title: Immunization with antigen-pulsed dendritic cells significantly improves the immune response to weak self-antigens.
abstract: Dendritic cells (DCs) are the only professional antigen-presenting cells endowed with the ability to stimulate naïve T cells and initiate a primary immune response. For this reason, DC-based immunization has been shown to be highly effective in eliciting CTL responses to viruses and tumor-associated antigens. Here we report on the use of DC immunization to enhance the B cell-mediated humoral immune response to highly conserved proteins and the application of this approach to the generation of monoclonal antibodies (mAbs) against these proteins. To illustrate the technique we describe the production of mAbs to class II transactivator (CIITA), the major histocompatibility complex (MHC) CIITA, a difficult immunogen owing to its high degree of identity among species. We show that mice immunized with a combination of an intravenous injection of DCs pulsed with recombinant fragments of CIITA followed by intraperitoneal injection of the antigen in incomplete Freund's adjuvant induced a detectable antibody response against CIITA, while sera from mice immunized using the traditional method (i.e. intraperitoneal immunization with 50mug of protein in complete Freund's adjuvant) gave an almost undetectable response. Furthermore, a total of four fusion experiments demonstrate that immunization with Ag-pulsed DCs is necessary for the efficient generation of hybridomas and a good yield of mAbs specific for the recombinant and the native endogenous CIITA protein. Conversely, four independent fusions carried out with splenocytes from mice immunized using the traditional method failed to produce anti-CIITA hybridomas. We propose that immunization with antigen-loaded DCs should be the method of preference when attempting to raise mAbs against weak self-immunogens.
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Vargas
authors.forename: Claudio
authors.initials: C
authors.lastname: Cortés
authors.forename: Leonardo
authors.initials: L
authors.lastname: Vargas
authors.forename: Mario
authors.initials: M
authors.lastname: Rosemblatt
authors.forename: María Rosa
authors.initials: MR
authors.lastname: Bono
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000097:blood; D001324:Autoantigens / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D019556:COS Cells; D002460:Cell Line; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation*; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods; D008546:Melanoma, Experimental / Q000276:immunology / Q000628:therapy; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D010446:Peptide Fragments / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D015534:Trans-Activators / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D001324:Autoantigens; C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D010446:Peptide Fragments; D015534:Trans-Activators