Characterization of T-cell clones specific to ovomucoid from patients with egg-white allergy.
BACKGROUND
Allergic reactions to foods are specific problems for infants and young children. Ovomucoid (OM) is one of the major allergens found in egg-white. We previously established several T-cell clones (TCCs) specific to OM in non-polarizing conditions from 4 patients (TM and YN are immediate-type, IH and YT are non-immediate-type) with egg-white allergy. We characterized their reactive epitopes, antigen-presenting molecules (HLA class II), and usage of TCR alpha and beta genes and the CDR3 loop sequence.


OBJECTIVE
The objective of this study was to characterize these seven clones (TM 1.3, TM1.4,YN 1.1, YN1.5, IH3.1, IH3.3 and YT6.1) for cytokine production patterns and cell-surface-marker phenotypes.


METHODS
We measured the production of cytokines, namely interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma) by stimulation with ovomucoid peptides and stained intracellular IL-4 and IFN-gamma, and determined cell-surface markers using anti-interleukin-12 receptor (IL-12R) beta1, anti-IL-12Rbeta2 and anti-interleukin-18 receptor alpha (IL-18Ralpha).


RESULTS
Most TCCs secreted both IL-4 and IFN-gamma in response to the OM peptide mixture, but the secretion patterns were variable; an IFN-gamma dominant pattern was seen in IH3.1 andYT6.1, an IFN-gamma>IL-4 pattern in TM1.3 and TM1.4, an IL-4> IFN-gamma pattern in YN1.5. In intracellular IFN-gamma and IL-4 staining, IFN-gamma single-positive cells were predominant in TM1.3, TM1.4, IH3.1 and YT6.1 and IFN-gamma and IL-4 double-positive cells were predominant in YN1.1, YN1.5 and IH3.3. All TCCs were IL-12Rbeta1-positive, and TM1.3, IH3.1, IH3.3 and YT6.1 were both IL-12Rbeta2- and IL-18Ralpha-positive. TM1.4 and YN1.1 were both IL-12Rbeta2- and IL-18Ralpha-negative. Based on these results, TM1.3 and TM1.4, IH3.1 and YT6.1 had a predominantly Th1 character and YN1.1, YN1.5, and IH3.3 possessed a predominantly Th0 character.


CONCLUSIONS
The phenotypes of TCCs were not in accordance with their clinical manifestations. TCCs established from patients with immediate-type hypersensitivity had either the Th1 or Th0 phenotype as well as those with non-immediate-type hypersensitivity.
Kondo
M
M
Department of Pediatrics, Graduate School of Medicine, Gifu University. Japan. g2104012@guedu.cc.gifu-u.ac.jp
Suzuki
K
K
Inoue
R
R
Sakaguchi
H
H
Matsukuma
E
E
Kato
Z
Z
Kaneko
H
H
Fukao
T
T
Kondo
N
N
D021181:Egg Hypersensitivity / Q000276:immunology*; D004529:Egg White / Q000009:adverse effects*; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000032:analysis / Q000096:biosynthesis; D015847:Interleukin-4 / Q000032:analysis / Q000096:biosynthesis; D010059:Ovomucin / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D015847:Interleukin-4; D010059:Ovomucin; D007371:Interferon-gamma