OBJECTIVETo understand the evolution of HIV-1 CRF07_BC envelope, we performed a longitudinal study on two patients during their early HIV-1 infection.

METHODSRNA was extracted from the plasma of the individuals and the C2-C5 fragments of the gp120 gene of HIV-1 were amplified by RT-PCR. Purified DNA segments were inserted into T easy vector and transformed into E. coli Top 10 competent cells. Positive clones were identified by blue-white screening, confirmed by PCR and sequenced by ABI 3700.

RESULTSThe samples were collected from the patients every 6 months from seroconversion time. The genetic diversity and divergence in env gene showed consistent increases over time. Our sequence analysis also revealed obvious non-synonymous change in env C1, C3 and V4 regions among these samples.

CONCLUSIONThe results support the concept that the consistent pattern of viral evolution existed during early phase of HIV-1 infection. C1, C3 and V4 region of env gene may be mainly immunological target during AIDS progression.