Characterization of BIS20x3, a bi-specific antibody activating and retargeting T-cells to CD20-positive B-cells.
This paper describes a bi-specific antibody, which was called BIS20x3. It retargets CD3varepsilon-positive cells (T-cells) to CD20-positive cells and was obtained by hybrid-hybridoma fusion. BIS20x3 could be isolated readily from quadroma culture supernatant and retained all the signalling characteristics associated with both of its chains. Cross-linking of BIS20x3 on Ramos cells leads to DNA fragmentation percentages similar to those obtained after Rituximab-cross-linking. Cross-linking of BIS20x3 on T-cells using cross-linking F(ab')2-fragments induced T-cell activation. Indirect cross-linking of T-cell-bound BIS20x3 via Ramos cells hyper-activated the T-cells. Furthermore, it was demonstrated that BIS20x3 effectively re-targets T-cells to B-cells, leading to high B-cell cytotoxicity. The results presented in this paper show that BIS20x3 is fully functional in retargeting T-cells to B-cells and suggest that B-cell lymphomas may represent ideal targets for T-cell retargeting bi-specific antibodies, because the retargeted T-cell is maximally stimulated in the presence of B-cells. Additionally, since B-cells may up-regulate CD95/ Fas expression upon binding of CD20-directed antibodies, B-cells will become even more sensitive for T-cell mediated killing via CD95L/ Fas L, and therefore supports the intention to use T-cell retargeting bi-specific antibodies recognizing CD20 on B-cell malignancies as a treatment modality for these diseases.
Withoff
S
S
Department of Pathology and Laboratory Medicine, University Hospital Groningen, Section Medical Biology - Laboratory Tumor Immunology, Hanzeplein 1, GZ Groningen, 9713, The Netherlands.
Bijman
M N
MN
Stel
A J
AJ
Delahaye
L
L
Calogero
A
A
Jonge
M W
MW
Kroesen
B J
BJ
Leij
L
L
D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification / Q000494:pharmacology; D018951:Antigens, CD20 / Q000276:immunology*; D017209:Apoptosis / Q000187:drug effects; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D017252:CD3 Complex; D002459:Cell Fusion; D002460:Cell Line; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006825:Hybridomas / Q000166:cytology / Q000276:immunology; D019169:Jurkat Cells; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D018951:Antigens, CD20; D017252:CD3 Complex; C115335:CD3E protein, human; D011948:Receptors, Antigen, T-Cell; D004247:DNA