Transcript NKp44L
"Vers un vaccin contre le SIDA :
rôle des cellules NK"
Professeur Patrice DEBRE
Laboratoire d’Immunologie Cellulaire et
Tissulaire
INSERM U945
Hôpital Pitié-Salpêtrière; Paris
Pathogen
Pathogenicity
Measles
Hépatitis
Polio
Rabies
Diphtéria
Tétanos
Cholera
Vaccines
Vaccine
INFECTION
virus
PATHOGENESIS
PATHOGENESIS
CD4 non
cells
CD4 infected
non infected
cells
CD4 infected cells
NK cells
cells
NK
NKp44L expression by CD4+ T cells
from HIV-infected patients
20
10
0
CD4
3- 4+ 8+ 3- 4+ 8+
Control PBMC
NKp44L
NKp44
-
+
NK
30
4
0
3
0
2
0
1
0
00
PBMC
40
% NKp44L
MHC-I
HIV+
p=0.002
250 500 750 1000
CD4 / mm3
40
p=0.005
20
10
0
0.1 1
10 100 1000
viral load(x 1000)
44L+
% NK Lysis
Kill
30
% NKp44L
% NKp44L
40
30
20 44L10
0
100/1 50/1 25/1 12.5/1
E/T ratio
Vieillard et al Proc Natl Acad Sci USA (2005)
NKp44L expression is induced by a specific gp41
motif
30
UT
20
3S
2.7%
17.4%
517 532
HR1
558
595
50/1
40
25/1 12/1 6/1
E/T ratio
30
10
HR2
643
0
20
HIV-1 gp41 Env
Fusion
Peptide
% NK lysis
CD4
10
NKp44L
NH2
+3S
678
TM
0
+3S
1
10
20
anti-3S (mg/ml)
3S motif
3S :
very conserved motif
& spécific to HIV-1
Vieillard et al Proc Natl Acad Sci USA (2005)
Vieillard et al AIDS (2006)
Anti-3S Ab : a predictive value for the evolution
of the disease ?
Multivariate study between 40 patients (first quartile) with
300
a slope CD4>2.7/month and 40 patients (last quartile) with slope
CD4<-6.9/month
200
100
0
Variable
0
400
800
CD4 count/mm3
1200
Odds-ratio IC95
Sexe
0.372
M
1
W
1.83 0.49-6.87
Age (x10y)
1.30
0.76-2.23
CD4 (x100)
0.58
0.42-0.81
Log VL
1.17
0.55-2.51
Anti-3S Ab 2.89
1.6-5.17
p
0.334
0.001
0.682
<0.001
(x100)
Vieillard et al AIDS (2006)
Unpublished data
Change in CD4 count from baseline
1.3: Anti-3S Ab : a predictive value for the
evolution of the disease ?
500
300
100
Anti-3S = POS
-100
Anti-3S= NEG
(7 CD4 / month)
-300
-500
0
6
12
18
24
30
36
Time since baseline (months)
Vieillard et al AIDS (2006)
Summary-1
Anti-3S
HIV-1
CD4
NKp44L
NK
Lysis
Conclusion-1
- NKp44L is specifically expressed on CD4+ T cells from HIV-1
patients;
- NKp44L is induced par a specific peptide from the gp41 HIV-1
protein;
- Anti-3S antibodies are predictive of the evolution of the disease
evolution.
No expression of NKp44L in CD4+ T cells infected by
HIV-1 : A new escape mechanism mediated by Nef
CD4 /AD8.00 2
NKp44L
200
150
UI
WT
52.1%
71.3%
GAG
68.1%
100
50
0
100 101 102
10
0
10
1
2
10
p2 4FITC
10
3
10
4
102 103 104 100 101 102
POL
73.6%
67.2%
103 104
gp41
gp120
150
HIV-p24
20
200
103 104 100 101
90.4%
100
*
50
0
100 101 102 103 104 100 101
15
200
150
10
102 103 104 100 101
NEF
TAT
11.7%
72.4%
102
103 104
VIF
60.2%
100
50
5
0
0 0
10 101
WT
Dnef
HIV viruses
0
4
102 103 10 10
101 102
103 104 100 101
102 103 104
NKp44L expression
Fausther Bovendo et al (In press)
Effect of Nef mutants on NKp44L expression
*
*
20
15
10
5
0
WT
Dnef
G2A
HIV Nef variants
P76/79A
L168/169A
Effect of Nef mutants on NK cytotoxicity
70
60
50
% NK lysis
40
30
20
10
0
100/1
50/1
25/1
E/T ratio
12.5/1
Conclusion-2
- NKp44L
cells;
is non-expressed on HIV-infected CD4+ T
- Retention of NKp44L by Nef HIV protein;
However,
- The mechanism of Nef inhibition remains unknown.
3- Vaccine strategies : Macaque model
« proof of concept »
3.1 : Macaque model of SHIV infection
3.2 : Preventive vaccination
2000
20
1500
15
1000
10
500
5
0
0
50
100
150
200
0
250
150
25
20
100
15
% NKp44L
25
anti-3S (U /mL)
2500
% NKp44L
CD4+ /mL
SHIV162P3-infected macaques model :
Relationship between CD4 cell decreases, NKp44L
expression and anti-3S Ab.
10
50
5
0
0
50
100
150
200
Days post-infection
Vieillard et al AIDS (2008)
0
250
Proofs of concept : Immunization of macaques
by the 3S peptide
3S
1500
3S
Viral load
1000 3S 3S
500
0
-400
-200
NS
106
104
102
1
200
0
50
0
50
100
150
200
2000
40
30
20
10
0
NS
108
CD4 / mm3
% CD4+NKp44L+
anti-3S (U/mL)
SHIV162P3
0
50
100
150
200
**
1500
*
1000
500
0
0
50
100
150
200
Days post-infection
KLH
KLH-3S
Vieillard et al Proc Natl Acad Sci USA (2008)
Effect of 3S vaccination on CD4 apoptosis, NK
activity et T cell-activation
**
50
40
**
*
20
10
*
10
0
UI
14
21
42
LN
Days post-infection
**
100
**
75
**
*
% CD4+CD69+
30
7.5
5
2.5
00
20
40
60
80
Days post-infection
50
25
0
0
14
21
42
Days post-infection
LN
Vieillard et al Proc Natl Acad Sci USA (2008)
Conclusions
1- Pathophysiology : role of NKp44L
- Depletion of non-infected CD4+ cells
- In infected cells: Escape mechanism by Nef
2- Immunotherapic interventions
- Preventive vaccine : in macaque model, we
have observed :
- high production of anti-3S Ab;
- low expression of NKp44L on CD4 cells.
Stable level of the CD4 cells
in absence of effect on the
viral load !
Acknowlegments
Pitié-Salpêtrière Hospital, Paris
France
Laboratory of Cellular and Tissular
Immunology
Hugues Fausther Bovendo
Vincent Vieilllard
Patrice Debré
CEA, Fontenay-aux-roses,
France
Laboratory of Immuno-Virology
Roger Le Grand
Nathalie Bosquet
Pasteur Institute, Paris, France
Department of virology
Clinical Epidemiology
Nathalie Sole-Foulon
Dominique Costagliola
Olivier Schwartz
Department of virology
Harvard University, Cambridge,
MA
Henry Agut
Daniel Candotti
Jack Strominger