Modified T-cell activation pattern during specific immunotherapy (SIT) in cat-allergic patients.
OBJECTIVE
The aim of the study was to analyse early effects of specific immunotherapy (SIT) on immune functions in cat-allergic patients.


METHODS
Immunological responses of peripheral blood mononuclear cells from eight cat-allergic patients were analysed before and after SIT in comparison with 11 nonallergic controls. Cells were stimulated in vitro with either bacterial superantigen, mitogen, or cat allergen. Production of IL-12 and TH1/TH2 cytokines was analysed by ELISA and lymphocyte subset distribution was assessed by flow-cytometry.


RESULTS
We found a significantly reduced secretion of IL-12 (P < 0.05) from cells of allergic individuals compared with the controls. This finding was associated with significantly lower IFN-gamma production after stimulation with allergen (P < 0.05) that did not increase during SIT. However, no significant differences were seen after stimulation with mitogen indicating an allergen specific IFN-gamma secretion response in allergic individuals. Prior to SIT IL-5 production was significantly higher in cells of allergic donors stimulated with allergen < 0.005 or mitogen (< 0.05). After reaching the maintenance dose for SIT, allergen-induced IL-5 production returned to normal levels, whereas it remained elevated after stimulation with mitogen. These changes were associated with a reduced frequency of CD45 RO T cells following SIT.


CONCLUSIONS
These results suggest that SIT exerts early effects on allergen-specific T-cell responses with selective inhibition of the up-regulated TH2 immune response.
Meissner
N
N
Department of Paediatrics, University Würzburg, Germany.
Kochs
S
S
Coutelle
J
J
Kussebi
F
F
Baumgarten
C
C
Løwenstein
H
H
Kunkel
G
G
Renz
H
H
D000485:Allergens / Q000276:immunology*; D000818:Animals; D001985:Bronchial Provocation Tests; D002415:Cats / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D003888:Desensitization, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D008875:Middle Aged; D012130:Respiratory Hypersensitivity / Q000628:therapy*; D012882:Skin Tests; D013601:T-Lymphocytes / Q000276:immunology*
D000485:Allergens; D016207:Cytokines