The neuronal GABAergic system in human lymphocytes

DIONISIO L; DE ROSA MJ; BOUZAT, C.; ESANDI MDEL C

Huerta Grande, Córdoba

Congreso; I Reunión Conjunta de Neurociencias; 2009

Sociedad Argentina de Investigación en Neurociencias y Taller Argentino de Neurociencias

The neuronal GABAergic system in human lymphocytes Dionisio L, De Rosa MJ, Bouzat C and Esandi MC. INIBIBB-Bahía Blanca, Argentina ldionisio@criba.edu.ar   γ-Amino butiric acid (GABA) is an ubiquitous neurotransmitter in the central nervous system but is also present in non neuronal cells. The goal of this study was to determine the neuronal components of the GABAergic system in lymphocytes and their functional significance. Using RT-PCR we determined expression of mRNA of different components of this system in resting and mitogen activated lymphocytes (PHA 10 mg/ml): i) GAD67, an isoform of the enzyme that synthetizes GABA; ii) VIAAT, the vesicular protein involved in GABA store; iii) GABA transporters (GAT1-2); iv) GABA-t, an enzyme that catabolizes GABA; v) alpha subunits (a1-6) of GABAA receptor; and vi) rho2 subunit of the GABAC receptor. The functionality of the transporters was evaluated by measuring uptake of radioactive GABA. The results demonstrated that the [3H]GABA uptake is 5-fold higher in activated lymphocytes than in resting ones. Using [3H]thymidine incorporation, we established that GABA and muscimol are able to modulate lymphocyte proliferation. Finally, we demonstrated that these GABA receptor agonists are capable to elicit macroscopic currents in activated lymphocytes. Our results revealed that lymphocytes have most of the essential components needed to constitute a GABAergic system. Pharmacological modulation of this system may provide new approaches for regulation of T cell respons