Effect of the presence of soluble CD4 on the thermostability (T90) of HIV-1.

1HIV-1 (LAI chimeric MCs) produced in 293T cells.2Concentration of 4-domain soluble CD4 (sCD4) required to decrease HIV-1 infectivity by 50%.3ΔT90 = (T90 in the presence of sCD4)−(T90 in the absence of sCD4). HIV-1 was treated with the indicated concentrations of sCD4 and immediately subjected to a range of temperatures for 1 h. Infectivity was measured in TZM-bl cells. nd, not determined due to insufficient infectivity at the indicated concentration of sCD4.