Biochemical features and antiviral activity of a monomeric catalytic antibody light‐chain 23D4 against influenza A virus

Abstract

ABSTRACT Catalytic antibodies have exhibited interesting functions against some infections viruses such as HIV, rabies virus, and influenza virus in vitro as well as in vivo. In some cases, a catalytic antibody light chain takes on several structures from the standpoint of molecular size (monomer, dimer, etc.) and/or isoelectronic point. In this study, we prepared a monomeric 23D4 light chain by mutating the C‐terminal Cys to Ala of the wild‐type. The mutated 23D4 molecule took a simple monomeric form, which could hydrolyze synthetic 4‐methyl‐coumaryl‐7‐amide substrates and a plasmid DNA. Because the monomeric 23D4 light chain suppressed the infection of influenza virus A/Hiroshima/37/2001 in an in vitro assay, the corresponding experiments were conducted in vivo , after the virus strain (which was taken from a human patient) was successfully adapted into BALB/cN Sea mice. In the experiments, a mixture of the monomeric 23D4 and the virus was nasally administered 1) with preincubation and 2) without preincubation. As a result, the monomeric 23D4 clearly exhibited the ability to suppress the influenza virus infection in both cases, indicating a potential drug for preventing infection of the influenza A virus.— Hifumi, E., Arakawa, M., Matsumoto, S., Yamamoto, T., Katayama, Y., Uda, T. Biochemical features and antiviral activity of a monomeric catalytic antibody light‐chain 23D4 against influenzaAvirus. FASEB J. 29, 2347‐2358 (2015). www.fasebj.org