T cell contamination in flow cytometry gating approaches for analysis of innate lymphoid cells

PLoS One. 2014 Apr 23;9(4):e94196. doi: 10.1371/journal.pone.0094196. eCollection 2014.


Innate lymphoid cells (ILCs) differ from T and B cells as they do not express genetically rearranged antigen receptors. The most prominent member of this group, NK cells, can be identified by numerous surface receptors such as natural cytotoxicity receptors (NCRs). However, novel groups of ILCs have recently been described and classified based on fate-determining transcription factors and cytokines being produced, similarly to T helper cells. Due to the lack of exclusive markers, ILCs are primarily defined by the paucity of lineage markers. Using RORc-fate-mapping mice, we found that the common lineage exclusion using CD3 yields an ILC population containing a large proportion of T cells with recombined TCR loci and low expression of CD3. Thus, we suggest adding CD5 as a marker for thorough elimination of T cells to avoid erroneous interpretations of ILC function in immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD3 Complex / metabolism
  • Cells, Cultured
  • Flow Cytometry / methods*
  • Immunity, Innate / physiology
  • Lymphocytes / cytology*
  • Lymphocytes / immunology*
  • Mice
  • T-Lymphocytes / cytology*
  • T-Lymphocytes / immunology*


  • CD3 Complex

Grant support

B.B. is supported by the Swiss National Science Foundation, the European Union FP7 project TargetBraIn (279017) and the Swiss multiple sclerosis society. K.N. is supported by the Boehringer Ingelheim Fonds (BIF), S.B. holds a MD-PhD fellowship from the Swiss National Science Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.