Toll-like receptor activation of equine mesenchymal stromal cells to enhance antibacterial activity and immunomodulatory cytokine secretion.
Vet Surg
; 50(4): 858-871, 2021 May.
Article
em En
| MEDLINE
| ID: mdl-33797775
ABSTRACT
OBJECTIVE:
To evaluate effects of Toll-like and nucleotide-binding oligomerization domain (NOD)-like receptor (TLR, NLR) ligand stimulation of equine mesenchymal stromal cells (MSCs) on antibacterial and immunomodulatory properties in vitro. STUDYDESIGN:
Controlled laboratory study. SAMPLE POPULATION Equine bone-marrow-derived MSCs (three horses).METHODS:
MSCs were stimulated with TLR (polyinosinicpolycytidylic acid [pIC] and lipopolysaccharide [LPS]) and NLR agonists (γ-d-Glu-mDAP [IE-DAP]) for 2 h, and plated at 1 × 105 cells/well 24 h. MSC-conditioned media (MSC-CM) were collected and assessed for antimicrobial peptide cathelicidin/LL-37 production, bactericidal action against multidrug-resistant planktonic and biofilm Staphylococcus aureus and neutrophil phagocytosis. Bacterial growth was measured by plating bacteria and counting viable colonies, reading culture absorbance, and live-dead staining with confocal microscopy imaging. Following initial comparison of activating stimuli, TLR3-agonist pIC protocols (cell density during activation and plating, culture time, %serum) were further optimized for bactericidal activity and secretion of interleukin-8 (IL-8), monocyte-chemoattractant-protein (MCP-1), and cathelicidin/LL37.RESULTS:
MSCs stimulation with pIC (p = .004) and IE-DAP (p = .03) promoted increased bactericidal activity, evidenced by reduced viable planktonic colony counts. PIC stimulation (2 × 106 cells/ml, 2 h, 10 µg/ml) further suppressed biofilm formation (p = .001), enhanced neutrophil bacterial phagocytosis (p = .009), increased MCP-1 secretion (p < .0001), and enhanced cathelicidin/LL-37 production, which was apparent when serum concentration in media was reduced to 1% (p = .01) and 2.5% (p = .05).CONCLUSION:
TLR-3 pIC MSCs activation was most effective to enhance antibacterial and cytokine responses, which were affected by serum reduction. CLINICALSIGNIFICANCE:
In vitro TLR-3 activation of equine MSCs tested here may be a strategy to improve antibacterial properties of MSCs to treat antibiotic-resistant infections.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fagocitose
/
Staphylococcus aureus
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Peptídeos Catiônicos Antimicrobianos
/
Receptores Toll-Like
/
Imunomodulação
/
Células-Tronco Mesenquimais
/
Cavalos
Tipo de estudo:
Guideline
Limite:
Animals
Idioma:
En
Revista:
Vet Surg
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Estados Unidos