Vpu Reduces Innate Sensing of HIV-1-infected cells by PDCs via a BST2-dependent process

Transcription

1 Vpu Reduces Innate Sensing of HIV-1-infected cells by PDCs via a -dependent process Mariana G. Bego, Édouard Bérubé-Côté, Johanne Mercier, and Éric A. Cohen Institut de Recherches Cliniques de Montréal. Department of Microbiology and Immunology. Université de Montréal, Montréal, Canada IAS 213 Towards an HIV Cure Symposium

2 /Tetherin: one gene (a few isoforms) and many roles NF-kB

3 Sensing of HIV-1 infected cells pdcs in contact with HIV infected cells release type-i IFN Weak Strong Signals: 1- Env-CD4 interaction 2- Membrane fusion, decapsidation and release of ssrna into TLR7+ endosome

4 Experimental design Freshly isolated PBMCs or enriched pdc TLR/IFN controls (22h) SUP: Type-I IFN Co-culture (22h) SUP: Type-I IFN IFN controls (22h) SUP: Type-I IFN NL4.3 WT/dU infected MT4 or Primary CD4+ T cells

5 Role of Vpu during innate sensing A BST-2 downregulation B HIV-1 particle release assay MT4-WT MT4-dU % Max % Max PI WT-GFPneg WT-GFPpos PI du-gfpneg du-gfppos C Co-culture X4 infected MT4 T cells and PBMCs

6 Role of Vpu during innate sensing During HIV-1 infection, presence of Vpu is able to partially control IFN production MT4 cells (X4 infection) Primary T cells (X4 infection) Primary T cells (X4/R5 infection) (n=12) (n=14) (n=11)

7 Role of during innate sensing A BST-2 downregulation MT4 shnt- WT MT4 shnt- du MT4 sh- WT MT4 sh- du % Max % Max % Max % Max PI 23 WT-GFPneg 51 WT-GFPpos 35 PI du-gfpneg du-gfppos PI 23 WT-GFPneg 23 WT-GFPpos 23 PI du-gfpneg du-gfppos B HIV-1 particle release assay C Co-culture of X4 infected MT4 sh and PBMCs Relative % of particles released du WT du WT MT4-shNT MT4-sh TypeI IFN (U/ml) du WT du WT MT4-shNT MT4-sh

8 Role of during innate sensing ns Relative % of IFN released *** *** *** Also seen after VSV-Ginduced superinfection of MT4 with R5 viruses, which completely downregulates surface du WT du WT MT4 shnt MT4 sh N=12 Control of innate sensing by Vpu is -dependent

9 Observations Reduction of IFN produced depends on Vpu expression Clusters? NO: Reduction of Vpu-dependent IFN production requires. Viral clusters? NO clusters % Max Vpu only partially reduces surface PI WT-GFPneg WT-GFPpos Neil, 28 WT du WT du HT18 (No ) HT18 + Hypothesis: Virus clusters limit the accessibility to surface, and prevent potential inhibitory interactions

10 Role of during innate sensing A Block using polyclonal rabbit serum a- MT4 Detection using mouse mab a- B % of surface staining Mou Iso Mou ab Rb ab (low) + mou ab Rb Iso (low) + mou ab 6 Rb ab (high) + mou ab 1 69 Rb Iso (high) + mou ab MT4 cells 3' block 18h block C Co-culture of MT4 with PBMCs for 18h D ** 6 ns Type-I IFN (U/ml) mock du WT mock du WT mock du WT noab PI a du WT du WT PI a

11 Model: as a pdc inhibitory ligand depletion:

12 Model: as a pdc inhibitory ligand blocking:

13 Model: as a pdc inhibitory ligand A- Use of that cannot cluster virus, but still inhibits ILT7

14 Model: as a pdc inhibitory ligand B- ILT7 depletion in pdcs

15 Innate sensing in presence of -dgpi dgpi is unable to retain viral particles Relative percentage of infectious particles released du WT du WT du WT SupT1 SupT1- SupT1-- dgpi (n=4)

16 Innate sensing in presence of -dgpi dgpi is unable to retain viral particles Relative percentage of infectious particles released du WT du WT du WT SupT1 SupT1- SupT1-- dgpi while is still able to block TLR signaling likely through ILT7 % of type-i IFN produced after TLR7 induction Block of TLR7 signaling pcmv_ha pcmv_hahu wt pcmv_hahu dgpi Both: - pcmv_ha-hu wt - pcmv_ha-hu dgpi are capable to block type-i IFN production from PBMC treated with TLR7 agonist. (n=4)

17 Innate sensing in presence of -dgpi A Levels of -dgpi B BST-2 downregulation SupT1-dGPI WT SupT1-dGPI du % Max % Max % Max SupT1 SupT1+IFN SupT1-dGPI SupT1 WT-GFPneg WT-GFPpos SupT1 du-gfpneg du-gfppos C Co-culture of X4 infected SupT1-dGPI and PBMCs 2,5 2, Type-I IFN (U/ml) 2, 1,5 1, 5 Type-I IFN (U/ml) 16, 12, 8, 4, mock du WT mock du WT mock du WT mock du WT SupT1 SupT1-dGPI SupT1 SupT1-dGPI

18 Role of ILT7 during innate sensing A B Relative % of IFN released *** *** % Max Non pdcs (PBMCs) pdcs (PBMCs) Enriched pdcs Enriched pdcs siilt du WT du WT PBMC pdc ILT7-PE C Relative % of IFN released *** ns D Relative % of IFN released *** ns du WT du WT du WT du WT PBMC pdc siilt7 pdc pdc siilt7

19 Interplay between Vpu and Through a highly sophisticated targeted regulation of particular isoforms, Vpu appears to promote HIV-1 release while at the same time interfering with pdc antiviral responses

20 Acknowledgements Mariana G. Bego Édouard Bérubé-Côté Members of the Dr Cohen s lab: pnl4.3 virus cloning (J. Richard; R. Murali) IRCM Clinic and blood donors! Financial support: Réseau Sida (FRQS)

21 A Negative selection Positive selection CD14 CD14 CD14 CD14.99 %.8% 88.8% 96.4% BDCA-2 BDCA-2 BDCA-2 BDCA-2 Fresh PBMC PBMC - pdc pdc 1 pdc 2 B C HIV donor: MT4 T cells HIV donor: 1ry CD4+ T cells IFN producer: donor#18 Type-I IFN (U/ml) 14, 12, 1, 8, 6, 4, 2, pDC pdc1 18 Type-I IFN (U/ml) 2,5 2, 1,5 1, 5 CD4 donor # pDC pdc1 18 IFN producer: donor#181 Type-I IFN (U/ml) 1, 8, 6, 4, 2, pDC pdc1 181 Type-I IFN (U/ml) 12, 1, 8, 6, 4, 2, CD4 donor # pDC pdc181 m X4-WT X4-dU R5-WT R5-dU

22 Additional controls A MT4 shnt MT4 sh B Percentage of GFP+ cells MT4 shnt WT MT4 shnt du MT4 sh WT MT4 sh du C Mock (GFP-) WT (GFP+) du (GFP+) MT4 alone Mock (GFP-) WT (GFP+) du (GFP+) PBMC after 24h in culture Co-culture D %GFP+ cells after co-culture relative to cells not in contact with PBMC h 48h 72h WT du WT du shnt sh