Linked Life Data

20508996

Source:http://linkedlifedata.com/resource/pubmed/id/20508996

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2010-6-16
pubmed:abstractText
Dual combinations of non-crossblocking epidermal growth factor receptor (EGF-R)-directed monoclonal antibodies were demonstrated to effectively induce complement-dependent cytotoxicity (CDC) of tumor cells, whereas individual antibodies were ineffective. Here the modulating effects of different antibody isotypes on CDC were studied by adding them as a third antibody. Two different combinations of non-crossblocking EGF-R antibodies of human IgG1 isotype, 018/003 and 425/005, were investigated against the A431 and A1207 cell lines. As a third antibody, human IgG1, IgA1, and IgA2 isotype variants of the therapeutic EGF-R antibody 225 were employed that bind to an EGF-R epitope distinct from the other EGF-R antibodies. In this model, the human IgG1 antibody proved to further enhance CDC, whereas both IgA antibodies significantly blocked CDC. The IgG1 and IgA variants increased target opsonization at similar levels, but the isotypes differed in their effects on C1q fixation. Addition of IgG1 significantly enhanced complement factor binding on the target surface, whereas both IgA antibodies reduced complement binding. Control experiments revealed this blocking effect to be not specific to IgA antibodies, but to antibody constructs incapable of activating the complement system. Interestingly, the effects caused by the IgA2 isotype were consistently stronger than those by IgA1, which may be caused by stronger steric hindrance due to its reduced hinge flexibility. These results demonstrate that monoclonal IgA antibodies inhibit IgG-mediated complement activation in vitro and suggest that the appearance of IgA antibodies within a polyclonal immune response might inhibit complement activation in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1661-4917
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
58
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
303-12
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Impact of human IgA antibodies on complement-dependent cytotoxicity mediated by combinations of EGF-R-directed antibodies.
pubmed:affiliation
Department of Internal Medicine IV, Nephrology and Hypertension, Christian-Albrechts-University, Schittenhelmstr. 12, 24105, Kiel, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't