TABLE 1.

Detection of FIV DNA and RTase activity in infected human cell cultures

Human cell line	FIV DNA detection (days p.i.)a		RTase activity (± SD)b with:
			Petaluma at:		V1CSF at:
	Day 3	Day 7	Day 3	Day 7	Day 3	Day 7
PBMC	21	21	5.5 ± 0.5*	7.6 ± 0.6*	6.3 ± 0.3*	8.2 ± 0.6*
Macrophages	14	14	6.9 ± 0.9*	6.1 ± 0.7*	6.4 ± 0.9*	9.2 ± 1.0*
THP-1 monocytes	3	ND	2.7 ± 0.4*	1.2 ± 0.2	1.6 ± 0.3	0.9 ± 0.1
Fetal astrocytes	5	ND	1.5 ± 0.3	1.5 ± 0.2	1.2 ± 0.2	1.2 ± 0.2
U373 astrocytes	5	ND	1.8 ± 0.2	0.9 ± 0.1	1.5 ± 0.2	0.9 ± 0.1

^aHigh-molecular-weight DNA from human PBMC and macrophages were amplified by nested PCR; FIV DNA was detected in the remaining cell lines by a single PCR round. ND, not detectable. 

^bRTase activity was assessed as the mean fold increase over uninfected cells, for which RTase levels averaged 4,500 ± 400 cpm/ml. Significant differences between infected and uninfected cultures were determined by using a two-tailed Student’s t test (∗, P < 0.01).