TY - JOUR
T1 - ERK1-based pathway as a new selective mechanism to modulate CCR5 with natural antibodies
AU - Venuti, Assunta
AU - Pastori, Claudia
AU - Siracusano, Gabriel
AU - Riva, Agostino
AU - Sciortino, Maria Teresa
AU - Lopalco, Lucia
PY - 2015/10/1
Y1 - 2015/10/1
N2 - Natural human Abs, recognizing an epitope within the first extramembrane loop of CCR5 (the main HIV coreceptor), induce a longlasting internalization (48 h) of the protein, whereas all known CCR5 modulating molecules show a short-term kinetics (60-90 min). Despite extensive studies on the regulation of CCR5 signaling cascades, which are the effect of concomitant CCR5 internalization by exogenous stimuli such as Abs, downstream signaling continues to be poorly understood. In this article, we report a hitherto unrecognized mechanism of CCR5 modulation mediated by G protein-dependent ERK1 activity. We further demonstrate that ERK1 is localized mainly in the cytoplasmic compartment and that it interacts directly with the CCR5 protein, thus provoking possible CCR5 degradation with a subsequent de novo synthesis, and that re-expression of CCR5 on the cell membrane required several days. In contrast, the RANTES treatment induces a recovery of the receptor on the cell membrane in short-term kinetics without the involvement of de novo protein synthesis. The said new pathway could be relevant not only to better understand the molecular basis of all pathologic conditions in which CCR5 is involved but also to generate new tools to block viral infections, such as the use of recombinant Abs.
AB - Natural human Abs, recognizing an epitope within the first extramembrane loop of CCR5 (the main HIV coreceptor), induce a longlasting internalization (48 h) of the protein, whereas all known CCR5 modulating molecules show a short-term kinetics (60-90 min). Despite extensive studies on the regulation of CCR5 signaling cascades, which are the effect of concomitant CCR5 internalization by exogenous stimuli such as Abs, downstream signaling continues to be poorly understood. In this article, we report a hitherto unrecognized mechanism of CCR5 modulation mediated by G protein-dependent ERK1 activity. We further demonstrate that ERK1 is localized mainly in the cytoplasmic compartment and that it interacts directly with the CCR5 protein, thus provoking possible CCR5 degradation with a subsequent de novo synthesis, and that re-expression of CCR5 on the cell membrane required several days. In contrast, the RANTES treatment induces a recovery of the receptor on the cell membrane in short-term kinetics without the involvement of de novo protein synthesis. The said new pathway could be relevant not only to better understand the molecular basis of all pathologic conditions in which CCR5 is involved but also to generate new tools to block viral infections, such as the use of recombinant Abs.
UR - http://www.scopus.com/inward/record.url?scp=84942475184&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84942475184&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.1500708
DO - 10.4049/jimmunol.1500708
M3 - Article
C2 - 26324779
AN - SCOPUS:84942475184
VL - 195
SP - 3045
EP - 3057
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 7
ER -