References of "El Abbas, Sophie"
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See detailCharacterisation of TLR7/8 in equine pulmonary alveolar macrophages
Tosi, Irène ULg; Frellstedt, Linda; Pirottin, Dimitri ULg et al

Poster (2015, October 08)

Purpose of the study: In both human and equine athletes, viral infections are common causes of respiratory diseases and of a sudden deterioration of expected performances. In both species, the underlying ... [more ▼]

Purpose of the study: In both human and equine athletes, viral infections are common causes of respiratory diseases and of a sudden deterioration of expected performances. In both species, the underlying mechanisms are still unclear, and an involvement of Toll-Like Receptors (TLRs), a fundamental link between innate and adaptive immunity, has been advocated. Our objectives were to verify the presence of TLR7 and TLR8, responsible for the early anti-viral response in mammals, in equine pulmonary alveolar macrophages (PAMs) and to assess their function through specific stimulation. Methods used: Equine PAMs were collected by broncho-alveolar lavage (BAL), isolated by adherence and stimulated with specific TLR7/8 ligands (an imidazoquinoline compound and single-stranded RNA), mimicking a viral attack. The expression of TLR7/8 was evaluated by rt-PCR and the ligand-induced production of cytokines (type I-IFNs and TNF-α) was assessed via ELISA. Summary of results: Our study demonstrated the expression of TLR7/8 in equine PAMs. QPCR analyses showed a high relative expression of genes coding for TLR7 and TLR8 on equine PAM. Stimulation with specific TLR7/8 ligands resulted in significantly up-regulated production of IFN-β and TNF-α, thereby confirming that TLR7/8 are functional in equine PAMs and that they play a role in the early pulmonary antiviral response. Conclusions: This study shows that TLR7 and TLR8 are present and functional in equine PAM and that they could play a role in the early pulmonary antiviral response. In terms of future perspectives, it is interesting to suggest that the extensively demonstrated efficacy of TLR7 and TLR8 synthetic ligands in the treatment of viral diseases in human medicine could motivate the pursuit of clinical trials in the equine patient for the therapeutic management or prevention of viral respiratory infections. [less ▲]

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See detailExperimental model of equine alveolar macrophage stimulation with TLR ligands.
Waldschmidt, Ingrid; Pirottin, Dimitri ULg; Art, Tatiana ULg et al

in Veterinary Immunology and Immunopathology (2013), 155(1-2), 30-37

Pulmonary diseases are common in horses and have a major economic impact on the equine industry. Some of them could be associated with an inadequate immune response in the lung, but methods to evaluate ... [more ▼]

Pulmonary diseases are common in horses and have a major economic impact on the equine industry. Some of them could be associated with an inadequate immune response in the lung, but methods to evaluate this response in horses are lacking. The aim of this study was to develop and validate an experimental model that could be applied in several physiological and pathological conditions to assess the innate immune response of equine pulmonary cells. Equine alveolar macrophages (AMs) obtained from bronchoalveolar lavages were isolated from other cells by adhesion. TLR2, 3, and 4 expression in AMs was studied and their responses to commercial ligands (respectively FSL-1, Poly(I:C), and LPS) were evaluated after determination of the appropriate dose and time of incubation. TLR responses were assessed by measuring cytokine production using (1) gene expression of TNFalpha, IFNbeta, Il-1beta, and IFNalpha by qPCR (indirect method); and (2) cytokine production for TNFalpha and IFNbeta by ELISA (direct method). TLR 2, 3, and 4 were expressed by AMs. TLR 2 stimulation with 10ng/mL of FSL-1 during 3h significantly increased IL-1beta and TNFalpha gene expression. TLR 3 stimulation with 1000ng/mL of Poly(I:C) during 1h increased IFNbeta, IFNalpha, Il-1beta and TNFalpha expression. TLR 4 stimulation with 100ng/mL of LPS during 3h increased TNFalpha, IFNbeta, and Il-1beta expression. Results obtained by ELISA quantification of TNFalpha and IFNbeta produced by AMs following stimulation during 6h were similar: FSL-1 increased TNFalpha production but not IFNbeta, Poly(I:C) and LPS increased production of IFNbeta and TNFalpha. In conclusion, pulmonary innate immunity of horses can be assessed ex vivo by measuring cytokine production following stimulation of AMs with TLR agonists. This experimental model could be applied under several conditions especially to improve the understanding of equine respiratory disease pathogenesis, and to suggest novel therapeutic opportunities. [less ▲]

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