling and inflammatory response pathways. Interestingly, AMs from mice that were previously vaccinated with BCG (scBCG) or from a model of contained TB (coMtb) had Mtb responses that were more similar to human AMs than control mice. We also identify species-specific pathways altered by infection differently in mouse and human macrophages, specifically in pathways related to cholesterol in AMs as well as MYC targets and Hedgehog signaling in MDMs/BMDMs. Lastly, to investigate downstream effects of the macrophage interferon responses, we examine macrophage expression of IL-10, an immunosuppressive cytokine induced by Type I Interferons, and c-Maf, a transcription factor required for IL-10 expression in myeloid cells. We find that c-Maf and IL-10 have significantly lower expression in AMs compared to MDMs in both humans and mice, suggesting one possible mechanism by which AMs mount a stronger interferon response following Mtb infection. Overall, these results highlight the dynamics of innate myeloid responses over the course of Mtb infection and the benefit of a combined analysis across species to reveal conserved and unique responses.
    DOI:  https://doi.org/10.1101/2025.02.28.640814
  8. Am J Transplant. 2025 Mar 17. pii: S1600-6135(25)00144-3. [Epub ahead of print]
      
    DOI:  https://doi.org/10.1016/j.ajt.2025.03.015
  9. Trends Immunol. 2025 Mar 19. pii: S1471-4906(25)00055-9. [Epub ahead of print]
      The devastating impact of respiratory infections demonstrates the critical need for novel prophylactic vaccines. In this opinion article, we advocate for bacterial immunotherapies as a complementary tool in our fight against respiratory infections. These immunotherapies can activate a wide spectrum of immunological mechanisms, with trained immunity (TI) being particularly significant. This phenomenon has led to the concept of trained immunity-based vaccines (TIbVs), which represent a novel approach in vaccinology. We discuss examples of TIbVs, including the tuberculosis vaccine Bacille Calmette-Guérin (BCG) and the polybacterial immunotherapy MV130. From our viewpoint, illustrating the mode of action and clinical evidence supports the proposal that TIbVs should be considered as next-generation vaccines to confer protection against a wide range of respiratory infections.
    Keywords:  BCG; MV130; TIbVs; innate immune memory; mucosal immunotherapy; trained immunity
    DOI:  https://doi.org/10.1016/j.it.2025.02.012
  10. mBio. 2025 Mar 19. e0013825
      Bordetella pertussis infects human upper airways and deploys an array of immunosuppressive virulence factors, among which the adenylate cyclase toxin (CyaA) plays a prominent role in disarming host phagocytes. CyaA binds the complement receptor-3 (CR3 aka αMβ2 integrin CD11b/CD18 or Mac-1) of myeloid cells and delivers into their cytosol an adenylyl cyclase enzyme that hijacks cellular signaling through unregulated conversion of cytosolic ATP to cAMP. We found that the action of as little CyaA as 22 pM (4 ng/mL) blocks macrophage colony-stimulating factor (M-CSF)-driven transition of migratory human CD14+ monocytes into macrophages. Global transcriptional profiling (RNAseq) revealed that exposure of monocytes to 22 pM CyaA for 40 hours in culture with 20 ng/mL of M-CSF led to upregulation of genes that exert negative control of monocyte to macrophage differentiation (e.g., SERPINB2, DLL1, and CSNK1E). The sustained CyaA action yielded downregulation of numerous genes involved in processes crucial for host defense, such as myeloid cell differentiation, chemotaxis of inflammatory cells, antigen presentation, phagocytosis, and bactericidal activities. CyaA-elicited signaling also promoted deacetylation and trimethylation of lysines 9 and 27 of histone 3 (H3K9me3 and H3K27me3) and triggered the formation of transcriptionally repressive heterochromatin patches in the nuclei of CyaA-exposed monocytes. These effects were partly reversed by the G9a methyltransferase inhibitor UNC 0631 and by the pleiotropic HDAC inhibitor Trichostatin-A, revealing that CyaA-elicited epigenetic alterations mediate transcriptional reprogramming of monocytes and play a role in CyaA-triggered block of monocyte differentiation into bactericidal macrophage cells.IMPORTANCETo proliferate on host airway mucosa and evade elimination by patrolling sentinel cells, the whooping cough agent Bordetella pertussis produces a potently immunosubversive adenylate cyclase toxin (CyaA) that blocks opsonophagocytic killing of bacteria by phagocytes like neutrophils and macrophages. Indeed, chemotactic migration of CD14+ monocytes to the infection site and their transition into bactericidal macrophages, thus replenishing the exhausted mucosa-patrolling macrophages, represents one of the key mechanisms of innate immune defense to infection. We show that the cAMP signaling action of CyaA already at a very low toxin concentration triggers massive transcriptional reprogramming of monocytes that is accompanied by chromatin remodeling and epigenetic histone modifications, which block the transition of migratory monocytes into bactericidal macrophage cells. This reveals a novel layer of toxin action-mediated hijacking of functional differentiation of innate immune cells for the sake of mucosal pathogen proliferation and transmission to new hosts.
    Keywords:  Bordetella pertussis; RTX toxins; cyclic AMP; differentiation; epigenetics; macrophages; monocytes
    DOI:  https://doi.org/10.1128/mbio.00138-25
  11. Sci Immunol. 2025 Mar 21. 10(105): eadr0547
      Aspergillus fumigatus causes life-threatening mold pneumonia in immunocompromised patients, particularly in those with quantitative or qualitative defects in neutrophils. Whereas innate immune cell cross-talk licenses neutrophil antifungal activity in the lung, the role of epithelial cells in this process is unknown. Here, we find that surfactant protein C (SPC)-expressing lung epithelial cells integrate infection-induced interleukin-1 and type III interferon signaling to produce granulocyte-macrophage colony-stimulating factor (GM-CSF) preferentially at local sites of fungal infection and neutrophil influx. Using in vivo models that distinguish the role of GM-CSF during acute infection from its homeostatic function in alveolar macrophage survival and surfactant catabolism, we demonstrate that epithelial-derived GM-CSF increases the accumulation and fungicidal activity of GM-CSF-responsive neutrophils, which is essential for host survival. Our findings establish SPC+ epithelial cells as a central player in regulating the quality and strength of neutrophil-dependent immunity against inhaled mold pathogens.
    DOI:  https://doi.org/10.1126/sciimmunol.adr0547
  12. Immunol Rev. 2025 Mar;330(1): e70019
      Childhood is a multifactorial disease, and recent research highlights the influence of early-life microbial communities in shaping disease risk. This review explores the roles of the gut and respiratory microbiota in asthma development, emphasizing the importance of early microbial exposure. The gut microbiota has been particularly well studied, with certain taxa like Faecalibacterium and Bifidobacterium linked to asthma protection, whereas short-chain fatty acids produced by gut microbes support immune tolerance through the gut-lung axis. In contrast, the respiratory microbiota, though low in biomass, shows consistent associations between early bacterial colonization by Streptococcus, Moraxella, and Haemophilus and increased asthma risk. The review also addresses the emerging roles of the skin microbiota and environmental fungi in asthma, though findings remain inconsistent. Timing is a critical factor, with early-life disruptions, such as antibiotic use, potentially leading to increased asthma risk. Despite significant advances, there are still unresolved questions about the long-term consequences of early microbial perturbations, particularly regarding whether microbial dysbiosis is a cause or consequence of asthma. This review integrates current findings, highlighting the need for deeper investigation into cross-organ interactions and early microbial exposures to understand childhood asthma pathophysiology.
    Keywords:  asthma; early life; microbiota
    DOI:  https://doi.org/10.1111/imr.70019
  13. Nat Commun. 2025 Mar 15. 16(1): 2559
      Disease tolerance is a host response to infection that limits collateral damage to host tissues while having a neutral effect on pathogen fitness. Previously, we found that the pathogenic lactic acid bacterium Streptococcus pyogenes manipulates disease tolerance using its aerobic mixed-acid fermentation pathway via the enzyme pyruvate dehydrogenase, but the microbe-derived molecules that mediate communication with the host's disease tolerance pathways remain elusive. Here we show in a murine model that aerobic mixed-acid fermentation inhibits the accumulation of inflammatory cells including neutrophils and macrophages, reduces the immunosuppressive cytokine interleukin-10, and delays bacterial clearance and wound healing. In infected macrophages, the aerobic mixed-acid fermentation end-products acetate and formate from streptococcal upregulate host acetyl-CoA metabolism and reduce interleukin-10 expression. Inhibiting aerobic mixed-acid fermentation using a bacterial-specific pyruvate dehydrogenase inhibitor reduces tissue damage during murine infection, correlating with increased interleukin-10 expression. Our results thus suggest that reprogramming carbon flow provides a therapeutic strategy to mitigate tissue damage during infection.
    DOI:  https://doi.org/10.1038/s41467-025-57348-x
  14. Microbiol Spectr. 2025 Mar 19. e0134424
      Staphylococcus aureus (S. aureus) infection is a serious threat to global health. This study aimed to investigate the anti-virulence efficacy of tigecycline against S. aureus. We used highly virulent S. aureus strains SA75 and JP30 to evaluate the effect of tigecycline on virulence, both of them isolated from the clinic. The MIC value of tigecycline against SA75 was 0.125 µg/mL, and that against JP30 was 0.25 µg/mL. Tigecycline did not affect the growth ability of bacteria at 0.015 µg/mL. Thus, subsequent discussions will focus on the effect of antibiotics at the latter subinhibitory concentrations that did not affect growth. First, the sub-MICs of tigecycline not only enhanced the sensitivity of S. aureus to oxidants and human whole blood but also weakened the hemolytic activity and cell adhesion level of S. aureus. Second, it undermined the survival of S. aureus in RAW264.7 and attenuated the macrophage inflammatory response induced by S. aureus. On the contrary, tigecycline decreased the hemolytic activity, as well as the skin abscess formation and bacterial burden in mice. Most importantly, it significantly decreased the expression of hla, hlgB, hlgC, spa, sbi, saeR, sak, tst, and coa genes by RT-qPCR and the protein expression of α-toxin. Altogether, the sub-MICs of tigecycline might be a promising agent to attenuate the virulence of S. aureus and its host immune response by inhibiting the SaeRS two-component system and the product of α-toxin.IMPORTANCEIn this study, the sub-MICs of tigecycline decreased the resistance of S. aureus to oxidants and human whole blood. Moreover, tigecycline weakened the cell adhesion level of S. aureus and skin abscess formation in mice by reducing bacterial burden. Remarkably, tigecycline decreased the hemolytic activity and significantly downregulated the expression of various virulence genes and α-toxin. This research highlighted that the sub-MICs of tigecycline might be a promising agent to attenuate the virulence of S. aureus by inhibiting the product of α-toxin.
    Keywords:  SaeRS two-component system; Staphylococcus aureus; host immune response; tigecycline; virulence; α-toxin
    DOI:  https://doi.org/10.1128/spectrum.01344-24
  15. Eur Respir Rev. 2025 Jan;pii: 240224. [Epub ahead of print]34(175):
      The airway epithelium is the first point of contact for inhaled pathogens. The role of epithelial cells in clearance, infection and colonisation of bacteria is established. The interactions of respiratory viruses and cilia is less understood, but viruses are known to target ciliated epithelial cells for entry, replication and dissemination. Furthermore, some respiratory viruses impair and/or enhance ciliary activity. This review examines what is known about the interactions between cilia and viral infection and how respiratory viruses effect cilia function with subsequent consequences for human health. We discuss the models which can be used to investigate the relationship between respiratory viruses and the host airway.
    DOI:  https://doi.org/10.1183/16000617.0224-2024
  16. ACS Infect Dis. 2025 Mar 19.
      Pneumonia caused by Staphylococcus aureus infection has consistently been a significant cause of morbidity and mortality worldwide. Extensive research to date indicates that N6-methyladenosine (m6A) modification plays a crucial role in the development and progression of various diseases. However, it remains unknown whether the m6A modification affects the progression of bacterial pneumonia. To explore this question, we assessed the levels of m6A as well as the expression of methyltransferases (METTL3 and METTL14), demethylase fat mass and obesity-related protein (FTO), and methylation reader proteins YTHDF1 and YTHDF2 in mice and MH-S cells during S. aureus infection. The levels of m6A and METTL3 were significantly upregulated in S. aureus-infected mice and MH-S cells. siMETTL3 knockdown resulted in more severe bacterial colonization, lung damage, increased inflammatory cytokines (IL-6, IL-1β, TNF-α), and mortality rates in mice as well as MH-S cells following the bacterial infection. Regulation of lung inflammation levels by METTL3 was associated with the activation of the MAPK/NF-κB/JAK2-STAT3 signaling pathway. Moreover, siMETTL3 mice exhibited an increased release of superoxides and exacerbated oxidative stress in the lungs following S. aureus infection, which was correlated with impaired mitochondrial autophagy mediated by the Pink1/Parkin pathway. Our findings provide previously unrecognized evidence of the protective role of METTL3 in S. aureus-induced acute pneumonia, indicating a potential therapeutic target for S. aureus infections.
    Keywords:  METTL3; Staphylococcus aureus; autophagy; m6A modification; oxidative stress; pneumonia
    DOI:  https://doi.org/10.1021/acsinfecdis.4c00938
  17. Front Microbiol. 2025 ;16 1559521
      The healthy gut microbiome is important in maintaining health and preventing various chronic and metabolic diseases through interactions with the host via different gut-organ axes, such as the gut-brain, gut-liver, gut-immune, and gut-lung axes. The human gut microbiome is relatively stable, yet can be influenced by numerous factors, such as diet, infections, chronic diseases, and medications which may disrupt its composition and function. Therefore, microbial resilience is suggested as one of the key characteristics of a healthy gut microbiome in humans. However, our understanding of its definition and indicators remains unclear due to insufficient experimental data. Here, we review the impact of key drivers including intrinsic and extrinsic factors such as diet and antibiotics on the human gut microbiome. Additionally, we discuss the concept of a resilient gut microbiome and highlight potential biomarkers including diversity indices and some bacterial taxa as recovery-associated bacteria, resistance genes, antimicrobial peptides, and functional flexibility. These biomarkers can facilitate the identification and prediction of healthy and resilient microbiomes, particularly in precision medicine, through diagnostic tools or machine learning approaches especially after antimicrobial medications that may cause stable dysbiosis. Furthermore, we review current nutrition intervention strategies to maximize microbial resilience, the challenges in investigating microbiome resilience, and future directions in this field of research.
    Keywords:  antibiotics; biomarkers; dysbiosis; human gut microbiome; microbiome recovery; perturbation; resilient gut microbiome
    DOI:  https://doi.org/10.3389/fmicb.2025.1559521
  18. DNA Cell Biol. 2025 Mar 19.
      The lung as an organ that is fully exposed to the external environment for extended periods, comes into contact with numerous inhaled microorganisms. Lung macrophages are crucial for maintaining lung immunity and operate primarily through signaling pathways such as toll-like receptor 4 and nuclear factor-κB pathways. These macrophages constitute a diverse population with significant plasticity, exhibiting different phenotypes and functions on the basis of their origin, tissue residence, and environmental factors. During lung homeostasis, they are involved in the clearance of inhaled particles, cellular remnants, and even participate in metabolic processes. In disease states, lung macrophages transition from the inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. These distinct phenotypes have varying transcriptional profiles and serve different functions, from combating pathogens to repairing inflammation-induced damage. However, macrophages can also exacerbate lung injury during prolonged inflammation or exposure to antigens. In this review, we delve into the diverse roles of pulmonary macrophages the realms in homeostasis, pneumonia, tuberculosis, and lung tumors.
    Keywords:  immune infiltration; lung cancer; pulmonary macrophages; signaling pathways
    DOI:  https://doi.org/10.1089/dna.2024.0211
  19. Immunol Rev. 2025 Mar;330(1): e70020
      Asthma, a chronic respiratory condition that has seen a dramatic rise in prevalence over the past few decades, now affects more than 300 million people globally and imposes a significant burden on healthcare systems. The key pathological features of asthma include inflammation, airway hyperresponsiveness, mucus cell metaplasia, smooth muscle hypertrophy, and subepithelial fibrosis. Cytokines released by lung epithelial cells, stromal cells, and immune cells during asthma are critical to pathological tissue remodeling in asthma. Over the past few decades, researchers have made great strides in understanding key cells involved in asthma and the cytokines that they produce. Epithelial cells as well as many adaptive and innate immune cells are activated by environmental signals to produce cytokines, namely, type 2 cytokines (IL-4, IL-5, IL-13), IFN-γ, IL-17, TGF-β, and multiple IL-6 family members. However, the precise mechanisms through which these cytokines contribute to airway remodeling remain elusive. Additionally, multiple cell types can produce the same cytokines, making it challenging to decipher how specific cell types and cytokines uniquely contribute to asthma pathogenesis. This review highlights recent advances and provides a comprehensive overview of the key cells involved in the production of cytokines and how these cytokines modulate airway remodeling in asthma.
    Keywords:  airway hyperresponsiveness; airway remodeling; allergy; asthma; cytokines; inflammation
    DOI:  https://doi.org/10.1111/imr.70020
  20. FASEB J. 2025 Mar 31. 39(6): e70408
      Intestinal microbes can beneficially impact host physiology, prompting investigations into the therapeutic usage of such microbes in a range of diseases. For example, human intestinal microbe Limosilactobacillus reuteri strains ATCC PTA 6475 and DSM 17938 are being considered for use for intestinal ailments, including colic, infection, and inflammation, as well as for non-intestinal ailments, including osteoporosis, wound healing, and autism spectrum disorder. While many of their beneficial properties are attributed to suppressing inflammatory responses, we postulated that L. reuteri may also regulate intestinal hormones to affect physiology within and outside of the gut. To determine if L. reuteri secreted factors impact the secretion of enteric hormones, we treated an engineered jejunal organoid line, NGN3-HIO, which can be induced to be enriched in enteroendocrine cells, with L. reuteri 6475 or 17938 conditioned medium and performed transcriptomics. Our data suggest that these L. reuteri strains affect the transcription of many gut hormones, including vasopressin and luteinizing hormone subunit beta, which have not been previously recognized as produced in the gut epithelium. Moreover, we find that these hormones appear to be produced in enterocytes, in contrast to canonical gut hormones produced in enteroendocrine cells. Finally, we show that L. reuteri conditioned media promote the secretion of enteric hormones, including serotonin, GIP, PYY, vasopressin, and luteinizing hormone subunit beta, and identify by metabolomics metabolites potentially mediating these effects on hormones. These results support L. reuteri affecting host physiology through intestinal hormone secretion, thereby expanding our understanding of the mechanistic actions of this microbe.
    Keywords:   Lactobacillus ; GIP; PYY; adipolin; enterocyte; enteroendocrine; hormone; kisspeptin; luteinizing hormone; small intestine; vasopressin
    DOI:  https://doi.org/10.1096/fj.202401669R
  21. J Infect Dis. 2025 Mar 17. pii: jiaf128. [Epub ahead of print]
      Neutrophil elastase (NE), the main protease of neutrophils, is involved in many of their functions, including prevention of infections. Despite its general importance, NE was previously thought to play no role in infections caused by Staphylococcus aureus, one of the leading bacterial pathogens. Here, using transgenic mice deficient in NE and a mouse model of localized skin infection, we demonstrate that NE is in fact needed for the containment of S. aureus and prevention of the systemic spread of this bacterium. This is apparently due to the role of NE in the formation of neutrophil extracellular traps.
    Keywords:   Staphylococcus aureus ; elastase; neutrophil; neutrophil extracellular traps; skin infection
    DOI:  https://doi.org/10.1093/infdis/jiaf128
  22. mBio. 2025 Mar 18. e0357124
      Many human microbiome members inhibit bacterial competitors by production of antimicrobial compounds whose expression needs to be tightly controlled to balance the costs and benefits of compound biosynthesis. The nasal commensal Staphylococcus lugdunensis outcompetes Staphylococcus aureus using the antimicrobial lugdunin. The lugdunin biosynthetic gene cluster (BGC) encodes two potential regulators whose roles have remained unknown. Deletion of the regulator genes lugR or lugJ led to increased lugdunin production and/or immunity. While LugR was found to repress the transcription of the biosynthetic lugRABCTDZ operon, LugJ repressed the lugIEFGH export and immunity genes. Both regulators bound to different inverted repeats in the controlled promoter regions. Notably, both repressors were released from cognate promoters to allow transcription upon addition of exogenous lugdunin. Even minor structural changes disabled lugdunin derivatives to induce expression of its BGC, which is consistent with inferior binding to the predicted LugR and LugJ binding pockets. Thus, lugdunin controls its own biosynthesis through a feed-forward mechanism probably to avoid futile production.IMPORTANCEBiosynthetic gene clusters (BGCs) are usually tightly controlled to avoid production of costly goods at inappropriate time points or unfavorable conditions. However, in most cases, the regulatory signals of these clusters have remained unknown. Frequently, quorum sensing or two-component regulatory systems are involved in BGC expression control. This study elucidates the sophisticated regulation of lugdunin biosynthesis and secretion via two independent regulators, LugR and LugJ. Although belonging to different families of repressors, both directly interact with the antimicrobial lugdunin and thereby enhance biosynthesis and secretion in a feed forward-like mechanism.
    Keywords:  biosynthetic gene cluster; coagulase-negative Staphylococci; gene regulation; lugdunin; protein modeling
    DOI:  https://doi.org/10.1128/mbio.03571-24
  23. Front Immunol. 2025 ;16 1558252
       Introduction: Bacterial pneumonia is a burdensome, costly disease and increasingly challenging to treat due to antibiotic resistance. Complex host-pathogen interactions regulate protective immunity. Neutrophils play a central role in pulmonary bacterial immunity, and mechanistic understanding of neutrophil functions in bacterial pneumonia has potential clinical and fundamental application. Nuclear receptor 4a1 (Nr4a1), a member of the nuclear orphan receptor family, has been described to regulate inflammation and immune development in a cell type-specific manner, but its role in pulmonary host defense is not well understood.
    Methods: Wild-type (WT) and Nr4a1-/- mice, as well as bone marrow chimeric and Gr-1+ antibody depleted mice, were infected with Klebsiella pneumoniae and assessed for bacterial burden in the lung and spleen, gene transcription, protein levels, histology and cellular abundance by flow cytometry in the lung. WT and Nr4a1-/- neutrophils were exposed to live Klebsiella pneumoniae to quantify bacterial killing, as well as bulk RNA sequencing to assess transcriptomic differences.
    Results: Nr4a1-deficient mice are highly susceptible to Klebsiella pneumoniae pneumonia, which was mediated by Nr4a1 expression in immune cells. Gr-1+ antibody depletion ameliorated the Nr4a1-dependent phenotype. Ex vivo, Nr4a1-deficient neutrophils had impaired bactericidal capacity, and transcriptomic analysis identified an Nr4a1-dependent host defense program in neutrophils.
    Discussion: Neutrophil Nr4a1 expression is critical for defense against K. pneumoniae infection by regulating the neutrophil transcriptome. These findings suggest targeting Nr4a1 signaling pathways in neutrophils may be useful for bacterial pneumonia treatment.
    Keywords:  Klebsiella pneumoniae; Nr4a1; Nur77; bacterial pneumonia; lung immunity; neutrophil
    DOI:  https://doi.org/10.3389/fimmu.2025.1558252
  24. Adv Exp Med Biol. 2025 ;1472 277-294
      The balance between health and disease is intrinsically linked to the interactions between microbial communities and the host. This complex environment of antagonism and synergy involves both prokaryotic and eukaryotic cells, whose collaborative metabolic pathways and immunomodulatory elements influence system homeostasis. As with the gut and other niches, the oral microbiome has the capacity to affect distal host sites. The ability to manipulate this environment holds the potential to impact local and systemic disease.With the increasing threat of antimicrobial resistance, novel approaches to reduce the burden of disease are essential. The use of probiotics and prebiotics is one such strategy. Probiotics introduce non-pathogenic bacteria into the environment to compete with pathogens for nutrients and attachment sites, or to produce metabolites that counteract disease aetiologies. Prebiotic compounds enhance the growth of health-associated organisms, offering additional benefits, whilst a conjunctive approach with probiotics potentially holds even greater promise. Though widely studied in the gastrointestinal context, their potential for treating oral diseases, such as dental caries and periodontitis, is less understood. Additionally, the use of microbial transplantations has demonstrated efficacy in other areas, reducing systemic inflammation and recolonising with commensal bacteria. Here we evaluate their use in the oral context and their modulatory impact on overall health.In this chapter, we discuss how pro- and prebiotic strategies seek to modulate both the oral and gut environments to promote oral health and prevent disease. We assess novel approaches for utilising health-associated microorganisms to combat oral disorders, either administered locally in the mouth or imparting influence through immune modulation via the oral-gut axis. By examining available clinical trial data, we aim to further understand the intricacies involved in this discipline. Furthermore, we consider the challenges facing the research community, including optimal candidate organism/compound selection and colonisation retention, as well as considerations for future research.
    Keywords:  Caries; Microbial transplantation; Microbiome; Oral–gut axis; Periodontal disease; Prebiotics; Probiotics
    DOI:  https://doi.org/10.1007/978-3-031-79146-8_17
  25. Front Immunol. 2025 ;16 1497174
       Introduction: Chitin is a highly abundant polysaccharide in nature and is linked to immune recognition of fungal infections and asthma in humans. Ubiquitous in fungi and insects, chitin is absent inmammals and plants and, thus, represents a microbeassociatedmolecular pattern (MAMP). However, highly polymeric chitin is insoluble, which potentially hampers recognition by host immune sensors. In plants, secreted chitinases degrade polymeric chitin into diffusible oligomers, which are "fed to" innate immune receptors and co-receptors. In human and murine immune cells, a similar enzymatic activity was shown for human chitotriosidase (CHIT1), and oligomeric chitin is sensed via an innate immune receptor, Toll-like receptor (TLR) 2. However, a complete system of generating MAMPs from chitin and feeding them into a specific receptor/co-receptor-aided sensing mechanism has remained unknown in mammals.
    Methods: The effect of the secreted chitinolytic host enzyme, CHIT1, on the TLR2 activity of polymeric chitin preparations from shrimps, house dust mites and the fungal pathogen Candida albicans was assessed in vitro using cell lines and primary immune cells. Moreover, the regulation of CHIT1 was analyzed.
    Results: Here, we show that CHIT1 converts inert polymeric chitin into diffusible oligomers that can be sensed by TLR1/TLR2 co-receptor/receptor heterodimers, a process promoted by the lipopolysaccharide binding protein (LBP) and CD14. Furthermore, we observed that Chit1 is induced via the b-glucan receptor Dectin-1 upon direct contact of immortalized human macrophages to the fungal pathogen Candida albicans, whereas the defined fungal secreted aspartyl proteases, Sap2 and Sap6, from C. albicans were able to degrade CHIT1 in vitro.
    Discussion: Our study shows the existence of an inducible system of MAMP generation in the human host that enables contact-independent immune activation by diffusible MAMP ligands with a striking similarity to the plant kingdom. Moreover, this study highlights CHIT1 as a potential therapeutic target for TLR2-mediated inflammatory processes that are fueled by oligomeric chitin.
    Keywords:  Candida albicans; N-acetyl-glucosamine; Toll-like receptor (TLR); chitin; chitotriosidase; inflammation; innate immunity; myeloid cell
    DOI:  https://doi.org/10.3389/fimmu.2025.1497174
  26. Biochem Pharmacol. 2025 Mar 19. pii: S0006-2952(25)00141-8. [Epub ahead of print] 116879
      Atopic dermatitis (AD) is a chronic inflammatory skin disorder requiring improved therapeutic strategies. This study investigates the potential of ultraviolet (UV)-treated riboflavin in AD treatment. Using a MC903-induced mouse model, we demonstrate that topical UV-treated riboflavin significantly attenuates AD progression. Mechanistically, UV-treated riboflavin suppresses macrophage nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation by reducing histone H3 lysine 9 lactylation (H3K9la) on NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC) promoter, decreasing interleukin-1β (IL-1β) secretion and subsequent keratinocyte-derived thymic stromal lymphopoietin (TSLP) production. It also directly inhibits inflammatory cytokine expression in keratinocytes. NLRP3 activation in vivo partially reverses these effects, confirming the central role of NLRP3 inflammasome inhibition. Our findings reveal a novel epigenetic mechanism of UV-treated riboflavin in modulating immune responses in AD, highlighting its potential as a therapeutic strategy for inflammatory skin disorders.
    Keywords:  AD; Histone lactylation; Macrophages; NLRP3; Riboflavin
    DOI:  https://doi.org/10.1016/j.bcp.2025.116879
  27. Front Cell Infect Microbiol. 2025 ;15 1456046
      There is increasing demand for novel antimicrobial agents to tackle the antimicrobial resistance crisis. Here we report that two Enterobacteriaceae-produced siderophores, enterobactin and salmochelin S4, inhibit the growth of Staphylococcus aureus isolates, including methicillin-resistance S. aureus (MRSA) clinical isolates. The IC50 for different S. aureus isolates were 2-5 µM for salmochelin S4 and 5-10 µM for enterobactin. This inhibitory activity was partially repressed by adding Fe+3. These siderophores also inhibited the growth of Enterococcus strains, including vancomycin-resistant enterococci (VRE) clinical isolates, though less effectively than for S. aureus. The growth of various Gram-negative bacteria was barely affected by these siderophores. These results shed new light on the role of enterobactin and salmochelin in bacterial physiology and ecology and have potential for the development of novel strategies to combat the rapid rise of multidrug-resistant bacteria.
    Keywords:  Staphylococcus aureus; antibiotic; enterobactin; salmochelin; siderophore
    DOI:  https://doi.org/10.3389/fcimb.2025.1456046
  28. Proc Natl Acad Sci U S A. 2025 Mar 25. 122(12): e2322762122
      Mechanical stretch can activate long-lived changes in fibroblasts, increasing their contractility and initiating phenotypic transformations. This activation, critical to wound healing and procedures such as skin grafting, increases with mechanical stimulus for cells cultured in two-dimensional but is highly variable in cells in three-dimensional (3D) tissue. Here, we show that static mechanical stretch of cells in 3D tissues can either increase or decrease fibroblast activation depending upon recursive cell-extracellular matrix (ECM) feedback and demonstrate control of this activation through integrated in vitro and mathematical models. ECM viscoelasticity, signaling dynamics, and cell mechanics combine to yield a predictable, but nonmonotonic, relationship between mechanical stretch and long-term cell activation. Results demonstrate that feedback between cells and ECM determine how cells retain memory of mechanical stretch and have direct implications for improving outcomes in skin grafting procedures.
    Keywords:  cell-matrix feedback; fibroblasts; mechanical memory; mechanobiology; mechanotransduction
    DOI:  https://doi.org/10.1073/pnas.2322762122
  29. J Nanobiotechnology. 2025 Mar 20. 23(1): 227
      Inflammatory bowel disease (IBD) is characterized by compromised intestinal barrier function and a lack of effective treatments. Probiotics have shown promise in managing IBD due to their ability to modulate the gut microbiota, enhance intestinal barrier function, and exert anti-inflammatory effects. However, the specific mechanisms through which probiotics exert these therapeutic effects in IBD treatment remain poorly understood. Our research revealed a significant reduction of Lactiplantibacillus plantarum (L. plantarum) in the gut microbiota of IBD patients. L. plantarum is a well-known probiotic strain in the list of edible probiotics, recognized for its beneficial effects on gut health, including its ability to strengthen the intestinal barrier and reduce inflammation. We demonstrated that supplementation with L. plantarum could alleviate IBD symptoms in mice, primarily by inhibiting apoptosis in intestinal epithelial cells through L. plantarum's bacterial extracellular vesicles (L. plant-EVs). This protective effect is dependent on the efficient uptake of L. plant-EVs by intestinal cells. Intriguingly, watermelon enhances L. plantarum colonization and L. plant-EVs release, further promoting intestinal barrier repair. Our findings contribute to the understanding of L. plant-EVs in the probiotic-based therapeutic approach for IBD, as they are promising candidates for nanoparticle-based therapeutic methods that are enhanced by natural diets such as watermelon. This study thereby offers a potential breakthrough in the management and treatment of IBD.
    Keywords:   Lactiplantibacillus plantarum ; Bacterial extracellular vesicles; Inflammatory bowel disease; Intestinal barrier; Watermelon
    DOI:  https://doi.org/10.1186/s12951-025-03280-7
  30. Biofilm. 2025 Jun;9 100264
      Biofilms are bacterial communities surrounded by a polymeric matrix that can form on implanted materials and biotic surfaces, resulting in chronic infection that is recalcitrant to immune- and antibiotic-mediated clearance. Therefore, biofilm infections present a substantial clinical challenge, as treatment often involves additional surgical interventions to remove the biofilm nidus, prolonged antimicrobial therapy to clear residual bacteria, and considerable risk of treatment failure or infection recurrence. These factors, combined with progressive increases in antimicrobial resistance, highlight the need for alternative therapeutic strategies to circumvent undue morbidity, mortality, and resource strain on the healthcare system resulting from biofilm infections. One promising option is reprogramming dysfunctional immune responses elicited by biofilm. Here, we review the literature describing immune responses to biofilm infection with a focus on targets or strategies ripe for clinical translation. This represents a complex and dynamic challenge, with context-dependent host-pathogen interactions that differ across infection models, microenvironments, and individuals. Nevertheless, consistencies among these variables exist, which could facilitate the development of immune-based strategies for the future treatment of biofilm infections.
    Keywords:  Bioengineering; Biofilm; Granulocytes; Immunology; Immunometabolism; Infection
    DOI:  https://doi.org/10.1016/j.bioflm.2025.100264
  31. Adv Exp Med Biol. 2025 ;1472 225-242
      Hormones are present in oral fluids and undergo dynamic changes throughout life. Hormonal changes can influence the interactions between the microbial community and the host. The oral microbiome is sensitive to changes in the oral environment, and hormonal fluctuations can create conditions that favour the growth of certain types of bacteria over others. Since the gingival niche harbours the resident microbial community in the biofilm form, while saliva has a transient microbiota in the planktonic form, both could modulate the host-microbial interaction under hormonal oscillations.The microbiome and hormones have a dynamic bidirectional interaction. Specific oral microorganisms can metabolize steroid hormones, disrupting their host regulation. Hormones can serve as host-microbial crosstalk related to health and disease. Hormonal imbalances are associated with systemic diseases such as polycystic ovary syndrome, endometriosis, cortisol-related conditions and oral cancer. Elucidating the complex relationship between steroid hormones and the oral microbiome offers valuable insights into the mechanisms of the disease and potential therapeutic avenues for maintaining oral and systemic health.
    Keywords:  Hormone; Microbial niches; Microbiome; Oestrobolome; Oral microbiome; Steroid hormones
    DOI:  https://doi.org/10.1007/978-3-031-79146-8_14
  32. Proc Natl Acad Sci U S A. 2025 Mar 25. 122(12): e2425309122
      Mycobacterium tuberculosis (Mtb) primarily infects macrophages. In vitro without antibiotics, wild-type Mtb hastens death of the macrophages, but the processes leading to rapid cell death are not well understood. Our earlier work indicated that the death of Mtb-infected mouse macrophages in vitro is markedly exacerbated by induction of interferon-β (IFN-β) [L. Zhang et al., J. Exp. Med. 18, e20200887 (2021)]. Here, we identified a key downstream response to IFN-β in the context of Mtb infection as the massive induction of cis-aconitate decarboxylase (ACOD1), not only in its canonical subcellular localization in mitochondria but also in the cytosol, where it bound to the lysosome-stabilizing protein HSP70. ACOD1's product, itaconate, protected Mtb-infected macrophages. However, the contrasting and predominant effect of high-level ACOD1 expression was to act in a noncatalytic manner to promote HSP70's degradation, leading to lysosomal membrane permeabilization (LMP). Mtb-induced macrophage death was markedly diminished by inhibitors of cysteine proteases, consistent with lysosome-mediated cell death. Neither ACOD1 inhibitors nor cysteine protease inhibitors are suitable for potential host-directed therapy (HDT) of tuberculosis. Instead, this work directs attention to how ACOD1 acts nonenzymatically to promote the degradation of HSP70.
    Keywords:  ACOD1; IRG1; lysosomes; macrophages; tuberculosis
    DOI:  https://doi.org/10.1073/pnas.2425309122
  33. Cell Mol Life Sci. 2025 Mar 19. 82(1): 122
      Investigating innate immunity and its signaling transduction is essential to understand inflammation and host defence mechanisms. Toll-like receptors (TLRs), an evolutionarily ancient group of pattern recognition receptors, are crucial for detecting microbial components and initiating immune responses. This review summarizes the mechanisms and outcomes of TLR-mediated signaling, focusing on motifs shared with other immunological pathways, which enhances our understanding of the innate immune system. TLRs recognize molecular patterns in microbial invaders, activate innate immunity and promote antigen-specific adaptive immunity, and each of them triggers unique downstream signaling patterns. Recent advances have highlighted the importance of supramolecular organizing centers (SMOCs) in TLR signaling, ensuring precise cellular responses and pathogen detection. Furthermore, this review illuminates how TLR pathways coordinate metabolism and gene regulation, contributing to adaptive immunity and providing novel insights for next-generation therapeutic strategies. Ongoing studies hold promise for novel treatments against infectious diseases, autoimmune conditions, and cancers.
    Keywords:  IRF3; Infectious diseases; Innate immunity; MyD88; NF-κB; TLRs; TRAF; TRIF
    DOI:  https://doi.org/10.1007/s00018-025-05631-x
  34. J Exp Med. 2025 Apr 07. pii: e20240496. [Epub ahead of print]222(4):
      BCG is the oldest vaccine in continuous use. While current intradermal vaccination regimens confer limited protection outside the context of pediatric extrapulmonary tuberculosis (TB), promising new data indicate that when administered mucosally or intravenously at a higher dose, BCG can induce sterilizing immunity against pulmonary TB in nonhuman primates. BCG is also known to promote nonspecific host resistance against a variety of unrelated infections and is a standard immunotherapy for bladder cancer, suggesting that this innate immune function may contribute to its protective role against TB. Here, we propose that both the mycobacterial-specific and off-target effects of BCG depend on the interplay of adaptive and innate cells and the cytokines they produce, and that the elucidation of this interaction should be a major strategy in the development of more effective BCG-based vaccines and immunotherapies.
    DOI:  https://doi.org/10.1084/jem.20240496
  35. Genes Dis. 2025 May;12(3): 101244
      Pulmonary fibrosis is a devastating lung disease without effective treatment options. Sphingosine-1-phosphate receptor 3 (S1pr3), a receptor for the lipid signaling molecule sphingosine-1-phosphate, has been shown to mediate the development of pulmonary fibrosis, although the underlying mechanism is not fully understood. Here, we found increased expression of S1pr3 in the lung during the process of bleomycin-induced pulmonary fibrosis in mice and specific overexpression of S1pr3 in the infiltrated M2 macrophages. We constructed LysM-Cre + /S1pr3 flox/flox mice, in which S1pr3 was conditionally depleted in myeloid cells, and this depletion protected mice from bleomycin-induced lung injury and fibrosis, with reduced M2 macrophage accumulation in the lung. Increased S1pr3 expression was found in bone marrow-derived macrophages after alternatively activated by IL4 ex vivo, while loss of S1pr3 attenuated IL-4-induced M2 polarization in bone marrow-derived macrophages by repressing the PI3K/Akt-Stat3 signaling pathway. Moreover, the S1pr3 inhibitors CAY10444 and TY52156 exerted protective effects on pulmonary fibrosis in mice. Taken together, our research showed that inhibition of S1pr3 ameliorates bleomycin-induced pulmonary fibrosis by reducing macrophage M2 polarization via the PI3K/Akt-Stat3 signaling pathway, indicating that S1pr3 may be a potential target for pulmonary fibrosis treatment.
    Keywords:  Bleomycin; IL-4; M2 polarization; Macrophage; Pulmonary fibrosis; S1pr3
    DOI:  https://doi.org/10.1016/j.gendis.2024.101244