VLA-2 blockade in vivo by vatelizumab induces CD4+FoxP3+ regulatory T cells

Int Immunol. 2019 May 21;31(6):407-412. doi: 10.1093/intimm/dxz018.


Integrin α2β1, also known as very late antigen (VLA)-2, is a collagen-binding molecule expressed constitutively on platelets. Vatelizumab, a monoclonal antibody targeting the α2 subunit (CD49b) of VLA-2, was recently investigated for its safety and efficacy during a Phase 2 clinical study in multiple sclerosis patients, as integrin-mediated collagen binding at the site of inflammation is central to a number of downstream pro-inflammatory events. In the course of this study, we could show that VLA-2 is expressed ex vivo on platelets, platelet-T-cell aggregates, as well as a small population of highly activated memory T cells. Even though the clinical trial did not meet its primary clinical end-point (reduction in the cumulative number of new contrast-enhancing lesions on magnetic resonance imaging (MRI)), we observed enhanced frequencies of regulatory T cells (TREG) following vatelizumab treatment. Elevated TREG frequencies might be explained by the inhibition of p38 mitogen-activated protein kinase (MAPK) signaling, which is critically involved in the polarization of T helper 17 (TH17) cells and is activated by the α2 integrin cytoplasmic domain. Our findings suggest that blockade of VLA-2 might be a way to safely shift the TH17/TREG balance by inducing TREGin vivo.

Keywords: VLA-2; integrin α2β1; p38 MAPK; regulatory T cells; vatelizumab.

Publication types

  • Clinical Trial, Phase II
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / therapeutic use*
  • Blood Platelets / metabolism*
  • CD4 Antigens / metabolism
  • Collagen / metabolism
  • Forkhead Transcription Factors / metabolism
  • Humans
  • Immunologic Memory
  • Integrin alpha2 / immunology
  • Integrin alpha2 / metabolism*
  • Integrin alpha2beta1 / antagonists & inhibitors
  • Integrin alpha2beta1 / metabolism*
  • Lymphocyte Activation
  • MAP Kinase Signaling System
  • Multiple Sclerosis / drug therapy*
  • Signal Transduction
  • T-Lymphocytes, Regulatory / immunology*
  • Th17 Cells / immunology*


  • Antibodies, Monoclonal
  • CD4 Antigens
  • FOXP3 protein, human
  • Forkhead Transcription Factors
  • Integrin alpha2
  • Integrin alpha2beta1
  • Collagen