title: Loss of macrophage-secreted lysozyme in HIV-1-associated dementia detected by SELDI-TOF mass spectrometry.
abstract: OBJECTIVE
  To identify which proteins are differentially secreted from monocyte/macrophages (M/M phi) of HIV-1 seropositive patients with HIV-1-associated dementia (HAD).
  
  
  METHODS
  To compare profiles of secreted M/M phi proteins from individuals with HAD, HIV-1 infection or controls using surface-enhanced laser desorption/ionization (SELDI)-time of flight (TOF) ProteinChip technology.
  
  
  METHODS
  M/M phi were isolated by Percoll gradient centrifugation and cultured from whole blood of 11 patients with HAD, 13 HIV-1 seropositive subjects with no dementia (HIV-1 group) and nine HIV-1 seronegative subjects (controls). M/M phi supernatants were removed after 7 days in culture and analyzed by SELDI-TOF. A 14.6 kDa-secreted protein in control M/M phi supernatants was significantly decreased in patients with HAD. The protein was purified from HIV-1 seronegative controls and identified by peptide mapping. Protein concentration in the supernatants was quantified by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  A 14.6 kDa protein was identified as lysozyme. Secreted lysozyme concentrations from M/M phi of patients with HAD (81 +/- 35 ng/ml) were significantly lower than that of the HIV-1 group (326 +/- 303 ng/ml) and controls (764 +/- 211 ng/ml). Intracellular lysozyme was similar in all three groups. All patients with HAD were on highly active antiretroviral therapy (HAART). There was no correlation between lysozyme, viral load, CD4 cell count or use of HAART.
  
  
  CONCLUSIONS
  A comparison of protein profiles from M/M phi supernatants of patients with HIV-1 infection indicated a specific protein consistently decreased in HAD. The protein was identified as lysozyme, a major macrophage defense protein. This further demonstrates macrophage dysfunction as a significant consequence of HAD.
authors.affiliation: Department of Laboratory Medicine, University of California, and Veterans Affairs Medical Center, San Francisco, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Sun
authors.forename: Hans C
authors.initials: HC
authors.lastname: Rempel
authors.forename: Lynn
authors.initials: L
authors.lastname: Pulliam
mesh_terms: D015526:AIDS Dementia Complex / Q000188:drug therapy / Q000201:enzymology* / Q000821:virology; D023241:Antiretroviral Therapy, Highly Active; D015415:Biomarkers / Q000097:blood; D018791:CD4 Lymphocyte Count; D015658:HIV Infections / Q000188:drug therapy / Q000201:enzymology / Q000821:virology; D015497:HIV-1; D006801:Humans; D008264:Macrophages / Q000201:enzymology*; D009113:Muramidase / Q000097:blood*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D019562:Viral Load
chemical_list: D015415:Biomarkers; D009113:Muramidase