title: Human immunodeficiency virus type 1 protease inhibitors block toll-like receptor 2 (TLR2)- and TLR4-Induced NF-kappaB activation.
abstract: Coinfections with opportunistic and pathogenic bacteria induce human immunodeficiency virus (HIV) replication through microbial antigen activation of NF-kappaB. Here, we assessed whether HIV type 1 protease inhibitors (PI) block microbial antigen activation of NF-kappaB. Human microvessel endothelial cells were transiently transfected with either endothelial cell-leukocyte adhesion molecule NF-kappaB luciferase or interleukin 6 (IL-6) promoter luciferase constructs by using FuGENE 6, and they were treated with PI (nelfinavir, ritonavir, or saquinavir) prior to stimulation with the Toll-like receptor 4 (TLR4) and TLR2 ligands, with lipopolysaccharide (LPS), soluble Mycobacterium tuberculosis factor, or Staphylococcus epidermidis phenol-soluble modulin, respectively, or with tumor necrosis factor alpha (TNF-alpha). Luciferase activity was measured by using a Promega luciferase kit. TNF-alpha release from the supernatant was measured by enzyme-linked immunosorbent assay. Cell death was assessed by lactate dehydrogenase assay. We observed that PI pretreatment blocked the TLR2- and TLR4- as well as the TNF-alpha-mediated NF-kappaB activation, in a dose-dependent manner. PI pretreatment also blocked the LPS-induced IL-6 promoter transactivation and TNF-alpha secretion. These data suggest that PI block HIV replication not only by inhibiting the HIV protease but also by blocking the TLR- and TNF-alpha-mediated NF-kappaB activation and proinflammatory cytokine production. These findings may help explain the immunomodulatory effects of PI, and they suggest an advantage for PI-containing drug regimens in the treatment of HIV-infected patients who are coinfected with opportunistic and pathogenic bacteria.
authors.affiliation: Department of Pediatrics, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Room 4220, Los Angeles, CA 90048, USA. ozlem.equils@cshs.org
authors.forename: Ozlem
authors.initials: O
authors.lastname: Equils
authors.forename: Alan
authors.initials: A
authors.lastname: Shapiro
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Madak
authors.forename: Chunren
authors.initials: C
authors.lastname: Liu
authors.forename: Daning
authors.initials: D
authors.lastname: Lu
mesh_terms: D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology; D004797:Enzyme-Linked Immunosorbent Assay; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000201:enzymology*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors* / Q000235:genetics; D016328:NF-kappa B / Q000187:drug effects*; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors* / Q000235:genetics; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000378:metabolism
chemical_list: D017320:HIV Protease Inhibitors; D015850:Interleukin-6; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; D007770:L-Lactate Dehydrogenase; D008156:Luciferases