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20-Hydroxy- And 20-carboxy-leukotriene (LT) B

Anne-Sophie Archambault, Samuel Poirier, Julie-S Lefebvre, Philippe-Pierre Robichaud, Marie-Chantal Larose, Caroline Turcotte, Cyril Martin, Véronique Provost, Luc H Boudreau, Patrick P McDonald, Michel Laviolette, etc.

J Leukoc Biol. 2019 Jun;105(6):1131-1142.

PMID: 30676680

Abstract:

Leukotriene B4 (LTB4 ) plays a prominent role in innate immunity as it induces phagocyte recruitment, the release of antimicrobial effectors, and as it potentiates the ingestion and killing of pathogens. In humans, LTB4 has a short half-life and is rapidly metabolized by leukocytes, notably into 20-OH- and 20-COOH-LTB4 by neutrophils. Although these LTB4 metabolites bind to the BLT1 receptor with high affinity, they activate neutrophils to a much lower extent than LTB4 . We thus postulated that LTB4 metabolites could dampen BLT1 -mediated responses, therefore limiting the impact of LTB4 on human neutrophil functions. We found that 20-OH-LTB4 and 20-COOH-LTB4 inhibited all of the LTB4 -mediated neutrophil responses we tested (migration, degranulation, leukotriene biosynthesis). The potencies of the different compounds at inhibiting LTB4 -mediated responses were 20-OH-LTB4 = CP 105,696 (BLT1 antagonist) > > 20-COOH-LTB4 ≥ resolvin E1 (RVE1 ). In contrast, the fMLP- and IL-8-mediated responses we tested were not affected by the LTB4 metabolites or RVE1 . 20-OH-LTB4 and 20-COOH-LTB4 also inhibited the LTB4 -mediated migration of human eosinophils but not that induced by 5-KETE. Moreover, using 20-COOH-LTB4 , LTB4 , and LTB4 -alkyne, we show that LTB4 is a chemotactic, rather than a chemokinetic factor for both human neutrophils and eosinophils. In conclusion, our data indicate that LTB4 metabolites and RVE1 act as natural inhibitors of LTB4 -mediated responses. Thus, preventing LTB4 ω-oxidation might result in increased innate immunity and granulocyte functions.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP158081993 CP-105,696 CP-105,696 158081-99-3 Price
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