Phorbol ester reduces constitutive nuclear NFχB and inhibits HIV-1 production in mature human monocytic cells

Abstract

NF kappa B is a potent mediator of specific gene expression in human monocytes and has been shown to play a role in transcription of the HIV-1 genome in promonocytic leukemias. There is little information available on the response of NF kappa B to cytokines in normal human monocytes. We have used a 32P-labeled oligonucleotide derived from human immunodeficiency virus (HIV-1) long terminal repeat, which contains a tandem repeat of the NF kappa B binding sequence, as a probe in a gel retardation assay to study this transcription factor. Using this assay, we have detected NF kappa B in extracts of nuclei from normal human monocytes. Treatment of normal monocytes with 12-0-tetradecanoyl phorbol-13-acetate (TPA) for 4-24 h caused the complete disappearance of NF kappa B from nuclear extracts of monocytes. A similar result was obtained with the mature monocytic leukemia cell line THP-1. The constitutive transcription factor SP1 was unaffected by addition of TPA. The disappearance of NF kappa B from the nucleus was concentration dependent between 10 and 50 ng/ml of phorbol ester. In THP-1 cells, TPA also induced a new, faster-migrating NF kappa B species not induced in monocytes. Protein kinase C inhibitor staurosporine, but not cyclic nucleotide-dependent protein kinase inhibitor HA-1004, also dramatically reduced constitutive levels of nuclear NF kappa B. Finally, TPA addition to monocytes infected with HIV-1 inhibited HIV-1 replication, as determined by reverse transcriptase assays, in a concentration-dependent manner. These results are in striking contrast to the increase in nuclear NF kappa B and HIV-1 replication induced by phorbol esters in promonocytic leukemia cells U937 and HL-60, and emphasize the importance of studying cytokine regulation of HIV-1 in normal monocytes.

The eukaryotic translation initiation factor eIF4E is a direct transcriptional target of NF-κB and is aberrantly regulated in acute myeloid leukemia

“…Consistent with previous findings (34), THP1 cells harbor constitutively active NF-κB. Nuclear lysates prepared from THP1 cells exhibited NF-κB specific binding for the four identified promoter elements (Figure 6A).…”

Myelomonocytic Cell Lines in Modeling HIV-1 Infection of the Bone Marrow

“…Given this observation, the HL-60 and OM-10.1 cell lines have been used in several studies that simply aim at examining the levels of CD4, CXCR4, and CCR5 or other surface markers under various cellular physiological conditions and drug treatments [138,[144][145][146][147][148][149][150][151][152][153][154][155][156][157][158][159]. These cells have also been used to screen methodologies or drugs that may inhibit HIV-1 infection or reduce transcriptional activation of the virus [117,[160][161][162][163][164][165][166][167][168][169][170][171][172][173]. These cell lines have also been used in studies of drug toxicity, permeability, and/or effects on cellular activation and differentiation to gain an understanding of what specific drugs might do to cells in the bone marrow [144,154,[174][175][176][177][178][179][180][181][182]…”

Endotoxin treatment of equine infectious anaemia virus-infected horse macrophage cultures decreases production of infectious virus.

“…HIV replication is inhibited by treatment of infected cells with a phorbol ester, interferon (IFN) and bacterial lipopolysaccharide (LPS) (Gendelman et al, 1990 a, b ;Kornbluth et al, 1990 ;Mufson et al, 1992 ;Poli et al, 1989 ;Shirazi & Pitha, 1992). The overall effects of cellular activation on lentivirus replication depend, in part, on the cell type used for in vitro studies.…”

“…The overall effects of cellular activation on lentivirus replication depend, in part, on the cell type used for in vitro studies. For example, cellular activation with a phorbol ester (Mufson et al, 1992) or LPS (Kornbluth et al, 1989) inhibits HIV replication in primary human monocytes, but stimulates virus replication in chronically infected cell lines (Chowdhury et al, 1990 ;Pomerantz et al, 1990). Activation of primary human macrophages with IFN has been found to inhibit early stages in HIV replication (Gendelman et al, 1990 b ;Kornbluth et al, 1990 ;Meylan et al, 1993) ; in contrast, activation of cell lines is thought to inhibit late stages in the virus life-cycle (Gendelman et al, 1990 b ;Poli et al, 1989).…”