Table 1.

Viruses Used in the Study

Proviral clone	RT mutations
pNL4-3	WT
pNL-K65R	K65R
pNL-M184V	M184V
pNL-ΔRT 5.1	K65R, D67N, S68G, K70R, K103N, T215Y, K219E
pNL-ΔRT 5.2	D67N, S68G, K70R, K103N, T215Y, K219E

Site-directed point mutants K65R and M184V were created in NL4-3 vector (1) by exchanging a 4.3-kb Sph1-Sal1 wild-type fragment with mutated fragment from pALTER mutagenesis vector. RT fragments (1–250 codons) of MDR clinical isolate (PSD5) were cloned into pNΔRTPR vector (6). resulting in ΔRT5.1 (PSD5.1) and ΔRT5.2 (PSD5.2) proviral clones.