Primary stage of feline immunodeficiency virus infection: viral dissemination and cellular targets.
The objective of this study was to identify cellular and organ targets of acute feline immunodeficiency virus (FIV) infection in vivo. Tissues of FIV-infected cats were studied at eight time points during the first 3 months after experimental infection. FIV nucleic acids were first detected by in situ hybridization 21 days after infection, approximately 1.5 weeks after lymph node enlargement was first observed and 3 weeks before the primary acute flu-like illness. The majority of FIV-infected cells were present in lymphoid organs, though low numbers of infected cells were noted in nonlymphoid organs as well. Germinal centers harbored many of the FIV-infected cells within lymphoid tissues. The thymic cortex was also a major site of early infection. Combined in situ hybridization and immunohistochemistry revealed that T lymphocytes were the primary target of early FIV infection in tissues of cats before the onset of clinical signs of acute illness. An unidentified population of mononuclear cells and a few macrophages were also infected. During the ensuing acute flu-like illness, the proportion of FIV-infected macrophages in tissues increased dramatically. This early shift in the predominant cellular localization of FIV from T lymphocytes to macrophages may be important for establishing viral persistence.
Beebe
A M
AM
Department of Internal Medicine, School of Medicine, University of California, Davis 95616.
Dua
N
N
Faith
T G
TG
Moore
P F
PF
Pedersen
N C
NC
Dandekar
S
S
D000818:Animals; D002415:Cats; D004279:DNA, Viral / Q000032:analysis; D016181:Feline Acquired Immunodeficiency Syndrome / Q000097:blood / Q000382:microbiology* / Q000473:pathology; D005260:Female; D016089:Immunodeficiency Virus, Feline / Q000254:growth & development*; D017403:In Situ Hybridization; D007422:Intestines / Q000382:microbiology / Q000473:pathology; D008198:Lymph Nodes / Q000382:microbiology / Q000473:pathology; D008264:Macrophages / Q000382:microbiology; D008297:Male; D012367:RNA, Viral / Q000032:analysis; D013154:Spleen / Q000382:microbiology / Q000473:pathology; D013601:T-Lymphocytes / Q000382:microbiology; D013950:Thymus Gland / Q000473:pathology; D013997:Time Factors; D014018:Tissue Distribution
D004279:DNA, Viral; D012367:RNA, Viral