| Multiple sclerosis (MS) has a relapsing-remitting nature in most patients, but the mechanisms underlying exacerbation of the disease are poorly understood. Autoimmunity towards central nervous system (CNS) components is involved in the perpetuation of MS. Epitope-spreading, the continuous broadening of the immune response towards CNS components, is found in MS and relapsing experimental autoimmune encephalomyelitis (EAE), but whether this process is the triggering force behind relapses is still controversial. Cervical lymph nodes (LN) are a major site of drainage of both cells and antigens injected into the brain of experimental animals. Recently, we have shown that brain-derived myelin components are also present in antigen presenting cells (APC) within the cervical LN during MS and demyelinating EAE in non-human primates. Although brain-injected model antigens induce a tolerogenic immune response in the cervical LN, it is unclear whether this holds also for debris resulting from inflammatory brain demyelination. The aim of this project is to elucidate the processes that take place in the cervical LN during demyelinating disease and to interfere in the ongoing immune process by targeting APC in the cervical LN. These studies will be performed with demyelinating mouse models with distinct underlying pathogenic mechanisms, as well as with LN from MS patients. Although both the anatomical organisation of cervical LN in man and mice, and the initiation of MS and experimental (autoimmune) demyelination are different, these models in mice provide the possibility to investigate the functional properties of myelin antigen containing cervical LN cells in brain demyelination in vivo, in vitro and in situ and to determine whether elimination, activation or inactivation of these cells alters the relapsing disease process. Three main questions will be addressed in this project: 1. Does myelin antigen transfer and presentation in cervical LN induce tolerance or immunity? 2. Are cervical LN cells, and in particular myelin antigen containing APC, instrumental in the relapsing nature of the disease? 3. Are myelin antigen containing cells in cervical LN a target for therapeutic intervention of an ongoing demyelinating process in the brain? These issues will be addressed in parallel using cervical LN of mice with demyelinating EAE and cervical LN of MS patients. The results of these studies will be compared to determine whether findings in mouse EAE models hold also for MS. It is anticipated that these studies will reveal pathophysiological significance of myelin antigen drainage to cervical LN in the immunological processes during EAE and MS, and will provide new concepts for targeted and non-invasive treatment of this disease. |