EPSTEIN-BARR-VIRUS PERMISSIVELY INFECTS HUMAN SYNCYTIOTROPHOBLASTS IN-VITRO AND INDUCES REPLICATION OF HUMAN T-CELL LEUKEMIA-LYMPHOMA VIRUSTYPE-I IN DUALLY INFECTED-CELLS
Fd. Toth et al., EPSTEIN-BARR-VIRUS PERMISSIVELY INFECTS HUMAN SYNCYTIOTROPHOBLASTS IN-VITRO AND INDUCES REPLICATION OF HUMAN T-CELL LEUKEMIA-LYMPHOMA VIRUSTYPE-I IN DUALLY INFECTED-CELLS, Virology, 229(2), 1997, pp. 400-414
Epstein-Barr virus (EBV) and human immunodeficiency virus type 1 (HIV-
1), as well as human T-cell leukemia-lymphoma virus type I (HTLV-I), m
ay interact in the pathogenesis of human retroviral infections. The pl
acental syncytiotrophoblast layer represents a barrier protecting the
fetal compartment from exposure to retroviruses. We studied the intera
ctions of EBV with HIV-I and HTLV-I in human term syncytiotrophoblast
cells to investigate the significance of double infections in transpla
cental transmission of human retroviruses. We found that syncytiotroph
oblast cells could be productively infected with EBV. Dual infection o
f the cells with EBV and HTLV-I resulted in full replication cycle of
otherwise latent HTLV-I. In contrast, the restricted permissiveness of
syncytiotrophoblasts for HIV-1 was not influenced by coinfection of t
he cells with EBV. infection of syncytiotrophoblast cells with EBV, bu
t not HTLV-I, induced interleukin-2 and interleukin-6 secretion, and a
ugmented secretion occurred on coinfection with both viruses. Coinfect
ion of syncytiotrophoblast cells with EBV and HTLV-I induced tumor nec
rosis factor-beta and transforming growth factor-beta 1 secretion, but
infection with either virus alone did not lead to secretion of these
cytokines. Permissive replication cycle of HTLV-I was induced by the E
BV immediate-early gene product Zta. Pseudotype formation between EBV
and HTLV-I in coinfected syncytiotrophoblast cells was not found. Our
data suggest: that activation of HTLV-I gene expression by EBV in coin
fected syncytiotrophoblast cells may be a mechanism for transplacental
transmission of HTLV-I. (C) 1997 Academic Press.