The monoclonal antibody CZ‐1 identifies a mouse CD45‐associated epitope expressed on interleukin‐2‐responsive cells

Randy R. Brutkiewicz, Carey L. O'Donnell, Joseph W. Maciaszek, Raymond M. Welsh, Mauricio Vargas‐Cortes

Research output: Contribution to journalArticle

5 Scopus citations


We have previously described a monoclonal antibody (mAb), CZ‐1, which reacts with an epitope expressed on most peripheral basophils, natural killer cells, B cells, and CD8+ T cells, but not with most thymocytes or peripheral CD4+ T cells. Here we show that mAb CZ‐1 defines a sialic acid‐dependent epitope associated with a subpopulation of CD45 molecules. This conclusion is based on the ability to block binding of mAb CZ‐1 by sialic acid, neuramin‐lactose, neuraminidase, and mAb to CD45RB, and by expression of the epitope on transfected W2 cells expressing exon B of CD45. The results suggest that the CZ‐1 epitope is a post‐translational modification expressed on a subpopulation of the CD45 molecules also expressing the B exon. Expression of the CZ‐1 epitope was required for freshly isolated lymphocytes to respond to interleukin‐2 (IL‐2). Depletion of CZ‐1+ cells by C or by cell sorting of thymocytes or splenocytes eliminated the IL‐2 responsive cells. The subpopulations of thymocytes and CD4+ splenocytes responding to IL‐2 were exclusively within the small CZ‐1+ subpopulation. mAb CZ‐1 was also used to subdivide CD45+ and CD45RB+ splenocytes into IL‐2‐responsive and ‐nonresponsive subpopulations. The CZ‐1 epitope was also expressed on virtually all lymphokine‐activated killer cell precursors. These data, thus, indicate that cells responsive to IL‐2 express this sialated modification of CD45.

Original languageEnglish (US)
Pages (from-to)2427-2433
Number of pages7
JournalEuropean Journal of Immunology
Issue number10
StatePublished - Oct 1993



  • CD45
  • Interleukin‐2
  • Monoclonal antibody CZ‐1
  • T lymphocyte

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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