17β-Estradiol increases the number of effector memory CD8⁺ lymphocytes in mice with contact hypersensitivity and among cultured splenocytes

Abstract

To determine how estrogen exacerbates allergies, the effects of 17β-estradiol (E2) on lymphocyte proliferation were investigated. BALB/c mice were ovariectomized, administered 3.2 μg E2, and sensitized with 50 μL 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one. After 7 days, their spleens were excised and flow cytometrically analyzed. The CD8⁺CD45RA⁻CCR7⁻ cell–to–CD8⁺ cell ratio in the spleen was greater in the E2-administered mice than in the controls. Splenocytes were cultured under concanavalin A stimulation, with or without E2. After 4 days, the above ratio was greater in the case of E2-treated splenocytes. E2 increases the number of effector memory CD8⁺ lymphocytes during sensitization in contact hypersensitivity.

Keywords::

• Contact hypersensitivity
• 17β-estradiol
• memory lymphocyte
• effector memory lymphocyte

Declaration of interest: This study was supported by Kakenhi, Grant-in-Aid for Young Scientists (B), of the Ministry of Education, Culture, Sports, Science and Technology of Japan (project number 19790410). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.