Development of novel heavy chain antibody-based therapeutics for polyomavirus infections

ABSTRACT BK and JC Polyomaviruses cause significant morbidity and mortality in immune suppressed patientsincluding progressive multifocal leukoencephalopathyPMLpolyomavirus associated nephropathyPVANand hemorrhagic cystitisCurrently there is no effective therapyprophylaxisor vaccination for any polyomavirusIn additionBK JC viruses replicate in the renal tubular and urothelial epitheliumso that infection is maintained in theimmune privilegedurinary spaceHencethere is an unmet need for a potent therapeutic prophylactic capable of targeting BK JC viruses in the urinary spaceThe overall goal of the proposed project is to develop a novel multivalent antibody based therapy for BK and JC polyomavirus infectionsIn the proposed workTeneoBioIncwill utilize a platform based on the production of fully human heavy chain antibodies in genetically engineered ratsUniRat systemUnlike conventional antibodiesheavy chain antibodies can be engineered to consist of only two heavy chainswithout light chainsan isolated heavy chainor astringof variable domainsso calleddomain UniAbsor UniDabsDue to their small sizeUniDAbs can be filtered into the urinethus targeting BK JC viruses that reside in the urinary spaceIn additionsince UniDAbs are fully humanadverse side effects associated with humanizedmurineand alternative multivalent antibody approachessuch as anti drug antibodiesare not anticipatedIt has been shown that HCAs UniDAbs as no more immunogenic than conventional AbsIn this proposal we first plan to generate heavy chain antibodies from UniRats immunized with BK JC derived virus like particles by developing an optimal immunization protocol for BK JC virus antibodies in UniRatsfollowed by an identification of the resulting BK JC virus specific heavy chain antibody leadsapproximatelyusing next generation sequencingNextwe will implement astage screening approach to selecthigh affinity anti BK JC heavy chain antibodiesIn the first stage we will search for sequence families that demonstrate high affinity binding and neutralization of multiple BK JC serotypesIn the second stagean additional round of high throughput vector assemblyexpressionand neutralization assays will be performed to yieldstable antibody candidatesFinallythe antibodies with the highest affinity will be further characterized by screening for broad neutralization of additional BK JC variantsThe selected broadly neutralizing heavy chain antibodies UniDAbs will undergo functional characterization to aid the generation of stable UniDab strings in a future phaseof this projectUpon successful completion of the proposed study at leastheavy chain antibodies will be selectedThese antibodies will serve in phase II as the basis for construction of high affinity virus specific UniDabsThese UniDabs will then be tested in pre clinical and finally clinical applications NARRATIVE BK and JC Polyomaviruses cause significant morbidity and mortality in immune suppressed patientsCurrently there is no effective therapyprophylaxisor vaccination for any polyomavirusThe main challenge of BK JC viral infection is that it is often maintained in the urinary spaceWe propose to develop a novel antibody based therapy for BK JC virus infection able to penetrate the urinary space using genetically engineered rats