TY - JOUR
T1 - Single domain antibodies from llama effectively and specifically block T cell ecto-ADP-ribosyltransferase ART2.2 in vivo
AU - Koch-Nolte, Friedrich
AU - Reyelt, Jan
AU - Schößow, Britta
AU - Schwarz, Nicole
AU - Scheuplein, Felix
AU - Rothenburg, Stefan
AU - Haag, Friedrich
AU - Alzogaray, Vanina
AU - Cauerhff, Ana
AU - Goldbaum, Fernando A.
PY - 2007/11
Y1 - 2007/11
N2 - The purpose of our study was to develop a tool for blocking the function of a specific leukocyte ecto-enzyme in vivo. ART2.2 is a toxin-related ectoenzyme that transfers the ADP-ribose moiety from NAD onto other cell surface proteins. ART2.2 induces T cell death by activating the cytolytic P2 X 7 purinoceptor via ADP-ribosylation. Here, we report the generation of ART2.2-blocking single domain antibodies from an immunized llama. The variable domain of heavy-chain antibodies (VHH domain) represents the smallest known antigen-binding unit generated by adaptive immune responses. Their long CDR3 endows VHH domains with the extraordinary capacity to extend into and block molecular clefts. Following intravenous injection, the ART2.2-specific VHH domains effectively shut off the enzymatic and cytotoxic activities of ART2.2 in lymphatic organs. This blockade was highly specific (blocking ART2.2 but not the related enzymes ART1 or ART2.1), rapid (within 15 min after injection), and reversible (24 h after injection). Our findings constitute a proof of principle that opens up a new avenue for targeting leukocyte ecto-enzymes in vivo and that can serve as a model also for developing new antidotes against ADP-ribosylating toxins.
AB - The purpose of our study was to develop a tool for blocking the function of a specific leukocyte ecto-enzyme in vivo. ART2.2 is a toxin-related ectoenzyme that transfers the ADP-ribose moiety from NAD onto other cell surface proteins. ART2.2 induces T cell death by activating the cytolytic P2 X 7 purinoceptor via ADP-ribosylation. Here, we report the generation of ART2.2-blocking single domain antibodies from an immunized llama. The variable domain of heavy-chain antibodies (VHH domain) represents the smallest known antigen-binding unit generated by adaptive immune responses. Their long CDR3 endows VHH domains with the extraordinary capacity to extend into and block molecular clefts. Following intravenous injection, the ART2.2-specific VHH domains effectively shut off the enzymatic and cytotoxic activities of ART2.2 in lymphatic organs. This blockade was highly specific (blocking ART2.2 but not the related enzymes ART1 or ART2.1), rapid (within 15 min after injection), and reversible (24 h after injection). Our findings constitute a proof of principle that opens up a new avenue for targeting leukocyte ecto-enzymes in vivo and that can serve as a model also for developing new antidotes against ADP-ribosylating toxins.
KW - ADP-ribosylation
KW - Enzyme inhibitors
KW - Leukocyte ecto-enzymes
KW - Recombinant antibodies
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U2 - 10.1096/fj.07-8661com
DO - 10.1096/fj.07-8661com
M3 - Article
C2 - 17575259
AN - SCOPUS:35948991091
VL - 21
SP - 3490
EP - 3498
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 13
ER -