RESUMO
The eradication of smallpox (variola) and the subsequent cessation of routine vaccination have left modern society vulnerable to bioterrorism employing this devastating contagious disease. The existing, licensed vaccines based on live vaccinia virus (VACV) are contraindicated for a substantial number of people, and prophylactic vaccination of large populations is not reasonable when there is little risk of exposure. Consequently, there is an emerging need to develop efficient and safe therapeutics to be used shortly before or after exposure, either alone or in combination with vaccination. We have characterized the human antibody response to smallpox vaccine (VACV Lister) in immunized volunteers and isolated a large number of VACV-specific antibodies that recognize a variety of different VACV antigens. Using this broad antibody panel, we have generated a fully human, recombinant analogue to plasma-derived vaccinia immunoglobulin (VIG), which mirrors the diversity and specificity of the human antibody immune response and offers the advantage of unlimited supply and reproducible specificity and activity. The recombinant VIG was found to display a high specific binding activity toward VACV antigens, potent in vitro VACV neutralizing activity, and a highly protective efficacy against VACV challenge in the mouse tail lesion model when given either prophylactically or therapeutically. Altogether, the results suggest that this compound has the potential to be used as an effective postexposure prophylaxis or treatment of disease caused by orthopoxviruses.
Assuntos
Anticorpos Antivirais/biossíntese , Antígenos Virais/imunologia , Vacina Antivariólica/imunologia , Varíola/prevenção & controle , Vacinas Sintéticas/imunologia , Vaccinia virus/imunologia , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/química , Anticorpos Antivirais/genética , Formação de Anticorpos , Especificidade de Anticorpos , Antígenos Virais/química , Antígenos Virais/genética , Doadores de Sangue , Feminino , Variação Genética , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina G/química , Imunoglobulina G/genética , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Análise de Sequência de DNA , Varíola/tratamento farmacológico , Varíola/imunologia , Vacina Antivariólica/administração & dosagem , Vacina Antivariólica/genética , Vacinação , Vacinas Sintéticas/genética , Vacinas Sintéticas/uso terapêutico , Vaccinia virus/classificação , Vaccinia virus/genéticaRESUMO
The humoral immune system in higher vertebrates is unique in its ability to generate highly diverse antibody responses against most pathogens as well as against certain malignancies. Several technologies have been developed to exploit this vast source of potentially therapeutic antibodies, including hybridoma technology, phage display and yeast display. Here, we present a novel, high-throughput technology (the Symplex Technology) for rapid direct cloning and identification of human antigen-specific high-affinity antibodies from single antibody-producing cells of immune individuals. The utility of the technology was demonstrated by isolation of diverse sets of unique high-affinity antibodies against tetanus toxoid and influenza virus from immunized volunteers. Hence, the Symplex Technology is a new method for the rapid isolation of high-affinity antibodies directly from humans.