| Autoimmune disease results from inappropriate immune responses directed at self-tissue, however, mechanisms that contribute to the immune dysregulation remain unclear. There is increasing evidence that CD4+ T cells play a central role in initiation and perpetuation of autoimmune diseases. Therefore, regulatory gene transfer into pathogenic autoantigen-specific T cells could not only inhibit further inflammation, but also promote immunotherapy.; In this thesis, it is demonstrated that transduction with pGC retroviral vectors into CD4+ T cells from autoantigen-stimulated T cell receptor (TCR) transgenic mice or antigen-activated immunized nontransgenic mice resulted in efficient and stable transduction of antigen-reactive cells. Transduced populations expressed upregulated levels of CD4 (CD4high) and were undergoing the mitosis phase of the cell cycle. In contrast, polyclonal activation of the same cultures resulted in transient transduction of nonspecific cells. Moreover, emission of the pGC reporter fluorophore directly correlated with expression of the upstream transgene.; Multiple sclerosis (MS) is an inflammatory disease of the human central nervous system (CNS) mediated by autoantigen-reactive T cells. Striking clinical, histopathological, and immunological similarities between MS and an experimentally induced disease in mice, experimental autoimmune encephalomyelitis (EAE) allow its use as a model for testing therapeutic approaches to MS. In this autoimmune model, the pathogenic CD4+ T cell exhibits a T helper 1 (Th1) phenotype characterized by heightened expression of type 1 cytokines that are pro-inflammatory and perpetuate autoimmune responses. Adoptive transfer of autoantigen-reactive CD4+ T cells transduced for Th2 "regulatory" cytokines (e.g., IL-4 and IL-10) that serve to counter the effects of pro-inflammatory cytokines were found to partially ameliorate EAE when administered prior to clinical signs. Overexpression of these cytokines were found to exacerbate disease. By contrast, adoptive transfer of CD4+ T cells transduced for high expression levels of the IL-12 receptor antagonist (IL-12 p40) resulted in protection from EAE or amelioration of established disease. Expression of IL-12 p40 suppressed gamma-IFN production in developing and effector (Th1) populations. Histological analysis confirmed long-term transgene expression in the CNS of treated recipients. Thus, adoptive immunotherapy using autoantigen-reactive CD4+ T cells provides local delivery of antagonist molecules and avoids potential systemic toxicities of transgene delivery. |
