Effect of natalizumab on circulating CD4+ T-cells in multiple sclerosis

• Published in: PloS one Vol. 7; no. 11; p. e47578
• Main Authors: Börnsen, Lars, Christensen, Jeppe Romme, Ratzer, Rikke, Oturai, Annette Bang, Sørensen, Per Soelberg, Søndergaard, Helle Bach, Sellebjerg, Finn
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 30.11.2012; Public Library of Science (PLoS)
• Subjects: Activation; Adult; Antibodies, Monoclonal, Humanized - pharmacology; Antibodies, Monoclonal, Humanized - therapeutic use; Antigens; Blood; Case-Control Studies; CD134 antigen; CD4 antigen; CD4-Positive T-Lymphocytes - drug effects; CD4-Positive T-Lymphocytes - immunology; CD4-Positive T-Lymphocytes - pathology; Cell adhesion & migration; Cell Migration Inhibition - drug effects; Cell Migration Inhibition - immunology; Cells, Cultured; Central nervous system; Central Nervous System - drug effects; Central Nervous System - immunology; Central Nervous System - pathology; Cytokines; Effector cells; Endothelium; Extravasation; Female; Flow cytometry; Gene expression; Gene Expression - drug effects; Humans; Immune response; Immune system; Immunologic Memory - drug effects; Immunological memory; Immunotherapy; Inflammation; Integrin alpha4beta1 - genetics; Integrin alpha4beta1 - immunology; Lesions; Ligands; Lymphocyte Activation - drug effects; Lymphocytes; Lymphocytes T; Male; Medicine; Memory cells; Monoclonal antibodies; Multiple sclerosis; Multiple Sclerosis - drug therapy; Multiple Sclerosis - immunology; Multiple Sclerosis - pathology; Myelin; Myelin Basic Protein - genetics; Myelin Basic Protein - immunology; Natalizumab; Neurology; Patients; Receptors, OX40 - genetics; Receptors, OX40 - immunology; Signal Transduction - drug effects; Studies; T cell receptors; T-Lymphocyte Subsets - drug effects; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - pathology; Transcription factors; Tumor Necrosis Factor-alpha - pharmacology; Tumor necrosis factor-α; VLA-4 antigen; Denmark
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0047578

In multiple sclerosis (MS), treatment with the monoclonal antibody natalizumab effectively reduces the formation of acute lesions in the central nervous system (CNS). Natalizumab binds the integrin very late antigen (VLA)-4, expressed on the surface of immune cells, and inhibits VLA-4 dependent transmigration of circulating immune-cells across the vascular endothelium into the CNS. Recent studies suggested that natalizumab treated MS patients have an increased T-cell pool in the blood compartment which may be selectively enriched in activated T-cells. Proposed causes are sequestration of activated T-cells due to reduced extravasation of activated and pro-inflammatory T-cells or due to induction of VLA-4 mediated co-stimulatory signals by natalizumab. In this study we examined how natalizumab treatment altered the distribution of effector and memory T-cell subsets in the blood compartment and if T-cells in general or myelin-reactive T-cells in particular showed signs of increased immune activation. Furthermore we examined the effects of natalizumab on CD4(+) T-cell responses to myelin in vitro. Natalizumab-treated MS patients had significantly increased numbers of effector-memory T-cells in the blood. In T-cells from natalizumab-treated MS patients, the expression of TNF-α mRNA was increased whereas the expression of fourteen other effector cytokines or transcription factors was unchanged. Natalizumab-treated MS patients had significantly decreased expression of the co-stimulatory molecule CD134 on CD4(+)CD26(HIGH) T-cells, in blood, and natalizumab decreased the expression of CD134 on MBP-reactive CD26(HIGH)CD4(+) T-cells in vitro. Otherwise CD4(+) T-cells from natalizumab-treated and untreated MS patients showed similar responses to MBP. In conclusion natalizumab treatment selectively increased the effector memory T-cell pool but not the activation state of T-cells in the blood compartment. Myelin-reactive T-cells were not selectively increased in natalizumab treated MS.