Generation of antibodies to the urokinase receptor (uPAR) by DNA immunization of uPAR knockout mice: membrane-bound uPAR is not required for an antibody response.
The urokinase receptor (uPAR) is a glycolipid-anchored cell surface glycoprotein that plays a central role in extracellular proteolysis during tissue remodeling processes including cancer invasion. Furthermore, uPAR is found on the surface of both dendritic cells (DCs) and T cells, and has been proposed to play a role in DC-induced T-cell activation and, therefore, in the induction of an immune response. In order to investigate the possibility of using DNA immunization for the generation of poly- and monoclonal antibodies to uPAR, we injected wild-type mice and mice deficient in uPAR (uPAR knockouts) intramuscularly with plasmid DNA encoding a carboxy-terminal truncated soluble form of the human uPAR. Multiple injections of 100 micro g of DNA resulted in a strong and specific antibody response in all mice irrespective of genotype. Antisera with a maximum titre of 32,000 were obtained, comparable with that obtained after immunization with recombinant uPAR. The subclass distribution of uPAR-specific antibodies in the sera demonstrated the induction of a mixed TH1/TH2 response, irrespective of the genotype of the mice. Our results demonstrate the possibility of generating high titre antibodies to uPAR by DNA immunization of wild-type as well as uPAR knockout mice, and that cell surface uPAR is not indispensable for the generation of a humoral immune response.
Pass
J
J
Finsen Laboratory, Rigshospitalet, Strandboulevarden, Copenhagen Ø, Denmark. jesper.pass@finsenlab.dk
Gårdsvoll
H
H
Lund
L R
LR
Danø
K
K
Høyer-Hansen
G
G
D000818:Animals; D000906:Antibodies / Q000097:blood; D000917:Antibody Formation / Q000235:genetics / Q000276:immunology*; D015153:Blotting, Western; D019556:COS Cells; D002522:Chlorocebus aethiops; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D010957:Plasmids / Q000235:genetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D055293:Receptors, Urokinase Plasminogen Activator; D014162:Transfection; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
D000906:Antibodies; D007074:Immunoglobulin G; C524898:PLAUR protein, human; C524899:Plaur protein, mouse; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D019444:Vaccines, DNA