Table 3. Infectivity of inferred ancestral neutralization-sensitive and resistant envs, EN1-AN1 and EN1-AN2, compared to the representative plasma virus clone E10-101603_017.

Virus Name	Autologous serum neutralization	Tropism	RLU
			R5	X4
EN1-AN1	1:204	DM	4	1
EN1-AN2	1:457	R5	3	0
E10-101603_017	1:57	R5	3	0

For serum neutralization, data indicate the reciprocal of the serum dilution that results in 50% inhibition (ID₅₀). For receptor tropism assays, the infectivity of pseudoviruses expressing luciferase on cells expressing CD4 and the chemokine receptors CCR5 (R5) or CXCR4 (X4)in relative luminescence units (RLUs) were measured according to the following scale: 0: < 5,000 RLU; 1: 5,001 to 15,000 RLU; 2: 15,001 to 150,000 RLU; 3: 150,001 to 1,000,000 RLU; 4: >1,000,000 RLU. DM indicates dual/mixed tropism.