CIQUIBIC   05472
CENTRO DE INVESTIGACIONES EN QUIMICA BIOLOGICA DE CORDOBA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Differential sorting of antibody to GM1 and cholera toxin after internalization in epithelial cells.
Autor/es:
IGLESIAS-BARTOLOMÉ, RAMIRO; COMIN, ROMINA; MOYANO ANA LIZ; DANIOTTI, JOSE LUIS
Lugar:
Carlos Paz, Cordoba
Reunión:
Congreso; 44 Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2008
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
<!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0cm;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"Times New Roman";
mso-ansi-language:PT-BR;
mso-fareast-language:PT-BR;}
@page Section1
{size:595.3pt 841.9pt;
margin:70.85pt 3.0cm 70.85pt 3.0cm;
mso-header-margin:35.4pt;
mso-footer-margin:35.4pt;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
Gangliosides are glycolipids
mostly located in the plasma membrane (PM). Antibodies to GM1 ganglioside are
present in patients with Guillain-Barré neuropathy syndrome (GBS) and in a
rabbit model of this disease. In this work, we investigated in different cell lines
the binding and intracellular fate of affinity purified IgG and IgM antibodies
to GM1 (GM1Ab) obtained from a rabbit model of GBS in comparing with the
transport of cholera toxin (CT), which binds with a high affinity GM1. We
demonstrated that in GM1-expressing CHO-K1 cells, GM1Ab is endocytosed and accumulated
at the endocytic recycling compartment. Then, internalized GM1Ab is recycled
back to the PM. Endocytosed GM1Ab colocalized to some extent with
co-endocytosed CT at early and recycling endosomes, but not in Golgi and
endoplasmic reticulum, where CT was also located. GM1Ab, in contraposition to
CT, showed a reduced internalization in COS-7 cells and neuronal cell lines
AH-SY5Y and Neuro2a. Results from photobleaching experiments revealed an
inverse correlation between the efficiency of endocytosis and lateral mobility
of GM1Ab in PM from these cell lines. Results indicate that GM1Ab and CT are
differentially endocytosed and sorted, providing the basis to gain further insight
into the mechanisms that operates in the intracellular trafficking and
pathological effect of CT and neuropathy-associated antibodies.