CD1c-reactive, Th2 cytokine producing T-cells in human autoimmune disease

The role of CD1-restricted T cells in autoimmunity was investigated by studying patients with systemic lupus erythematosus (SLE). CD4-.CD8- double negative (DN) T-cell lines were derived from the peripheral blood of patients with SLE and from healthy donors in the presence of CD1+ antigen presenting cells. Double negative T-cell lines were restricted by CD1c and produced IL-4 but not IFN-γ. In contrast, CD1c-reactive T-cells from healthy donors produced no IL-4 and produced considerable amounts of IFN-γ. B-lymphoblastoid cell lines transfected with CD1c and CD1c+ peripheral blood B-cells induced IL-4 production from SLE-derived double negative T-cell lines, suggesting that cognate recognition of a self antigen could take place in the context of CD1c. Finally, CD1c-reactive T-cells responded to CD1c lacking an endosomal. targeting signal, indicating that antigen presentation is independent of endosomal processing. These data suggest that CD1c-reactive, Th2 T cells in SLE could interact with B cells and alter antibody responses in autoimmune disease.