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Unpublished data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