Table 1.

Neutralization and infectivity phenotypes of mutagenized envelopes

Parent and V5 mutantenv clonesRelative infectivityaRelative neutralization resistanceb
Clone no. or nameE6 mutation(s) introduced into V5
V511
E64.10128
1V420I2.458
2E460I1.061
3L544PNINT
4A562SNINT
5N565H1.412
6Q582L1.572
7V420I+E460I1.638
8V420I+L544P0.15NT
9V420I+A562SNINT
10V420I+N565H1.928
11V420I+Q582L2.548
12E460I+L544PNINT
13E460I+A562SNINT
14E460I+Q582L1.754
15A562S+N565H0.26NT
16N565H+Q582L1.404
17V420I+E460I+L544P0.15NT
18V420I+E460I+A562SNINT
19V420I+A562S+N565H0.28NT
20V420I+N565H+Q582L2.378
21E460I+A562S+N565H0.23NT
22A562S+N565H+Q582L1.274
23V420I+E460I+A562S+N565H1.34NT
24V420I+L544P+N565H+Q582L0.21NT
25V420I+A562S+N565H+Q582L1.838
26L544P+A562S+N565H+Q582LNINT
27V420I+E460I+A562S+N565H+Q582L3.8816
28V420I+L544P+A562S+N565H+Q582L1.9264
29V420I+E460I+L544P+A562S+N565H+Q582L2.12128
  • a Relative infectivity was determined asX M/X V5 for a giveny, calculated by using the best-fit lines determined by regression analysis of the log-transformed luciferase activity determinations (light units) as a function of the inoculum dilution.X M is the value obtained for the particular mutant, and X V5 is the value obtained for V5.y values used for comparisons were intermediate between the curves being compared. Calculations were performed by using Microsoft Excel. NI, not infectious.

  • b Relative neutralization resistance was determined as N V5/N M, where N is the neutralization titer of the reference serum (31). Minor variation was observed in specific neutralization titers observed in different experiments, but the relative effects of the various mutations on neutralization resistance were highly consistent. NT, not tested.