Avid Bioservices Inc (CDMO)

[jazzbeerman]

5. PPHM's / Chen's mab IS1 neutralizes 7 out of 7 HIV strains -------------



This was Haynes work, at the Gates conference, funded with CHAVI money, using Chen's / (PPHM's) mab.


Pojen Chen's IS1 mab has shown some very interesting results. Here is an abstract from the Seattle Gates HIV vaccine conf last fall. Work that was done by Haynes Duke/CHAVI/Gates team, along with - you guessed it- Pojen Chen.


P10-22
Neutralization of HIV-1 primary isolates in PBMC assays
by monoclonal anti-lipid antibodies derived from a
patient with anti-phospholipid syndrome.


MA Moody1, D Montefiori1, MK Plonk1, H Liao1, S Xia1, TC Gurley1,
SM Alam1, P Chen2 and BF Haynes1


1 Duke University Medical Center, Durham, NC, USA;
2 UCLA School of Medicine, Los Angeles, CA, USA


Background: Rare human anti-envelope monoclonal antibodies (Mabs) that
broadly neutralize HIV-1 have been made, but HIV-1+ or vaccinated subjects
rarely make broadly reactive neutralizing antibodies. The observations
that 2F5, 4E10 and 1b12 are polyspecific antibodies and that AIDS may
be rare in patients with primary autoimmune diseases have prompted the
hypothesis that patients with autoimmune diseases who have defects in
tolerance mechanisms may be able to make antibodies that have anti-HIV-1
activity. Thus, we have assayed Mabs derived from anti-phospholipid
syndrome patients for their ability to neutralize HIV-1.

Methods: IS1 and IS4 are human Mabs derived from a patient with antiphospholipid
syndrome. Both are autoantibodies that react with cardiolipin
and phosphatidylserine. IS4 promotes thrombosis in a murine pinch-induced
thrombosis model while IS1 is not prothrombotic and, therefore, is nonpathogenic.
Neutralization assays used were pseudovirus assays in TZM/bl
cells and whole virus assays in peripheral blood mononuclear cells (PBMC).
Interaction of antibodies with Env and lipids was determined by surface
plasmon resonance (SPR) and flow cytometry.

Results: IS1 and IS4 Mabs had no neutralizing activity against HIV-1 primary
isolate pseudoviruses in the TZM/bl assay. In the PBMC assay, however,
both IS1 and IS4 neutralized 7/7 primary isolates tested (Torno, PAVO,
6535, DU123, DU156, DU151, and DU172; IC80s ranged from 0.06-4.1ug/
mL). Against SHIV and SIV viruses IS1 and IS4 neutralized SHIV SP162P3
at IC80s of 0.06 and 0.2μg/mL, respectively, while neither Mab neutralized
SHIV 89,6P or SIVmac239. Using SPR, neither IS1 nor IS4 reacted with
recombinant HIV-1 wild-type Envs. By flow cytometry, neither Mab labeled
viable uninfected T cell lines or PBMC; however, both IS1 and IS4 Mabs
reacted strongly with the surface of virus infected T cells.

Conclusion: Select anti-membrane polyspecific antibodies bind to HIV-1
infected but not uninfected cells, are non-pathogenic, and have anti-HIV-1
neutralizing activity in vitro in PBMC but not pseudovirus assays. It will be
of interest to determine if such non-pathogenic antibodies are protective in
passive therapy trials in vivo in non-human primates. Study of the mechanism
of neutralization of these antibodies and their B cells of origin may provide
clues to novel ways to safely induce protective antibodies to HIV-1.

Supported by the Center for HIV/AIDS Vaccine Immunology AI067854,
CHAVI 005 protocol.

http://www.hivvaccineenterprise.org/_dwn/Late_Breaker_Abstracts.pdf



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