Rendomab B4, a monoclonal antibody that discriminates the human endothelin B receptor of melanoma cells and inhibits their migration.

Metastatic melanoma is an aggressive cancer with a poor prognostic, and the design of new targeted drugs to treat melanoma is a therapeutic challenge. A promising approach is to produce monoclonal antibodies (mAbs) against the endothelin B receptor (ETB), which is known to be overexpressed in melanoma and to contribute to proliferation, migration and vasculogenic mimicry associated with invasiveness of this cancer. We previously described rendomab-B1, a mAb produced by DNA immunization.

Generation and characterization of rendomab-B1, a monoclonal antibody displaying potent and specific antagonism of the human endothelin B receptor.

Endothelin B receptor (ETBR) is a G protein-coupled receptor able to bind equally to the three identified human endothelin peptides. It is expressed primarily on vascular endothelial cells and involved in various physiological processes including vascular tone homeostasis, enteric nervous system development, melanogenesis and angiogenesis. Furthermore, overactivation or overexpression of ETBR have been associated with the development of various diseases such as cardiovascular disorders and cancers.

High level prokaryotic expression of anti-Müllerian inhibiting substance type II receptor diabody, a new recombinant antibody for in vivo ovarian cancer imaging.

Prescription of therapeutic antibodies has radically modified the prognosis of some important diseases. However, the very high cost of these new drugs is a problem for public health organizations, which require assessment of the effectiveness of the antibody for each patient before beginning or during the treatment. In vivo immunoimaging is particularly well adapted to meet this demand.

Electroporation-aided DNA immunization generates polyclonal antibodies against the native conformation of human endothelin B receptor.

Endothelin B receptor (ET(B)R) is a G protein-coupled receptor (GPCR) specific for endothelin peptides (including endothelin-1, ET1), which mediates a variety of key physiological functions in normal tissues, such as modulation of vasomotor tone, tissue differentiation, or cell proliferation. Moreover, ET(B)R, overexpressed in various cancer cells including melanoma, has been implicated in the growth and progression of tumors, as well as in controlling T cell homing to tumors. To gather information on receptor structure and function, antibodies are generally considered choice molecular probes, but generation of such reagents against the native conformation of GPCRs is a real technical challenge.

Electrotransfer of cDNA coding for a heterologous prion protein generates autoantibodies against native murine prion protein in wild-type mice.

Prion diseases (e.g., Creutzfeldt-Jakob disease in humans) are always fatal neurodegenerative disorders characterized by conversion of the ubiquitous cellular prion protein (PrP(c)) into a pathological conformer.

Curative properties of antibodies against prion protein: a comparative in vitro study of monovalent fragments and divalent antibodies.

Prion diseases, which include Creutzfeldt-Jakob disease (CJD) in humans, are a group of devastating neurodegenerative disorders for which no therapy is yet available. However, passive immunotherapy appears to be a promising therapeutic approach, given that antibodies against the cellular prion protein (PrPc) have been shown in vitro to antagonize deposition of the disease-associated prion protein (PrPSc). Nevertheless, in vivo deleterious side effects of injected anti-PrP antibodies have been reported, mainly due to their Fc fragments and divalence.

Generating antibodies against the native form of the human prion protein (hPrP) in wild-type animals: a comparison between DNA and protein immunizations.

Generation of therapeutic antibodies against human proteins is hampered by the difficulty of obtaining large quantities of correctly folded immunogens when following classic immunization procedures. Here we compared several genetic immunization protocols for their potential ability to generate high levels of antibodies against proteins expressed in their native form. We chose as a model the prion protein (PrP) because it has been demonstrated that the recognition of the native conformation of PrP is an absolute prerequisite for anti-PrP antibodies to be used as therapeutic tools for prion diseases, a group of lethal neurodegenerative disorders.

Polyclonal anti-idiotypic antibodies which mimic an epitope of the human prion protein.

Immunization with anti-idiotypic (anti-Id) antibodies, used as surrogate antigens, has led to promising results, notably in active immunotherapy of cancers, essentially because it breaks immunological tolerance against self-tumor-associated antigens. The aim of the present study was to provide a proof-of-principle that this vaccination approach could be envisaged also in the field of prion diseases, caused by the accumulation of an aggregated pathological isoform of the highly tolerogenic self-prion protein (PrP), and for which no therapy is available. We investigated the possibility of raising anti-Id antibodies mimicking the human PrP (hPrP), using as immunogens either a peptide derived from the paratope of an anti-PrP mAb or the entire antibody.

Expression and detection strategies for an scFv fragment retaining the same high affinity than Fab and whole antibody: Implications for therapeutic use in prion diseases.

Since antibodies currently constitute the most rapidly growing class of human therapeutics, the high-yield production of recombinant antibodies and antibody fragments is a real challenge. Using as model a monoclonal antibody directed against the human prion protein that we prepared previously and tested for its therapeutic value, we describe here experimental conditions allowing the production of large quantities (up to 35 mg/l of bacterial culture) of correctly refolded and totally functional single chain fragment variable (scFv). These quantities were sufficient to characterize the binding properties of this small recombinant fragment through in vitro and ex vivo approaches.

Enhancement of antibody responses in DNA vaccination using a vector encoding a universal T-helper cell epitope.

DNA vaccination appears as a very promising approach to raise protective antibodies against a variety of proteins from pathogens or tumor cells, but is often hindered by the low immunogenicity of the genetic vectors used for the immunizations. To enhance the humoral response through improvement of the antigenic presentation of newly synthesized proteins upon vaccination, we engineered a plasmid coding for a low immunogenic protein (an scFv, i.e.

Pharmacological properties of peptides derived from an antibody against the tachykinin NK1 receptor for the neuropeptide substance P.

Two peptides were derived from the structural analysis of a previously described monoclonal antibody [Mol. Immunol. 37 (2000) 423] against the tachykinin NK(1) receptor for the neuropeptide substance P.

Use of DNA immunization to produce polyclonal antibodies against the native human neurokinin-1 receptor for substance P.

Antibodies against the native form of the human NK1 receptor (hNK1R) for the neuropeptide substance P (SP), an important immunoregulator, are difficult to produce using classical immunization techniques. We show here that mice immunized with a plasmid harboring hNK1R cDNA developed antibodies recognizing extracellular epitopes of native hNK1R expressed on CHO cell membranes, as shown by FACS and immunofluorescence analysis, some antibodies being specifically directed against the second extracellular loop (E2) of the receptor. This original strategy, DNA immunization, thus efficiently generated new immunological tools to further analyse the role of SP in the regulation of immune cell functions.

Anti-allergen antibodies can be neutralized by antibodies obtained against a peptide complementary to the allergen: towards a new peptide therapy for allergy.

The concept of specific immune treatment against allergic diseases requires the development of antibodies capable of specifically neutralizing anti-allergen antibodies. The aim of the present study was to investigate whether a novel approach, consisting in raising anti-idiotypic blocking antibodies through peptide immunization, could be envisaged in the field of allergy. Using allergy to cow's milk as a model, we prepared polyclonal antibodies against a peptide that is complementary (i.