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Visualizing Antigen Specific CD4+ T Cells using MHC Class II Tetramers
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Published on: March 6, 2009

The tetraspanin CD9 is preferentially expressed on the human CD4(+)CD45RA+ naive T cell population and is involved in

H Kobayashi1, O Hosono, S Iwata

  • 1Division of Clinical Immunology, Advanced Clinical Research Center, Institute of Medical Science, University of Tokyo, Tokyo, Japan.

Clinical and Experimental Immunology
|June 16, 2004
PubMed

Human CD4+ T cells can be divided into reciprocal memory and naive T cell subsets based on their expression of CD45 isoforms and CD29/integrin beta1 subunit. To identify unique cell surface molecules on human T cells, we developed a new monoclonal antibody termed anti5H9. Binding of anti5H9 triggers a co-stimulatory response in human peripheral blood T cells. Retrovirus-mediated expression cloning has revealed that the antigen recognized by anti5H9 is identical to the tetraspanin CD9. We now show that human CD9 is preferentially expressed on the CD4(+)CD45RA+ naive T cell subset, and that CD9(+)CD45RA+ T cells respond preferentially to the recombinant beta2-glycoprotein I, compared to CD9-CD45RA+ T cells. Furthermore, anti5H9 inhibits both the recombinant beta2-glycoprotein I- and the recall antigen tetanus toxoid-specific T cell proliferation. These results suggest that the tetraspanin CD9 plays an important role in T cell activation.

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