HIV type 1 (HIV-1) envelope glycoproteins (Env) mediate virus entry and are the target of neutralizing antibodies. Binding of the metastable HIV-1 Env trimer to the CD4 receptor triggers structural rearrangements that mediate Env conformational transitions from a closed conformation to a more open state through an intermediate step. Recent studies have revealed new insights on the dynamics, regulation, and molecular mechanisms of Env transitions along the entry pathway. In this study, we provide an overview of the current knowledge on Env conformational dynamics and the relationship between Env conformational states and neutralization selectivity of the broadly neutralizing antibodies that develop in 10%–20% of infected individuals and may provide guidance for the development of an effective HIV-1 vaccine.
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