Thermostability (T90 values) and sensitivity to soluble (4-domain) CD4 of HIV-1 PSVs bearing Envs from acute phase virion panels (clades A, B and C).

1Infectivities were determined in TZM-bl cells and the resulting relative light units (RLUs) were categorized as follows: +/−, 80,000–149,999; +, 150,000–349,999; ++, 350,000–999,999; +++, ≥1,000,000.2T90, the temperature in °C at which HIV-1 infectivity decreases by 90% in 1 h, and the standard error of the mean (SEM) of at least three independent experiments.3sCD4 IC50 data taken from ref. [79].4nd, not determined.