Background
Upon entry into a cell, the HIV core plays a pivotal part in many of the interactions that lead to successful viral replication. The HIV core has evolved to interact with proteins necessary for replication and evade proteins that inhibit replication. We aim to characterize the mechanisms of capsid (CA) recognition by known and novel antiviral proteins.
Methods
Here we use poorly adapted CA mutant viruses to learn more about the mechanisms of capsid recognition by host antiviral proteins. N57A, A77V, and A105T CA mutant viruses that have altered interactions with host factors including CPSF6 and nuclear pore proteins. To identify host genes that contribute to reduced fitness of these mutant viruses we use HIV-CRISPR screening, a screening approach that allows us to uncover proviral and antiviral genes.
Results
TRIM5ɑ was a top hit for the screens using the N57A and A105T CA mutants. While CA mutants that lack CypA binding are known to be hypersensitive to TRIM5ɑ the N57A and A105T TRIM5ɑ-sensitive viruses maintain CypA binding. Therefore, other mechanisms are implicated in their TRIM5ɑ susceptibility.
Conclusions
Through screening of additional CA mutant viruses, we aim to map mutations and characteristics in CA that lead to changes in TRIM5ɑ restriction. Additionally, we are determining the mechanism of TRIM5ɑ recognition of the mutant viruses using depletion and binding assays. This insight into TRIM5ɑ recognition of the CA will give us new understanding of how our host cellular defenses inhibit HIV.
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