Hematopoietic target cells of anemogenic subgroup C versus nonanemogenic subgroup A feline leukemia virus.
Feline leukemia viruses (FeLVs) belonging to interference subgroup C induce fatal anemia resembling human pure red cell aplasia (PRCA). Subgroup A FeLVs, although closely related genetically to FeLVs of subgroup C, do not induce PRCA. The determinants for PRCA induction by a molecularly cloned prototype subgroup C virus (FeLV-Sarma-C [FSC]) have been localized to the N-terminal 241 amino acids of the surface glycoprotein (SU) gp70. To investigate whether the anemogenic activity of FSC reflects a unique capacity to infect erythroid progenitor cells, we used correlative immunogold, immunofluorescence, and cytological staining to study prospectively the hemopoietic cell populations infected by either FSC or FeLV-FAIDS-61E-A (F6A), a prototype of subgroup A virus. The results demonstrated that although only FSC-infected animals developed erythrocyte aplasia, the env SU and the major core protein (p27) were expressed in a surprisingly large fraction of the lymphoid, erythroid, and myeloid lineage marrow cells in both FSC- and F6A-infected cats. Between days 8 and 17 postinoculation, gp70 and p27 were detected in 43 to 73% of erythroid, 25 to 75% of lymphoid, and 35 to 50% of myeloid lineage cells, regardless of whether the cats were infected with FSC or F6A. Thus, anemogenic subgroup C and nonanemogenic subgroup A FeLVs have similar hemopoietic cell tropism and infection kinetics, despite their divergent effects on erythroid progenitor cell function. Acute anemia induction by subgroup C FeLV, therefore, does not reflect a unique tropism for marrow erythroid cells but rather indicates a unique cytopathic effect of the SU on erythroid progenitor cells.
Dean
G A
GA
Department of Pathology, Colorado State University, Fort Collins 80523.
Groshek
P M
PM
Mullins
J I
JI
Hoover
E A
EA
D000818:Animals; D001853:Bone Marrow / Q000382:microbiology / Q000473:pathology; D002415:Cats; D015672:Erythroid Precursor Cells / Q000382:microbiology*; D015683:Gene Products, gag / Q000096:biosynthesis; D007150:Immunohistochemistry; D005256:Leukemia Virus, Feline / Q000145:classification / Q000472:pathogenicity / Q000502:physiology*; D016582:Leukemia, Feline / Q000382:microbiology; D012010:Red-Cell Aplasia, Pure / Q000382:microbiology*; D013047:Specific Pathogen-Free Organisms; D014759:Viral Envelope Proteins / Q000096:biosynthesis; D014764:Viral Proteins / Q000096:biosynthesis / Q000302:isolation & purification
D015683:Gene Products, gag; D014759:Viral Envelope Proteins; D014764:Viral Proteins