RESUMO
Genetically attenuated microorganisms, pathogens, and some commensal bacteria can be engineered to deliver recombinant heterologous antigens to stimulate the host immune system, while still offering good levels of safety. A key feature of these live vectors is their capacity to stimulate mucosal as well as humoral and/or cellular systemic immunity. This enables the use of different forms of vaccination to prevent pathogen colonization of mucosal tissues, the front door for many infectious agents. Furthermore, delivery of DNA vaccines and immune system stimulatory molecules, such as cytokines, can be achieved using these special carriers, whose adjuvant properties and, sometimes, invasive capacities enhance the immune response. More recently, the unique features and versatility of these vectors have also been exploited to develop anti-cancer vaccines, where tumor-associated antigens, cytokines, and DNA or RNA molecules are delivered. Different strategies and genetic tools are constantly being developed, increasing the antigenic potential of agents delivered by these systems, opening fresh perspectives for the deployment of vehicles for new purposes. Here we summarize the main characteristics of the different types of live bacterial vectors and discuss new applications of these delivery systems in the field of vaccinology.
Assuntos
Animais , Humanos , Vacinas Bacterianas/imunologia , Portadores de Fármacos , Infecções Bacterianas/prevenção & controle , Vacinas Bacterianas/genética , Neoplasias/terapia , Organismos Geneticamente Modificados/genética , Organismos Geneticamente Modificados/imunologia , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologiaRESUMO
Genetically attenuated microorganisms, pathogens, and some commensal bacteria can be engineered to deliver recombinant heterologous antigens to stimulate the host immune system, while still offering good levels of safety. A key feature of these live vectors is their capacity to stimulate mucosal as well as humoral and/or cellular systemic immunity. This enables the use of different forms of vaccination to prevent pathogen colonization of mucosal tissues, the front door for many infectious agents. Furthermore, delivery of DNA vaccines and immune system stimulatory molecules, such as cytokines, can be achieved using these special carriers, whose adjuvant properties and, sometimes, invasive capacities enhance the immune response. More recently, the unique features and versatility of these vectors have also been exploited to develop anti-cancer vaccines, where tumor-associated antigens, cytokines, and DNA or RNA molecules are delivered. Different strategies and genetic tools are constantly being developed, increasing the antigenic potential of agents delivered by these systems, opening fresh perspectives for the deployment of vehicles for new purposes. Here we summarize the main characteristics of the different types of live bacterial vectors and discuss new applications of these delivery systems in the field of vaccinology.
Assuntos
Humanos , Animais , Vacinas Bacterianas/imunologia , Portadores de Fármacos , Infecções Bacterianas/prevenção & controle , Vacinas Bacterianas/genética , Neoplasias/terapia , Organismos Geneticamente Modificados/genética , Organismos Geneticamente Modificados/imunologia , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologiaRESUMO
One of the most important events in fed-batch fermentations is the definition of the moment to start the feeding. This paper presents a methodology for a rational selection of the architecture of an artificial intelligence (AI)system, based on a neural network committee (NNC),which identifies the end of the batch phase. The AI systemwas successfully used during high cell density cultivations of recombinant Escherichia coli. The AI algorithm wasvalidated for different systems, expressing three antigens to be used in human and animal vaccines: fragments of surface proteins of Streptococcus pneumoniae (PspA), clades 1 and 3, and of Erysipelothrix rhusiopathiae (SpaA). Standard feed-forward neural networks (NNs), with a single hidden layer, were the basis for the NNC. The NN architecture with best performance had the following inputs: stirrer speed, inlet air, and oxygen flow rates, carbon dioxide evolution rate, and CO2 molar fraction in the exhaust gas.