Related Experiment Videos
Interference between D30N and L90M in selection and development of protease inhibitor-resistant human
Wataru Sugiura1, Zene Matsuda, Yoshiyuki Yokomaku
1AIDS Research Center, National Institute of Infectious Diseases, Musashimurayama, Tokyo 2080011, Japan. wsuguira@nih.go.jp
Abstract:
We studied the evolutionary relationships between the two protease inhibitor (PI) resistance mutations, D30N and L90M, of human immunodeficiency virus type 1 (HIV-1). The former is highly specific for nelfinavir resistance, while the latter is associated with resistance to several PIs, including nelfinavir. Among patients with nelfinavir treatment failure, we found that D30N acquisition was strongly suppressed when L90M preexisted. Thus, D30N/L90M double mutations not only were detected in a very limited number of patients but also accounted for a minor fraction within each patient. In the disease course, the D30N and L90M clones readily evolved independently of each other, and later the D30N/L90M double mutants emerged. The double mutants appeared to originate from the D30N lineage but not from the L90M lineage, or were strongly associated with the former. However, their evolutionary pathways appeared to be highly complex and to still have something in common, as they always contained several additional polymorphisms, including L63P and N88D, as common signatures. These results suggest that D30N and L90M are mutually exclusive during the evolutionary process. Supporting this notion, the D30N/L90M mutation was also quite rare in a large clinical database. Recombinant viruses with the relevant mutations were generated and compared for the ability to process p55gag and p160pol precursor proteins as well as for their infectivity. L90M caused little impairment of the cleavage activities, but D30N was detrimental, although significant residual activity was observed. In contrast, D30N/L90M demonstrated severe impairment. Thus, the concept of mutual antagonism of the two mutations was substantiated biochemically and functionally.
Insights
The D30N and L90M mutations in human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) appear mutually exclusive. Their co-occurrence is rare and functionally antagonistic, impacting viral processing and infectivity.
Area of Science:
- Virology
- Molecular Biology
- Evolutionary Biology
Background:
- Protease inhibitor (PI) resistance mutations D30N and L90M are key in human immunodeficiency virus type 1 (HIV-1) treatment failure.
- D30N is specific to nelfinavir resistance, while L90M confers broader PI resistance.
- Understanding the evolutionary interplay between these mutations is crucial for optimizing HIV-1 therapy.
Purpose of the Study:
- To investigate the evolutionary relationships and mutual exclusivity of HIV-1 PI resistance mutations D30N and L90M.
- To determine the biochemical and functional consequences of these mutations, individually and in combination.
Main Methods:
- Analysis of mutation acquisition in patients with nelfinavir treatment failure.
- Examination of evolutionary pathways and co-occurrence in clinical databases.
- Generation and functional characterization of recombinant HIV-1 viruses with specific mutations.
Main Results:
- D30N acquisition was suppressed when L90M preexisted, indicating mutual exclusivity.
- D30N/L90M double mutations were rare and appeared to originate primarily from the D30N lineage.
- Biochemical assays showed D30N significantly impaired viral precursor protein processing, with D30N/L90M causing severe impairment.
Conclusions:
- The D30N and L90M mutations exhibit mutual antagonism during HIV-1 evolution.
- This antagonism is supported by their rarity in clinical settings and functional impairment of viral processing.
- Findings provide biochemical and functional evidence for the mutually exclusive nature of these key PI resistance mutations.