Therapeutic Antibody Fragments to Treat New World Hemorrhagic Fevers

DIEP, ANN; SAWAYA, MICHAEL; PENICHET, MANUEL; ZIEGENBEIN, JAMES ; CASCIO, DUILIO; HELGUERA, GUSTAVO; PAYÉS, CRISTIAN; DANIELS-WELLS, TRACY; RODRIGUEZ, JOSÉ

Los Angeles

Jornada; UCLA Undergraduate Research Week; 2017

Universidad de California en Los Angeles

Viral hemorrhagic fevers are a deadly threat to our species. New treatments are required to safeguard against the deadly action of New World Hemorrhagic Fever (NWHF) viruses: clade B pathogens that include Junin, Machupo, Sabia, Guaranito, and Chapare. We aim to develop therapeutic agents targeting the port of entry of these viruses into human cells, a cell surface protein known as the transferrin receptor (TfR1). To do so, we have optimized our purification of the recombinant ectodomain of human TfR1 produced in human cells. The protein is isolated from supernatant and purified by affinity chromatography against a nickel resin through a hexa-his tag. Further purification by size exclusion chromatography leads to a single monomeric species of TfR1 that can be purified in complex with the antigen binding fragment (Fab) from a previously published antibody (Ab) targeting TfR1. We have begun crystal trials of the Fab-TfR1 complex to obtain atomic views of their interaction and elucidate the mechanism of antibody blockade of NWHF virus entry into human cells.