R. Hines et W. Maury, DH82 cells: a macrophage cell line for the replication and study of equineinfectious anemia virus, J VIROL MET, 95(1-2), 2001, pp. 47-56
In vivo, tissue macrophages have been implicated as an important cell for t
he replication of equine infectious anemia virus (EIAV). Laboratory investi
gations of EIAV;macrophage interactions, however, have been hampered by the
laborious blood monocyte isolation procedures. Tn addition. adherent equin
e macrophage cultures generally have poor long-term viability and are resis
tant to transfection. This report describes an adherent canine macrophage-l
ike cell line, DH82. that supports the replication of EIAV. This cell line
was easily transfectable and supported EIAV Tat transactivation of the LTR.
Electrophoretic mobility shift assays were carried out to determine which
transcription factor binding sites within the LTR enhancer region were boun
d by DH82 nuclear extracts. IL was found that five: different motifs were o
ccupied. The ets motifs that are bound by PU.1 in primary macrophage nuclea
r extracts: specifically interacted with DH82 nuclear extracts. In addition
, the PEA-2, Lvb and Oct motifs that are occupied by fibroblast nuclear ext
racts were also bound by DH82 nuclear extracts. Finally, the methylation-de
pendent binding protein (MDBP) site that is: bound by all nuclear extracts
investigated to date demonstrated specific interactions with DH82 nuclear e
xtracts. The observation that both macrophage-specific and fibroblast-speci
fic motifs were utilized by DH82 nuclear extracts suggested that both macro
phage-adapted and fibroblast-adapted EIAV could replicate in DH82 cells. In
deed, infectivity studies demonstrated that strains of virus that exclusive
ly replicate in macrophages can replicate in DH82 cells and fibroblast-adap
ted strains of virus can also replicate in these cells. Finally, these cell
s could be transfected readily with the EIAV molecular clone, pSPeiav19-2.
and virus spread was detected within the culture. In conclusion, this study
has identified a useful cell line that should facilitate the study of EIAV
expression and replication. (C) 2001 Elsevier Science B.V. All rights rese
rved.