Abstract:With 18 monoclonal antibody (mAb) products currently on the market and more than 100 in clinical trials, it is clear that engineered antibodies have come of age as biopharmaceuticals. In fact, by 2008, engineered antibodies are predicted to account for >30% of all revenues in the biotechnology market. Smaller recombinant antibody fragments (for example, classic monovalent antibody fragments (Fab, scFv)) and engineered variants (diabodies, triabodies, minibodies and single-domain antibodies) are now emerging as… Show more
“…12 However, practical use of systemically administered recombinant antibody fragments is limited, by problems related to large-scale production and biodistribution. 9,17 In situ secretion of therapeutic antibodies is an attractive alternative to systemic administration of antibody fragments. In situ expression potentially circumvents problems of tumor penetration and compensates for the rapid blood clearance of antibody fragments and could make the antibody less immunogenic and better tolerated.…”
Section: Discussionmentioning
confidence: 99%
“…In situ expression potentially circumvents problems of tumor penetration and compensates for the rapid blood clearance of antibody fragments and could make the antibody less immunogenic and better tolerated. 9,17 The use of gene therapy methods offers additional benefits by achieving sustained and effective concentrations of therapeutic antibodies directly at points of target intervention. In fact, we have previously shown that human T lymphocytes, transduced ex vivo to secrete the aCEA/aCD3 diabody in autocrine manner, inhibited the growth of CEA-positive tumors.…”
Section: Discussionmentioning
confidence: 99%
“…[6][7][8] Bispecific antibodies are non-natural immunoglobulin-based molecules that contain two distinct binding specificities. 9 Bispecific antibodies redirect the cytolytic activity of a variety of immune effector cells toward tumor cells by binding to cell activation molecules with one domain and to specific tumor-associated antigen on cancer cells with the other. T-cell-activating bispecific antibodies have shown great potential for the treatment of malignant diseases in both animal models 7,8,11 and humans.…”
Several works have shown the feasibility of engineering functional blood vessels in vivo using human endothelial cells (ECs). Going further, we explored the therapeutic potential of neovessels after gene-modifying the ECs for the secretion of a therapeutic protein. Given that these vessels are connected with the host vascular bed, we hypothesized that systemic release of the expressed protein is immediate. As a proof of principle, we used primary human ECs transduced with a lentiviral vector for the expression of a recombinant bispecific aCEA/aCD3 antibody. These ECs, along with mesenchymal stem cells as a source of mural cells, were embedded in Matrigel and subcutaneously implanted in nude mice. High antibody levels were detected in plasma for 1 month. Furthermore, the antibody exerted a therapeutic effect in mice bearing distant carcinoembryonic-antigen (CEA)-positive tumors after inoculation of human T cells. In summary, we show for the first time the therapeutic effect of a protein locally secreted by engineered human neovessels.
“…12 However, practical use of systemically administered recombinant antibody fragments is limited, by problems related to large-scale production and biodistribution. 9,17 In situ secretion of therapeutic antibodies is an attractive alternative to systemic administration of antibody fragments. In situ expression potentially circumvents problems of tumor penetration and compensates for the rapid blood clearance of antibody fragments and could make the antibody less immunogenic and better tolerated.…”
Section: Discussionmentioning
confidence: 99%
“…In situ expression potentially circumvents problems of tumor penetration and compensates for the rapid blood clearance of antibody fragments and could make the antibody less immunogenic and better tolerated. 9,17 The use of gene therapy methods offers additional benefits by achieving sustained and effective concentrations of therapeutic antibodies directly at points of target intervention. In fact, we have previously shown that human T lymphocytes, transduced ex vivo to secrete the aCEA/aCD3 diabody in autocrine manner, inhibited the growth of CEA-positive tumors.…”
Section: Discussionmentioning
confidence: 99%
“…[6][7][8] Bispecific antibodies are non-natural immunoglobulin-based molecules that contain two distinct binding specificities. 9 Bispecific antibodies redirect the cytolytic activity of a variety of immune effector cells toward tumor cells by binding to cell activation molecules with one domain and to specific tumor-associated antigen on cancer cells with the other. T-cell-activating bispecific antibodies have shown great potential for the treatment of malignant diseases in both animal models 7,8,11 and humans.…”
Several works have shown the feasibility of engineering functional blood vessels in vivo using human endothelial cells (ECs). Going further, we explored the therapeutic potential of neovessels after gene-modifying the ECs for the secretion of a therapeutic protein. Given that these vessels are connected with the host vascular bed, we hypothesized that systemic release of the expressed protein is immediate. As a proof of principle, we used primary human ECs transduced with a lentiviral vector for the expression of a recombinant bispecific aCEA/aCD3 antibody. These ECs, along with mesenchymal stem cells as a source of mural cells, were embedded in Matrigel and subcutaneously implanted in nude mice. High antibody levels were detected in plasma for 1 month. Furthermore, the antibody exerted a therapeutic effect in mice bearing distant carcinoembryonic-antigen (CEA)-positive tumors after inoculation of human T cells. In summary, we show for the first time the therapeutic effect of a protein locally secreted by engineered human neovessels.
“…The modular nature of V H Hs and V NAR s has been widely and productively exploited in the development of antibody-based drugs (reviewed in Ref. 5 ).10.1080/19420862.2018.1489633-F0001Figure 1.Domain structures of camelid heavy chain-only IgG, shark immunoglobulin new antigen receptor (IgNAR) and conventional vertebrate tetrameric IgG. The variable domain(s) of each antibody molecule are shown in yellow and the antigen-combining site is indicated by a red box.…”
Single-domain antibodies (sdAbs), the autonomous variable domains of heavy chain-only antibodies produced naturally by camelid ungulates and cartilaginous fishes, have evolved to bind antigen using only three complementarity-determining region (CDR) loops rather than the six present in conventional VH:VL antibodies. It has been suggested, based on limited evidence, that sdAbs may adopt paratope structures that predispose them to preferential recognition of recessed protein epitopes, but poor or non-recognition of protuberant epitopes and small molecules. Here, we comprehensively surveyed the evidence in support of this hypothesis. We found some support for a global structural difference in the paratope shapes of sdAbs compared with those of conventional antibodies: sdAb paratopes have smaller molecular surface areas and diameters, more commonly have non-canonical CDR1 and CDR2 structures, and have elongated CDR3 length distributions, but have similar amino acid compositions and are no more extended (interatomic distance measured from CDR base to tip) than conventional antibody paratopes. Comparison of X-ray crystal structures of sdAbs and conventional antibodies in complex with cognate antigens showed that sdAbs and conventional antibodies bury similar solvent-exposed surface areas on proteins and form similar types of non-covalent interactions, although these are more concentrated in the compact sdAb paratope. Thus, sdAbs likely have privileged access to distinct antigenic regions on proteins, but only owing to their small molecular size and not to general differences in molecular recognition mechanism. The evidence surrounding the purported inability of sdAbs to bind small molecules was less clear. The available data provide a structural framework for understanding the evolutionary emergence and function of autonomous heavy chain-only antibodies.
“…Fabs, which contain the complementary‐determining regions (CDRs) of antibodies, can be expressed as fusion proteins and are monovalent 8, 9, 10. The latter fact facilitates their use as LUCIDs.…”
We introduce a general method to transform antibodies into ratiometric, bioluminescent sensor proteins for the no‐wash quantification of analytes. Our approach is based on the genetic fusion of antibody fragments to NanoLuc luciferase and SNAP‐tag, the latter being labeled with a synthetic fluorescent competitor of the antigen. Binding of the antigen, here synthetic drugs, by the sensor displaces the tethered fluorescent competitor from the antibody and disrupts bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. The semisynthetic sensors display a tunable response range (submicromolar to submillimolar) and large dynamic range (ΔR
max>500 %), and they permit the quantification of analytes through spotting of the samples onto paper followed by analysis with a digital camera.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
