P Chen1, G Bauer, J Mitchell, R Factor, R Markham, D H Schwartz. 1. Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA.
Abstract
OBJECTIVES: To ascertain the effects of N-acetyl-cysteine (NAC) and L-2-oxothiazolidine-4-carboxylic acid (OTC) on HIV replication in resting T lymphocytes mixed with chronically infected U1 promonocytic cells; examine the phenotypes of NAC- and OTC-treated cells; and monitor HIV recovery from hu-PBMC SCID mice (SCID mice infected with HIV-1BaL reconstituted with human peripheral blood mononuclear cells) treated with oral OTC. DESIGN AND METHODS: Unstimulated PBMC from uninfected donors preincubated for 2 days with pH-adjusted NAC or OTC were cultured at a concentration of 1 x 10(6) cells/ml with 100 U1 cells that were chronically infected with HIV-1IIIB. HI-1 production in the presence or absence of zidovudine was measured by p24 assay at 1-3 weeks, and results were compared with values from the same cell cultures maintained without NAC or OTC exposure. In some experiments U1 cells were separated from PBMC by a 0.4 micron membrane. NAC-treated and -untreated cells were subjected to FACS analysis of multiple-cell-surface adhesion and activation molecules and the results were compared. Hu-PBMC SCID mice were fed OTC for 3 days prior to infection with HIV-1BaL and for the next 3 weeks. Mice were then sacrificed and peritoneal lavage cells were cultured for virus analysis. RESULTS: Unstimulated, non-dividing PBMC supported high levels of HIV replication when in direct contact with U1 cells in the presence of NAC or OTC; CD2 and CD54 (I-CAM1) were down-regulated on NAC-treated PBMC; and OTC-treated mice produced significantly higher yields of HIV-1 from peritoneal cells than did untreated mice. CONCLUSIONS: At concentrations < or = 5 mM, NAC and OTC potentiate HIV growth in unstimulated PBMC in vitro and in SCID mice. Caution in the use of these agents as antiviral monotherapies is advisable.
OBJECTIVES: To ascertain the effects of N-acetyl-cysteine (NAC) and L-2-oxothiazolidine-4-carboxylic acid (OTC) on HIV replication in resting T lymphocytes mixed with chronically infected U1 promonocytic cells; examine the phenotypes of NAC- and OTC-treated cells; and monitor HIV recovery from hu-PBMC SCIDmice (SCIDmice infected with HIV-1BaL reconstituted with human peripheral blood mononuclear cells) treated with oral OTC. DESIGN AND METHODS: Unstimulated PBMC from uninfected donors preincubated for 2 days with pH-adjusted NAC or OTC were cultured at a concentration of 1 x 10(6) cells/ml with 100 U1 cells that were chronically infected with HIV-1IIIB. HI-1 production in the presence or absence of zidovudine was measured by p24 assay at 1-3 weeks, and results were compared with values from the same cell cultures maintained without NAC or OTC exposure. In some experiments U1 cells were separated from PBMC by a 0.4 micron membrane. NAC-treated and -untreated cells were subjected to FACS analysis of multiple-cell-surface adhesion and activation molecules and the results were compared. Hu-PBMC SCIDmice were fed OTC for 3 days prior to infection with HIV-1BaL and for the next 3 weeks. Mice were then sacrificed and peritoneal lavage cells were cultured for virus analysis. RESULTS: Unstimulated, non-dividing PBMC supported high levels of HIV replication when in direct contact with U1 cells in the presence of NAC or OTC; CD2 and CD54 (I-CAM1) were down-regulated on NAC-treated PBMC; and OTC-treated mice produced significantly higher yields of HIV-1 from peritoneal cells than did untreated mice. CONCLUSIONS: At concentrations < or = 5 mM, NAC and OTC potentiate HIV growth in unstimulated PBMC in vitro and in SCIDmice. Caution in the use of these agents as antiviral monotherapies is advisable.