Functional Stability of Unliganded Envelope Glycoprotein Spikes among Isolates of Human Immunodeficiency Virus Type 1 (HIV-1)
Figure 8
Thermostabilities (T90 values) of acute phase standard panel viruses (PSVs) of clades A, B and C, and lack of a relationship with susceptibility to soluble CD4.
(A) Bar graph indicating the various T90 values with that of the thermostable HIV-1JR-CSF, and thermolabile HIV-1ADA indicated with dashed lines. Env panel members that are thermostable (T90≥48°C), intermediate in thermostability (43°C<T90<48°C), and thermolabile (T90≤43°C) are indicated by filled, hatched and open bars, respectively. (B) Bell curve (normal distribution) in T90 values of HIV-1 Envs used in this study, including Envs from acute phase panels of clades A, B and C (Tables 1 and 2), n = 34. Mean, 44.2°C; Std. Dev., 2.4°C; Range, 40.0–49.0°C. The curve-fit (nonlinear regression lorentzian) was made using Prism software (Graphpad, CA). (C) Lack of correlation between T90 and reported IC50 values of soluble CD4 against HIV-1 standard Env panels (clades B and C). Soluble CD4 IC50 data are taken from Wu et al [79], excluding resistant isolates (IC50>50 µg/ml) for which exact values are undetermined.