B lymphocytes and plasma cells express functional E-selectin by constitutive activation of NF-kappaB.
E-selectin (CD62E), a cell adhesion molecule for most leukocytes, is known to be expressed exclusively on the cytokine-stimulated endothelial cells mainly by inductive activation of NF-kappaB. Using immunohistochemistry and in situ hybridization, we showed that B lymphocytes and plasma cells in the spleens and lymph nodes from nude mice (T-lymphocyte-deficient), but not from SCID mice (T- and B-lymphocyte-deficient), expressed E-selectin prior to cytokine stimulation. The expression of E-selectin was also confirmed on human B lymphocytes isolated from peripheral bloods. The mouse J774A.1 monocytes could adhere to the marginal zones of mouse spleens in an E-selectin Ab inhibitable manner, suggesting the functional activity of the expressed E-selectin. In addition, ARH-77 cells, a cell line derived from human plasma cells, were found to express E-selectin mRNA and protein and to have a NF-kappaB activity for an E-selectin promoter. NF-kappaB antagonists, such as TPCK (tosylsulfonyl phenylalanyl chloromethyl ketone), dexamethasone and a IkappaBalpha mutant plasmid could inhibit both the NF-kappaB activity and the expression of E-selectin. Transfection with an E-selectin promoter-driven reporter gene construct further verified the E-selectin promoter activity in ARH-77 cells. Again, TPCK, dexamethasone, and the IkappaBalpha mutant plasmid could neutralize this activity. These findings suggest that B lymphocytes and plasma cells can express E-selectin, which is functional for monocytic leukocytes, by a mechanism of constitutive activation of NF-kappaB.
Liu
L P
LP
Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China.
Xia
Y F
YF
Yang
L
L
DiDonato
J A
JA
DiCorleto
P E
PE
Zhong
C P
CP
Geng
J G
JG
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002448:Cell Adhesion; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology; D019040:E-Selectin / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D016513:Mice, SCID; D009000:Monocytes / Q000276:immunology; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010950:Plasma Cells / Q000276:immunology*; D012333:RNA, Messenger / Q000096:biosynthesis; D013154:Spleen / Q000276:immunology
D019040:E-Selectin; D016328:NF-kappa B; D012333:RNA, Messenger; D003907:Dexamethasone