FIBROBLASTS, EPITHELIAL-CELLS, ENDOTHELIAL-CELLS AND SMOOTH-MUSCLE CELLS ARE MAJOR TARGETS OF HUMAN CYTOMEGALOVIRUS-INFECTION IN LUNG AND GASTROINTESTINAL TISSUES
C. Sinzger et al., FIBROBLASTS, EPITHELIAL-CELLS, ENDOTHELIAL-CELLS AND SMOOTH-MUSCLE CELLS ARE MAJOR TARGETS OF HUMAN CYTOMEGALOVIRUS-INFECTION IN LUNG AND GASTROINTESTINAL TISSUES, Journal of General Virology, 76, 1995, pp. 741-750
High titre replication of human cytomegalovirus (HCMV) in cell culture
is restricted to primary human fibroblasts. During acute infection in
vivo, HCMV nucleic acids and antigens have been found in various orga
ns. Using only morphological criteria, inconsistent data have been rep
orted about the cell types that can be infected by HCMV. In particular
, the role of fibroblasts in organ infections has remained unclear. To
define accurately the target cells of HCMV in vivo, tissue sections f
rom lung and gastrointestinal tract of patients suffering from acute H
CMV infection were investigated using immunohistochemical double-label
ling analyses. Monoclonal antibodies with defined specificity against
immediate early (IE), early (E) and late (L) viral antigens and antibo
dies directed against cell marker proteins were employed to identify i
nfected cells. The results demonstrated that a broad spectrum of cells
was infected by HCMV in vivo. Consistent with their susceptibility in
culture, fibroblasts formed a major population of HCMV-infected cells
. In contrast, haemopoietic cells were only infrequently stained with
virus-specific antibodies. Fibroblasts, epithelial cells, endothelial
cells, smooth muscle cells and macrophages appeared to be permissive f
or HCMV replication. Contrary to this, polymorphonuclear cells showed
only IE gene expression, indicating that these cells were abortively i
nfected. The analysis of the distribution of infected cells in tissue
supported the hypothesis that endothelial cells and monocytes/macropha
ges may play a crucial role in the haematogenous spread of HCMV; in co
ntrast, fibroblasts, smooth muscle cells and epithelial cells may form
the cell populations important for the multiplication and spread of t
he virus in infected tissues.