Amino acid copolymer-specific IL-10-secreting regulatory T cells that ameliorate autoimmune diseases in mice

Abstract

IL-10-secreting regulatory T cell lines specific to glatiramer acetate [poly(Y,E,A,K)n] or poly(Y,F,A,K)n have been established from the enlarged spleen and lymph nodes that result from copolymer treatment of SJL mice in which experimental autoimmune encephalomyelitis was induced by PLP139-151. These CD4+CD25+T cell lines secrete high levels of IL-10 and IL-13 but only small amounts of IL-4 and virtually no TGF-β, IL-17, IL-6, IFN-γ, or TNF-α. Their phenotypes are particularly characterized by the absence of Foxp3 and the presence of two TNFR family members, CD30 and GITR. The lines proliferated specifically to the immunizing copolymers but were autoantigen-nonspecific, in that the same T cell line could suppress autoimmunity induced by three different autoantigens in SJL mice, i.e., PLP139-151(EAE), MBP85-99 (EAE), and bovine peripheral nerve myelin (experimental autoimmune neuritis), indicating they function by bystander suppression.

Promoting tolerance to proteolipid protein-induced experimental autoimmune encephalomyelitis through targeting dendritic cells

“…4A). In one of the experiments, as a positive control, an additional group of SJL mice was coimmunized with 500 μg of the synthetic amino acid copolymer poly(F,Y,A,K)n, which has previously been shown to ameliorate PLP139-151-induced EAE by the generation of IL-10-secreting Tr1-like Tregs (25,26). Disease was induced 10 d later by PLP139-151/CFA/PT administration.…”

T cell receptors in an IL-10-secreting amino acid copolymer-specific regulatory T cell line that mediates bystander immunosuppression

“…This is not surprising because these 2 random copolymers, FYAK and GA (YEAK), share 3 amino acids. In addition, the ''␣␤1'' TCR transfectant that recognizes both FYAK and GA must recognize an epitope distinct from the epitope in GA that cross-reacts with the J5 immunomodulatory peptide (26) (that can also induce regulatory T cells) because J5 stimulates neither the TCR transductant nor the cell line from which the ''␣␤1'' TCR was obtained (10). In further experiments, it will be important to use J5 and other immunomodulatory peptides with defined sequences to examine these issues.…”

“…Supernatant for ELISA was harvested from hybridoma-T cells stimulated with antigens and APC after 48 h as described in ref. 10. The IL-2 ELISA kit was purchased from eBioscience.…”

“…T cell lines were established from spleens of SJL mice as described, using either the random amino acid copolymer FYAK or the autoantigen PLP139-151 as the immunogen (10,(24)(25)(26). The primary lines were restimulated 3 times at 2-week intervals in IL-2.…”

“…More recently, a random copolymer, poly-(F,Y,A,K)n, called FYAK, that appears to be more effective than GA in several mouse models of EAE has been extensively studied (10). Both copolymers ameliorate EAE by induction of regulatory T cells that secrete the immunomodulatory cytokine IL-10 principally, and other cytokines in smaller amounts (10). These IL-10 secreting T cells belong to the family of cytokinesecreting T cells, including Tr1 and Th3 cells (3,11), which mediate bystander immunosuppression.…”