Expression of Th-2 cytokines interleukin-4 and -5 and of Th-1 cytokine interferon-gamma in ovalbumin-exposed sensitized Brown-Norway rats.
We determined the expression of Th-2 type cytokines, interleukin-4 (IL-4) and IL-5, and of the Th-1 type cytokine, interferon-gamma (IFN-gamma), in the Brown-Norway rat. Rats were intraperitoneally sensitized with ovalbumin and 21 days later were either exposed to ovalbumin or saline aerosol. The value -log PC300 (PC300 = concentration of acetylcholine needed to increase baseline lung resistance by 300%) was 2.49 +/- 0.15 in sensitized, exposed rats, was higher than in sensitized, saline-exposed or naive rats (1.54 +/- 0.27 and 1.63 +/- 0.06 respectively, P < 0.05). There was a significant increase in eosinophils in bronchoalveolar lavage fluid and in airway submucosal airway tissues in the sensitized exposed group. Reverse-transcriptase polymerase chain reaction was performed on total lung RNA using primers for IL-4, IL-5, IFN-gamma and beta-actin. IL-4 and IL-5 mRNA levels in control and sensitized saline-exposed rats were not detectable, but increased levels were found in sensitized and ovalbumin-exposed rats with levels of 0.25 +/- 0.01 and 0.98 +/- 0.02% of beta-actin mRNA as assessed by densitometric measurements. Expression of IFN-gamma mRNA was significantly reduced in sensitized and ovalbumin-exposed rats. As in asthmatic airways, there is an increased expression of Th-2 cytokines, IL-4 and IL-5, together with a reduction in the Th-1 cytokine, IFN-gamma, thus supporting a role for Th-2 cytokines in allergic eosinophilic inflammation.
Haczku
A
A
Department of Thoracic Medicine, National Heart & Lung Institute, London, UK.
Macary
P
P
Haddad
E B
EB
Huang
T J
TJ
Kemeny
D M
DM
Moqbel
R
R
Chung
K F
KF
D000818:Animals; D004195:Disease Models, Animal; D006967:Hypersensitivity / Q000276:immunology*; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000378:metabolism*; D015847:Interleukin-4 / Q000378:metabolism*; D015848:Interleukin-5 / Q000378:metabolism*; D008168:Lung / Q000276:immunology*; D008297:Male; D010047:Ovalbumin / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D015848:Interleukin-5; D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma; D010047:Ovalbumin