The function of the glucose transporter type l in human antibody-secreting plasma cells?? 
 
Mrika Zagrada, Hans-Martin Jäck, Katharina Pracht 
 
Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany 
 
The glucose transporter type 1 (GLUT1) is encoded by the SLC2A1 gene and transports glucose into the cytoplasm. SLC2A1 mutations that result in reduced GLUT1 activity cause GLUT1 deficiency syndrome (GLUT1-DS) in humans. GLUT1-DS patients show symptoms such as epileptic seizures and developmental disorders, but nothing is known about their adaptive immune responses. We could show that GLUT1 is synthesized in the B cell lineage of mice, with the highest abundance in antibody-secreting plasmablasts and plasma cells. In addition, B cell-specific ablation of SLC2A1 resulted in impaired plasma cell differentiation and antibody glycosylation. Therefore, we hypothesize that GLUT1 is also crucial for producing and glycosylating antibodies in human plasma cells. If correct, we expect to find GLUT-1 production in human B lineage cells and an impaired humoral immune response in GLUT1-DS patients.?? 
To this end, we could detect GLUT1 by western blotting in activated naive B cells from the blood of healthy donors. Currently, we are testing whether GLUT1-DS patients have a reduced B cell-mediated immune response by analyzing vaccine-related serum antibody titers and determining the antibody production and metabolism in vitro activated B cells from GLUT1-DS patients. 
 
Supported by grants from the IZKF Erlangen to KP and the German Research Foundation (GRK2599 and TRR130) to HMJ