Background: The therapeutic efficacy of adipose-derived stem cells (ASCs) has been investigated for numerous clinical indications, including autoimmune and neurodegenerative diseases. Less is known using the crude adipose product called stromal vascular fraction (SVF) as therapy, although our previous studies demonstrated greater efficacy at late-stage disease compared to ASCs in the experimental autoimmune encephalomyelitis (EAE) mouse, a model of multiple sclerosis. In this study, SVF cells and ASCs were administered during the pathogenic progression, designated as early disease, to elucidate immunomodulatory mechanisms when high immune cell activities associated with autoimmune signaling occur. These implications are essential for clinical translation when considering timing of administration for cell therapies. Methods: We investigated the effects of SVF cells and ASCs by analyzing the spleens, peripheral blood, and central nervous system tissues throughout the course of EAE disease following administration of SVF cells, ASCs, or vehicle. In vitro, immunomodulatory potentials of SVF cells and ASCs were measured when exposed to EAE-derived splenocytes. Results: Interestingly, treatment with SVF cells and ASCs transiently enhanced the severity of disease directly after administration, substantiating this critical immunomodulatory signaling. More importantly, it was only the EAE mice treated with SVF cells that were able to overcome the advancing pathogenesis and showed improvements by the end of the study. The frequency of lesions in spinal cords following SVF treatment correlated with diminished activities of the T helper type 1 cells, known effector cells of this disease. Co-cultures with splenocytes isolated from EAE mice revealed transcripts of interleukin-10 and transforming growth factor-β, known promoters of regulatory T cells, that were greatly expressed in SVF cells compared to ASCs, and expression levels of signaling mediators related to effector T cells were insignificant in both SVF cells and ASCs. Conclusion: This is the first evidence, to date, to elucidate a mechanism of action of SVF treatment in an inflammatory, autoimmune disease. Our data supports key immunomodulatory signaling between cell therapies and T cells in this T cell-mediated disease. Together, treatment with SVF mediated immunomodulatory effects that diminished effector cell activities, promoted regulatory T cells, and reduced neuroinflammation.