title: Stem-loop binding protein is a multifaceted cellular regulator of HIV-1 replication.
abstract: A rare subset of HIV-1-infected individuals is able to maintain plasma viral load (VL) at low levels without antiretroviral treatment. Identifying the mechanisms underlying this atypical response to infection may lead to therapeutic advances for treating HIV-1. Here, we developed a proteomic analysis to compare peripheral blood cell proteomes in 20 HIV-1-infected individuals who maintained either high or low VL with the aim of identifying host factors that impact HIV-1 replication. We determined that the levels of multiple histone proteins were markedly decreased in cohorts of individuals with high VL. This reduction was correlated with lower levels of stem-loop binding protein (SLBP), which is known to control histone metabolism. Depletion of cellular SLBP increased promoter engagement with the chromatin structures of the host gene high mobility group protein A1 (HMGA1) and viral long terminal repeat (LTR), which led to higher levels of HIV-1 genomic integration and proviral transcription. Further, we determined that TNF-α regulates expression of SLBP and observed that plasma TNF-α levels in HIV-1-infected individuals correlated directly with VL levels and inversely with cellular SLBP levels. Our findings identify SLBP as a potentially important cellular regulator of HIV-1, thereby establishing a link between histone metabolism, inflammation, and HIV-1 infection.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Lynne D
authors.initials: LD
authors.lastname: Tucker
authors.forename: John M
authors.initials: JM
authors.lastname: Asara
authors.forename: Collins K
authors.initials: CK
authors.lastname: Cheruiyot
authors.forename: Huafei
authors.initials: H
authors.lastname: Lu
authors.forename: Zhijin J
authors.initials: ZJ
authors.lastname: Wu
authors.forename: Michael C
authors.initials: MC
authors.lastname: Newstein
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dooner
authors.forename: Jennifer
authors.initials: J
authors.lastname: Friedman
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Lally
authors.forename: Bharat
authors.initials: B
authors.lastname: Ramratnam
mesh_terms: D002453:Cell Cycle; D002843:Chromatin / Q000378:metabolism; D015658:HIV Infections / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology; D025741:HMGA1a Protein / Q000378:metabolism; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D007249:Inflammation; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D000072417:Protein Domains; D020543:Proteome; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D019562:Viral Load; D014779:Virus Replication; D039221:mRNA Cleavage and Polyadenylation Factors / Q000378:metabolism*
chemical_list: D002843:Chromatin; D006657:Histones; D009687:Nuclear Proteins; D020543:Proteome; C092663:SLBP protein, human; D014409:Tumor Necrosis Factor-alpha; D039221:mRNA Cleavage and Polyadenylation Factors; D025741:HMGA1a Protein