title: H- and L-rich ferritins suppress antibody production, but not proliferation, of human B lymphocytes in vitro.
abstract: The effect of human spleen(L-rich) and heart(H-rich) ferritins on the proliferation and differentiation of human B lymphocytes was studied in comparison with that of holo- and apo-transferrins. Ferritins rich in H and L chain, as well as the transferrins, did not inhibit the proliferative response of resting and activated B cells stimulated with polyclonal B-cell mitogen, Staphylococcus aureus Cowan strain I. In contrast, the ferritins, but not the transferrins, clearly suppressed the antibody production by B blasts in T-cell-independent as well as T-cell-dependent system. Kinetic study showed that inhibitory action of ferritins on immunoglobulin (Ig) production was caused at an early stage of B-cell differentiation. The cytoplasmic Ig-containing cells decreased in proportion to the reduction of Ig secretion. The evidence that ferritin inhibited Ig synthesis of Epstein-Barr virus-transformed human B-lymphoblastoid cell line also supported the idea that the effect of ferritin was directed toward the antibody-producing B lymphocytes. The molecular analysis showed that the inhibitory effect of ferritin was regulated at the transcriptional level of the Ig generation signal. Our results suggest that H- and L-rich ferritins exert their inhibitory action on the differentiation of B cells maturing into Ig-producing cells.
authors.affiliation: Department of Internal Medicine, Shimane Medical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Morikawa
authors.forename: F
authors.initials: F
authors.lastname: Oseko
authors.forename: S
authors.initials: S
authors.lastname: Morikawa
mesh_terms: D000917:Antibody Formation / Q000187:drug effects*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D005293:Ferritins / Q000494:pharmacology*; D006801:Humans; D007075:Immunoglobulin M / Q000235:genetics; D008213:Lymphocyte Activation / Q000187:drug effects*; D012333:RNA, Messenger / Q000032:analysis; D014168:Transferrin / Q000494:pharmacology
chemical_list: D007075:Immunoglobulin M; D012333:RNA, Messenger; D014168:Transferrin; D005293:Ferritins