Previous Article | Next Article ![]()
J. Virol., Apr 1996, 2086-2094, Vol 70, No. 4
P Dal Monte, C Bessia, A Ripalti, MP Landini, A Topilko, B Plachter, JL Virelizier and S Michelson
The human cytomegalovirus (HCMV) open reading frame UL83 encodes a
phosphoprotein of 64 to 68kDa (pp65) which is a major constituent of this
virion and dense bodies. To determine the importance of the HCMV gene in
the virus cycle, we studied HCMV replication in astrocytoma cells stably
transfected with a retroviral vector carrying an antisense UL83 cDNA.
Reverse transcription-PCR detected antisense RNA in the cytoplasm. The
steady-state level of a 4-kb RNA containing coding sequences for pp65 was
significantly reduced after infection of antisense cells. Concomitant with
this, levels of expression of pp65 and pp71 (UL82) were severely reduced.
Extracellular HCMV production was almost completely blocked, irrespective
of the multiplicity of infection or the time after infection studied. The
block occurred at an early phase, since immediate-early protein synthesis
occurred normally, while several late proteins (e.g., pp150 [ppUL32] and
assembly protein [UL80]) were absent or strongly inhibited. Normal
replication of herpes simplex virus and of a pp65 deletion mutant of HCMV
(RVAd65), lacking target sequences of antisense RNA, demonstrated the
specificity of the block for wild-type HCMV in the antisense-stabilized
cells and indicated that the block was not due to indirect interference
with cellular genes. Our results appear to contradict those of Schmolke et
al (S. Schmolke, H.F. Kern, P. Drescher, G. Jahn, and B. Plachter, J.
Virol. 69:5959-5968, 1995), which show that UL83 is a nonessential gene for
HCMV replication in vitro. This contradiction is discussed in light of the
fact that the 4-kb mRNA, which codes for pp65 and was targeted in
UL83-antisense cell lines, may be a bicistronic mRNA which also codes for
pp71 (UL82). Thus, interference of expression from the genes encoding pp65
and pp71 by blocking of this putative bicistronic message leads to severe
impairment of viral replication.
Copyright © 1996, American Society for Microbiology
Stably expressed antisense RNA to cytomegalovirus UL83 inhibits viral replication
Unite d'Immunologie Virale, Institut Pasteur, Paris, France.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»