Reciprocal patterns of allergen-induced GATA-3 expression in peripheral blood mononuclear cells from atopics vs. non-atopics.
BACKGROUND
T helper (Th)2 cytokines are considered to play a central role in the induction and expression of allergic disease. However, the relative importance of individual cytokines is unclear, and overall disease pathogenesis appears to involve the coordinate activities of a range of Th2 cytokines acting in sequence or in parallel. The present study examines an alternative approach to the study of cytokine gene function in atopy, focusing instead upon T cell transcription factors (TFs) which play a role in the regulation of multiple cytokine genes.


OBJECTIVE
To investigate the allergen-induced expression of the TF GATA-3 and c-Maf in peripheral blood mononuclear cells (PBMCs) and in cytokine-driven Th polarization.


METHODS
PBMC from house dust mite (HDM)-atopic and non-atopics were stimulated in vitro with allergen or anti-CD3/IL-2. TF expression was analysed by semiquantitative RT-PCR and major findings were validated by real-time PCR. Cell separations were performed to analyse the contribution of CD45RO+ cells. CD4+ cord blood cells were Th1 or Th2 polarized in vitro by exogenous cytokines and TF expression analysed by Northern blot and real-time PCR. Results We demonstrate for the first time that during differentiation of CD4+ CD45RA+ naïve human T cells towards Th2 commitment, and during allergen-specific reactivation of peripheral CD4+ CD45RO+ Th2 memory cells in established atopics, expression of the Th2-associated TF GATA-3 is rapidly up-regulated, whereas T cells from non-atopics display equally rapid GATA-3 down-regulation under identical conditions of allergen stimulation.


CONCLUSIONS
These findings identify Th2-associated TFs as key determinants of the atopic phenotype, suggesting their unique potential as therapeutic targets for disease control.
Macaubas
C
C
TVW Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Perth, Australia.
Lee
P T
PT
Smallacombe
T B
TB
Holt
B J
BJ
Wee
C
C
Sly
P D
PD
Holt
P G
PG
D000328:Adult; D000485:Allergens / Q000494:pharmacology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology; D002478:Cells, Cultured; D003199:Computer Systems; D016207:Cytokines / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000097:blood* / Q000378:metabolism; D004391:Dust; D005260:Female; D050990:GATA3 Transcription Factor; D006801:Humans; D006967:Hypersensitivity / Q000097:blood*; D008297:Male; D008925:Mites / Q000276:immunology*; D009000:Monocytes / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051257:Proto-Oncogene Proteins c-maf; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D012016:Reference Values; D015534:Trans-Activators / Q000097:blood*
D000485:Allergens; D016207:Cytokines; D004268:DNA-Binding Proteins; D004391:Dust; D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; C495607:MAF protein, human; D011518:Proto-Oncogene Proteins; D051257:Proto-Oncogene Proteins c-maf; D015375:Receptors, Interleukin-2; D015534:Trans-Activators