EAE is mediated by a heterogeneous population of T cells in myelin-immunized mice. Hence, disease might develop in the absence of CXCR3 secondary to the compensatory action of encephalitogenic CCR6+ Th17 cells. However, selleck chemical in the current study, we show for the first time that blockade or genetic deficiency
of either CXCR3 or of its primary ligand has no impact on clinical EAE induced by the adoptive transfer of highly polarized Th1 effector cells. Our data illustrate the fact that, although highly targeted immunotherapies might have more favorable side effect profiles, they are also more likely to be rendered ineffective by inherent redundancies in chemokine and cytokine networks that arise at sites of neuroinflammation. Multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS), is the most common cause of Selleck SCH772984 nontraumatic disability among young adults in the United States and Europe. The majority of patients with MS present with a relapsing remitting course, characterized by episodes of neurological disability separated by clinically quiescent periods. Disease exacerbations correlate with focal breakdown of the blood–brain barrier and infiltration of the CNS by circulating leukocytes, as reflected by the appearance of gadolinium-enhancing lesions on magnetic resonance imaging (MRI) scans of the brain
and spinal cord (SC) . Drugs that block leukocyte trafficking have been shown to ameliorate MS in phase FER 3 clinical trials. Hence, gadolinium-enhancing lesions and clinical relapses are suppressed by the administration of a mAb specific for the adhesion molecule, α4 integrin, or by treatment with a sphingosine-1-phosphate receptor modulator that prevents the egress of lymphocytes from lymphoid tissues [2, 3]. Sphingosine-1-phosphate receptors and α4 integrin are widely expressed on lymphocytes. The introduction of reagents that antagonize those molecules represents a significant advance in MS therapeutics. However, there remains a need for novel drugs that modulate more restricted subsets
of T cells in order to maintain clinical efficacy while perturbing protective immunity to the minimum extent possible. In this context, chemokines and their receptors are attractive therapeutic targets for the management of autoimmune disease. It has long been recognized that the T cells that accumulate in MS lesions are enriched for expression of the chemokine receptor CXCR3 [4-6]. The ELR− CXC chemokines, CXCL9 and CXCL10, which are ligands of CXCR3, are expressed by astrocytes and microglia in spatial proximity to perivascular infiltrates [4, 7]. Similarly, CNS infiltrates of mice with experimental autoimmune encephalomyelitis (EAE, widely used as an animal model of MS) are characterized by a preponderance of CXCR3+ IFN-γ+ T cells and upregulation of CXCL10 in adjacent astrocytes [8-11].