Characterization of a highly pathogenic molecular clone of feline immunodeficiency virus clade C.
We have derived and characterized a highly pathogenic molecular isolate of feline immunodeficiency virus subtype C (FIV-C) CABCpady00C. Clone FIV-C36 was obtained by lambda cloning from cats that developed severe immunodeficiency disease when infected with CABCpady00C (Abbotsford, British Columbia, Canada). Clone FIV-C36 Env is 96% identical to the noninfectious FIV-C isolate sequence deposited in GenBank (FIV-Cgb; GenBank accession number AF474246) (A. Harmache et al.) but is much more divergent in Env when compared to the subgroup A clones Petaluma (34TF10) and FIV-PPR (76 and 78% divergence, respectively). Clone FIV-C36 was able to infect freshly isolated feline peripheral blood mononuclear cells and primary T-cell lines but failed to productively infect CrFK cells, as is typical of FIV field isolates. Two-week-old specific-pathogen-free cats infected with FIV-C36 tissue culture supernatant became PCR positive and developed severe acute immunodeficiency disease similar to that caused by the uncloned CABCpady00C parent. At 4 to 5 weeks postinfection (PI), 3 of 4 animals developed CD4(+)-T-cell depletion, fever, weight loss, diarrhea, and opportunistic infections, including ulcerative stomatitis and tonsillitis associated with abundant bacterial growth, pneumonia, and pyelonephritis, requiring euthanasia. Histopathology confirmed severe thymic and systemic lymphoid depletion. Interestingly, the dam also became infected with a high viral load at 5 weeks PI of the kittens and developed a similar disease syndrome, requiring euthanasia at 11 weeks PI of the kittens. This constitutes the first report of a replication-competent, infectious, and pathogenic molecular clone of FIV-C. Clone FIV-C36 will facilitate dissection of the pathogenic determinants of FIV.
de Rozières
Sohela
S
Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Mathiason
Candace K
CK
Rolston
Matthew R
MR
Chatterji
Udayan
U
Hoover
Edward A
EA
Elder
John H
JH
D000595:Amino Acid Sequence; D000818:Animals; D016516:CD4-CD8 Ratio; D002415:Cats; D002478:Cells, Cultured; D003001:Cloning, Molecular; D030541:Databases, Genetic; D016181:Feline Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000473:pathology / Q000821:virology; D023061:Gene Order / Q000235:genetics; D015686:Gene Products, env / Q000737:chemistry; D014644:Genetic Variation / Q000235:genetics; D016089:Immunodeficiency Virus, Feline / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D008221:Lymphoid Tissue / Q000821:virology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012313:RNA / Q000235:genetics; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology; D020079:Terminal Repeat Sequences / Q000235:genetics; D014162:Transfection
D015686:Gene Products, env; D012367:RNA, Viral; C039919:RNA, recombinant; D012313:RNA