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

Corte-Real S, Collins C, Aires da Silva F, Silmas P, Barbas Iii C, Chang Y, Moore P and Goncalves J
Source: Blood
Publication Date: (2005)
Issue: 106(12): 3797-3802
Research Area:
Immunotherapy / Hematology
Cells used in publication:
Species: human
Tissue Origin: blood
Species: human
Tissue Origin: blood
Species: human
Tissue Origin:
Nucleofector® I/II/2b
Kaposi's sarcoma associated herpesvirus (KSHV) latency associated nuclear antigen (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 domain fragments (scFv) fragments 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 punctuate, nuclear pattern. This morphologically apparent LANA1 dispersion correlates to loss of viral episome by molecular analysis. These data suggest a novel approach to anti-herpes viral therapy and confirms LANA1 is critical target for neutralization of KSHV viral latency.