Activation of basophils by stem cell factor: comparison with insulin-like growth factor-I.
BACKGROUND
Basophils are an active participant in the pathogenesis of local inflammation in allergic diseases such as asthma, but it is not fully known how basophil activation is regulated in inflamed tissue.


OBJECTIVE
In order to clarify the control mechanisms of basophil activation in chronic inflammation and at remodeling sites, we analyzed the effects of fibroblast-derived cytokines, stem cell factor (SCF), and insulin-like growth factor-I (IGF-I) on basophils.


METHODS
The effects of SCF and IGF-I on degranulation and surface activation marker expression by basophils were assessed and compared.


RESULTS
SCF enhanced human basophil histamine release elicited by some, but not all, secretagogues; degranulation in response to IgE- or FcepsilonRI-mediated stimulation and 12-o-tetradecanoyl-phorbol-13-acetate (TPA) was enhanced by SCF. SCF slightly enhanced ionophore A23187-induced histamine release by basophils from some donors, but it failed to affect the release elicited by monocyte chemoattractant protein-1 (MCP-1), formylmethionyl-leucyl-phenylalanine (FMLP) or C5a. The repertoire of secretagogues responsive to SCF was similar to that of IGF-I. Expression levels of both CD11b and CD69 markers were significantly enhanced by the combination of SCF and IGF-I.


CONCLUSIONS
These results suggest that SCF and IGF-I may modify the activation of basophils in a similar and/or synergistic fashion. Interaction of basophils with these cytokines might be involved in the pathogenesis of local inflammation and the remodeling process in asthma.
Koketsu
R
R
Department of Allergy and Rheumatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
Suzukawa
M
M
Kawakami
A
A
Komiya
A
A
Ra
C
C
Yamamoto
K
K
Yamaguchi
M
M
D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology / Q000378:metabolism*; D001491:Basophils / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D039481:CD11b Antigen / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D015550:Cell Degranulation / Q000187:drug effects*; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000276:immunology / Q000494:pharmacology*; D037181:Lectins, C-Type; D011994:Recombinant Proteins / Q000494:pharmacology; D019089:Stem Cell Factor / Q000276:immunology / Q000494:pharmacology*; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D039481:CD11b Antigen; D007334:Insulin-Like Growth Factor I; D037181:Lectins, C-Type; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D000099192:CD69 Antigens