Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1991-4-22
pubmed:abstractText
The regulatory role of CR1 and CR2 on B cell activation and proliferation has been investigated by using B cells from patients with chronic lymphocytic leukemia. The chronic lymphocytic leukemia B cells are clonal expansions of B lymphocytes frozen at specific stages of activation. They displayed two patterns of response upon surface Ig (sIg) cross-linking in terms of in vitro proliferation and intracellular free Ca2+ mobilization: cells from patient F (first pattern) proliferated in the presence of mitogenic anti-mu antibodies, whereas cells from patient A (second pattern) did not respond to sIg cross-linking but proliferated in the presence of low m.w. B cell growth factor and IL-2. Coculture of A or F cells with C3b-bearing SRBC led to a two- to four-fold increase in thymidine incorporation in cultures containing low m.w. B cell growth factor but not in cultures containing rIL-2. This enhanced proliferation was inhibited by F(ab')2 polyclonal rabbit antihuman CR1 antibodies. Only cells which proliferated in the presence of anti-mu (cells F) responded to cross-linking of sIg with a rise in intracellular Ca2+. No increase in calcium mobilization was observed after co-cross-linking of CR1 and sIg on A and F cells with mAb or polyclonal anti-CR1 antibodies. Co-cross-linking of CR2 with sIg only led to an enhanced intracellular Ca2+ rise in F cells but not in A cells. The lack of CR2-mediated synergy in Ca2+ rise in A cells indicates that the synergy occurs only if there is a proper coupling of sIg to phospholipase C. CR1-induced proliferation of B cells does not involve the signaling pathways of sIg. These results provide additional evidences for the role of C3 fragments in modulation of human B cell activation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1766-72
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Differential effects of the stimulation of complement receptors CR1 (CD35) and CR2 (CD21) on cell proliferation and intracellular Ca2+ mobilization of chronic lymphocytic leukemia B cells.
pubmed:affiliation
INSERUM U 108, Hôpital Saint-Louis, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't