Diazepam effect on T lymphocytes in a model of Experimental autoimmune encephalomyelitis (EAE)

FERNÁNDEZ HURST, NICOLÁS; ROTH GERMAN A.

Los Cocos, Córdoba

Congreso; LXI Reunión Científica Anual de la Sociedad Argentina de Inmunología (SAI); 2013

Sociedad Argentina de Inmunología (SAI)

Experimental autoimmune encephalomyelitis (EAE) is an animal model that mimics many of the clinical and pathological features of the human disease, multiple sclerosis. In rats challenged for EAE we previously demonstrated that treatment with Diazepam reduce the incidence and clinical signs of the disease. Also Diazepam diminishes many immunological parameters such as DTH reaction, proliferation against the encephalitogenic myelin basic protein (MBP), and anti-MBP antibody production. The aim of the present work was to evaluate the cellular and molecular mechanism underlying the Diazepam effect on isolated T cells involved in cellular immune response during the development of the disease. The animals were sensitized with myelin in complete Freund?s adjuvant to induce EAE and sacrificed during the acute phase of the disease (12-14 days post induction). The mononuclear cells (MNC) were isolated from popliteal lymph nodes and the population of T lymphocytes was about 75% of the total cells. We evaluated the effect of Diazepam on cell viability, apoptosis induction, proliferation and cytokine production. Using a viability assay with MTT, we show that Diazepam does not have a toxic effect at least up to concentration of 25 μM. This drug does not have a significant pro-apoptotic effect on MNC, but we observed that reduce proliferation and the production of a pro-Inflammatory cytokine (IFN gamma) in presence of an inespecific mitogen in a dose dependent manner. In conclusion, Diazepam has a direct inhibitory effect in the proliferation and activation of T lymphocytes and this could be one of mechanisms that contribute to the beneficial effects previously observed with Diazepam in vivo during the development of EAE.