A functional gammadeltaTCR/CD3 complex distinct from gammadeltaT cells is expressed by human eosinophils.
BACKGROUND
Eosinophils are effector cells during parasitic infections and allergic responses. However, their contribution to innate immunity has been only recently unravelled.


RESULTS
Here we show that human eosinophils express CD3 and gammadelta T Cell Receptor (TCR) but not alphabeta TCR. Surface expression of gammadeltaTCR/CD3 is heterogeneous between eosinophil donors and inducible by mycobacterial ligands. Surface immunoprecipitation revealed expression of the full gammadeltaTCR/CD3 complex. Real-time PCR amplification for CD3, gamma and delta TCR constant regions transcripts showed a significantly lower expression in eosinophils than in gammadeltaT cells. Limited TCR rearrangements occur in eosinophils as shown by spectratyping analysis of CDR3 length profiles and in situ hybridization. Release by eosinophils of Reactive Oxygen Species, granule proteins, Eosinophil Peroxidase and Eosinophil-Derived Neurotoxin and cytokines (IFN-gamma and TNF-alpha) was observed following activation by gammadeltaTCR-specific agonists or by mycobacteria. These effects were inhibited by anti-gammadeltaTCR blocking antibodies and antagonists. Moreover, gammadeltaTCR/CD3 was involved in eosinophil cytotoxicity against tumor cells.


CONCLUSIONS
Our results provide evidence that human eosinophils express a functional gammadeltaTCR/CD3 with similar, but not identical, characteristics to gammadeltaTCR from gammadeltaT cells. We propose that this receptor contributes to eosinophil innate responses against mycobacteria and tumors and may represent an additional link between lymphoid and myeloid lineages.
Legrand
Fanny
F
Inserm U547, Lille, France.
Driss
Virginie
V
Woerly
Gaëtane
G
Loiseau
Sylvie
S
Hermann
Emmanuel
E
Fournié
Jean-Jacques
JJ
Héliot
Laurent
L
Mattot
Virginie
V
Soncin
Fabrice
F
Gougeon
Marie-Lise
ML
Dombrowicz
David
D
Capron
Monique
M
D017252:CD3 Complex / Q000096:biosynthesis*; D047209:Eosinophil Peroxidase / Q000378:metabolism; D047208:Eosinophil-Derived Neurotoxin / Q000378:metabolism; D004804:Eosinophils / Q000378:metabolism* / Q000382:microbiology; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D009163:Mycobacterium bovis / Q000378:metabolism; D017382:Reactive Oxygen Species; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013499:Surface Properties; D013601:T-Lymphocytes / Q000166:cytology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D017252:CD3 Complex; D017382:Reactive Oxygen Species; D016692:Receptors, Antigen, T-Cell, gamma-delta; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D047209:Eosinophil Peroxidase; D047208:Eosinophil-Derived Neurotoxin