Type I interferon induces inhibitory 16-kD CCAAT/ enhancer binding protein (C/EBP)beta, repressing the HIV-1 long terminal repeat in macrophages: pulmonary tuberculosis alters C/EBP expression, enhancing HIV-1 replication.
We have previously observed that HIV-1 replication is suppressed in uninflamed lung and increased during tuberculosis. In vitro THP-1 cell-derived macrophages inhibited HIV-1 replication after infection with Mycobacterium tuberculosis. Suppression of HIV-1 replication was associated with inhibition of the HIV-1 long terminal repeat (LTR) and induction of ISGF-3, a type I interferon (IFN)-specific transcription factor. Repression of the HIV-1 LTR required intact CCAAT/enhancer binding protein (C/EBP) sites. THP-1 cell-derived macrophages infected with M. tuberculosis, lipopolysaccharide, or IFN-beta induced the 16-kD inhibitory C/EBPbeta isoform and coincidentally repressed HIV-1 LTR transcription. C/EBPbeta was the predominant C/EBP family member produced in THP-1 macrophages during HIV-1 LTR repression. In vivo, alveolar macrophages from uninflamed lung strongly expressed inhibitory 16-kD C/EBPbeta, but pulmonary tuberculosis abolished inhibitory C/EBPbeta expression and induced a novel C/EBP DNA binding protein. Therefore, in vitro, proinflammatory stimulation produces an IFN response inhibiting viral replication by induction of a C/EBPbeta transcriptional repressor. THP-1 cell-derived macrophages stimulated with type I IFN are similar to alveolar macrophages in the uninflamed lung in vivo. In contrast, the cellular immune response in active pulmonary tuberculosis disrupts this innate immunity, switching C/EBP expression and allowing high level viral replication.
Division of Pulmonary and Critical Care Medicine and Bellevue Chest Service, New York University Medical Center, New York 10016, USA.
Y
Y
Honda
L
L
Rogers
K
K
Nakata
B Y
BY
Zhao
R
R
Pine
Y
Y
Nakai
K
K
Kurosu
W N
WN
Rom
M
M
Weiden
D001483:Base Sequence; D001665:Binding Sites; D018893:Bronchoalveolar Lavage; D022762:CCAAT-Enhancer-Binding Proteins; D004279:DNA, Viral; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015536:Down-Regulation; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D016898:Interferon-alpha / Q000378:metabolism* / Q000494:pharmacology; D016899:Interferon-beta / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D016676:Macrophages, Alveolar / Q000378:metabolism; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014157:Transcription Factors; D014397:Tuberculosis, Pulmonary / Q000378:metabolism*; D014779:Virus Replication
D022762:CCAAT-Enhancer-Binding Proteins; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D016898:Interferon-alpha; D009687:Nuclear Proteins; D014157:Transcription Factors; D016899:Interferon-beta