HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Published online before print August 16, 2007

This Article Full Text Full Text (PDF) All Versions of this Article: jlb.0107035v1 82/5/1126    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Clark, G. J. Articles by Hart, D. N. J. Search for Related Content PubMed PubMed Citation Articles by Clark, G. J. Articles by Hart, D. N. J.

(Journal of Leukocyte Biology. 2007;82:1126-1135.)
© 2007 by Society for Leukocyte Biology

Novel human CD4⁺ T lymphocyte subpopulations defined by CD300a/c molecule expression

Mater Medical Research Institute, Brisbane, Queensland, Australia

¹ Correspondence: Immunoregulation Team, DC Program, Mater Medical Research Institute, Aubigny Place, Raymond Tce, South Brisbane, Queensland 4101, Australia. E-mail: gclark{at}mmri.mater.org.au

The CD300c (CMRF-35A) and CD300a (CMRF-35H) molecules are leukocyte surface proteins that are part of a larger family of immunoregulatory molecules encoded by a gene complex on human chromosome 17. The CMRF-35 monoclonal antibody binds to an epitope common to both molecules, expressed on most human leukocyte populations, apart from B lymphocytes and a subpopulation of CD4⁺ and CD8⁺ T lymphocytes. We describe the CMRF-35^pos and CMRF-35^– fractions of CD4⁺ T lymphocytes. The CMRF-35^pos fraction can further be divided into CMRF-35⁺⁺ and CMRF-35⁺CD4⁺ T lymphocyte subpopulations. Resting peripheral CD4⁺ T lymphocytes express CD300a mRNA and very low amounts of CD300c. Activation results in an initial decrease in CD300a gene expression before an increase in both CD300a and CD300c gene expression. The up-regulated expression of these genes was associated with increased CMRF-35 binding to activated T lymphocytes. The CMRF-35^– fraction of CD4⁺ T lymphocytes proliferated to a greater extent than the CMRF-35^pos fraction, in response to mitogens or allogeneic antigen. The poor proliferation of the CMRF-35^pos CD4⁺ in response to mitogens was explained by increased apoptosis within this subpopulation. The recall antigen, tetanus toxoid, stimulated the CMRF-35⁺⁺CD4⁺CD45RO⁺ but not the CMRF-35^–CD4⁺CD45RO⁺ subpopulation. Resting CMRF-35⁺⁺ CD4⁺ lymphocytes express low levels of IFN- mRNA. Within 18 h following in vitro activation, CMRF-35⁺⁺ CD4⁺ lymphocytes express more IFN- mRNA and protein compared with the CMRF-35^–CD4⁺ lymphocytes, however, after 24 h, both the CMRF-35⁺ and CMRF-35^–CD4⁺ T lymphocytes were able to produce IFN-. The CMRF-35⁺⁺CD4⁺ T lymphocyte population contains the Th₁ memory effector cells.

Key Words: CD300a • CD300c • T lymphocytes

This article has been cited by other articles:

				X. Ju, M. Zenke, D. N. J. Hart, and G. J. Clark CD300a/c regulate type I interferon and TNF-{alpha} secretion by human plasmacytoid dendritic cells stimulated with TLR7 and TLR9 ligands Blood, August 15, 2008; 112(4): 1184 - 1194. [Abstract] [Full Text] [PDF]