Linked Life Data

18566448

Source:http://linkedlifedata.com/resource/pubmed/id/18566448

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-6-20
pubmed:abstractText
Binding of the CD20 mAb rituximab (RTX) to B lymphocytes in normal human serum (NHS) activates complement (C) and promotes C3b deposition on or in close proximity to cell-bound RTX. Based on spinning disk confocal microscopy analyses, we report the first real-time visualization of C3b deposition and C-mediated killing of RTX-opsonized B cells. C activation by RTX-opsonized Daudi B cells induces rapid membrane blebbing and generation of long, thin structures protruding from cell surfaces, which we call streamers. Ofatumumab, a unique mAb that targets a distinct binding site (the small loop epitope) of the CD20 Ag, induces more rapid killing and streaming on Daudi cells than RTX. In contrast to RTX, ofatumumab promotes streamer formation and killing of ARH77 cells and primary B cells from patients with chronic lymphocytic leukemia. Generation of streamers requires C activation; no streaming occurs in media, NHS-EDTA, or in sera depleted of C5 or C9. Streamers can be visualized in bright field by phase imaging, and fluorescence-staining patterns indicate they contain membrane lipids and polymerized actin. Streaming also occurs if cells are reacted in medium with bee venom melittin, which penetrates cells and forms membrane pores in a manner similar to the membrane-attack complex of C. Structures similar to streamers are demonstrable when Ab-opsonized sheep erythrocytes (non-nucleated cells) are reacted with NHS. Taken together, our findings indicate that the membrane-attack complex is a key mediator of streaming. Streamer formation may, thus, represent a membrane structural change that can occur shortly before complement-induced cell death.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
181
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
822-32
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Complement activation on B lymphocytes opsonized with rituximab or ofatumumab produces substantial changes in membrane structure preceding cell lysis.
pubmed:affiliation
Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't