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The 11 th International Workshop on KSHV & Related Agents, Birmingham, UK
Immunology II Abstract 47
INFECTION OF LYMPHOID CELLS BY KSHV IN CULTURED PRIMARY HUMAN
TONSILLAR LYMPHOID CELLS EX VIVO
Jinjong Myoung and Don Ganem
HHMI and Departments of Microbiology and Medicine, UCSF
Abstract
KSHV is known to infect B cells in vivo and is a causative agent of rare human B cell
lymphomas (PELs). Paradoxically, however, established B cell lines are resistant to
infection in vitro, which has greatly retarded progress in understanding the biology of
KSHV in its natural lymphoid compartment. We prepared primary human lymphoid
aggregate cultures (HLACs) from tonsils, and examined their infectability by KSHV.
Recombinant virus (rKSHV.219) expressing GFP under the EF1α promoter was prepared
from induced Vero cells latently infected with this virus. Tonsil cells were infected with
rKSHV, then subjected to flow cytometric analysis. When tonsil cells were infected with
an MOI of 0.75, 15% of CD19+ cells became GFP-positive. Surprisingly, in the same
culture many more T cells (54% of CD3+ cells) were shown to be GFP+; CD8+ T cells
were consistently more susceptible than CD4+ T cells. This difference in infectivity in T
cell subsets became more prominent when PHA was used to activate the T cells prior to
infection. When exposed to chemical inducers of lytic growth, infected HLAC cultures
displayed enhanced production of infectious KSHV.214, demonstrating that HLACs are
competent to support the complete lytic cycle of KSHV. No immortalization or blastic
transformation has yet been observed in infected HLACs. However, GFP+ B cells were
significantly enriched when assessed at d13 post-infection, while the proportion of GFP+
T cells decreased significantly by d13 PI. These data suggest that KSHV infection
provides survival advantage in B cells, but not in T cells.
Presenting author Email: jinjong.myoung@ucsf.edu
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