Cytokine expression and regulation of human plasma cells: disappearance of interleukin-10 and persistence of transforming growth factor-beta 1.
Less is known about the cytokine expression and regulation of normal plasma cells compared to that of activated B cells or myeloma cells. This study shows that nonproliferating (hydroxyurea-treated), immunoglobulin (Ig)-secreting cells generated from human B cells in the EL-4 culture system no longer express interleukin (IL)-6 mRNA, progressively lose IL-10 mRNA, but continue to express transforming growth factor (TGF)-beta 1 mRNA. Secretion of TGF-beta 1 protein was demonstrated. On the other hand, and in contrast to the suppression of B cell proliferation and Ig secretion, the basal or the IL-6/IL-10 stimulated Ig secretion of nonproliferating cells was not inhibited by recombinant TGF-beta 1. Plasma cells isolated from human bone marrow expressed neither IL-6 nor IL-10 mRNA; only TGF-beta 1 mRNA was detected by reverse transcription-polymerase chain reaction analysis. Such plasma cells may be on average more "aged" cells than those generated in vitro. Thus, plasma cells persistently express TGF-beta 1, a known suppressor of various lymphoid and hemopoietic cell activities, but do not limit their own Ig secretion via this cytokine.
Matthes
T
T
Department of Medicine, Hôpital Cantonal Universitaire, Genève, Switzerland.
Werner-Favre
C
C
Zubler
R H
RH
D000921:Antibody-Producing Cells / Q000378:metabolism; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000235:genetics; D015850:Interleukin-6 / Q000096:biosynthesis; D010950:Plasma Cells / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics
D015850:Interleukin-6; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D016753:Interleukin-10