Gamma irradiation up-regulates expression of B cell differentiation molecule CD23 by NF-kappaB activation.
Gamma irradiation (gamma-IR) is reported to have diverse effects on immune cell apoptosis, survival and differentiation. In the present study, the immunomodulatory effect of a low dose gamma-IR (5~10 Gy) was investigated, focusing on the role of NF-kappaB in the induction of the B cell differentiation molecule, CD23/FceRII. In the human B cell line Ramos, gamma-IR not only induced CD23 expression, but also augmented the IL-4-induced surface CD23 levels. While gamma-IR did not cause STAT6 activation in these cells, it did induce both DNA binding and the transcriptional activity of NF-kappaB in the IkappaB degradation-dependent manner. It was subsequently found that different NF-kappaB regulating signals modulated the gamma-IR-or IL-4-induced CD23 expression. Inhibitors of NF-kappaB activation, such as PDTC and MG132, suppressed the gamma-IR-mediated CD23 expression. In contrast, Ras, which potentiates gamma-IR-induced NF-kappaB activity in these cells, further augmented the gamma-IR- or IL-4-induced CD23 levels, The induction of NF-kappaB activation and the subsequent up-regulation of CD23 expression by gamma-IR were also observed in monocytic cells. These results suggest that gamma-IR, at specific dosages, can modulate immune cell differentiation through the activation of NF-kappaB, and this potentially affects the immune inflammatory response that is mediated by cytokines.
Laboratory of Immunology, Department of Biological Science, Sungkyunkwan University, Suwon 440-746, Korea.
Hyun-Sook
HS
Rho
Soon-Suk
SS
Park
Choong-Eun
CE
Lee
D001402:B-Lymphocytes / Q000378:metabolism* / Q000528:radiation effects*; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D005720:Gamma Rays; D006801:Humans; D015847:Interleukin-4 / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017455:Receptors, IgE / Q000235:genetics / Q000378:metabolism*; D050800:STAT6 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism; D015854:Up-Regulation; D018631:ras Proteins / Q000378:metabolism
D016328:NF-kappa B; D017455:Receptors, IgE; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D015534:Trans-Activators; D015847:Interleukin-4; D018631:ras Proteins