Eosinophil cdTCR Expression Figure 6. Intraindividual variability between eosinophils and cdT cells in rearranged Vd1-Jd3 and Vd2-Cd TCR sequences. (A) TCR locus organization with positions of the PCR probes used for sequence amplification. (B–C) Sequence alignment of Vd1-Jd3 (B) and Vd2-Cd (C) regions analyzed from IGMT database, differentiated cdT cells and peripheral blood eosinophils obtained from the same allergic donors for. The two most frequent sequences are presented for cdT cells. Grey boxes indicate mismatch. doi:10.1371/journal.pone.0005926.g006 induced/up-regulated, in particular upon incubation with ligands. Our results show that cdTCR surface expression was induced upon incubation in the presence of a natural mycobacterial ligand as well as following overnight culture. The molecular mechanism underlying this later finding remains unknown. Our results indicate that CD3e expression, both at mRNA and protein levels, was consistently lower than cdTCR. Due to the requirement of this CD3 subunit for surface expression of the receptor complex, it is tempting to speculate that the very low CD3e expression probably accounts for the low surface expression of the whole complex on eosinophils although further experiments would be required for a formal demonstration. This low receptor expression PLoS ONE | www.plosone.org 9 June 2009 | Volume 4 | Issue 6 | e5926