Soluble CD127 potentiates IL-7 activity in vivo in healthy mice

Abstract

Introduction: Soluble forms of cytokine receptors can be involved in the endogenous regulation of cytokine activity. Soluble interleukin 7 receptor α (sCD127) naturally binds IL-7, therefore there is interest in its potential application as an immunotherapeutic agent to regulate IL-7. With the hypothesis that sCD127 enhances IL-7 activity, thus promoting T-cell proliferation in vivo, we sought to assess the effect of sCD127, IL-7 or IL-7 + sCD127 treatment on CD4⁺ and CD8⁺ T-cells in the blood and spleen of mice.

Methods: Peripheral blood mononuclear cells and splenocytes were prepared, and analyzed for T-cell number, phenotype and proliferation (Ki67⁺ ) by flow cytometry.

Results: IL-7 treatment induced T-cell proliferation, increased T-cell number, and triggered T-cell differentiation each of which was enhanced with the addition of sCD127. IL-7 + sCD127 treatment significantly increased spleen weight over that seen with IL-7 treatment alone. More pronounced proliferation and a greater increase in cell number was observed in CD8⁺ T-cells relative to the effect on CD4⁺ T-cells.

Conclusions: These findings suggest that the addition of sCD127 enhances IL-7-mediated T-cell proliferation and suggests a potential therapeutic use for sCD127.

Keywords: CD4+ T-cell; CD8+ T-cell; T-cell proliferation; interleukin-7 (IL-7); soluble IL-7Rα (sCD127).