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More MS news articles for November 2002

Transfer of Central Nervous System Autoantigens and Presentation in Secondary Lymphoid Organs

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12421916&dopt=Abstract

J Immunol 2002 Nov 15;169(10):5415-5423
De Vos AF, Van Meurs M, Brok HP, Boven LA, Hintzen RQ, Van Der Valk P, Ravid R, Rensing S, Boon L, Hart BA, Laman JD.
Departments of. Immunology and Neurology, Erasmus Medical Centre, Rotterdam, The Netherlands. Department of Immunobiology, Biomedical Primate Research Centre, Rijswijk, The Netherlands. Department of Pathology, Free University Academic Hospital, Amsterdam, The Netherlands. Netherlands Brain Bank, Amsterdam, The Netherlands. Department of Veterinary Medicine and Primate Husbandry, German Primate Centre, Gottingen, Germany. Tanox Pharma, Amsterdam, The Netherlands.

Dendritic cells are thought to regulate tolerance induction vs immunization by transferring Ags and peripheral signals to draining lymph nodes (LN).

However, whether myelin Ag transfer and presentation in LN occurs during demyelinating brain disease is unknown.

In this study, we demonstrate redistribution of autoantigens from brain lesions to cervical LN in monkey experimental autoimmune encephalomyelitis (EAE) and in multiple sclerosis (MS).

Immunohistochemical analysis revealed significantly more cells containing myelin Ags in cervical LN of monkeys with EAE compared with those of healthy control monkeys.

Myelin Ags were observed in cells expressing dendritic cell/macrophage-specific markers, MHC class II, and costimulatory molecules.

Moreover, these cells were directly juxtaposed to T cells, suggesting that cognate interactions between myelin-containing APC and T cells are taking place in brain-draining LN.

Indeed, myelin Ag-reactive T cells were observed in cervical LN from marmosets and rhesus monkeys.

Importantly, these findings were paralleled by our findings in human tissue.

We observed significantly more myelin Ag-containing cells in LN of individuals with MS compared with those of control individuals.

These cells expressed APC markers, as observed in marmosets and rhesus monkeys.

These findings suggest that during MS and EAE, modulation of T cell reactivity against brain-derived Ags also takes place in cervical LN and not necessarily inside the brain.

A major implication is that novel therapeutic strategies may be targeted to peripheral events, thereby circumventing the blood-brain barrier.