Effect of Stress-Free Therapy on immune system: Induction of Interleukin 10 expression in lymphocytes through activation of CD19(+) CD24(hi) CD38(hi) regulatory B Cells

Background and aims: Mild thermal treatment with "Pinpoint Plantar Long-wavelength Infrared Light Irradiation (PP-LILI)" named as Stress-Free Therapy(®) increases peripheral-deep body temperature and blood flow, and improves multiple disorders including hyperpiesia, type II diabetes and cardiovascular patients. Immunomodulatory effects of PP-LILI were investigated.

Materials and methods: Seven healthy individuals and 4 people with underlying medical condition (UMC) participated in this study. Participants were given PP-LILI stimuli twice a week over 3 weeks and followed with placebo stimuli over 3 weeks. This set of sessions was repeated 3 times. For analyses, fresh peripheral mononuclear cells from participants were stained with fluorescencedye conjugated monoclonal antibodies and changes in populational compositions and IL-10 expression levels were observed by flow cytometry.

Results: Distinct expression of IL-10 in lymphocytes was induced by PP-LILI from the second session in the healthy individuals. This induction was terminated during the following placebo sessions. PP-LILI induced activation of CD19(+) CD24(hi) CD38(hi) regulatory B cells in every session prior to induce the IL-10 in major lymphocytes. Activated regulatory B cells in the individuals with UMC decreased as same levels of healthy individuals after second PP-LILI session and re-activated with the stimuli. Significant population changes in neither regulatory T cells nor proinflammatory IL-17A expressing CD4(+) T cells were observed.

Conclusions: PP-LILI is a potent immunomodulatory inducer that activates regulatory B cells and consequent IL-10 expression in lymphocytes. Moreover, its stimulatory intervals down-regulate the higher activation of regulatory B cells and lymphocyte's IL-10 expression occurred by UMC to the healthy people's level.