CD8+ alphabeta T cells can mediate late airway responses and airway eosinophilia in rats.
BACKGROUND
The function of CD8+ T-cell subsets in mediating late allergic responses is incompletely understood.


OBJECTIVE
We sought to test the hypothesis that CD8+ alphabeta T cells are proinflammatory in the airways in vivo by using a well-characterized animal model and the technique of adoptive transfer.


METHODS
Brown Norway rats were administered CD8 + alphabeta T cells (10 6 ) intraperitoneally purified from lymph node cells of either naive or ovalbumin (OVA)-sensitized rats and were challenged with aerosolized OVA 2 days later. Control rats were sensitized to 100 mug of OVA in Al(OH) 3 subcutaneously or sham sensitized to saline and were OVA challenged 2 weeks later.


RESULTS
The OVA-sensitized and OVA-challenged group and the recipients of OVA-primed CD8+ alphabeta T cells had significant late airway responses calculated from lung resistance measured for an 8-hour period after challenge compared with the naive CD8 + alphabeta T cell-transferred group and the sham-sensitized control group. The number of eosinophils in bronchoalveolar lavage fluid increased in the OVA-sensitized group and the OVA-primed CD8+ alphabeta T-cell recipients compared with numbers in the naive CD8+ alphabeta T-cell recipients and the sham-sensitized control group. IL-4 and IL-5 cytokine mRNA expression in bronchoalveolar lavage fluid increased in the OVA-sensitized group and the OVA-primed CD8+ alphabeta T-cell recipients compared with that in the sham-sensitized group.


CONCLUSIONS
We conclude that antigen-primed CD8 + alphabeta T cells might have a proinflammatory role in allergen-driven airway responses in the rat.
Isogai
Susumu
S
Department of Medicine, McGill University, Montreal, Quebec, Canada.
Taha
Rame
R
Tamaoka
Meiyo
M
Yoshizawa
Yasuyuki
Y
Hamid
Qutayba
Q
Martin
James G
JG
D019264:Adoptive Transfer; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D004802:Eosinophilia / Q000209:etiology*; D008171:Lung Diseases / Q000209:etiology*; D008297:Male; D010047:Ovalbumin / Q000276:immunology; D051381:Rats; D011914:Rats, Inbred BN; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis*
D016207:Cytokines; D016693:Receptors, Antigen, T-Cell, alpha-beta; D010047:Ovalbumin