TY - JOUR
T1 - Binding characteristics and tumor targeting of a covalently linked divalent CC49 single-chain antibody
AU - Beresford, Guy W.
AU - Pavlinkova, Gabriela
AU - Booth, Barbara J.M.
AU - Batra, Surinder K.
AU - Colcher, David
PY - 1999/6/8
Y1 - 1999/6/8
N2 - Multivalency is a recognized means of increasing the functional affinity of single-chain Fvs (scFvs) for optimizing tumor uptake. A unique divalent single-chain Fv protein [sc(Fv)2], based on the variable regions of the monoclonal antibody (MAb) CC49, has been generated that differs from other dimeric single-chain constructs in that a linker sequence (L) is encoded between the repeated V(L) and V(H) domains (V(L)-L-V(H)L-V(L)-L-V(H)). This construct was expressed in soluble form in Escherichia call and purified by ion-exchange and gel-filtration chromatography. Purity and immunoreactivity were determined by SDS-PAGE, HPLC and competitive RIA. sc(Fv)2 exhibited a relative K(A) (3.34 x 107 M-1) similar to that of the native IgG (1.14 x 108 M-1) as determined by BIAcore analysis. Pharmacokinetic studies showed rapid blood clearance for sc(Fv)2, with a T(1/2) less than 40 min. Whole- body clearance analysis also revealed rapid clearance, suggesting no significant retention in the extravascular space or normal tissues. Biodistribution studies of radiolabeled sc(Fv)2 showed tumor uptake greater than 6% ID/g after 30 min, which remained at this level for 6 hr. High tumor uptake and retention of sc(Fv)2 coupled with rapid blood and whole-body clearance makes this dimeric scFv of MAb CC49 a strong candidate for imaging and therapeutic applications.
AB - Multivalency is a recognized means of increasing the functional affinity of single-chain Fvs (scFvs) for optimizing tumor uptake. A unique divalent single-chain Fv protein [sc(Fv)2], based on the variable regions of the monoclonal antibody (MAb) CC49, has been generated that differs from other dimeric single-chain constructs in that a linker sequence (L) is encoded between the repeated V(L) and V(H) domains (V(L)-L-V(H)L-V(L)-L-V(H)). This construct was expressed in soluble form in Escherichia call and purified by ion-exchange and gel-filtration chromatography. Purity and immunoreactivity were determined by SDS-PAGE, HPLC and competitive RIA. sc(Fv)2 exhibited a relative K(A) (3.34 x 107 M-1) similar to that of the native IgG (1.14 x 108 M-1) as determined by BIAcore analysis. Pharmacokinetic studies showed rapid blood clearance for sc(Fv)2, with a T(1/2) less than 40 min. Whole- body clearance analysis also revealed rapid clearance, suggesting no significant retention in the extravascular space or normal tissues. Biodistribution studies of radiolabeled sc(Fv)2 showed tumor uptake greater than 6% ID/g after 30 min, which remained at this level for 6 hr. High tumor uptake and retention of sc(Fv)2 coupled with rapid blood and whole-body clearance makes this dimeric scFv of MAb CC49 a strong candidate for imaging and therapeutic applications.
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U2 - 10.1002/(SICI)1097-0215(19990611)81:6<911::AID-IJC12>3.0.CO;2-O
DO - 10.1002/(SICI)1097-0215(19990611)81:6<911::AID-IJC12>3.0.CO;2-O
M3 - Article
C2 - 10362138
AN - SCOPUS:0033046339
VL - 81
SP - 911
EP - 917
JO - International Journal of Cancer
JF - International Journal of Cancer
SN - 0020-7136
IS - 6
ER -