Targeting HIV-1 Nef to Improve the Recognition of HIV-1 Infected … · 2013. 12. 5. · HIV Nef...
Transcript of Targeting HIV-1 Nef to Improve the Recognition of HIV-1 Infected … · 2013. 12. 5. · HIV Nef...
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Targeting HIV-1 Nef to Improve the
Recognition of HIV-1 Infected Cells
Shariq MujibArdalan Bozorgzad
Nasra Aidarus
Saleh Fadel
Thomas Smithgall
Mario Ostrowski
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• We have no conflicts to report
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HIV Nef• HIV regulatory protein, Nef = negative effector. Nef is expressed early in the viral life cycle.
Has multiple roles
• Plays a key role in immune evasion by down modulating expression of CD4, MHC-I among
other targets.
• Enhances viral release and prevents super infection (thereby reducing viral cytopathic
effects).
• Deletions in Nef � Long Term Non-Progressors (LTNP).
• SIV vaccine challenges with Nef deleted virus ���� lower viral load and acquisition with
future SIV challenges.
Arhel and Kirchhoff, Current topics in microbiology and immunology (2009)
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Nef-mediated HLA-A/B ����
Evasion of CD8 T cell
response ���� persistence of
infected cell
MHC-I
Downregulation
4
• Acquired novel small molecule inhibitors that
prevent Nef-mediated SFK activation (Dr. Smithgall,
U Pittsburgh).
• These drugs have been characterized on cell lines
(H9 etc.) and shown o be effective on Hck only (not
present in T cells.)
�IFN-Υ
Janeway et al. Immunobiology
6th Ed
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Nef protects HIV-1 infected cells from CD8 T cell mediated
recognition and killing by downmodulating MHC Repressing
this role of Nef could enhance CTL responses directed
against the infected cell, thereby eliminating it.
Hypothesis
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Diphenylfuropyrimidines – SFK Inhibitors Diphenylpyrazole– Nef Binding
(E)-4-((3-chlorophenyl)diazenyl)-5-hydroxy-3-(4-nitro-
phenyl)-1H-pyrazole-1-carbothioamide
B9
Bind to the ATP-binding site, Thr338, of Hck and Lyn
preventing SFK phosphorylation. Shown to be Nef
dependent.
Directly bind Nef, Asn126,
preventing Nef interaction with
SFK
Nef inhibitors – Two separate mechanisms
Emert-Sedlak et al. ACS Chem Biol. (2009)
Emert-Sedlak et al. Cell Chem. Biol. (2013)
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Hypothesis: Nef downregulation of MHC-I during early
reactivation of latent reservoir prevents elimination of
latently infected cells.
1. Characterize the Nef inhibitors on primary CD4 T cells: Can they prevent MHC-I
downregulation in infected cells?
2. Functional role: Autologous T cell recognition assays to determine
enhancement of HIV-1 specific CD8 T cell function cocultured with Nef
inhibited CD4 T cells:
- Readout of assay: IFN-γ production and CD107a degranulation
Outline of Experiments
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Isolate and prime
CD4 T cells
Chronic HIV-1 on
HAART
(VL<50copies)
Infection of
CD4 T cells.
Three sets:
mock(uninfected),
NL4-3 ΔNef, and NL4-3
[Cultured with
drugs]
Isolate
autologous
CD8 T cells.
Rested
overnight.
Expt. 1: Stain
for MHC-I
levels in
infected cells
Analysis of
data. All done
by flow
cytometry.
D=0
Expt. 2: CD8 T
cell coculture.
6h assay to
measure CD8 T
cell effector
function. IFN-γ
and CD107a
2 5 6 7
Methods - Timeline
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MOCK NL4-3 ΔNef NL4-3 WT
MH
C-I
HIV Gag
% of MHC-I downregulated cells
within the HIV infected subset
HIV-1 infection and MHC-I ����
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MH
C-I
HIV Gag
DFP-4APDFP-4A (backbone)
DFP-4AB DFP-4AF TS2
2CB9
No Drug (NL4-3 WT)
Representative Example with each of the drugs
TS2 2CB9
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DFP-4A
No D
rug 4A
0
20
40
60 NS; p = 0.0621
% M
HC
dow
nre
gula
ted c
ells
DFP-4AP
No D
rug
4AP
0
10
20
30
40 **; p = 0.0020
% M
HC
dow
nre
gula
ted c
ells
DFP-4AB
No D
rug
4AB
0
10
20
30
40 **; p = 0.0038
% M
HC
dow
nre
gula
ted c
ells
DFP-4AF
No D
rug
4AF
0
10
20
30
40 **; p = 0.0018%
MH
C d
ow
nre
gula
ted c
ells
%MHC-I Nef-SFK inhibitors (DFP)
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2C
No D
rug
2C
0
10
20
30
40
50 NS; p = 0.7271(*p = 0.0306 outlier)
% M
HC
dow
nre
gula
ted c
ells
B9
No D
rug B9
0
10
20
30
40
50 *; p = 0.0280
% M
HC
dow
nre
gula
ted c
ells
TS2
No D
rug
TS2
0
20
40
60
80 NS; p = 0.7988
% M
HC
dow
nre
gula
ted c
ells
%MHC-I Nef-interacting Drugs
Nef inhibitors effectively prevents MHC-I �compared to NL4-3 infection in the absence of
drugs.
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Hypothesis: Nef downregulation of MHC-I during early
reactivation of latent reservoir prevents elimination of
latently infected cells.
1. Characterize the Nef inhibitors on primary CD4 T cells: Can they prevent MHC-I
downregulation in infected cells?
2. Functional role: Autologous T cell recognition assays to determine
enhancement of HIV-1 specific CD8 T cell function cocultured with Nef
inhibited CD4 T cells:
- Readout of assay: IFN-γ production and CD107a degranulation
Outline of Experiments
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T Cell Recognition Assay
Primary CD4 T cells infected (NL4-3 or
NL4-3 ΔNef)
3-4 day infection (~30% of CD4 T cells
infected by p24 FACS staining) cultured with
inhibitors
Coculture the T cells @ 1:1 CD8:CD4 ratio
6 hour culture with Brefeldin A and CD107a
(degranulation)
Isolated autologous whole CD8 T cells from
chronic HIV infected on treatment
Readout = IFN-γ+, CD107a+, CD8+ T cells
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MOCK NL4-3 WT
IFN
-γ
CD107a
T Cell Recognition Assay
Gated on CD8 T cells
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DFP-4AP (dNef)N
o Dru
g (dN
ef)
4AP
(dN
ef)
0
5
10
15 NS; p = 0.0620
%CD107a+ IFNg+
DFP-4A
No D
rug (W
T)
4A (W
T)
0
5
10
15 NS; p = 0.7626
%CD107a+ IFNg+
DFP-4A (dNef)
No D
rug (d
Nef
)
4A (d
Nef
)
0
5
10
15 NS; p = 0.6336
%CD107a+ IFNg+
DFP-4AP
No D
rug
4AP
0
5
10
15 *, p = 0.0231
%CD107a+ IFNg+
CD8 Response – Nef-SFK (DFP)
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DFP-4AB
No D
rug
4AB
0
5
10
15 *, p = 0.0207
%C
D107a+ IFN
g+
DFP-4AF
No D
rug
4AF
0
5
10
15 **, p = 0.0054
%C
D107a+ IFN
g+
DFP-4AB (dNef)
No D
rug (d
Nef
)
4AB
(dN
ef)
0
5
10
15 NS; p = 0.4647
%C
D107a+ IFN
g+
DFP-4AF (dNef)N
o Dru
g (dN
ef)
4AF (d
Nef
)
0
5
10
15 NS; p = 0.0827
%C
D107a+ IFN
g+
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TS2
No D
rug
TS2
0
5
10
15 NS, p = 0.2547
%C
D107a+ IFN
g+
TS2 (dNef)
No D
rug (d
Nef
)
TS2
(dN
ef)
0
5
10
15 NS; p = 0.8578
%C
D107a+ IFN
g+
B9
No D
rug
B9
0
5
10
15 **, p = 0.0027
%C
D107a+ IFN
g+
B9 (dNef)
No D
rug (d
Nef
)
B9
(dN
ef)
0
5
10
15 NS; p = 0.2980
%CD107a+ IFNg+
CD8 Response – Nef-interacting drugs
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2C
No D
rug 2C
0
5
10
15 *, p = 0.0291
%C
D107a+ IF
Ng
+
2C (dNef)
No D
rug (d
Nef
)
2C (d
Nef
)
0
5
10
15 NS; p = 0.2165
%C
D107a+ IF
Ng
+
NL4-3 ΔNef virus does not improve CD8 T cell
response in the presence of drugs.
Significant, albeit moderate, improvement of
CD8 T cell function observed only in the
presence of Nef expression.
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Summary
• Novel drugs appear to prevent MHC-I downregulation in primary CD4 T cells.
• Suppression of MHC-I downregulation correlates with improved CD8 T cell effector
function as measured by:
- ����IFN-γ production; and
- ����CD107a (degranulation)
• Effects were Nef dependent as evident by NL4-3 ΔNef controls.
• First study demonstrating improvement of T cell function with Nef drugs. Suggests another
approach towards HIV-1 eradication.
• Will establish role for CD8 T cells in elimination assays investigating long-term killing of
HIV-infected cells in vitro in the presence of drugs.
HIV-1 Nef:
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Acknowledgements
Mario Ostrowski
Saleh Fadel
Ardy
Nasra Aidarus
Sonya MacParland
Kiera Clayton
Jun Liu
Nur-ur-Rahman
Jordan Schwartz
Elizabeth Yue
Undergrad students
Ostrowski Lab: Dr. Rupert Kaul’s Lab
Dr. Kelly MacDonald’s lab
University of Pittsburgh
Dr. Thomas Smithgall
Dr. Lori Emert-Sedlak
Blood/Leukapheresis Donors
Queen Elizabeth
Scholarship in Science and
Technology