Burton, DR

Holmes, MA

Kim, M

Kraft, Z

Reinherz, EL

Scherer, E

Sellhorn, G

Song, L

Stamatatos, L

Strong, RK

Xu, H

English

PubMed

Reinherz EL

Kraft Z

Sellhorn G

Holmes MA

Kim M

Song L

Scherer E

Xu H

Burton DR

Stamatatos L

Strong RK

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Retrovirology

P04-04. The specific phospholipid binding and neutralizing activities of the anti-HIV antibody 4E10 are separable

H Xu

E Scherer

L Song

M Kim

MA Holmes

G Sellhorn

Z Kraft

EL Reinherz

DR Burton

L Stamatatos

RK Strong

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BioMed Central
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Retrovirology
Open AccessPoster presentation
P04-04. The specific phospholipid binding and neutralizing activities 
of the anti-HIV antibody 4E10 are separable
H Xu*1,4, E Scherer2, L Song3, M Kim3, MA Holmes1, G Sellhorn6, Z Kraft6, 
EL Reinherz3, DR Burton5, L Stamatatos6 and RK Strong1
Address: 1Basic Science, Fred Hutchinson Cancer Research Center, Seattle, WA, USA, 2University of Oxford, Oxford, UK, 3Dana-Farber Cancer 
Institute, Harvard Medical School, Boston, MA, USA, 4Seattle Biomedical Research Institute, Seattle, WA, USA, 5The Scripps Research Institute, La 
Jolla, CA, USA and 6Seattle Biomedical Research Institute, University of Washington, Seattle, WA, USA
* Corresponding author    
Background
Human 4E10 is one of the broadest-specificity, HIV-1
neutralizing, monoclonal antibodies described to date,
recognizing a linear, membrane-proximal epitope on
gp41. Although the apparent rarity of 4E10-like antibody
responses in HIV infections is suggested to result from
their elimination through B cell tolerance mechanisms to
self-antigens, the lipid cross-reactivity of 4E10 has also
been suggested to derive from virus-specific membrane
binding outside of the MPER, rather than auto-reactivity,
that contributes to neutralization potency.
Methods
To investigate how 4E10 interacts with membrane com-
ponents (particularly phospholipids like cardiolipin), and
whether such interactions contribute to neutralization
mechanisms, we have introduced two mutations into
4E10 Fv constructs: W(H100)A and G(L50)E. The binding
of 4E10 and these mutants to liposomes of varying com-
position, to 4E10 epitope peptides and to soluble mono-
meric and trimeric HIV Env gp140 was then assayed by
surface plasmon resonance.
Results
These analyses revealed that wild type and mutant 4E10
Fvs all bind with the same affinity to epitope peptides and
monomeric and trimeric gp140s, but that the affinities for
gp140s are uniformly ten-fold weaker than to peptides.
Addition of cardiolipin to liposomes increases wild-type,
but not mutant, 4E10 Fv SPR binding responses, suggest-
ing that the mutations individually and cleanly attenuate
specific 4E10/lipid interactions. However, 4E10 Fv bind-
ing to lipid bilayers of any composition is extremely weak.
While the W(H100)A affects neutralization significantly,
the G(L50)E mutation, selected to disrupt a possible
phosphate-binding site on 4E10, does not decrease neu-
tralization efficiency against diverse HIV-1 isolates.
Conclusion
This dichotomy suggests that specific lipid interactions
and neutralization by 4E10 are formally separable. Addi-
tional EPR experiments suggest an alternate explanation
for the effect of the W(H100)A on neutralization: this
mutation reduces the ability of 4E10 to wedge the MPER
out of the membrane.
from AIDS Vaccine 2009
Paris, France. 19–22 October 2009
Published: 22 October 2009
Retrovirology 2009, 6(Suppl 3):P32 doi:10.1186/1742-4690-6-S3-P32
<supplement> <title> <p>AIDS Vaccine 2009</p> </title> <editor>Anna Laura Ross</editor> <note>Meeting abstracts – A single PDF containing all abstracts in this Supplement is available <a href="http://www.biomedcentral.com/content/files/pdf/1742-4690-6-S3-full.pdf">here</a>.</note> <url>http://www.biomedcentral.com/content/pdf/1471-2105-10-S12-info.pdf</url> </supplement>
This abstract is available from: http://www.retrovirology.com/content/6/S3/P32
© 2009 Xu et al; licensee BioMed Central Ltd. 


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P04-04. The specific phospholipid binding and neutralizing activities of the anti-HIV antibody 4E10 are separable

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