Efficient Persistence of Extrachromosomal KSHV DNA Mediated by Latency-Associated Nuclear Antigen

TLDR

Primary effusion lymphoma cells contain KSHV episomes and express the viral latency‑associated nuclear antigen LANA. LANA colocalizes with KSHV DNA in interphase nuclei and mitotic chromosomes, is necessary and sufficient for episome persistence, and tethers the viral DNA to chromosomes during mitosis to ensure efficient segregation to daughter cells.

Abstract

Primary effusion lymphoma (PEL) cells harbor Kaposi's sarcoma–associated herpesvirus (KSHV) episomes and express a KSHV-encoded latency-associated nuclear antigen (LANA). In PEL cells, LANA and KSHV DNA colocalized in dots in interphase nuclei and along mitotic chromosomes. In the absence of KSHV DNA, LANA was diffusely distributed in the nucleus or on mitotic chromosomes. In lymphoblasts, LANA was necessary and sufficient for the persistence of episomes containing a specific KSHV DNA fragment. Furthermore, LANA colocalized with the artificial KSHV DNA episomes in nuclei and along mitotic chromosomes. These results support a model in which LANA tethers KSHV DNA to chromosomes during mitosis to enable the efficient segregation of KSHV episomes to progeny cells.