Ly49D receptor expressed on immature B cells regulates their IFN-gamma secretion, actin polymerization, and homing.
Low levels of IFN-gamma secreted by immature B cells prevent their own migration and homing to the lymph nodes and premature encounter with Ag. In this study we followed the mechanism regulating IFN-gamma secretion by immature B cells. We show that the MHC class I receptor, Ly49D, is expressed on immature B cells and is down-regulated during maturation. Activation of this receptor leads to increase in IFN-gamma transcription and translation and results in the altered ability of B cells to polymerize actin in response to chemokine stimulation. Moreover, we show that H2-D blockage inhibits the ability of immature B cells to transcribe the IFN-gamma gene and results in rescue of cytoskeletal rearrangement. Thus, Ly49D that is expressed on immature B cells recognizes MHC class I on the peripheral tissues, inducing the secretion of low levels of IFN-gamma and thereby down-regulating immature B cell homing to the lymph nodes or to sites of inflammation.
Department of Immunology, Weizmann Institute of Science, Rehovot, Israel.
Gili
G
Hart
Liat
L
Flaishon
Shirly
S
Becker-Herman
Idit
I
Shachar
D000199:Actins / Q000378:metabolism*; D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D000950:Antigens, Ly / Q000096:biosynthesis / Q000502:physiology*; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002454:Cell Differentiation / Q000276:immunology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002465:Cell Movement / Q000235:genetics / Q000276:immunology*; D006183:H-2 Antigens / Q000235:genetics / Q000276:immunology / Q000502:physiology; D064532:Histocompatibility Antigen H-2D; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D037181:Lectins, C-Type; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D055650:NK Cell Lectin-Like Receptor Subfamily A; D014176:Protein Biosynthesis / Q000276:immunology; D016201:Receptors, Lymphocyte Homing / Q000096:biosynthesis / Q000502:physiology*; D055630:Receptors, NK Cell Lectin-Like; D014158:Transcription, Genetic / Q000276:immunology; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
D000199:Actins; D019138:Antibodies, Blocking; D000950:Antigens, Ly; D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D064532:Histocompatibility Antigen H-2D; C527092:Klra4 protein, mouse; D037181:Lectins, C-Type; D055650:NK Cell Lectin-Like Receptor Subfamily A; D016201:Receptors, Lymphocyte Homing; D055630:Receptors, NK Cell Lectin-Like; D007371:Interferon-gamma