differential impact of il-7 and il-15 on hiv reservoir persistence
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Differential impact of IL-7 and IL-15 on HIV reservoir persistence. Claire Vandergeeten, PhD. IAS, Rome, July 18th 2011. Why are we interested in the study of the role of IL-7 and IL-15 on HIV reservoir persistence?. - PowerPoint PPT PresentationTRANSCRIPT
Differential impact of IL-7 and IL-15 on HIV reservoir persistence
Claire Vandergeeten, PhD
IAS, Rome, July 18th 2011
• HIV persists in memory T cells (Chun, Proc Natl Acad Sci U S A, 1997; Wong, Science, 1997; Finzi, Nat Med, 1999)
• Persistence by homeostatic proliferation (Chomont, Nat Med, 2009)
• IL-7 and IL-15 are involved in the maintenance of memory CD4 T-cells (Kondrack, J Exp Med, 2003; Lenz, Proc Natl Acad Sci U S A, 2004)
• What are the role of IL-7 and IL-15 on HIV persistence?
Why are we interested in the study of the role of IL-7 and IL-15 on HIV reservoir persistence?
Impact of IL-7 therapy on the HIV reservoir size (1)
• ACTG5214 clinical trial (10 virally suppressed subjects)
• A single injection of 4 rhIL-7 doses (3, 10, 30 or 60 µg/kg) or placebo
0 10 20 300
25
50
75
IL-7
placebo
% C
D4+
Ki6
7+
IL-7 induces proliferation of CD4 T cells
Day 0 Day 4 Day 28IL-7
injection
PBMCs PBMCsPBMCs
Days
Impact of IL-7 therapy on the HIV reservoir size (2)
IL-7 does not increase the frequency of reservoir cells within the CD4 compartmentIL-7 increases the absolute number of CD4 T cells harboring HIV DNA
Day 0 Day 280
200
400
600
800
p=0.03
Int H
IV D
NA
per m
L of
blo
od
Day 0 Day 280
500
1000
1500
2000
Int H
IV D
NA
per 1
06 CD
4 T
cells
• Integrated HIV DNA was measured by a semi-nested Real Time PCR (Alu PCR)
Gen
etic
div
ersi
ty (%
)
0
1
2
3
4
0
2
4
6
8
Baseline CD3/CD28
Day 0 Day 8
Baseline CD3/CD28
Day 0 Day 8
Gen
etic
div
ersi
ty (%
)
P = 0.0002
P = NS
P = NS
P < 0.0001
P = NS
P = NS
IL-7 1ng ml–1
IL-7 10ng ml–1
IL-7 1ng ml–1
IL-7 10ng ml–1
Sub
ject
1
Sub
ject
2
Impact of IL-7 on HIV reservoir diversity
• CD4 T-cells from successfully treated subjects were stimulated with IL-7 (1 or 10 ng/mL)
• HIV reservoir diversity was evaluated by sequence of the env gene after 8 days.
IL-7 maintains HIV reservoir diversity in vitro
Although IL-7 restores CD4 T cell count through cell proliferation (Sereti, Blood, 2009; Levy, JCI, 2009) it also increases the number of CD4 T cells harboring HIV integrated DNA
IL-15 is another c cytokine involved in the maintenance of T cell memory
Evaluation of the effect of IL-15 and IL-7 on:
• Viability of CD4 T cells
• Activation and proliferation of CD4 T cells
• Viral production from latently infected CD4 T cells
• CD4 T-cells were stimulated with IL-7 or IL-15 at 10 ng/mL. • Viability was measured by flow cytometry after 6 days.
Impact of IL-7 and IL-15 on viability of CD4 T cells
Both IL-7 and IL-15 promote survival of CD4 T cells
NS IL-7 10 ng/mL
IL-15 10 ng/mL
80
85
90
95
100
% v
iabi
lity
Impact of IL-7 and IL-15 on activation and proliferation of CD4 T cells
• CD4 T-cells were stimulated with IL-7 or IL-15 at 10 ng/mL. • Proliferation and activation were measured by flow cytometry after 6 days.
IL-7 induces higher levels of cell proliferation than IL-15IL-7 and IL-15 induce similar levels of activation markers
% C
D4+
Ki6
7+
% C
D4+
HLA
-DR
+
% C
D4+
PD
-1+
NS IL-7 10 ng/mL
IL-15 10 ng/mL
0
2
4
6
8
NS IL-7 10 ng/mL
IL-15 10 ng/mL
0
5
10
15
20
p=0.004
NS IL-7 10 ng/mL
IL-15 10 ng/mL
0
3
6
9
12
IL-15 reactivates HIV production from latently infected cells in vitro
IL-15 induced viral production in latently infected cells very efficiently when compared to IL-7 ( 4 fold increase)
Impact of IL-7 and IL-15 on HIV reservoir reactivation
#1#2#3#4#5#6
• CD4 T-cells from successfully treated subjects were stimulated with IL-7 or IL-15 at 10 ng/mL in the presence of ARV.
• Viral production was measured by a sensitive real time PCR after 6 days.
Vira
l RN
A co
py
p = 0.04
NS CD3/CD28
IL-7 10 ng/mL
IL-15 10 ng/mL
0
3000
6000
9000
12000
Conclusion
• IL-7 increases the absolute number of CD4 T cells harboring integrated HIV DNA in vivo and maintain the genetic diversity of the reservoir in vitro
• IL-7 and IL-15 induce proliferation, activation and survival of CD4 T cells
• IL-15 induce viral production very efficiently when compared to IL-7
IL-15 should be considered as a possible candidate to achieve HIV eradication
IL-15IL-7
ARV
CD4 T cells
Integrated HIV DNA
HIV viral particles
Differential impact of IL-7 and IL-15 on HIV reservoir
Acknowledgments
VGTI Florida:Nicolas ChomontRafick-Pierre SekalySandrina DaFonsecaRémi Fromentin
ACTG5214 study :Michael LedermanIrini Sereti