Argos Therapeutics Presents Research on the Development and Evaluation of Immunotherapies for HIV

-Abstracts Presented at Keystone Symposia on HIV Immunobiology-
DURHAM, N.C.--(Business Wire)--
Argos Therapeutics today announced the presentation of an abstract related to
its Arcelis HIV immunotherapy program at the Keystone Symposia Global Health
Series conference on HIV Immunobiology, held March 22 - 27 in Keystone, CO. The
poster presentation details important research on the immunosuppressive
properties of HIV, and how this research may influence the development of HIV
immunotherapies.

The abstract, titled "The Immunosuppressive Properties of the HIV Vpr protein
are Linked to a Single Highly Conserved Residue, R90," details the study of
IL-12 suppression by the HIV viral protein R (Vpr) in monocyte-derived dendritic
cells (DC). IL-12 is a critical cytokine that is secreted by macrophages,
monocytes and dendritic cells, and is suppressed by Vpr, implicating Vpr as an
important virulence factor in HIV infection. Researchers hypothesized that the
Vpr protein may be required to establish productive HIV infection, because it
disables antigen presenting cells of the first infected mucosal tissues.

Analysis revealed that previously reported C terminal Vpr mutations do not
alleviate the block of IL-12 secretion; however, a novel single conservative
amino acid substitution, R90K, completely reverses the suppression. Further
analysis demonstrated that R90 may not directly regulate the IL-12 pathway, but
instead alleviates the suppressive effect through lowering Vpr intracellular
levels. As a result, this study supports Vpr as an HIV virulence factor during
HIV infection, and for the first time, provides a link between evolutionary
conservation of Vpr and its ability to suppress IL-12 secretion by DCs.

"This abstract demonstrates Argos` scientific leadership in understanding the
immunobiology of HIV and provides important information for others who are
developing HIV immunotherapies," said Charles Nicolette, Ph.D., Chief Scientific
Officer and Vice President of Research and Development at Argos Therapeutics.
"The findings from our research on the Vpr protein should be considered in the
design of future immunotherapies that incorporate Vpr as an antigen."

The abstract was authored by: Irina Tcherepanova, Aijing Starr, Melissa Adams,
Brad Lackford, David Calderhead, Don Healey, Mohamed-Rachid Boulassel,
Jean-Pierre Routy and Charles Nicolette.

The development of Argos` Arcelis HIV immunotherapy program is part of the
Company`s broad collaboration with Kyowa Hakko Kirin Co., Ltd.

About Argos Therapeutics, Inc.

Argos is an immunotherapy company developing new treatments for cancer,
infectious and autoimmune diseases, and transplantation rejection. The Company
has generated multiple platform technologies and a diverse pipeline of products
based on its expertise in the biology of dendritic cells - the master switch
that turns the immune system on or off. www.argostherapeutics.com

MacDougall Biomedical Communications
Jennifer Greenleaf-Conrad, 781-235-3060
or
Argos Therapeutics
Jeff Abbey, 919-287-6308

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