A critical role for IL-18 in transformation and maturation of naive eosinophils to pathogenic eosinophils

• Published in: Journal of allergy and clinical immunology 2018-07, Vol.142 (1), p.301-305
• Main Authors: Venkateshaiah, Sathisha Upparahalli, Mishra, Akanksha, Manohar, Murli, Verma, Alok K., Rajavelu, Priya, Niranjan, Rituraj, Wild, Laurianne G., Parada, Nereida A., Blecker, Uwe, Lasky, Joseph A., Mishra, Anil
• Format: Article
• Language: English
• Subjects: Allergies; Asthma; Cytokines; Data analysis; Gene expression; Human subjects; Interleukin 18; Laboratories; Leukocytes (eosinophilic); Lungs; Patients; Proteins; Rodents; Transgenic animals
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2018.02.011

CD101 expressing eosinophils have been described as IL-5–dependent lung-specific inflammatory eosinophils in a house dust mite (HDM)–induced mouse model of asthma, which is different from the IL-5–independent residential eosinophils detected in healthy mouse lungs.4 Previously, we also reported CD101- and CD274-expressing eosinophils that are induced in the blood of patients with eosinophilic esophagitis (EoE), and their numbers increase with disease severity and decrease after treatment.5 Here we validate our previous findings of CD101- and CD274-expressing eosinophils in patients with EoE and further report that both these subsets are also present in the blood of patients with other allergic diseases, such as asthma (Fig 1, A-D). [...]differences in eosinophil size and granularity of IL-18– and IL-5–generated eosinophils were established by performing flow cytometric analysis, which indicated that IL-18–derived eosinophils are more granular and larger in size (Fig 3, E). IFN-γ induction in the lungs of Aspergillus allergen–challenged asthmatic mice was reported recently,10 and it has been reported that CD274 expression on immune cells is influenced by IFN-γ. [...]the possibility exists that in the absence of in vivo endogenous IL-18, allergen-induced IFN-γ influences weak CD274 expression on lung eosinophils. [...]this study also shows some discrepancy in expression levels of CD101 in the blood of healthy human subjects and mice, which might be due to the well-controlled conditions of age, environment, and food provided to the mice.