RE: Autoimmunity Academy17 May 2018 00:51
If you look through thursday @ https://autoimmunity.kenes.com/2018/Pages/Interactive-programm.aspx#.Wvy1Jogvy00 you can see tyhe whole breakdown of the program tomorrow:
PL07 PARALLEL SESSION
LUPUS: WHAT IS NEW?
17-May-2018 10:30 12:30
Abstract:
THE P140 PEPTIDE, A HEAT SHOCK PROTEIN INHIBITOR, MODULATES LYSOSOMAL PATHWAYS FOR LUPUS THERAPY
Background
P140/LupuzorTM is a phosphopeptide exhibiting significant protective properties in MRL/lpr lupus-prone mice and patients with SLE. It is currently under evaluation in phase III-clinical trials in the US and Europe.
Method
Various biochemical methods to examine the interaction between P140 and HSPA8 in vitro and in vivo were used.
Results
One of our key findings regarding the P140 mode of action is that in vitro P140 binds and inhibits heat shock proteins HSPA8/HSC70, a chaperone protein that plays important roles in various cellular functions. We show that it decreases HSPA8 expression on gene and protein levels, both in vivo in MRL/lpr mice that received the peptide intravenously, and in vitro, in MRL/N-1 cells, a fibroblast cell line derived from the MRL splenocytes. We discovered also that P140 significantly affects the capacity of HSPA8 to shuttle between cytosol and nucleus upon heat shock. Another important cellular function of HSPA8 is its role in chaperone-mediated autophagy (CMA), a selective autophagic pathway also mediated by chaperones HSP90AA1 and lysosomal receptor LAMP2A. By purifying lysosomes (where P140 accumulates) from the liver and spleen of MRL/lpr mice pre-treated or not with P140, and incubating these lysosomes with CMA substrates, we observed a decrease of intra-lysosome uptake of CMA substrates, confirming in vivo the inhibition effect of P140 on CMA.
Conclusion
The inhibition effect of P140 on HSPA8 is not only important for lupus therapy where HSPA8 has been reported to be overexpressed, but potentially also in other autoinflammatory diseases, including neurological diseases, where modulation of HSPA8 is needed.
Co-authors
F. Wang 1, I. Tasset 2, A.M. Cuervo 2, S. Muller 1
1CNRS- Institut de Biologie Mol�culaire et Cellulaire, Immunopathologie et Chimie Th�rapeutique, Strasbourg, France
2Albert Einstein College of Medicine, Department of Developmental and Molecular Biology, New York, USA