Table 1.

Quantitation of VSV giant cell formation in HECA2 cells

TreatmentaNo. of S/fieldbNo. of nuclei/synctiumc% Nuclei associated with S
None
 9 hpi28812.0
 24 hpi34.54888.0
NH4Cl
 1 mM40.51737.5
 20 mM00
Bfm A1
 1 nM00
 100 nM00
Virusd
 VSVIND 365794
 VSVNJ/CA 603083
  • a At 9 hpi, fusion was detected only in untreated cells. All other values were determined at 24 hpi.

  • b The average number of giant cells or syncytia (S) was determined by counting giant cells in random fields of 20× micrographs of DAPI-stained monolayers. Only cells with more than four nuclei per cell were considered syncytia.

  • c Determined by using the formula (mockn − INn)/NS, where mockn is the mean number of single nuclei determined from random fields in noninfected monolayers (mockn = 1,875), INn is the mean number of single nuclei per random 20× field in infected monolayers (data not shown), and NS is the mean number of syncytia per random field.

  • d In a separate experiment, HECA2 cells were mock infected or infected with VSVIND or VSVNJ/CA. Giant cell formation was determined as described above.