Cladribine Reduces Trans-Endothelial Migration of Memory T Cells across an In Vitro Blood-Brain Barrier

Rachel K Ford; Pierre Juillard; Simon Hawke; Georges E Grau; Felix Marsh-Wakefield

doi:10.3390/jcm11206006

Cladribine Reduces Trans-Endothelial Migration of Memory T Cells across an In Vitro Blood-Brain Barrier

J Clin Med. 2022 Oct 12;11(20):6006. doi: 10.3390/jcm11206006.

Authors

Rachel K Ford¹, Pierre Juillard¹, Simon Hawke^{1

2}, Georges E Grau¹, Felix Marsh-Wakefield^{1

3

4}

Affiliations

¹ Vascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia.
² Central West Neurology and Neurosurgery, Orange, NSW 2800, Australia.
³ Liver Injury and Cancer Program, Centenary Institute, Sydney, NSW 2050, Australia.
⁴ Human Cancer and Viral Immunology Laboratory, The University of Sydney, Sydney, NSW 2006, Australia.

Abstract

Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system (CNS) induced by immune dysregulation. Cladribine has been championed for its clinical efficacy with relatively minor side effects in treating MS. Although it is proposed that cladribine exerts an anti-migratory effect on lymphocytes at the blood-brain barrier (BBB) in addition to its lymphocyte-depleting and modulating effects, this has not been properly studied. Here, we aimed to determine if cladribine treatment influences trans-endothelial migration of T cell subsets across an inflamed BBB. Human brain endothelial cells stimulated with pro-inflammatory cytokines were used to mimic the BBB. Peripheral blood mononuclear cells were obtained from healthy controls, untreated and cladribine-treated MS patients. The trans-endothelial migration of CD4⁺ effector memory T (T^EM) and CD8⁺ central memory T (T^CM) cells was reduced in cladribine-treated MS patients. CD28 expression was decreased on both CD4⁺ T^EM and CD8⁺ T^CM cells, suggesting lowered peripheral activation of these cells thereby maintaining the integrity of the BBB. In addition, these cells have likely reconstituted following cladribine treatment, revealing a long-term anti-migratory effect. These results highlight new mechanisms by which cladribine acts to control MS pathogenesis.

Keywords: T cells; blood–brain barrier; cladribine; multiple sclerosis; spectral flow cytometry; trans-endothelial migration.

Abstract

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