Eosinophil cdTCR Expression Figure 4. Immunolocalization and Subunit composition of surface-expressed cdTCR/CD3 complex on human eosinophils. (A) Immunofluorescence and confocal microscopy (insets) analysis of cdTCR/CD3 chains expression on cytospin eosinophil preparations after 18 h culture. Staining with anti-aTCR, anti-bTCR antibodies and control goat IgG is represented. Arrowheads indicate some positive cells. (B) Surface of eosinophils and cdT cells was biotin-labelled. Cells were lysed and complexes were immunoprecipitated, using anti-cdTCR or isotype control antibodies. Immunoprecipitated proteins were resolved on a reducing 14% SDS-PAGE and transferred to PVDF membrane. Biotinylated proteins were revealed using ABC-HRP and chemiluminescence. Positions of the TCR and CD3 subunits are marked. Material corresponding to the total and to 1/ 10th of the material was loaded for eosinophils and cdT cells respectively. Dashed lines indicate that non adjacent lanes of the same gel have been joined on the Figure. doi:10.1371/journal.pone.0005926.g004 amplified and quantified by real-time PCR in eosinophils purified to homogeneity (100%) and cdT lymphocyte subsets or Colo-205 colon carcinoma cells as positive and negative controls respective- ly. Expression of the various chains was 300 to 4,000 fold lower in eosinophil population than in cdT lymphocyte population, while CD8 expression was absent in eosinophils but present in cdT lymphocytes (Figure 5A). Amplification of Vd1-Jd3, Vd2-Cd and VcI-JcP rearranged transcripts but not Vd1-Jd4 was also detected PLoS ONE | www.plosone.org 6 June 2009 | Volume 4 | Issue 6 | e5926