HIV1 Vpr dysregulates type I and type II IFN response by plasmacytoid dendritic cells and NK cells

1
HIV-1 Vpr dysregulates type I and type II IFN
response by plasmacytoid dendritic cells and NK
cells
2
Role of pDCs NK cell biology
pDCs
Type I Interferons
Inhibition of viral replication
Adapted from Degli-Esposti Nature Reviews
Immunology 2005
3
Impairment of NK and pDC immune responses in
chronic HIV infection

• Decreased NK cell numbers/ subpopulations and
  functions in chronic progressive HIV infection
  (Ahmad A Curr HIV Res 2003, Fauci A Nat Rev Imm
  2005)
• Quantitative loss of pDCs and Dysfunction of pDCs
  (Barron MA J Infect Dis 2003, Donaghy H Blood
  2003)

4
Role of Vpr as an modulator of immune responses

• Induction of G2 cycle arrest in PBMC (Poon B
  Science 1998)
• Induction of apoptosis following cell cycle
  arrest (Stewart SA J Virol 1997)
• Inhibition of DC maturation and macrophage
  activation (Muthumani K Int Immunol 2005)

5
Hypothesis HIV-1 Vpr can directly affect pDC
function. Vpr can indirectly inhibit NK cell
activation by impairing pDC/NK cells interplay.
6
Isolation of NK cells and pDCs
pDCs
NK cells
2.4
53.3
pre Sorting
8.8
CD16 APC-Cy7
pDCs
CD56dim NK cells
Post Sorting
7
Experimental setup
pDCs
1. Isolation of pDCs
2. pDC culture
5. Analysis of pDCs
HIV-1 Vpr
3. Pretreatment with Vpr
4. Stimulation with CpG
8
Vpr inhibits IFN-a productionby pDCs
9
Vpr does not induce apoptosis in pDCs
Medium
CpG
Vpr
VprCpG
- IL-3
10
Experimental setup
NK cells
1. Isolation of NK cells
2. Culture of NK cells
5. Analysis
HIV-1 Vpr

• Altered phenotype?
• Functional impairment?

3. Pretreatment with Vpr
4. Stimulation
11
Vpr does not interfere with NK activaction
Vpr 10 ng/ml
Vpr 0.1 ng/ml
- PMA/Iono
Vpr 1000 ng/ml
3.09
60.91
59.21
61.78
12
Experimental setup
NK cells
pDCs
1. Isolation of pDCs and NK cells
2. Coculture of pDCs with NK cells
5. Analysis
HIV-1 Vpr

• Altered phenotype?
• Functional impairment?

3. Pretreatment with Vpr
4. Stimulation with CpG
13
CpG stimulated pDC upregulate CD69 expression on
NK cells
CD69 APC
pDCs
CD56 FITC
14
HIV-1 Vpr inhibits pDC induced IFN-g secretion of
NK cells
plt0,05
15
Vpr does not affect pDC induced increased killing
of NK cells
16
Summary

• Vpr directly affected IFN-a release by pDCs
• This effect was not induced by Vpr-mediated
  apoptosis
• Vpr did not hamper NK activation per se
• Vpr significantly hampered IFN-g production of NK
  cells
• Vpr did not inhibit pDC induced CD69 expresssion
  on NK cells and did not affect increased
  cytoxicity of NK cells

17
Acknowledgements
Maren Mönkemeyer Nupur Bhatnagar
Dr. med. Dirk Meyer-Olson Dr. med. Hans
Heiken Prof. Dr. RE Schmidt
Susanne Kruse Marlies Daniel MD/PhD Program
Prof. Dr. Ulrich Schubert (University of Erlangen)
Dr. Thorsten Volgmann (Blood Bank Springe)
Dr. Matthias Ballmaier Christina Reimer
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Natural Killer cells
Two distinct NK subsets CD56bright CD56dim
Fauci Nature Reviews Immunology 2005 Colucci
Nature Reviews Immunology 2003
20
Role of pDCs in immunity
Type I Interferons
pDCs
NK cell
Adapted from Degli-Esposti Nature Reviews
Immunology 2005
21
Effect of HIV viraemia on NK cells
Fauci A. S. et al. Nature Reviews Immunology 2005
22
NK cells and pDCs post sorting
CD56dim NK cells
pDCs