55 research outputs found
Expansion of CD4+CD25+ and CD25- T-Bet, GATA-3, Foxp3 and RORγt Cells in Allergic Inflammation, Local Lung Distribution and Chemokine Gene Expression
Allergic asthma is associated with airway eosinophilia, which is regulated by
different T-effector cells. T cells express transcription factors T-bet, GATA-3,
RORγt and Foxp3, representing Th1, Th2, Th17 and Treg cells respectively. No
study has directly determined the relative presence of each of these T cell
subsets concomitantly in a model of allergic airway inflammation. In this study
we determined the degree of expansion of these T cell subsets, in the lungs of
allergen challenged mice. Cell proliferation was determined by incorporation of
5-bromo-2′-deoxyuridine (BrdU) together with 7-aminoactnomycin (7-AAD).
The immunohistochemical localisation of T cells in the lung microenvironments
was also quantified. Local expression of cytokines, chemokines and receptor
genes was measured using real-time RT-PCR array analysis in tissue sections
isolated by laser microdissection and pressure catapulting technology. Allergen
exposure increased the numbers of T-bet+,
GATA-3+, RORγt+ and
Foxp3+ cells in CD4+CD25+
and CD4+CD25- T cells, with the greatest expansion of
GATA-3+ cells. The majority of
CD4+CD25+ T-bet+,
GATA-3+, RORγt+ and
Foxp3+ cells had incorporated BrdU and underwent
proliferation during allergen exposure. Allergen exposure led to the
accumulation of T-bet+, GATA-3+ and
Foxp3+ cells in peribronchial and alveolar tissue,
GATA-3+ and Foxp3+ cells in perivascular
tissue, and RORγt+ cells in alveolar tissue. A total of 28
cytokines, chemokines and receptor genes were altered more than 3 fold upon
allergen exposure, with expression of half of the genes claimed in all three
microenvironments. Our study shows that allergen exposure affects all T effector
cells in lung, with a dominant of Th2 cells, but with different local cell
distribution, probably due to a distinguished local inflammatory milieu
SnRK2 protein kinases represent an ancient system in plants for adaptation to a terrestrial environment
The SNF1-related protein kinase 2 (SnRK2) family includes key regulators of osmostress and abscisic acid (ABA) responses in angiosperms and can be classified into three subclasses. Subclass III SnRK2s act in the ABA response while ABA-nonresponsive subclass I SnRK2s are regulated through osmostress. Here we report that an ancient subclass III SnRK2-based signalling module including ABA and an upstream Raf-like kinase (ARK) exclusively protects the moss Physcomitrella patens from drought. Subclass III SnRK2s from both Arabidopsis and from the semiterrestrial alga Klebsormidium nitens, which contains all the components of ABA signalling except ABA receptors, complement Physcomitrella snrk2− mutants, whereas Arabidopsis subclass I SnRK2 cannot. We propose that the earliest land plants developed the ABA/ARK/subclass III SnRK2 signalling module by recruiting ABA to regulate a pre-existing dehydration response and that subsequently a novel subclass I SnRK2 system evolved in vascular plants conferring osmostress protection independently from the ancient system
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