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Comparative requirements for the restriction of retrovirus infection by TRIM5alpha and TRIMCyp

Felipe Diaz-Griffero1, Alak Kar, Mark Lee

  • 1Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Pathology, Division of AIDS, Harvard Medical School, Boston, MA 02115, USA.

Virology
|October 9, 2007
PubMed

Insights

TRIM5alpha and TRIMCyp are restriction factors that block retroviral infections. Their distinct domain requirements highlight mechanistic similarities and differences in antiviral activity against viruses like HIV-1 and FIV.

Area of Science:

  • Virology
  • Immunology
  • Genetics

Background:

  • Restriction factors TRIM5alpha (primates) and TRIMCyp (owl monkeys) inhibit retroviral entry.
  • TRIM5alpha from rhesus monkeys (TRIM5alpha rh) is more potent against HIV-1 and FIV than human TRIM5alpha (TRIM5alpha hu).
  • TRIMCyp restricts HIV-1, SIV agm, and FIV, reducing viral capsid levels post-entry.

Purpose of the Study:

  • To investigate the domain requirements of TRIMCyp and TRIM5alpha in restricting different retroviruses.
  • To compare the mechanisms of action between TRIMCyp and TRIM5alpha.

Main Methods:

  • Comparative analysis of TRIMCyp and TRIM5alpha domain functions.
  • Assessment of retroviral restriction potency by different TRIM variants.
  • Investigation of specific TRIM domains, including RING, B-box 2, and B30.2 variable region 1.

Main Results:

  • TRIMCyp potently restricted FIV without RING and B-box 2 domains, unlike TRIM5alpha rh which required them.
  • Variable region 1 of TRIM5alpha rh's B30.2 domain enhanced restriction of HIV-1, FIV, and equine infectious anemia virus.
  • Both TRIMCyp and TRIM5alpha reduced cytosolic viral capsid levels early in infection.

Conclusions:

  • TRIMCyp and TRIM5alpha share mechanistic similarities in retroviral restriction despite differing domain requirements.
  • Specific domains, like TRIM5alpha rh's B30.2 variable region 1, play crucial roles in antiviral potency.
  • Understanding these factors provides insights into host-pathogen interactions and viral evasion strategies.

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