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.
Human immunodeficiency virus type 1 protease inhibitors block toll-like receptor 2 (TLR2)- and TLR4-Induced NF-ΚB activation, Equils O, Shapiro A, Madak Z, Liu C, Lu D, Antimicrobial Agents Chemotherapy, 2004 October, 48(10), 3905-11, PMID: 15388451
- Rac1 and Toll-IL-1 receptor domain-containing adapter protein mediate Toll-like receptor 4 induction of HIV-long terminal repeat, Equils O, Madak Z, Liu C, Michelsen KS, Bulut Y, Lu D, J ,Immunology, 2004 Jun 15;172(12):7642-6, PMID:15187145
- Toll-like receptor 2 (TLR2) and TLR9 signaling results in HIV-long terminal repeat trans-activation and HIV replication in HIV-1 transgenic mouse spleen cells: implications of simultaneous activation of TLRs on HIV replication, Equils O, Schito ML, Karahashi H, Madak Z, Yarali A, Michelsen KS, Sher A, Arditi M.J, Immunology. 2003 May 15; 170(10):5159-64, PMID:12734363
Rac1 and Toll-IL-1 receptor domain-containing adapter protein mediate Toll-like receptor 4 induction of HIV-long terminal repeat, Equils O, Madak Z, Liu C, Michelsen KS, Bulut Y, Lu D, J ,Immunology, 2004 Jun 15;172(12):7642-6, PMID:15187145