Increased quinolinate immunoreactivity in the peripheral blood monocytes/macrophages from SIV-infected monkeys.
Quinolinate (QUIN), a metabolite in the kynurenine pathway of tryptophan degradation and a neurotoxin that is thought to act through the NMDA receptor system, was localized in cultured peripheral blood monocytes/macrophages from SIV-infected monkeys using a recently developed immunohistochemical method. Significant increases in QUIN immunoreactive (IR) cells were detected in all five SIV-infected monkeys examined. Multinucleated giant cells, a hallmark of lentiviral infection, were visible in selected samples. Treatment with the QUIN precursors, tryptophan and kynurenine, increased the number of QUIN-IR cells in both the control and SIV-infected preparations, perhaps by a mass action mechanism. We hypothesize that in SIV-infected monkeys, infiltrating monocytes/macrophages contribute to the high level of brain QUIN and associated neuropathology.
Namboodiri
A M
AM
Department of Biology, Georgetown University, Washington DC 20057, USA.
Venkateshan
C N
CN
Narayanan
R
R
Blinder
K
K
Moffett
J R
JR
Gajdusek
D C
DC
Gravell
M
M
Gibbs
C J
CJ
D000818:Animals; D000918:Antibody Specificity; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured / Q000166:cytology / Q000276:immunology / Q000821:virology; D007150:Immunohistochemistry; D007737:Kynurenine / Q000494:pharmacology; D008253:Macaca mulatta; D008264:Macrophages / Q000737:chemistry / Q000378:metabolism / Q000821:virology*; D009000:Monocytes / Q000737:chemistry / Q000378:metabolism / Q000821:virology*; D017378:Quinolinic Acid / Q000276:immunology* / Q000378:metabolism; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000378:metabolism; D015302:Simian Immunodeficiency Virus; D014364:Tryptophan / Q000494:pharmacology
D007737:Kynurenine; D014364:Tryptophan; D017378:Quinolinic Acid