Impaired autoimmune T helper 17 cell responses following DNA vaccination against rat experimental autoimmune encephalomyelitis.

Background: We have previously shown that vaccination with DNA encoding the encephalitogenic peptide myelin oligodendrocyte glycoprotein (MOG)(91-108) (pMOG) suppresses MOG(91-108)-induced rat Experimental Autoimmune Encephalomyelitis (EAE), a model for human Multiple Sclerosis (MS). The suppressive effect of pMOG is dependent on inclusion of CpG DNA in the plasmid backbone and is associated with early induction of Interferon (IFN)-beta.

Principal Findings: In this study we examined the mechanisms underlying pMOG-induced protection.

Differential macrophage expression of IL-12 and IL-23 upon innate immune activation defines rat autoimmune susceptibility.

Rodents typically demonstrate strain-specific susceptibilities to induced autoimmune models such as experimental arthritis and encephalomyelitis. A common feature of the local pathology of these diseases is an extensive infiltration of activated macrophages (MPhi). Different functional activation states can be induced in MPhi during innate immune activation, and it is this differential activation that might be important in susceptibility/resistance to induction or perpetuation of autoimmunity.

Protective DNA vaccination against experimental autoimmune encephalomyelitis is associated with induction of IFNbeta.

DNA vaccines encoding encephalitogenic peptides protect against subsequent development of rat experimental autoimmune encephalomyelitis (EAE) through unknown mechanisms. We investigated immune cell phenotypes at different time points after DNA vaccination with vaccine encoding myelin oligodendrocyte glycoprotein peptide 91-108 and subsequent induction of EAE. In protected rats, we observed (i) no alterations in antigen-specific Th2 or Th3 responses, (ii) reduced MHC II expression on splenocytes early after EAE induction, (iii) antigen-specific upregulation of IFNbeta upon recall stimulation and (iv) reduced IL-12Rbeta2 on lymphocytes.

Comparing the pathogenesis of experimental autoimmune encephalomyelitis in CD4-/- and CD8-/- DBA/1 mice defines qualitative roles of different T cell subsets.

Experimental autoimmune encephalomyelitis (EAE) was induced with myelin oligodendrocyte glycoprotein (MOG(1-125)) in CD4(-/-) and CD8(-/-) DBA/1 mice. Both gene-deleted mice developed clinical signs of EAE, albeit milder than in wild-type mice, suggesting that both CD4(+) and CD8(+) cells participate in disease development. Demyelination and inflammation in the central nervous system was reduced in the absence of CD8(+) T cells.

Vaccination with myelin oligodendrocyte glycoprotein adsorbed to alum effectively protects DBA/1 mice from experimental autoimmune encephalomyelitis.

To prevent an organism from developing autoimmunity the body limits the number of autoreactive cells through thymic negative selection and regulates their activity through induction of suppressor T cells. Development of antigen-specific therapies provides an interesting opportunity to imitate the body's own, often effective, method of protection. Our study demonstrates that DBA/1 mice could be protected from experimental autoimmune encephalomyelitis induced through injection of recombinant myelin oligodendrocyte glycoprotein (rMOG) when they were previously immunized intraperitoneally with rMOG adsorbed to aluminium hydroxide.

Suppressive DNA vaccination in myelin oligodendrocyte glycoprotein peptide-induced experimental autoimmune encephalomyelitis involves a T1-biased immune response.

Vaccination with DNA encoding a myelin basic protein peptide suppresses Lewis rat experimental autoimmune encephalomyelitis (EAE) induced with the same peptide. Additional myelin proteins, such as myelin oligodendrocyte glycoprotein (MOG), may be important in multiple sclerosis. Here we demonstrate that DNA vaccination also suppresses MOG peptide-induced EAE.