5-lipoxygenase- and Glucocorticoid-dependent eosinophilia in a novel surgical model in mice.
Int Immunopharmacol
; 94: 107440, 2021 May.
Article
in En
| MEDLINE
| ID: mdl-33588174
ABSTRACT
BACKGROUND:
Subcutaneous implants of heat-coagulated egg white (egg white implants, EWI) induce intense local eosinophilia and prime for hyperreactivity following airway ovalbumin challenge. The roles of allergen sensitization, surgical trauma-induced glucocorticoids, and the 5-lipoxygenase (5-LO) pathway were hitherto unexplored in this model, in which quantitative recovery and large-scale purification of the eosinophils from the inflammatory site for functional and immunopharmacological studies are difficult to achieve.METHODS:
We overcame this limitation by shifting the implantation site to the peritoneal cavity (EWIp), thereby enabling quantitative leukocyte retrieval.RESULTS:
By day 7 post-surgery, eosinophil counts reached ~ 30% of all leukocytes recovered. Eosinophilia was prevented by a) induction of allergen-specific oral tolerance to ovalbumin, the main allergen in egg white; b) inactivation of the 5-lipoxygenase pathway; c) blockade of endogenous glucocorticoid signaling by pretreatment with metirapone plus mifepristone before surgery. Highly purified eosinophils (~99% pure) could be obtained from the peritoneal exudate of EWIp-carrier mice in 2 simple, antibody-free steps. Preparative-scale yields, suitable for most biochemical, pharmacological, and molecular applications, were routinely obtained, and could be further enhanced through addition of pre-or post-surgery immunization steps (active or adoptive). The recovered eosinophils were fully functional in vivo, as demonstrated by the transfer of purified eosinophils into eosinophil-deficient Δdbl-GATA-1-KO mice, which upon subsequent challenge with eotaxin-1 present secondary accumulation of neutrophils, but not of mononuclear phagocytes.CONCLUSION:
These findings document glucocorticoid-, allergen- and 5-lipoxygenase-dependent eosinophilia, which makes EWIp carriers an abundant source of pure, nontransgenic eosinophils for immunopharmacological studies.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Arachidonate 5-Lipoxygenase
/
Allergens
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Ovalbumin
/
Eosinophilia
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Glucocorticoids
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Int Immunopharmacol
Year:
2021
Document type:
Article