Characteristics of amino acid sequences of envelop protein V3 loop of human immunodeficiency virus type 1 quasi-species in long-term non-progressors infected with human immunodeficiency virus type 1 / 中华传染病杂志

ABSTRACT

Objective To investigate the characteristics of V3 loop amino acid sequences of human immunodeficiency virus type 1 (HIV-1) quasi-species in long-term non-progressors (LTNP)infected with HIV. Methods End-point limiting dilution polymerase chain reaction (EPLD PCR) was used to amplify the env gene c2-v3-c3 region of single HIV-1 provirus from five LTNPs at sequential time points. The PCR products were then sequenced and the amino acid sequences of V3 loop were analyzed by sequence confirm analysis technology. Results The results showed that there were one to ten kinds of polymorphisms in the V3 region of HIV-1 quasi-species which were found from the serial samples of the five LTNP. However, the sequences of the predominant strains were either completely consistent or at most changed at one or two residues in the serial samples of individual patient. The tetramer compositions of the tip of V3 loop were consistent in each patient. It was GPGR in four patients and GPGK in one patient. It was speculated the co-receptor of HIV-1 was CC chemokine receptor (CCR)-5 based on the amino acids at the residue 11 and residue 25 of V3 loop and the net charge of V3 loop. Conclusions There are various polymorphisms at the HIV V3 loop in LTNP. However, the tetramer composition of the tip part of V3 loop is stable. The LTNP are very likely infected with non-syncytium inducing (NSI) strain.