IL-10 induces a Th2 cell tolerance in allergic asthma.
BACKGROUND
Interleukin (IL)-10 induces a long-term antigen-specific anergy in human CD4+ T cells.


METHODS
Peripheral blood mononuclear cells (PBMCs) were isolated from house dust mite (Dermatophagoides farinae, Der f)-sensitized asthmatic patients. PBMCs were stimulated with Der f antigen for 72 h immediately after purification or after 48 h of resting culture with medium, and IL-10 and IL-5 in the culture supernatant were measured. PBMCs were also stimulated with Der f antigen for 7 days either immediately after purification or after 48 h of resting culture, after which cells were collected. Secondary proliferative responses of these cells to stimulation for 3 days with Der f antigen and mitomycin C-treated PBMCs as antigen-presenting cells or with phorbol myristate acetate (PMA) plus calcium ionophore were investigated.


RESULTS
Stimulation of PBMCs with Der f antigen immediately after purification significantly increased the proliferative response and IL-5 production. Stimulation of PBMCs with Der f antigen after resting culture with medium alone for 48 h significantly decreased IL-5 production and markedly increased IL-10 production. Although activation of cells with Der f antigen immediately after purification significantly increased secondary proliferative responses, stimulation after 48 h of resting culture failed to increase secondary proliferative responses. However, proliferation recovered when cells were activated with PMA plus calcium ionophore.


CONCLUSIONS
These results suggest that antigen-specific Th2 cells are anergized by IL-10 and that Th2 cell tolerance may suppress eosinophilic inflammation in allergic asthma.
Adachi
M
M
First Department of Internal Medicine, Showa University, Tokyo, Japan.
Oda
N
N
Kokubu
F
F
Minoguchi
K
K
D000485:Allergens / Q000276:immunology*; D000818:Animals; D002478:Cells, Cultured; D004391:Dust; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects; D016753:Interleukin-10 / Q000276:immunology* / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008925:Mites; D018418:Th2 Cells / Q000276:immunology*
D000485:Allergens; D004391:Dust; D016753:Interleukin-10