TABLE 1.

Effect of human serum on the CD14-dependent inhibition of DV infection of MO/Mφ by LPS^a

Expt no.	Virus titer in PFU/ml (% inhibition) with (+) or without (−):
	−ΔAHS				+ΔAHS
	−LPS	+LPS	+MY4, +LPS	+MoS3, +LPS	−LPS	+LPS	+MY4, +LPS	+MoS39, +LPS
1	2.31 × 105	8.46 × 104 (63.4)	2.20 × 105 (4.7)	2.46 × 105 (−6.5)	6.53 × 104	3.50 × 103 (94.6)	5.07 × 104 (22.4)	6.67 × 104 (−2.1)
2	2.74 × 105	9.23 × 104 (66.3)	2.43 × 105 (11.2)	ND	1.14 × 105	1.03 × 104 (90.9)	1.21 × 105 (−6.1)	ND

^aSeven-day-old primary human MO/Mφ obtained from two different donors (i.e., experiments 1 and 2) were used. The cells were infected with DV at an MOI of 3 PFU per cell. Viral adsorption was performed in serum-free α-MEM (−ΔAHS) or α-MEM containing 3% ΔAHS (+ΔAHS), either with or without 5 μg of LPS per ml (+LPS and −LPS, respectively) for 2.5 h. Before coincubation of LPS and DV, some cultures were pretreated overnight with 20 μg of MY4 per ml (+MY4) or 30 μg of MoS39 (+MoS39) per ml. After 44 h of infection, culture supernatants were harvested and assayed to determine the infectious-DV titers. ND, not determined.