Cytokine profiles of BAL T cells and T-cell clones obtained from human asthmatic airways after local allergen challenge.
BACKGROUND
This study assessed the heterogeneity of cytokine expression in asthma before and after local allergen challenge.


METHODS
BAL T cells were obtained 10 min or 24 h after local endobronchial allergen challenge in atopic asthmatic subjects. T cells were cloned by direct limiting dilution. mRNA expression was assessed by RT-PCR, and cytokine protein production by ELISA.


RESULTS
Unstimulated baseline BAL T cells expressed mRNA for IFN-gamma, IL-13, and TNF-alpha. A minority of samples expressed IL-4 and IL-5, but no IL-3 mRNA was detected. PHA stimulation increased expression of IL-3, IL-4, and IL-5 mRNA in 4/6 samples. IL-13 and GM-CSF mRNA were found in BAL cells after allergen challenge, but expression of IFN-gamma was reduced. Both IL-4 and IL-3 were strongly upregulated after PHA stimulation, while the expression of TNF-alpha and IFN-gamma was reduced, compared to equivalent baseline samples. Seventeen panels of BAL T-cell clones were derived (average cloning efficiency 1/40 T cells). Seven panels survived to 8 weeks for analysis. Clones derived 4 h after saline challenge showed strong mRNA signals for IL-13, IL-4, and IFN-gamma, whereas clones derived 24 h after allergen challenge expressed IL-13, GM-CSF, IL-3, IL-4, and often IL-5 (i.e., closer to the Th2 profile). There was considerable heterogeneity in the patterns of cytokine mRNA and protein production by different clones.


CONCLUSIONS
T cells from asthmatic airways produce IL-13, IFN-gamma, and TNF-alpha, but after allergen challenge, type 2 cytokines are upregulated. mRNA and protein analysis provide complementary information on airways T-cell cytokine profiles.
Bodey
K J
KJ
Southampton General Hospital, UK.
Semper
A E
AE
Redington
A E
AE
Madden
J
J
Teran
L M
LM
Holgate
S T
ST
Frew
A J
AJ
D000485:Allergens / Q000009:adverse effects*; D001249:Asthma / Q000276:immunology / Q000473:pathology*; D001980:Bronchi / Q000473:pathology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D002999:Clone Cells; D016207:Cytokines / Q000378:metabolism*; D005541:Forced Expiratory Volume; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000473:pathology*; D007371:Interferon-gamma / Q000235:genetics; D018793:Interleukin-13 / Q000235:genetics / Q000378:metabolism; D007377:Interleukin-3 / Q000235:genetics / Q000378:metabolism; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D015848:Interleukin-5 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012129:Respiratory Function Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000737:chemistry / Q000166:cytology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D000485:Allergens; D016207:Cytokines; D018793:Interleukin-13; D007377:Interleukin-3; D015848:Interleukin-5; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor