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Cell- and Tissue-based Measures of
Viral Persistence Are Associated with
Immune Activation and
PD-1-Expressing CD4+ T cells
H Hatano1, V Jain1, PW Hunt1, JN Martin1, TH Lee2, E
Sinclair1, JM McCune1, F Hecht1, MP Busch1,2, SG Deeks1
1University
of California, San Francisco, CA, USA
2Blood Systems Research Institute, San Francisco, CA, USA
What are the determinants of
HIV persistence?
• Determinants of HIV persistence during long-term
HAART remain unknown, but may include:
– Ongoing viral replication (Buzon, Nat Med 2010)
– Potency of HIV-specific responses
• Mucosal HIV-specific T cell responses (Hatano, JID 2011)
Higher Levels of GALT HIV-specific CD8+ T Cells Are
Associated with Lower Levels of Proviral DNA
CD4
1.5
% Gag-specific
CD4+ T cells (GALT)
% Gag-specific
CD8+ T cells (GALT)
CD8
1.0
0.5
0.0
0
1
2
log10 Proviral DNA
(per mil PBMC)
rho = - 0.50, p = 0.03
5
4
3
2
1
0
0
1
2
log10 Proviral DNA
(per mil PBMC)
rho = - 0.42, p = 0.07
Hatano et al, JID 2011
What are the determinants of
HIV persistence?
• Determinants of HIV persistence during long-term
HAART remain unknown, but may include:
– Persistent immune activation
• Immune activation levels remain elevated despite effective
HAART-mediated viral suppression
– Negative regulators that reverse activated state (PD-1)
(Chomont, Nat Med 2009)
• PD-1high CD4+ T cells have high levels of proviral DNA
• Triggering of PD-1 inhibits HIV transcription, and inhibiting the
PD-1/PD-L1 interaction increases HIV production
• PD-1 expressing CD4+ T cells → Preferential reservoir for HIV
• Understanding the causes of persistent
inflammation are important for preventing nonAIDS morbidity and for strategies towards cure
Study Objectives
• To assess the relationship between measurements
of viral persistence and immune activation
– Plasma RNA
– Cell-associated RNA and proviral DNA
– Tissue-associated RNA and proviral DNA
• To determine the relationship between treatment
response and
– T cell activation/dysfunction
– Viral persistence
• To identify potential interventions to decrease HIV
persistence
Methods
• 190 HAART-suppressed subjects identified
from UCSF SCOPE/OPTIONS cohorts
• Ultrasensitive plasma HIV RNA
– Modified Roche CAP/CTM v2.0 (LOD <5 copies/mL)
• Cell-associated RNA
• Proviral DNA
• Immune activation (% CD4+ and CD8+ T cells)
– CD38+HLA-DR+, PD-1
• Gut-associated lymphoid tissue (GALT)
samples were obtained from 14 subjects
Baseline Characteristics
(n=190)
CD4 count (cells/mm3)
523
Age (years)
51
Gender (% male)
92%
Duration VL suppression (months)
31
Nadir CD4 count (cells/mm3)
113
No Association Between Low-Level Plasma RNA
Levels and T Cell Activation
All p-values > 0.20
Modest Association Between Cell-Based Measures
of Viral Persistence and T Cell Activation
rho = 0.23, p = 0.014
rho = 0.16, p = 0.057
rho = 0.22, p = 0.008
rho = 0.14, p = 0.088
Highly Significant Association between
Proviral DNA Levels and Frequency of PD-1
Expressing CD4+ T Cells
rho = 0.28, p = 0.0005
These observations
are consistent with
PD-1 being a
marker of latently
infected CD4+ T
cells (Chomont et
al, Nature Med
2009)
Strong Association Between Viral Persistence in
GALT and T Cell Activation
What is the relationship between treatment
response and…
-Viral Persistence?
-T Cell Activation/Dysfunction?
Will treated subjects with a low CD4+ T cell count
require unique curative strategies?
Plasma RNA Levels Similar
in Low and High CD4+ Groups
Plasma HIV RNA
(copies/mL)
150
p = NS
100
50
0
Low CD4
High CD4
Cell-Associated RNA and Proviral DNA Levels Are
Higher in Low CD4+ Group
p = 0.008
p = 0.001
CD4+ T Cell Activation and PD-1 Expression
are Higher in Low CD4+ Group
20
p < 0.0001
%PD1+ CD4+ T cells
%CD38+HLA-DR+
CD4+ T cells
25
15
10
5
0
p < 0.0001
40
20
0
High CD4
15
p < 0.0001
10
5
0
Low CD4
High CD4
Low CD4
%CD38+HLA-DR+CCR5+PD1+
CD4+ T cells
Low CD4
%CD38+HLA-DR+PD1+
CD4+ T cells
60
4
High CD4
p < 0.0001
2
0
Low CD4
High CD4
% CD45RA-CCR7+PD1+
CD4+ T cells
Higher Frequencies of PD-1 Expressing
TCM CD4+ T Cells in Low CD4+ Group
20
15
p < 0.0001
10
5
0
6
4
p < 0.0001
2
0
Low CD4
High CD4
High CD4
% CD45RA-CCR7+CD38+HLA-DR+CCR5+PD1+
CD4+ T cells
% CD45RA-CCR7+CD38+HLA-DR+PD1+
CD4+ T cells
Low CD4
1.5
1.0
p < 0.0001
0.5
0.0
Low CD4
High CD4
Conclusions I.
• No associations between ultrasensitive
plasma HIV RNA levels and immune
activation
• Cell-based measurements of viral
persistence were modestly but
consistently associated with markers of
immune activation/dysfunction and
frequency of PD-1 expressing CD4+ T
cells
• Stronger positive correlation between
tissue-based measurements of viral
persistence and immune activation
Potential Eradication Strategies
• Highly significant association between
proviral DNA levels and frequency of PD-1
expressing CD4+ T Cells
• Phase I study of an anti-PD-1 monoclonal
antibody aimed at clearing the latent
reservoir is in development (ACTG 5301)
ACTG 5301 Study Schema
• Study Design: Single arm, dose-finding study
• Population:
– HIV-infected female and male subjects ≥ 18 years of age.
Females of reproductive potential are excluded from the
study.
– Screening CD4+ T cell count > 350 cells/mm3
– Plasma HV RNA < 75 copies/mL while taking HAART for
previous 36 months
• Sample size: 40 (10 subjects in each dose cohort)
• Study duration: 16 weeks
• Intervention: Single IV dose of open-label MK3475
at dose of 0.1, 1, 3, or 10 mg/kg
Conclusions II.
• Treated patients with a low CD4+ T cell
count had:
– Higher cell-based measures of viral
persistence
– Expansion of CD4+ T cells expressing PD-1
• Most consistently observed in the central memory
compartment
• Treated individuals with low CD4+ T cell
counts may be more difficult to cure
and/or will require unique interventions
Implications
• Understanding the causes of viral persistence
and inflammation in the setting of HAART are
necessary to develop new strategies towards
cure
• Future studies of viral persistence should focus
on cell- and tissue-based measurements of viral
persistence, not on plasma RNA (Chun, JID 2008; Yukl, JID 2010;
Hatano, JID 2011)
Acknowledgements
UCSF/SFGH/PHP
Vivek Jain
Peter Hunt
Ma Somsouk
Jeffrey Martin
Frederick Hecht
Steven Deeks
UCSF/SFGH/DEM
Elizabeth Sinclair
Joseph M. McCune
UCSF/SFVAMC
Steven Yukl
Joseph Wong
Roche, Inc.
Tri Do
UCSF/BSRI
Tzong-Hae Lee
Michael Busch
VGTI Florida
Nicolas Chomont
Rafick Sekaly
Funding
NIAID K23AI075985