The effects of CD8+gammadelta T cells on late allergic airway responses and airway inflammation in rats.
BACKGROUND
Gamma-delta (gammadelta) T cells regulate immune responses to foreign protein at mucosal surfaces. Whether they can modify allergen-induced early (EAR) and late airway responses (LAR) is unknown.


OBJECTIVE
We have tested the hypothesis that the CD8+ subtype of gammadelta T cells decreases allergen-induced LAR and airway eosinophilia in the rat.


METHODS
Brown Norway rats were administered, intraperitoneally, 3.5 x 10(4) lymph node CD8+gammadelta T cells from naive or sensitized rats. The recipients were sensitized to ovalbumin (OVA) in Al(OH)(3) 3 days after cell transfer and challenged with aerosolized OVA 14 days later. Serum IgE was measured before allergen challenge. After challenge, lung resistance was monitored for 8 hours and then bronchoalveolar lavage (BAL) was analyzed for eosinophil major basic protein (MBP), IL-4, IL-5, IL-13, and IFN-gamma messenger RNA-expressing cells.


RESULTS
gammadelta T cells from naive donors significantly decreased LAR in OVA-challenged sensitized rats, whereas MBP(+) eosinophils were decreased by both gammadelta T cells from naive and sensitized donors. EAR and serum IgE levels were unchanged. The expression of IL-4, IL-5, and IL-13 by BAL cells of gammadelta T cell recipients was attenuated compared with OVA-challenged controls. This was accompanied by an increase in the expression of IFN-gamma.


CONCLUSIONS
Our results are consistent with a suppressive role of CD8+gammadelta T cells on allergic airway responses. However, only gammadelta T cells from naive donors inhibit LAR.
D019264:Adoptive Transfer; D000485:Allergens / Q000008:administration & dosage; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004802:Eosinophilia / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D018448:Models, Immunological; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism; D012130:Respiratory Hypersensitivity / Q000209:etiology / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D000485:Allergens; D016207:Cytokines; D012333:RNA, Messenger; D016692:Receptors, Antigen, T-Cell, gamma-delta; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma; D010047:Ovalbumin