Assuntos
Bovinos/microbiologia , Coxiella burnetii/genética , Reservatórios de Doenças/veterinária , Placenta/microbiologia , Febre Q/veterinária , Animais , Coxiella burnetii/classificação , Coxiella burnetii/isolamento & purificação , Reservatórios de Doenças/microbiologia , Feminino , Genótipo , Cabras/microbiologia , Humanos , Tipagem Molecular , Países Baixos/epidemiologia , Filogenia , Gravidez , Febre Q/epidemiologia , Febre Q/microbiologia , Carneiro Doméstico/microbiologia , Carrapatos/microbiologiaRESUMO
The therapeutic parenteral application of llama single-domain antibody fragments (VHHs) is hampered by their small size, resulting in a fast elimination from the body. Here we describe a method to increase the serum half-life of VHHs in pigs by fusion to another VHH binding to porcine immunoglobulin G (pIgG). We isolated 19 pIgG-binding VHHs from an immunized llama using phage display. Six VHHs were genetically fused to model VHH K 609 that binds to Escherichia coli F4 fimbriae. All six yeast-produced genetic fusions of two VHH domains (VHH2s) were functional in ELISA and bound to pIgG with high affinity (1-33 nM). Four pIgG-binding VHH2s were administered to pigs and showed a 100-fold extended in vivo residence times as compared to a control VHH2 that does not bind to pIgG. This could provide the basis for therapeutic application of VHHs in pigs.