Intrabodies targeting the Kaposi sarcoma-associated herpesvirus latency antigen inhibit viral persistence in lymphoma cells

Blood. 2005 Dec 1;106(12):3797-802. doi: 10.1182/blood-2005-04-1627. Epub 2005 Aug 9.

Abstract

Kaposi sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen-1 (LANA1) is essential for the maintenance and segregation of viral episomes in KSHV latently infected B cells. We report development of intracellular, rabbit-derived antibodies generated by phage display technology, which bind to N-terminal LANA1 epitopes and neutralize the chromosome-binding activity of LANA1. Although these cloned single-chain variable fragments (scFvs) show relatively low binding affinities for the LANA1 viral antigen in in vitro assays, they nonetheless outcompete KSHV-seropositive human sera for LANA1 epitope binding. In heterologous cells, intracellular intrabody expression inhibits LANA1-dependent plasmid maintenance of both an artificial plasmid containing KSHV LANA1 binding sequences and a bacterial artificial chromosome containing the entire KSHV genome. In KSHV naturally infected primary effusion lymphoma cells, intracellular intrabody expression causes a reduction or loss of the typical LANA1 punctate, nuclear pattern. This morphologically apparent LANA1 dispersion correlates to loss of viral episome by molecular analysis. These data suggest a novel approach to antiherpes viral therapy and confirm LANA1 is critical target for neutralization of KSHV viral latency.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Viral / genetics
  • Antigens, Viral / immunology*
  • Cell Line
  • Herpesvirus 8, Human / physiology
  • Humans
  • Immunoglobulin Variable Region / immunology
  • Immunoglobulin Variable Region / pharmacology*
  • Lymphoma / virology*
  • Molecular Sequence Data
  • Nuclear Proteins / genetics
  • Nuclear Proteins / immunology*
  • Peptide Library
  • Rabbits
  • Sarcoma, Kaposi / immunology
  • Sarcoma, Kaposi / virology*
  • Transfection
  • Virus Latency / drug effects*

Substances

  • Antigens, Viral
  • Immunoglobulin Variable Region
  • Nuclear Proteins
  • Peptide Library
  • latency-associated nuclear antigen