The immune system is remarkably efficient in discriminating self from nonself and is equipped with an array of effector mechanisms designed to destroy foreign (nonself) entities. However, in certain pathological conditions, the immune system mistakenly recognizes a self tissue as foreign and initiates a destructive immune response against tissue-specific self “antigens”.  These pathological conditions, known as autoimmune diseases, account for a wide array of human diseases including arthritis, diabetes, myasthenia gravis, and multiple sclerosis among many others. Our research is focused upon the molecular and cellular basis of an autoimmune disease known as experimental autoimmune encephalitis (EAE). In this disease, experimental animals experience a paralytic autoimmune attack against the myelin sheath of central nervous system axons. Due to the clinical and histological features of this disease, EAE is widely regarded as a relevant animal model for human demyelinating diseases such as multiple sclerosis.

Our primary research interest involves devising a novel class of tolerogenic vaccines as a therapy for multiple sclerosis.   These vaccines consist of cytokine-neuroantigen (NAg) fusion proteins and have been shown to restore homeostatic self tolerance in EAE.  Antigen-specific regimens of tolerance induction promise to have improved efficacy compared to general immunosuppressive approaches because the anti-inflammatory activity of these tolerogenic vaccines is focused exclusively on the small percentage of relevant pathogenic T cells.  Thus, these vaccines obviate the need for global immune suppression.  Furthermore, antigen-specific therapies are known to induce antigen-specific tolerance which is remembered by the immune system as a learned tolerance.  Antigen-specific delivery regimens therefore will require temporary rather than chronic administration, will be effective at lower doses, and will exhibit superior efficacy and cost-effectiveness with fewer adverse side effects.

We have tested several of these cytokine-antigen fusion proteins in the EAE rodent model of multiple sclerosis.  Four cytokine-NAg fusion proteins were potent inhibitors of EAE. The fusion proteins incorporated the IL-2 cytokine as the N-terminal domain (the IL2-NAg fusion protein), the secreted IL-16 cytokine as the C-terminal domain (the NAgIL16 fusion protein), the IFN-beta cytokine as the N-terminal domain (IFN-beta-NAg fusion protein), or the GM-CSF cytokine as the N-terminal domain (the GMCSF-NAg fusion protein).  The antigenic domain of each fusion protein was comprised of the major encephalitogenic determinant of myelin basic protein (referred to as the neuroantigen or NAg).  These fusion proteins were highly effective tolerogens and could be used as pre-treatments to inhibit a subsequent encephalitogenic challenge.  These fusion proteins also were highly effective in stopping progression of disease when treatment was initiated during an ongoing attack.  Our future research is dedicated to understanding the molecular and cellular mechanisms underlying the tolerogenic activity of these vaccines.  We are also engaged in translational research to develop the clinical application of these vaccines for treatment of multiple sclerosis.

Blanchfield, J. L., and M. D. Mannie. 2010. A GMCSF-neuroantigen fusion protein is a potent tolerogen in experimental autoimmune encephalomyelitis (EAE) that is associated with efficient targeting of neuroantigen to APC. J. Leukocyte Biology In press.

Mannie, M., R. H. Swanborg, and J. A. Stepaniak. 2009. Experimental autoimmune encephalomyelitis in the rat. Curr Protoc Immunol Chapter 15:Unit 15 12.

Mannie, M. D., D. J. Abbott, and J. L. Blanchfield. 2009. Experimental autoimmune encephalomyelitis in Lewis rats: IFN-beta acts as a tolerogenic adjuvant for induction of neuroantigen-dependent tolerance. J Immunol 182:5331-5341.

Mannie, M. D., J. L. Devine, B. A. Clayson, L. T. Lewis, and D. J. Abbott. 2007. Cytokine-neuroantigen fusion proteins: new tools for modulation of myelin basic protein (MBP)-specific T cell responses in experimental autoimmune encephalomyelitis. J Immunol Methods 319:118-132.

Mannie, M. D., B. A. Clayson, E. J. Buskirk, J. L. DeVine, J. J. Hernandez, and D. J. Abbott. 2007. IL-2/neuroantigen fusion proteins as antigen-specific tolerogens in experimental autoimmune encephalomyelitis (EAE): correlation of T cell-mediated antigen presentation and tolerance induction. J Immunol 178:2835-2843.

Mannie, M. D., and D. J. Abbott. 2007. A fusion protein consisting of IL-16 and the encephalitogenic peptide of myelin basic protein constitutes an antigen-specific tolerogenic vaccine that inhibits experimental autoimmune encephalomyelitis. J Immunol 179:1458-1465.

Mannie, M. D., T. J. McConnell, C. Xie, and Y. Q. Li. 2005. Activation-dependent phases of T cells distinguished by use of optical tweezers and near infrared Raman spectroscopy. J Immunol Methods 297:53-60.

Mannie, M. D., J. G. Dawkins, M. R. Walker, B. A. Clayson, and D. M. Patel. 2004. MHC class II biosynthesis by activated rat CD4+ T cells: development of repression in vitro and modulation by APC-derived signals. Cell Immunol 230:33-43.

Mannie, M. D., D. J. Fraser, and T. J. McConnell. 2003. IL-4 responsive CD4+ T cells specific for myelin basic protein: IL-2 confers a prolonged postactivation refractory phase. Immunol Cell Biol 81:8-19.

Walker, M. R., and M. D. Mannie. 2002. Acquisition of functional MHC class II/peptide complexes by T cells during thymic development and CNS-directed pathogenesis. Cell Immunol 218:13-25.

Mannie, M. D. 2001. T cell-mediated antigen presentation: a potential mechanism of infectious tolerance. Immunol Res 23:1-21.

Walker, M. R., and M. D. Mannie. 2001. T cell recognition of rat myelin basic protein as a TCR antagonist inhibits reciprocal activation of antigen-presenting cells and engenders resistance to experimental autoimmune encephalomyelitis. Eur J Immunol 31:1894-1899.

Mannie, M. D.,and M. R. Walker. 2001. Feedback activation of T-cell antigen-presenting cells during interactions with T-cell responders. J Leukoc Biol 70:252-260.

Norris, M. S., T. J. McConnell, and M. D. Mannie. 2001. Interleukin-2 promotes antigenic reactivity of rested T cells but prolongs the postactivational refractory phase of activated T cells. Cell Immunol 211:51-60.

Mannie, M. D., and M. S. Norris. 2001. MHC class-II-restricted antigen presentation by myelin basic protein-specific CD4+ T cells causes prolonged desensitization and outgrowth of CD4- responders. Cell Immunol 212:51-62.

Patel, D. M., R. W. Dudek, and M. D. Mannie. 2001. Intercellular exchange of class II MHC complexes: ultrastructural localization and functional presentation of adsorbed I-A/peptide complexes. Cell Immunol 214:21-34.

Patel, D. M., and M. D. Mannie. 2001. Intercellular exchange of class II major histocompatibility complex/peptide complexes is a conserved process that requires activation of T cells but is constitutive in other types of antigen presenting cell. Cell Immunol 214:165-172.

Arnold, P. Y., and M. D. Mannie. 1999. Vesicles bearing MHC class II molecules mediate transfer of antigen from antigen-presenting cells to CD4+ T cells. Eur J Immunol 29:1363-1373.

Mannie, M. D. 1999. Immunological self/nonself discrimination: integration of self vs nonself during cognate T cell interactions with antigen-presenting cells. Immunol Res 19:65-87.

Walker, M. R., G. A. White, J. P. Nardella, and M. D. Mannie. 1999. An autologous self-antigen differentially regulates expression of I-A glycoproteins and B7 costimulatory molecules on CD4- CD8- T helper cells. J Leukoc Biol 66:120-126.

Patel, D. M., P. Y. Arnold, G. A. White, J. P. Nardella, and M. D. Mannie. 1999. Class II MHC/peptide complexes are released from APC and are acquired by T cell responders during specific antigen recognition. J Immunol 163:5201-5210.