Therapeutic immunization with HIV-1 Tat
reduces immune activation and loss of
regulatory T-cells and improves immune
function in subjects on HAART
(phase II trial, ISS T-002)
Barbara Ensoli, MD, PhD
National AIDS Center
Istituto Superiore di Sanità
Rome, Italy
www.ias2011.org
 Effective HAART is often unable to restore immune homeostasis and is
associated with novel non-AIDS-defining diseases
 CD4+ T cells and monocyte-macrophages of virologically-suppressed
individuals still express multi-spliced transcripts encoding HIV regulatory
proteins (e.g. Tat, Nef)
 A phase II randomized, open label, multicentric clinical trial with Tat
given 3 or 5 times monthly at 7.5 or 30 g doses (ISS T-002,
Clinicaltrials.gov: NCT00751595) was conducted in 160 individuals under
effective HAART (VL50 copies/ml) with CD4+ T cell counts 200 cells/L
and any pre-HAART CD4 nadir
 Eighty-eight individuals enrolled with the same criteria in a parallel
prospective observational study at the same clinical sites (ISS OBS T-002,
Clinicaltrials.gov: NCT01024556) were examined as reference group
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ISS T-002 Humoral and cellular immune response against Tat
IgM
IgG
IgA
Total
100000
Ant-Tat antibody titers (GM, range)
Anti-Tat antibody responders (%)
100
90
80
70
60
50
40
30
20
10
0
7.5 μg (3x)
7.5 μg (5x)
30 μg (3x)
10000
1000
100
10
1
IgM
30 μg (5x)
Anti-Tat Ab response: p=0.0139 (Chi-Square for Trend)
Responders (%)
IL-2
45
100
IL-4
*
40
**
35
30
IgA
IgM
7.5 μg
Responders (%)
IFN
50
IgG
IgG
IgA
30 μg
CD4 T cell proliferation
CD8 T cell proliferation
90
*
80
70
*
**
60
*
25
50
20
40
15
30
10
20
5
10
0
0
7.5 μg
30 μg
7.5 μg
30 μg
7.5 μg
30 μg
McNemar’s Test: *p<0.05; **p<0.01
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7.5 μg
30 μg
7.5 μg
30 μg
ISS T-002 and OBS studies - CD4+ T cells and B cells
Changes from baseline
T-002
OBS
120
100
CD4+ cells/μl
CD4+ T cells/μl
120
80
60
80
60
40
40
20
20
0
-20
0
w 12
w 20
w 48
w 72
w 96
w 12
w 20
7.5 μg
-40
w 48
w 72
w 96
-20
30 μg
-60
-60
-80
-80
-100
-100
-120
-120
100
100
90
90
80
70
60
*
50
w 72
w 96
*
80
70
60
30
20
20
10
10
0
w 12
w 20
w 48
w 72
w 96
7.5 μg
w 12
w 20
w 48
30 μg
w 72
w 96
0
-10
-30
-20
-40
-30
-50
-60
w 48
40
*
30
-20
w 20
50
40
-10
w 12
-40
B cells/μl
B cells/μl
100
-40
t-test for paired data: *p<0.05
-50
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w12
w20
w48
w72
w96
ISS T-002 and OBS studies - T regulatory Cells
Changes from baseline
T-002
OBS
*
*
*
*
*
*
*
t-test for paired data: *p<0.05
T-reg increase was associated with reduction of immune activation and
inflammation markers (CD38+/CD8+ T cells, neopterin, 2-microglobulin,
total IgG)
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ISS T-002 CD4+ and CD8+ T cells phenotype
CD4 naive
CD4 Tem
CD4 Tcm
CD4 T cells (%)
100%
90%
80%
*
*
50.7
50.4
48.5
45.3
22.8
24.5
22.8
24.8
29.5
26.4
25.1
28.7
30.0
29.5
w0
w8
w12
w20
w48
w72
46.2
70%
47.5
50.8
60%
50%
40%
24.3
16.2
19.6
30%
20%
10%
36.3
0%
CD8 naive
CD8 Tem
w84
CD8 Tcm
CD8 T cells (%)
100%
90%
21.1
21.5
22.1
22.8
*
20.3
22.3
*
21.9
*
80%
70%
*
60%
50%
*
*
53.1
50.4
50.7
49.4
49.1
48.5
44.9
25.7
28.1
27.1
27.8
30.6
29.3
33.2
w0
w8
w12
w20
t-test for paired data: *p<0.05
w48
w72
w84
40%
30%
20%
10%
0%
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ISS T-002 Cellular Immune Response
IL-2
IL-4
IFN-
100
Responders (%)
90
**
80
70
60
50
**
IL-4
IFN-
80
70
*
60
40
30
30
20
20
10
10
**
*
0
7.5 μg
30 μg
CD4
7.5 μg
30 μg
*
70
60
7.5 μg
30 μg
CD4
**
80
30 μg
CD8
100
90
7.5 μg
Responders (%)
30 μg
*
100
80
7.5 μg
30 μg
*
60
50
40
40
30
30
20
20
10
10
0
0
7.5 μg
30 μg
7.5 μg
30 μg
7.5 μg
30 μg
7.5 μg
30 μg
7.5 μg
30 μg
CD4
*
70
50
IL-4
100
90
80
70
60
50
40
30
20
10
0
7.5 μg
CD8
**
90
IL-2
**
90
40
7.5 μg
Responders (%)
IL-2
100
50
0
Anti-CEF
Responders (%)
Responders (%)
IFN-
Anti-Candida
Responders (%)
Anti-Env
30 μg
100
90
80
70
60
50
40
30
20
10
0
**
30 μg
7.5 μg
Baseline
McNemar’s Test: *p<0.05; **p<0.01
Up to Week 48
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30 μg
CD8
**
7.5 μg
7.5 μg
30 μg
ISS T-002 Conclusions
 Immunization with Tat was safe and induced durable humoral and cellular anti-Tat
immune responses
 Increase of T-reg and reduction of immune activation (CD38 expression on CD8+ T
cells and biochemical markers) were associated with stable increases of CD4+ T
cells and B lymphocytes, increases of naïve and central memory CD4+ and CD8+ T
cell subsets, reduction of effector memory CD4+ and CD8+ T cells, and with
increases of T cell responses against Env and recall antigens (Candida, CMV, EBV,
Flu)
 More immune-compromised individuals experienced greater therapeutic effects
These findings indicate that Tat immunization represents a promising therapeutic
tool to intensify HAART efficacy and to restore the immune homeostasis (B. Ensoli et
al., PLoS ONE, 2010)
A phase II randomized, double blinded, placebo controlled, therapeutic trial of Tat
immunization in 200 ARV-treated, virologically suppressed individuals with CD4+ T
cells 200/μL is starting in South Africa (ISS T-003) in cooperation with NDOH and
SAAVI
www.ias2011.org
ACKNOWLEDGMENTS
NATIONAL AIDS CENTER – ISS
CLINICAL TRIALS DIVISION
O. Longo
S. Bellino
C. Sgadari
S. Marcotullio
F. Cammisa
G. Fornari Luswergh
JOINT ISS/S. GALLICANO
CORE LABORATORY SITE
A. Tripiciano
V. Francavilla
A. Scoglio
M. Campagna
M. Ruiz-Alvarez
D. Scaramuzzi
F. Stivali
A. Arancio
G. Paniccia
C. Ariola
F. Ensoli
VIRUS-HOST INTERACTION AND
CORE LAB OF IMMUNOLOGY
DIVISION
A. Cafaro
S. Moretti
M.R. Pavone Cossut
G. Barillari
P. Monini
CLINICAL SITES
Ospedale A. di Savoia, Torino
Ospedale S. Raffaele, Milano
Ospedale Sacco, Milano
Spedali Civili, Brescia
Azienda Osp. San Gerardo, Monza
Arcispedale S. Anna, Ferrara
Policlinico Universitario, Modena
Ospedale S. M. Annunziata, Firenze
IFO - San Gallicano, Roma
Ospedale S.M. Goretti, Latina
Policlinico Universitario, Bari
DSMB
P. Popoli - Italy
M.J. Mirò - Spain
V. Miller - USA
F. Menniti Ippolito - Italy
IAB
J. Holmgren - Sweden
J.A. Levy - USA
F. Goebel - Germany
C.A. Guzman - Germany
L. Moretta - Italy
S. Osmanov - Switzerland
G.V. Zuccotti - Italy
A. Cassone - Italy
K. Moelling - Switzerland
www.ias2011.org
C R O-OPERA SRL
S. De Naro
E. Ottonello
L. Michellini
G. Bergamaschi
F. Montanaro
O. Picconi
N. Ngo Dinh
F. Barattini
AVITECH-DIATHEVA SRL
E. Laguardia
M. Magnani
INJECTALIA SRL
AIDS Help-Line, ISS
A. Luzi
A. Colucci
P. Gallo
R. Valli
A. Santoro
A. D’Agostini
CAB
Gay Center: A. Poto
NADIR Onlus: R. Biondi
GITA:V. Cantarella
NPS: M. Formisano