Allo-antigen stimulated CD8+ T-cells suppress NF-κB and Ets-1 DNA binding activity, and inhibit phosphorylated NF-κB p65 nuclear localization in CD4+ T-cells.
CD8+ T-cells of asymptomatic HIV-1 carriers (AC) suppress human immunodeficiency virus type 1 (HIV-1) replication in a class I major histocompatibility complex (MHC-I)-restricted and -unrestricted manner. In order to investigate the mechanism of MHC-I-unrestricted CD8+ T-cell-mediated HIV-1 suppression, we previously established allo-antigen stimulated CD8+T-cells from HIV-1-uninfected donors. These allo-antigen stimulated CD8+ T-cells suppressed HIV-1 replication in acutely infected autologous CD4+ T-cells when directly co-cultured. To elucidate the mechanism of HIV-1 replication suppression, we analyzed DNA-binding activity and phosphorylation of transcriptional factors associated with HIV-1 replication by electrophoresis mobility shift assay and Western blotting. When CD4+ T-cells were cultured with allo-antigen stimulated CD8+ T-cells, the reduction of NF-κB and Ets-1 DNA-binding activity was observed. Nuclear localization of NF-κB p65 and Ets-1 was suppressed in CD4+ T-cells. Although NF-κB p65 and Ets-1 are known to be regulated by protein kinase A (PKA), no difference was observed in the expression and phosphorylation of the PKA catalytic subunit in CD4+ T-cells cultured with PHA-treated CD8+ T-cells or allo-antigen stimulated CD8+ T-cells. Cyclic AMP is also known to enter through gap junctions, but the suppression of HIV-1 replication mediated by allo-antigen stimulated CD8+ T-cells was not affected by the gap junction inhibitor. The nuclear transport of phosphorylated NF-κB p65 (Ser276) was inhibited only in CD4+ T-cells cultured with allo-antigen stimulated CD8+ T-cells. Our results indicate that allo-antigen stimulated CD8+ T-cells suppress the transcriptional activity of NF-κB p65 or Ets-1 in an antigen-nonspecific manner, and inhibit the nuclear transport of phosphorylated NF-κB p65 (Ser276).
1 Division of Clinical Immunology, Graduate School of Medical Sciences, Kitasato University , Sagamihara, Japan .
Ryuichi
R
Nagashima
Fumitaka
F
Kawakami
Shinichiro
S
Takahashi
Fumiya
F
Obata
Makoto
M
Kubo
D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D015967:Gene Expression Regulation, Viral; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D006801:Humans; D007519:Isoantigens / Q000494:pharmacology*; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D021381:Protein Transport; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
C494041:ETS1 protein, human; D007519:Isoantigens; D016328:NF-kappa B; D050784:Proto-Oncogene Protein c-ets-1; D000242:Cyclic AMP; D051057:Proto-Oncogene Proteins c-akt; D017868:Cyclic AMP-Dependent Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases