Human B-cell growth-inhibitory activity of eosinophil cationic protein.
The effect of eosinophil cationic protein (ECP) upon proliferation of human B cell lines or purified B cells was studied. ECP inhibited proliferation of the human lymphoblastoid cell lines CBL and GM-1056 at doses of 0.1-5 ng/mL during 2-4 days of culture. The inhibitory effect of ECP was reversible and not due to toxic damage. Moreover, inhibition could be blocked by anti-ECP serum while the control serum failed to do so. Of various cytokines tested--including interleukin (IL)-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6; interferon (IFN)-alpha or IFN-gamma--IL-4 reduced the inhibition, while other cytokines failed to do so. The reduction of inhibition was specific to IL-4 since reduction by IL-4 was blocked by anti-IL-4 antibody but not by the control antibody. ECP also inhibited proliferation of tonsillar small resting B cells stimulated with anti-mu antibody plus low molecular weight B-cell growth factor (BCGF) or of large activated B cells. In contrast, ECP had no effect on proliferation of unstimulated small resting B cells. This inhibition was also reduced by IL-4 specifically. These results indicate that ECP may also act as a B-cell regulating factor.
Kimata
H
H
Department of Pediatrics, Faculty of Medicine, Kyoto University Hospital, Japan.
Yoshida
A
A
Ishioka
C
C
Jiang
Y
Y
Mikawa
H
H
D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D001798:Blood Proteins / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D016207:Cytokines / Q000494:pharmacology; D047091:Eosinophil Granule Proteins; D004804:Eosinophils; D006801:Humans; D066298:In Vitro Techniques; D015847:Interleukin-4 / Q000494:pharmacology; D012260:Ribonucleases
D001798:Blood Proteins; D016207:Cytokines; D047091:Eosinophil Granule Proteins; D015847:Interleukin-4; D012260:Ribonucleases