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Peptide-based Identification of Functional Motifs and their Binding Partners
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Peptide-based Identification of Functional Motifs and their Binding Partners

Published on: June 30, 2013

Conservation of Nef function across highly diverse lineages of SIVsmm

Jan Schmökel1, Hui Li, Elizabeth Bailes

  • 1Institute of Virology, University of Ulm, 89081 Ulm, Germany. jan.schmoekel@uniklinik-ulm.de

Retrovirology
|April 11, 2009
PubMed
Abstract

Insights

Simian immunodeficiency virus (SIVsmm) Nef proteins from various lineages function similarly in human cells, suggesting strain-specific, not lineage-specific, variations influence SIVsmm

Area of Science:

  • Virology
  • Immunology
  • Genetics

Background:

  • Simian immunodeficiency virus (SIVsmm) infects sooty mangabeys (SMs) without causing disease but is pathogenic in humans and macaques.
  • SIVsmm exhibits significant genetic diversity across different lineages.
  • Understanding lineage-specific differences in SIVsmm biology is crucial for explaining cross-species transmission and pathogenesis.

Purpose of the Study:

  • To investigate potential lineage-specific functional differences in the SIVsmm Nef accessory protein.
  • To assess the role of Nef in viral persistence, transmission, and pathogenesis across different SIVsmm lineages.

Main Methods:

  • Examined Nef alleles from five distinct SIVsmm lineages.
  • Assessed Nef protein functions including CD4, MHC-I, CD28, and CD3 modulation in human cells.
  • Evaluated effects on T cell responsiveness, virion infectivity, and virus replication in human peripheral blood mononuclear cells.

Main Results:

  • Nef alleles from all SIVsmm lineages modulated host cell surface proteins (CD4, MHC-I, CD28, CD3) and invariant chain (Ii).
  • Nef generally suppressed T cell activation, enhanced virion infectivity, and promoted replication in human cells.
  • Significant variations in Nef functional activity were observed between SIVsmm strains, but not between lineages.

Conclusions:

  • SIVsmm Nef alleles are functionally active in human cells without requiring lineage-specific adaptive changes.
  • Strain-specific differences in Nef function, rather than lineage-specific ones, likely influence SIVsmm virological and immunological characteristics.
  • These strain-specific Nef variations may impact viral fitness and pathogenicity in cross-species infections.

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