Table 2.

Podocyte proliferation in the presence/absence of Nef expression at nonpermissive and permissive temperatures (NPT and PT)a

VirusMorphology at NPTProliferation at NPTbProliferation at PTCF at NPTcCF at PT
a CF, colony formation in soft agar; Dediff, dedifferentiated, elongated, and refractile; Diff, differentiated, flattened, non-refractile, multiple projections with typical foot processes.
b The cells grown to 50% confluence at PT (33° C) and then shifted to NPT (37° C) for a week. +, fivefold increase in cell count by trypan blue dye exclusion in Nef-expressing cells compared with vector or Δnef; ++, tenfold increase in cell count; +++, 20-fold increase in cell count; −, no significant increase in cell number. At PT, cells infected with all of the above viruses had almost similar count at confluence; however, cells with functional nef lost contact inhibition and continued to grow as illustrated in Figure 6.
c The cells in soft agar were incubated at NPT (37° C). The methodology is described in Materials and Methods: +, 0.05 to 0.1% cells showing colony formation in soft agar; ++, 0.1 to 0.3% cells showing colony formation; +++, 0.3% and higher cells showing colony formation; −, no colony formation.
NL4-3: ΔG/P-EGFPDediff+++++++
NL4-3: ΔG/P-EGFP/ΔNefDiff+++
NL4-3: ΔG/P-EGFP/Tat-NefDediff+++++++