Abstract Summary/Description
Australian Bat Lyssavirus (ABLV) is a highly pathogenic virus belonging to the family Rhabdoviridae, similar to the classic Rabies virus (RABV), which causes fatal encephalitis in mammals. Each year, RABV is responsible for over 55,000 deaths, with approximately 3 billion people at risk of infection. Current vaccines and treatments have limited effectiveness against bat lyssaviruses like ABLV. In addition to requiring multiple doses, the high cost of Rabies Immune Globulin (RIG), which is often derived from human sources, makes these treatments inadequate for protecting at-risk populations. Therefore, there is a pressing need for affordable immunotherapeutics that maintain broad coverage. Lyssaviruses utilize their trimeric surface glycoprotein (G) for receptor binding and membrane fusion during viral entry, making it an attractive target for therapy. Previously identified neutralizing monoclonal antibodies can target domain III of the lyssavirus G protein. In this study, we enhance immune recognition of the conserved lyssavirus-G domain III by immunizing camelid mice (nanomice) and isolating a panel of nanobodies. The isolated nanobodies demonstrated strong competition with ABLV-neutralizing mAb RVC20 in Bio-layer interferometry assays, suggesting their potential for neutralization. Following further confirmation of their neutralizing ability through cell-fusion assays, selected nanobodies will be tandem fused and engineered into an IgG format to increase their potency and breadth of coverage. In summary, our work highlights the potential of nanobodies as an affordable, effective, and easily engineered alternative to traditional antibodies for combating ABLV infections, with the prospect of developing a pan-lyssavirus therapeutic.
