The extract of syngeneic keratinocytes enhances IgE production from BALB/c mouse splenic lymphocytes in vitro.

Morimoto Kenichi

Nabeshima Yukiko

Mochizuki Mitsuru

Oomizu Souichi

Yamamoto Shoso

Hide Michihiro

Archives of Dermatological Research

Background: The increase of serum IgE levels is closely associated with atopic dermatitis. We have previously revealed that cellular extract of PAM212 cells (PAM-extract), BALB/c mouse keratinocyte cell line, induced a remarkable increase of serum IgE levels, in vivo, when subcutaneously injected into BALB/c mice. However, precise mechanism of IgE-increasing activity was unclear. Objective: To elucidate the mechanism of IgE-increase in sera of BALB/c mice induced by PAM-extract, we explored the direct influence of PAM-extract on immunoglobulin production and class-switching in the culture of splenic lymphocytes and purified B-cells, in vitro. Methods: Splenic lymphocytes or purified B-cells obtained from BALB/c mice were cultured with various combinations of IL-4, anti-CD40 antibody, and PAM-extract for seven days. IgE and IgG concentrations of culture supernatants were measured by ELISA. Epsilon germ-line transcriptions were assessed by RT-PCR from the cultured cells. Results: IgE and IgG concentrations in culture supernatant of splenic lymphocytes were increased by an addition of PAM-extract in the presence of both IL-4 and anti-CD40 antibody. Epsilon germ-line transcript was also induced in parallel to the increase of IgE production. Similar results were obtained when purified B-cells were employed in stead of whole splenic lymphocytes. Conclusion: The cellular extract of keratinocyte promotes immunoglobulin class-switching to IgE and IgE production from mouse splenic B-cells in an IL-4- and CD40-stimuli-dependent manner. Such enhancement may account for the increase of serum IgE in patients with dermatitis in association with a Th2 microenvironment.

immunoglobulin E

keratinocyte

B-lymphocyte

immunoglobulin class switching

atopic dermatitis

Medical sciences [ 490 ]

eng

Springer

Copyright (c) 2006 Springer-Verlag. "The original publication is available at www.springerlink.com"

[ISSN] 0340-3696

[DOI] 10.1007/s00403-005-0636-y

[NCID] AA0054724X

[PMID] 16402182

[DOI] http://dx.doi.org/10.1007/s00403-005-0636-y isVersionOf