Novel Camelid Antibody Fragments Targeting Recombinant Nucleoprotein of Araucaria hantavirus: A Prototype for an Early Diagnosis of Hantavirus Pulmonary Syndrome

摘要: In addition to conventional antibodies, camelids produce immunoglobulins G composed exclusively of heavy chains in which the antigen binding site is formed only by single domains called VHH. Their particular characteristics make VHHs interesting tools for drug-delivery, passive immunotherapy and high-throughput diagnosis. Hantaviruses are rodent-borne viruses Bunyaviridae family. Two clinical forms infection known. Hemorrhagic Fever with Renal Syndrome (HFRS) present in Old World, while Hantavirus Pulmonary Syndrome (HPS) found on American continent. There is no specific treatment HPS its diagnosis carried out molecular or serological techniques, using mainly monoclonal antibodies hantavirus nucleoprotein (N) detect IgM IgG patient serum. This study proposes use of camelid VHHs develop alternative methods diagnosing confirming HPS. Phage display technology was employed obtain VHHs. After immunizing one Lama glama against recombinant N protein (prND85) a Brazilian hantavirus strain, VHH regions were isolated construct an immune library. displayed fused M13KO7 phage coat III selection steps performed immobilized prND85. selection, eighty clones recognized specifically protein. These sequenced, grouped based mainly CDRs, five clones were analyzed western blot (WB), surface plasmon resonance (SPR) device, ELISA. Besides ability recognize prND85 by WB, all selected showed affinity constants nanomolar range. Additionaly, clone KC329705 able to detect prND85 solution, as well native viral antigen. Findings support hypothesis that could be a powerful tool development rapid accurate diagnostic assays, which essential provide supportive care patients reduce high mortality rate associated infections.