Evidence of feline immunodeficiency virus replication in cultured Kupffer cells.
OBJECTIVE
To determine if cultured feline Kupffer cells (KC) are as permissive for feline immunodeficiency virus (FIV) as cultured human liver macrophages are for HIV. Two types of infection likely to be relevant to the in vivo situation were used. KC were infected with either free virus or autologous infected peripheral blood mononuclear cells (PBMC).


METHODS
Feline KC were isolated by centrifugal elutriation from collagenase-perfused liver; cultured cells were characterized by their morphological appearance and their erythrophagocytotic properties. After infection, viral replication was measured by enzyme-linked immunosorbent assay, reverse transcriptase activity, immunofluorescence assay, in situ hybridization and electron microscopic observations.


RESULTS
Three days after isolation, 85% of cultured KC were able to internalize red blood cells; 45% were CD4-positive and 65% expressed a 24 kD protein thought to be a receptor for FIV (CD9). After the addition of autologous infected PBMC or cell-free supernatant of chronically infected IRC4 cells to KC cultures, a peak of viral replication was detected at day 28. Antigen revealed by immunofluorescence assay was present in only 0.4%, and viral RNA was detected by in situ hybridization in 2% of the infected cells.


CONCLUSIONS
FIV can replicate in cultured feline KC without inducing any cytopathic effect, which suggests that these cells may play a role in the physiopathology of FIV infection.
Martin
J P
JP
INSERM U-74, Louis Pasteur University, Strasbourg, France.
Bingen
A
A
Braunwald
J
J
Nonnenmacher
H
H
Valle
M
M
Gut
J P
JP
Koehren
F
F
de Monte
M
M
Kirn
A
A
D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D002415:Cats; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D016655:HIV Core Protein p24 / Q000096:biosynthesis / Q000276:immunology; D016089:Immunodeficiency Virus, Feline / Q000254:growth & development* / Q000276:immunology; D017403:In Situ Hybridization; D007728:Kupffer Cells / Q000648:ultrastructure / Q000821:virology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008099:Liver / Q000166:cytology; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D013997:Time Factors; D014779:Virus Replication
D000956:Antigens, Viral; D015704:CD4 Antigens; D016655:HIV Core Protein p24; D012194:RNA-Directed DNA Polymerase