The flotillins are integral membrane proteins in lipid rafts that contain TCR-associated signaling components: Implications for T-cell activation

Ndaisha Slaughter, Isett Laux, Xiaolin Tu, Julian Whitelegge, Xiaoming Zhu, Rita Effros, Perry Bickel, Andre Nel

Research output: Contribution to journalArticle

57 Scopus citations

Abstract

Lipid rafts play an important role in signal integration and cellular activation by the T-cell antigen receptor (TCR). We demonstrate that flotillin-1 and flotillin-2 are important structural raft components, which redistribute to the site of TCR engagement. An antibody to flotillin-1 was able to immobilize other TCR-associated raft components. Although rafts purified from unstimulated cells demonstrated abundant Lck but inabundant LAT, rafts from stimulated cells include an abundance of both components. This suggests dynamic changes in lipid raft composition during CD3/CD28 costimulation. Stimulation of primary human CD4+ T cells leads to increased GM1 and flotillin-1 expression in the surface membrane, where these components colocalize. This may reconstitute new signaling complexes required for T-cell activation. Altered lipid raft composition and function may play a role in the decline of antigen responsiveness in senescent T cells. In this regard, we observed an increase in the raft-associated gangliolipid, GM1, in resting human CD4+ and CD8+ lymphocytes with aging.

Original languageEnglish (US)
Pages (from-to)138-151
Number of pages14
JournalClinical Immunology
Volume108
Issue number2
DOIs
StatePublished - Aug 1 2003

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ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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