Patterns of expression, membrane localization, and effects of ectopic expression suggest a function for MS4a4B, a CD20 homolog in Th1 T cells

Blood. 2006 Mar 15;107(6):2400-8. doi: 10.1182/blood-2005-08-3340. Epub 2005 Nov 17.


The membrane-spanning 4A (MS4A) family of proteins includes CD20, Fc epsilonRIbeta, and HTm4, whose genes are grouped in a chromosomal location that is associated with increased susceptibility to allergy and atopic asthma. One family member, Chandra/MS4a4B, was reported to be expressed in T helper 1 (Th1) T cells but not Th2 T cells. In the present study, Ms4a4b was isolated in a screen of genes differentially expressed during thymocyte development. MS4a4B was detected in immature CD4- CD8- CD44+ CD25- thymocytes, turned off during further stages of thymocyte development and reexpressed in mature single-positive thymocytes. MS4a4B expression was found in naive CD8+ and CD4+ peripheral T cells and natural killer (NK) cells but not in B cells. MS4a4B is expressed at the cell surface with its C-terminus located in the cytoplasm. When expressed in a T-cell hybridoma by retroviral vector, MS4a4B protein constitutively associated with lipid raft microdomains, whereas in primary T cells endogenous MS4a4B protein became enriched in rafts after T-cell activation. Overexpression of MS4a4B in primary CD4+ T-cell blasts enhanced T-cell receptor (TCR)-induced Th1 cytokine production. These results suggest that MS4a4B expression is tightly regulated during T-cell development and that MS4a4B expression promotes Th1 function and/or differentiation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD20
  • Gene Expression Profiling
  • Gene Expression Regulation / immunology*
  • Killer Cells, Natural / metabolism
  • Lymphocyte Activation / immunology
  • Membrane Microdomains / immunology*
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Mice
  • T-Lymphocytes / metabolism
  • Th1 Cells / metabolism*
  • Thymus Gland / metabolism
  • Transfection


  • Antigens, CD20
  • Membrane Proteins
  • Ms4a4b protein, mouse