Background: Photobiomodulation (PBM) therapy was previously shown to reduce the clinical severity of disease and modulated pro- and anti-inflammatory cytokines in an animal model of multiple sclerosis (MS). Objective: Previous observations were extended to determine the effect of PBM therapy on peripheral blood mononuclear cells and CD4+ T cells isolated from persons with MS (PwMS) and healthy donors. Methods: Using an in vitro cell culture system, isolated cells were activated and treated with red or near-infrared light wavelengths to determine the effect of PBM on the production of interferon gamma and interleukin-10 (IL-10). Results: PBM modulated cytokine production in MS subjects and healthy donors in a dose- and wavelength-dependent manner, with MS subjects and healthy donors responding differently to administered light. In addition, disease severity affected the response of immune cells, for instance, 670 nm increased IL-10 production associated with increased disease severity. Conclusions: The data show that PBM therapy has the potential to modulate pro- and anti-inflammatory cytokines in PwMS over the course of disease. Further experiments applying PBM treatment directly on patients should be carried out with extreme caution to avoid severe imbalance in the immune response.
Keywords: CD4+ cells; cytokines; multiple sclerosis; peripheral blood mononuclear cells; photobiomodulation.