HEPATOCYTE
TROPISM OF CYTOMEGALOVIRUS: AN EXPERIMENTAL STUDY IN VITRO
Fang F, Nie XS, Li H, Dong YS
Department of Pediatrics, Tongji Hospital,
Tongji Medical School, Huazhong Science and Technology University, Wuhan,
China
Objective: To determine whether
cytomegalovirus (CMV) is able
to directly infect hepatocytes.
Methods: ~{"Y~}human
hepatocytes (L-02 cell line) were attacked by human CMV (HCMV, AD169
strain). Human embryo lung (HEL) fibroblasts and co-cultured L-02 and HEL
cells severed as controls. ~{"Z~}. The primary cultured murine
hepatocyes (PMH) were infected by murine CMV (MCMV, Smith strain) at the 8th
day of culture. Viral infection of cells were confirmed by observing the
cytopathic effects (CPE) under the light microscope and viral particles
within cells under the electron microscope, and detecting HCMV
immediate-early antigens (IEA) and early antigens (EA) by immunofluorescent
assay and MCMV IE gene by in situ hybridization.
Results: The viral markers were
obviously positive in both infected HEL and PMH cells, in which classic CPE
and a large number of viral particles were found. The ultrastructures of
PMH were destroyed, as revealed by disappearance of the bile canalicula and
organelles. But L-02 cells remained
the normal
structures and shapes in which no viral particles, IEA and EA markers were
found. It was interesting that the co-cultured HEL and L-02 cells
respectively showed the same results as they were treated alone.
Conclusions: Our study showed that
the primary cultured murine hepatocytes can be directly infected by MCMV
which provide a cell model system for investigating the mechanism of CMV
hepatitis. The changes or loss of HCMV receptors on the surface of L-02
cells could be the reason why they were not susceptible to HCMV infection
after a longer time of culture.
Key words:
cytomegalovirus
hepatocyte cell tropism