Publications & Reports

CD4 and MHC class 1 down-modulation activities of nef alleles from brain- and lymphoid tissue-derived primary HIV-1 isolates.

Gray LR, Gabuzda D, Cowley D, Ellett A, Chiavaroli L, Wesselingh SL, Churchill MJ, Gorry PR
Center for Virology, Burnet Institute, 85 Commercial Rd, Melbourne, 3004 VIC, Australia.


Human immunodeficiency virus type 1 (HIV-1) nef undergoes adaptive evolution in the central nervous system (CNS), reflecting altered requirements for HIV-1 replication in macrophages/microglia and brain-specific immune selection pressures. The role of Nef in HIV-1 neurotropism and pathogenesis of HIV-associated dementia (HAD) is unclear. In this study, we characterized 82 nef alleles cloned from brain, cerebral spinal fluid, spinal cord, and blood/lymphoid tissue-derived HIV-1 isolates from seven subjects with HAD. CNS isolate-derived nef alleles were genetically compartmentalized and had reduced sequence diversity compared to those from lymphoid tissue isolates. Defective nef alleles predominated in a brain-derived isolate from one of the seven subjects (MACS2-br). The ability of Nef to down-modulate CD4 and MHC class 1 (MHC-1) was generally conserved among nef alleles from both CNS and lymphoid tissues. However, the potency of CD4 and MHC-1 down-modulation was variable, which was associated with sequence alterations known to influence these Nef functions. These results suggest that CD4 and MHC-1 down-modulations are highly conserved functions among nef alleles from CNS- and lymphoid tissue-derived HIV-1 isolates that may contribute to viral replication and escape from immune surveillance in the CNS.


  • Journal: Journal of Neurovirology
  • Published: 01/02/2011
  • Volume: 17
  • Issue: 1
  • Pagination: 82-91