Korean J Asthma Allergy Clin Immunol.  2006 Jun;26(2):122-128.

Cellular Sources of T-bet in Asthma are Determined by Atopic Status

Abstract

BACKGROUND: T-bet is considered as a master transcriptional factor that appears to regulate lineage commitment of CD4+ T cells in part by activating the TH1 cytokine IFN-gamma. As the IFN-gamma is also produced by CD8+ T cells, CD56+CD3- NK cells and CD56+CD3+ NKT cells, T-bet may also be expressed in these cells. However, expression and cellular sources of this factor are still unknown in asthmatics.
OBJECTIVE
Our aim was to investigate the expressions of T-bet in the peripheral blood mononuclear cells (PBMCs) according to presence of atopy and asthma. METHOD: PBMCs were obtained from nonatopic controls, atopic asthmatics and nonatopic asthmatics. Expressions of T-bet according to lymphocytes subtype were analyzed using three-color flow cytometry. RESULT: Among the T-bet expressing lymphocytes, percentage of CD3+ T cells and CD56+CD3- NK cells were similar in nonatopic controls. CD3+ T cells were prominent source of T-bet compared to CD56+CD3- NK cells in nonatopic asthmatics (P<0.05). CD56+CD3- NK cells were prominent sources of T-bet compared to CD3+ T cells in atopic asthmatics (P<0.05). The proportion of T-bet positive CD56+CD3+ NKT cells of both controls and nonatopic asthmatics had a high tendency compared to the atopic asthmatics.
CONCLUSION
This result provides the first evidence about cellular sources of T-bet in PBMCs of asthmatics. The main source of T-bet is different according to presence of atopy.

MeSH Terms

Asthma*
Flow Cytometry
Killer Cells, Natural
Lymphocytes
Natural Killer T-Cells
T-Lymphocytes