Protection of Tregs, suppression of Th1 and Th17 cells, and amelioration of experimental allergic encephalomyelitis by a physically-modified saline

• Published in: PloS one Vol. 7; no. 12; p. e51869
• Main Authors: Mondal, Susanta, Martinson, Jeffrey A, Ghosh, Supurna, Watson, Richard, Pahan, Kalipada
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.12.2012; Public Library of Science (PLoS)
• Subjects: Adoptive Transfer; Animals; Antigens; Autoimmune diseases; Autoimmunity; Biology; Blotting, Western; Cytokines; Cytokines - genetics; Cytokines - metabolism; Disease; Disease Models, Animal; Drugs; Encephalomyelitis; Encephalomyelitis, Autoimmune, Experimental - immunology; Encephalomyelitis, Autoimmune, Experimental - prevention & control; Enzyme-Linked Immunosorbent Assay; Experimental allergic encephalomyelitis; Female; Flow Cytometry; Forkhead Transcription Factors - metabolism; Foxp3 protein; Genotype & phenotype; Health aspects; Helper cells; Immunoenzyme Techniques; Immunomodulation; Immunoregulation; Incubation; Inflammation - immunology; Inflammation - prevention & control; Ligands; Lymphocytes; Lymphocytes T; Medicine; Mice; Multiple sclerosis; Nitric oxide; Nitric Oxide - metabolism; Nitric-oxide synthase; Oxygen; Oxygen enrichment; Pathogenesis; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; Saline solutions; Side effects; Sodium Chloride - pharmacology; Splenocytes; T cells; T-Lymphocytes, Regulatory - immunology; TCP/IP (Network protocols); Th1 Cells - immunology; Th17 Cells - immunology; Tuberculosis; United States > US; Illinois; Chicago Illinois
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0051869

In multiple sclerosis (MS) and other autoimmune diseases, the autoreactive T cells overcome the resistance provided by the regulatory T cells (Tregs) due to a decrease in the number of Foxp3-expressing Tregs. Therefore, upregulation and/or maintenance of Tregs during an autoimmune insult may have therapeutic efficacy in autoimmune diseases. Although several immunomodulatory drugs and molecules are available, most present significant side effects over long-term use. Here we have undertaken an innovative approach to upregulate Tregs and achieve immunomodulation. RNS60 is a 0.9% saline solution generated by subjecting normal saline to Taylor-Couette-Poiseuille (TCP) flow under elevated oxygen pressure. RNS60, but not NS (normal saline), RNS10.3 (TCP-modified saline without excess oxygen) and PNS60 (saline containing excess oxygen without TCP modification), was found to upregulate Foxp3 and enrich Tregs in MBP-primed T cells. Moreover, RNS60, but not NS, RNS10.3 and PNS60, inhibited the production of nitric oxide (NO) and the expression of iNOS in MBP-primed splenocytes. Incubation of the cells with an NO donor abrogated the RNS60-mediated upregulation of Foxp3. These results suggest that RNS60 boosts Tregs via suppression of NO production. Consistent to the suppressive activity of Tregs towards autoreactive T cells, RNS60, but not NS, RNS10.3, or PNS60, suppressed the differentiation of Th17 and Th1 cells and shifted the balance towards a Th2 response. Finally, RNS60 treatment exhibited immunomodulation and ameliorated adoptive transfer of experimental allergic encephalomyelitis, an animal model of MS, via Tregs. These results describe a novel immunomodulatory property of RNS60 and suggest its exploration for therapeutic intervention in MS and other autoimmune disorders.