Sensitivity of HIV-1 infectivity to heat (T<sub>90</sub>) is linked to Env.

1<p>T<sub>90</sub>, the temperature 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.</p>2<p>HIV-1 PSVs, produced by transfection of 293T cells using <i>env</i> expression plasmids pSVIIIexe7 (JR-CSF, JR-FL, ADA), pCAGGS (SF162, SIVmac239), pcDNA3.1 (LAI), or pVSV-G (VSV-G) in combination with the backbone vectors pSG3Δenv (clade B) or Q23Δenv (clade A).</p>3<p>HIV-1 MCs are LAI-chimeras (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021339#s2" target="_blank">Materials and Methods</a>) and fully replication competent. Virions were produced by transfection of 293T cells, or through passage in MT-2/CCR5ΔCT cells, as indicated.</p>4<p><i>nd</i>, not determined, or material unavailable.</p>