Upregulation of the release of granulocyte-macrophage colony-stimulating factor from keratinocytes stimulated with cysteine protease activity of recombinant major mite allergens, Der f 1 and Der p 1.
BACKGROUND
Although exposure to mite allergens is an important risk factor for the production of IgE and is associated with various allergic diseases, there has been uncertainty as to the route of exposure by which sensitization occurs. Cystatin A is a skin-derived dominant inhibitor against proteolytic activity of major mite allergens, Der f 1 and Der p 1, and blocks the upregulation of IL-8 release from human keratinocytes stimulated with the allergens. We analyzed whether the stimulation of keratinocytes with the allergens upregulates the release of granulocyte-macrophage colony-stimulating factor (GM-CSF), which has many actions relevant to allergic diseases including atopic dermatitis, and if so, whether cystatin A can block this process.


METHODS
Normal human keratinocytes and the human keratinocyte cell line HaCaT were stimulated with recombinant group 1 allergens in the absence or presence of cystatin A.


RESULTS
Stimulation with the recombinant allergens upregulated the release of GM-CSF from normal human keratinocytes in a culture with high calcium concentration and HaCaT cells, which could be inhibited by the addition of cystatin A. The allergens exhibiting proteolytic activity did not digest cystatin A. Proteolytic activity of recombinant Der f 1 was partially regenerated after incubation with keratinocytes even without preactivation by L-cysteine.


CONCLUSIONS
Proteolytic activity of recombinant Der f 1 and Der p 1 upregulates GM-CSF and IL-8 release from keratinocytes in vitro, suggesting possible contributions to sensitization through the skin and the perpetuation of atopic dermatitis, as well as a homeostatic role for cystatin A against inflammation of the skin.
Ogawa
Takasuke
T
Atopy (Allergy) Research Center, Juntendo University School of Medicine, Tokyo, Japan.
Takai
Toshiro
T
Kato
Takeshi
T
Kikuchi
Yuko
Y
Niyonsaba
François
F
Ikeda
Shigaku
S
Okumura
Ko
K
Ogawa
Hideoki
H
D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D060829:Arthropod Proteins; D002460:Cell Line; D015891:Cystatins / Q000494:pharmacology; D003546:Cysteine Endopeptidases / Q000276:immunology / Q000378:metabolism; D003876:Dermatitis, Atopic / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology*; D006801:Humans; D016209:Interleukin-8 / Q000276:immunology; D015603:Keratinocytes / Q000187:drug effects / Q000276:immunology*; D011480:Protease Inhibitors / Q000494:pharmacology; D039981:Pyroglyphidae / Q000276:immunology*; D015854:Up-Regulation / Q000187:drug effects
D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D015891:Cystatins; D016209:Interleukin-8; D011480:Protease Inhibitors; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003546:Cysteine Endopeptidases; C451159:Dermatophagoides farinae antigen f 1; C451162:Dermatophagoides pteronyssinus antigen p 1