Cultivation and identification of 3TC-resistant HIV-1 strain
Objective To gain stable 3TC-resistant HIV-1 strain originated from Chinese HIV-1 B′ strain. Methods HIV-1 B′ strain isolated from Henan province, China was cultured and passaged with the medium containing double increased 3TC. by 3-5 generations of passage, the 50% inhibitory concentrations of cultures(IC_ 50) were tested. The partial HIV-1 pol gene were amplified and sequenced, the sequence were interpreted with genotypic drug resistance result by the tool from Stanford. Results After 6 generation of passage, the IC_ 50 to 3TC had increased 8.3-fold from 0.008 μmol/L to 0.15 μmol/L. In the 7 th generation, the IC_ 50 dramatically increased to more than 110 000-fold(2048 μmol/L), genotypic analysis showed that a significant mutation had happened in the position of 184(Met→Ile) of pol gene, the genotype and phenotype of 3TC resistance remained stable after the 5 th generation of cultivation in the absence of drug. Conclusion A rather stable 3TC-resistant variant was established from HIV-CNHN24. This strain can be used for the assessment of the new drug effect and the research of HIV-1 drug resistance.