Objective: To investigate the anti-inflammatory and immunomodulatory properties of tulathromycin in vitro and in experimental models of Actinobacillus pleuropneumoniae-induced pleuropneumonia and zymosan-induced pulmonary inflammation in pigs.
Animals: Blood samples from six 8- to 30-week-old healthy male pigs for the in vitro experiment and sixty-five 3-week-old specific pathogen-free pigs.
Procedures: Neutrophils and monocyte-derived macrophages were isolated from blood samples. Isolated cells were exposed to tulathromycin (0.02 to 2.0 mg/mL) for various durations and assessed for markers of apoptosis and efferocytosis. For in vivo experiments, pigs were inoculated intratracheally with A pleuropneumoniae, zymosan, or PBS solution (control group) with or without tulathromycin pretreatment (2.5 mg/kg, IM). Bronchoalveolar lavage fluid was collected 3 and 24 hours after inoculation and analyzed for proinflammatory mediators, leukocyte apoptosis, and efferocytosis.
Results: In vitro, tulathromycin induced time- and concentration-dependent apoptosis in neutrophils, which enhanced their subsequent clearance by macrophages. In the lungs of both A pleuropneumoniae- and zymosan-challenged pigs, tulathromycin promoted leukocyte apoptosis and efferocytosis and inhibited proinflammatory leukotriene B4 production, with a concurrent reduction in leukocyte necrosis relative to that of control pigs. Tulathromycin also attenuated the degree of lung damage and lesion progression in A pleuropneumoniae-inoculated pigs.
Conclusions And Clinical Relevance: Tulathromycin had immunomodulatory effects in leukocytes in vitro and anti-inflammatory effects in pigs in experimental models of A pleuropneumoniae infection and nonmicrobial-induced pulmonary inflammation. These data suggested that in addition to its antimicrobial properties, tulathromycin may dampen severe proinflammatory responses and drive resolution of inflammation in pigs with microbial pulmonary infections.
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http://dx.doi.org/10.2460/ajvr.76.6.507 | DOI Listing |
Phagocytic clearance of apoptotic cancer cells (efferocytosis) by tumor-associated macrophages (TAMs) contributes in a substantial manner to the establishment of an immunosuppressive tumor microenvironment. This puts in context our observation that the female steroid hormone 17β-estradiol (E2) facilitates tumor immune resistance through cancer cell extrinsic Estrogen Receptor (ERalpha;) signaling in TAMs. Notable was the finding that E2 induces the expression of CX3CR1 in TAMs to enable efferocytosis of apoptotic cancer cells which results in the suppression of type I interferon (IFN) signaling.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road, Beijing 100193, China.
In clinical mastitis of dairy cows, the abnormal accumulation of apoptotic cells (ACs) and subsequent secondary necrosis and inflammation pose significant concerns, with macrophage-mediated efferocytosis, crucial for ACs clearance, remaining unexplored in this context. In nonruminants, MER proto-oncogene tyrosine kinase (MERTK) receptors are essential for efferocytosis and A Disintegrin and Metalloproteinase 17 (ADAM17) is thought to play a role in regulating MERTK integrity. This study aimed to delineate the in situ role of efferocytosis in clinical mastitis, with a particular focus on the interaction between MERTK and ADAM17 in bovine macrophages.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2024
Department of Periodontology, Tianjin Medical University School and Hospital of Stomatology & Tianjin Key Laboratory of Oral Soft and Hard Tissues Restoration and Regeneration, No.12 Qixiangtai Road, Heping District, Tianjin 300070, PR China; Tianjin Medical University Institute of Stomatology, No.12 Qixiangtai Road, Heping District, Tianjin 300070, PR China. Electronic address:
Objectives: Periodontitis is an inflammatory and destructive disease caused by dental plaque, which can result in the immune microenvironment disorders and loss of periodontal support tissue. In order to promote the restoration of local microenvironment stability, a functional biomaterial Gelatin methacryloyl @MP196/exos based on characteristics of disease occurrence is designed.
Methods: Transmission electron microscopy, nanosight particle tracking analysis and western blot analysis were applied to prove the presence of exos in GelMA@MP196/exos.
Adv Healthc Mater
December 2024
State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing, 210009, China.
During acute respiratory distress syndrome (ARDS), delayed apoptosis of neutrophils and impaired efferocytosis of macrophages constitute two critical limiting steps, leading to secondary inflammatory storm and posing a significant threat to human health. However, due to the failure of previous single target-centric treatments to effectively address these two limiting steps in controlling the inflammatory storm, no available therapies are approved for ARDS treatment. Herein, inspired by spontaneous inflammation resolution, two kinds of Apoptosis and Efferocytosis Restored Nanoparticles (AER NPs) are proposed to overcome these two limiting steps for counteracting severe inflammatory storm.
View Article and Find Full Text PDFJ Cell Mol Med
December 2024
Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan, USA.
Macrophage efferocytosis (clearance of apoptotic cells) is crucial for tissue homeostasis and wound repair, where macrophages secrete factors that promote resolution of inflammation and regenerative signalling. This study examined the role of efferocytic macrophage-associated CCL2 secretion, its influence on mesenchymal stem/progenitor cell (MSPC) chemotaxis, and in vivo cell recruitment using Ccr2 (KO) mice with disrupted CCL2 receptor signalling in two regenerative models: ossicle implants and ulnar stress fractures. Single cell RNA sequencing and PCR validation indicated that efferocytosis of various apoptotic cells at bone injury sites (osteoblasts, pre-osteoblasts, MSPC) upregulated CCL2.
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