Association of TRIMCyp and TRIM5α from assam macaques leads to a functional trade-off between HIV-1 and N-MLV inhibition

TRIM5α restricts retroviruses in a species-specific manner. Cyclophilin A was independently retrotransposed into the TRIM5 loci in different species, leading to the generation of antiviral TRIM5-cyclophilin A(TRIMCyp) proteins. Previously, we found that assam macaques express a TRIMCyp chimera(am TRIMCyp), along with a TRIM5α allelic protein(am TRIM5α). Herein,we investigated the antiviral activity of am TRIMCyp and am TRIM5α individually, as well as their interaction and joint effects.am TRIMCyp showed a divergent restriction pattern from am TRIM5α. Although both proteins potently restricted the replication of HIV-1, only am TRIM5α inhibited N-MLV. Remarkably, cellular anti-HIV-1 activity increased when am TRIMCyp and am TRIM5α were coexpressed, indicating a synergistic block of HIV-1 replication. Consistently, PMBCs from heterozygous am TRIM5α/TRIMCyp showed stronger resistance to HIV-1 infection than those from am TRIM5α/TRIM5α homozygotes. The anti-HIV-1 synergistic effect was dependent on the am TRIMCyp-am TRIM5α interaction. In contrast, am TRIMCyp completely abrogated the anti-N-MLVactivity mediated by am TRIM5α, showing a dominant-negative effect, indicating that the generation of am TRIMCyp was involved in the trade-off between divergent restriction activities. Our results provide a new paradigm to study functional trade-offs mediated by allelic proteins, a theoretical basis for utilizing animal models with various TRIM5 alleles, as well as novel HIV-1 gene therapy strategies.

TRIM5α restricts retroviruses in a species-specific manner. Cyclophilin A was independently retrotransposed into the TRIM5 loci in different species, leading to the generation of antiviral TR1M5-cyclophilin A （TRIMCyp） proteins. Previously, we found that assam macaques express a TRIMCyp chimera （amTRIMCyp）, along with a TRIM5α allelic protein （amTRIM5α）. Herein, we investigated the antiviral activity of amTRIMCyp and amTRIM5α individually, as well as their interaction and joint effects. amTRIMCyp showed a divergent restriction pattern from amTRIM5αc Although both proteins potently restricted the replication of HIV-1, only amTRIM5αt inhibited N-MLV. Remarkably, cellular anti-HIV-1 activity increased when amTRIMCyp and amTRIM5αt were coexpressed, indicating a synergistic block of HIV-1 replication. Consistently, PMBCs from heterozygous amTRIM50t/TRIMCyp showed stronger resistance to HIV-1 infection than those from amTRIM5a/TRIM5α homozygotes. The anti-HIV-1 synergistic effect was dependent on the amTRIMCyp-amTRIM5α interaction. In contrast, amTRIMCyp completely abrogated the anti-N-MLV activity mediated by amTRIM5α, showing a dominant-negative effect, indicating that the generation of amTRIMCyp was involved in the trade-off between divergent restriction activities. Our results provide a new paradigm to study functional trade-offs mediated by allelic proteins, a theoretical basis for utilizing animal models with various TRIM5 alleles, as well as novel HIV-1 gene therapy strategies.