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- Che, Karlhans Fru, et al.
(författare)
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p38 Mitogen-Activated Protein Kinase/Signal Transducer and Activator of Transcription-3 Pathway Signaling Regulates Expression of Inhibitory Molecules in T Cells Activated by HIV-1-Exposed Dendritic Cells
- 2012
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Ingår i: Molecular Medicine. - : Feinstein Institute for Medical Research. - 1076-1551 .- 1528-3658. ; 18:8, s. 1169-1182
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Tidskriftsartikel (refereegranskat)abstract
- Human immunodeficiency virus type 1 (HIV-1) infection enhances the expression of inhibitory molecules on T cells, leading to T-cell impairment. The signaling pathways underlying the regulation of inhibitory molecules and subsequent onset of T-cell impairment remain elusive. We showed that both autologous and allogeneic T cells exposed to HIV-pulsed dendritic cells (DCs) upregulated cytotoxic T-lymphocyte antigen (CTLA-4), tumor-necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), lymphocyte-activation gene-3 (LAG3). T-cell immunoglobulin mucin-3 (TIM-3), CD160 and certain suppression-associated transcription factors, such as B-lymphocyte induced maturation protein-1 (BLIMP-1), deltex homolog 1 protein (DTX1) and forkhead box P3 (FOXP3), leading to T-cell suppression. This induction was regulated by p38 mitogen-activated protein kinase/signal transducer and activator of transcription-3 (P38MAPK/STAT3) pathways, because their blockade significantly abrogated expression of all the inhibitory molecules studied and a subsequent recovery in T-cell proliferation. Neither interleukin-6 (IL-6) nor IL-10 nor growth factors known to activate STAT3 signaling events were responsible for STAT3 activation. Involvement of the P38MAPK/STAT3 pathways was evident because these proteins had a higher level of phosphorylation in the HIV-1-primed cells. Furthermore, blockade of viral CD4 binding and fusion significantly reduced the negative effects DCs imposed on primed T cells. In conclusion, HIV-1 interaction with DCs modulated their functionality, causing them to trigger the activation of the P38MAPK/STAT3 pathway in T cells, which was responsible for the upregulation of inhibitory molecules. Online address: http://www.molmed.org doi: 10.2119/molmed.2012.00103
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| 2. |
- Che, Karlhans Fru, et al.
(författare)
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Cross Talk between P38MAPK and STAT3 Regulates Expression of Negative Costimulatory Molecules and Transcriptional Repressors in HIV-1 Primed T cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- HIV-1 infection enhances the expression of negative costimulatory molecules on T cellsleading to T cell impairment. The signaling pathway underlying the regulation ofinhibitory molecules and the subsequent onset of T cell impairment remains to beinvestigated. Herein, we showed that the T cells activated by HIV-pulsed dendritic cells(DCs) upregulated CTLA-4, TRAIL, LAG-3, TIM-3, and CD160 and suppressionassociated transcription factors BLIMP-1, DTX1, and FOXP3, leading to T cellsuppression. The induction of suppressor T cells was regulated by the signal transducerand activator of transcription 3 (STAT3) molecules as blockade of this pathwaysignificantly down regulates the expression of inhibitory molecules. The cytokines IL-6and IL-10 were not responsible for STAT3 activation as their neutralization could neitherrecover T cell proliferation nor decrease the expression of negative costimulatorymolecules. Contrarily, we demonstrated that the intracytoplasmic cross-talk of P38Mitogen-Activated Protein Kinase (MAPK) with STAT3 was responsible as blockade ofthe P38MAPK significantly impaired negative costimulatory molecular expression andthe subsequent recovery of T cell proliferation. Notably, the blockade of viral access toDC cytosol, via CD4 binding and fusion, significantly reduced the negative effects DCsimposed on the primed T cells. In conclusion, viral access to cytosol modulated theDCs- T cell priming to induce T cells with upreguled expression of negativecostimulatory molecules in a P38MAPK/STAT3 pathway dependent fashion
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