Inducing Antibodies with
Rationally-designed
HIV Vaccines
Susan Zolla-Pazner, Ph. D.
New York University School of Medicine
Department of Pathology
Problems with Whole Env Immunogens
• Sequence and antigenic diversity
• Conformational masking of critical
epitopes
• Evolution to escape the effects of Abs
• Poor induction of Abs with broad
anti-viral functions
• Inability as a vaccine reagent to
induce a long-lived Ab response (<6
months)
Antigenic Determinants on the HIV Envelope
V3 loop
gp120
gp41
Modified from D R Burton, R A Weiss Science 2010;329:770-773
Published by AAAS
Structural Vaccinology Approach
• Required steps:
– Generate neutralizing monoclonal Abs
– Select mAbs with broad reactivity
– Crystallize mAbs
– Analyze bioinformatics data
– Model the epitope
– Design and generate recombinant
epitope-scaffold immunogens
– Immunize animals
– Assess immune response
Study
Ab
Study
Epitope
In vivo
Studies
Structural Vaccinology Approach
• Required steps:
– Generate neutralizing monoclonal Abs
– Select mAbs with broad reactivity
– Crystallize mAbs
– Analyze bioinformatics data
– Model the epitope
– Design and generate recombinant
epitope-scaffold immunogens
– Immunize animals
– Assess immune response
Study
Ab
Study
Epitope
In vivo
Studies
Structural Vaccinology Approach
• Required steps:
– Generate neutralizing monoclonal Abs
– Select mAbs with broad reactivity
– Crystallize mAbs
– Analyze bioinformatics data
– Model the epitope
– Design and generate recombinant
epitope-scaffold immunogens
– Immunize animals
– Assess immune response
Study
Ab
Study
Epitope
In vivo
Studies
Crystallographic Analysis of
Anti-V3 mAbs Complexed with V3 Peptides
V3/mAb 447:
“Ladle-like” V3 binding
V3/mAb 2219:
“Cradle-like” V3 binding
(V. Burke et al, Structure, 2009)
Structural Vaccinology Approach
• Required steps:
– Generate neutralizing monoclonal Abs
– Select mAbs with broad reactivity
– Crystallize mAbs
– Analyze bioinformatics data
– Model the epitope
– Design and generate recombinant
epitope-scaffold immunogens
– Immunize animals
– Assess immune response
Study
Epitope
Two-thirds of the 35 Residues
in V3 are Conserved
Structural Vaccinology Approach
• Required steps:
– Generate neutralizing monoclonal Abs
– Select mAbs with broad reactivity
– Crystallize mAbs
– Analyze bioinformatics data
– Model the epitope
– Design and generate recombinant
epitope-scaffold immunogens
– Immunize animals
– Assess immune response
Study
Epitope
The Conserved Structure of the V3 Crown
A
Hydrophilic face
of circlet
Arch
Band
Hydrophobic face
of circlet
Almond et al., ARHR 2010.
Jiang et al., Nature Struct. Mol. Biol., 2010
Structural Vaccinology Approach
• Required steps:
– Generate neutralizing monoclonal Abs
– Select mAbs with broad reactivity
– Crystallize mAbs
– Analyze bioinformatics data
– Model the epitope
– Design and generate recombinant
epitope-scaffold immunogens
– Immunize animals
– Assess immune response
Study
Epitope
Design of
Recombinant V3-scaffold Immunogen
Example: V3-Cholera Toxin B
M. Totrov et al., Virology, 2010.
Structural Vaccinology Approach
• Required steps:
– Generate neutralizing monoclonal Abs
– Select mAbs with broad reactivity
– Crystallize mAbs
– Analyze bioinformatics data
– Model the epitope
– Design and generate recombinant epitopescaffold immunogens
– Immunize animals
– Assess immune response
Immunization Protocol
gp120 DNA prime
P1
P2
6 weeks
Pre-bleed
P3
V3-CTB boost
B1
6 weeks
B2
4 weeks
2 weeks
Post-boost
50% Neutralizing Ab Response vs. Tier 1 Viruses
Responders: O 1/5
1:10-99
O 2/5 O 3/5
1:100-999
O 4/5 O 5/5
1:1000-9999
>1:10,000
Tier
1A
1A
1B
1B
1B
1B
1B
1B
1B
Clade
C
B
B
B
B
C
B
AG
C
Virus
MW965
SF162
BaL
Bx08
BZ167
TV1.21
S1196
T271-11
25710
CTBwt
O
O
<10
O
ND
ND
<10
ND
ND
O O O
O
O O
O
ND
O
ND
O
O
ND
O O O
O O O
O O O
O O O
O
O O O
B
3074
C
B+3074
C+3074
ND
O
O
ND
O
O
ND
O O O
O
<10
ND
O O O
50% Neutralizing Ab Responses vs.
Standard Tier 2 Panel of Clade B and C Viruses
Responders: O 1/5
O2/5 O 3/5
O 4/5 O 5/5
NT50 = 1:10-99
Clade
B
B
C
C
B
C
C
C
B
Virus
6535
RHPA
259.7
ZM135M
ZM233M
WITO
160.33
Du156.
12
CAP210
ZM109
QH0692
CTBwt
<10
<10
<10
<10
O
<10
O
O
<10
B
<10
<10
<10
<10
<10
<10
<10
<10
O
3074
O
<10
<10
O
<10
<10
O
O
<10
C
O
<10
O
<10
<10
<10
O
O
<10
B+3074 <10
<10
O
O
O
O
O
O
O
C+3074
<10
O
<10
<10
<10
O
O
<10
O
Neutralizing Abs are Detectable
60 Weeks after the Last Boost
Post 3rd Post 1st
Prime
Boost
Post 2nd
Boost
% Neutralization
vs. Bx08
D % Neutralization
100
80
60
40
20
0
6
12
16
25
Weeks
Weeks
58
68
76
Antigenic Determinants on the HIV Envelope
V2 loop
gp120
gp41
Modified from D R Burton, R A Weiss Science 2010;329:770-773
Published by AAAS
Functions of the V2 Loop
–Not essential for infectivity
–Binds to α4β7 integrin on
activated T cells
–With V3, protects the
chemokine receptor binding site
Planned Design of V2 Immunogens
• Use the same structural vaccinology
approach as used for V3.
• Identify “hidden” conserved structure
within the 2nd variable loop.
• Engraft this generic structure into a
scaffold.
• Use V2-scaffold as a boost to elicit crossreactive V2 Abs with multiple anti-viral
functions.
V2 and V3 are Similar in Their Patterns
of Amino Acid Conservation
V2
V2
V3
V3
(S. Zolla-Pazner and T. Cardozo, 2010)
Conclusions: #1
• The structural vaccinology approach has succeeded in
inducing cross-clade neutralizing Abs based on the
use of a gp120 DNA prime and a V3-scaffold protein
boost.
• The development of the boost was the result of
revealing a generic conserved structure with the third
sequence “variable region”.
• This prime/boost vaccine approach can focus the Ab
response on selected epitopes.
• Neutralizing Abs were detectable >1 year after the last
boost.
Conclusions: #2
• More than one epitope needs to be targeted for
an effective vaccine.
• The same principles that guided the successful
development of the V3-scaffold immunogens
are being applied to V2, and can ultimately be
applied to more complex epitopes (QNE,
CD4bs, etc.)
NYU School of
Medicine
Mirek Gorny
Sandy Sharpe
Cohen
Connie Williams
Barbara Volsky
Xiang-Peng Kong
Xunqing Jiang
Tim O’Neal
Tim Cardozo
David Almondy
James Swetnam
Suman Laal
Phillipe Nyambi
Valicia Burke
Xunqing Jiang
Higuang Li
Jared Sampson
Brett Spurrier
April Killikelly
Collaborators
University of Massachusetts
School of Medicine
Shan Lu
Shixia Wang
Molsoft, Inc.
Max Totrov
Ruben Abagyan
Harvard Medical School
Michael Seaman
NYU Medical Center