Regulation of transforming growth factor-β1 synthesis by murine T lymphocytes and its effect on IgA antibody response = 마우스 T세포의 transforming growth factor-β1 합성 조절 작용 및 IgA 항체

Abstract

It has been reported that Transforming growth factor-^1 (TGF-^1) acts as an IgA isotype switching factor in vitro. Thus，the present study was designed to investigate whether or not TGF-分 1 has such possibility in vivo. First, mouse spieen T helper cell line was established, stimulated with polyclonal activator(concanavalin A) and the supernatants was added to surface IgA negative (slgA') B cell culture* The acid activated T cell supernatants could enhance IgA isotype production but not IgM or IgG. This specific activity of the supernatants was completely disappered with treatment of anti-TGF냉 1 antibody. This results suggest that TGF-^1 produced by T cell can act as an IgA isotype switching factor. Secondly, in order to understand the molecular mechanisms of TGF-/91 regulation by T cell, initially EL-4 thymoma line was stimulated with TPA and TGF-^1 mRNA was detected by northern blot. TGF-^1 mRNA could be induced in this system, and the message was increased up to 48h. Finally, the EL-4 supernatents was assayed using TGF-/91 sensitive cell Hne(MV 1LU). The acid activated supernatants from EL-4 cell line contained substantial amounts of active TGF -^1.

Taken together, the results from the present study suggest that TGF-分 1 gene can be expressed by T cell at the RNA and protein level, and the synthesized TGF-斤 1 can induce specifically IgA production by slgA - B cells.